US20040070019A1 - Integrated circuit metal-insulator-metal capacitors including hemispherical grain lumps - Google Patents
Integrated circuit metal-insulator-metal capacitors including hemispherical grain lumps Download PDFInfo
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- US20040070019A1 US20040070019A1 US10/715,273 US71527303A US2004070019A1 US 20040070019 A1 US20040070019 A1 US 20040070019A1 US 71527303 A US71527303 A US 71527303A US 2004070019 A1 US2004070019 A1 US 2004070019A1
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- hemispherical grain
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- 229910052751 metal Inorganic materials 0.000 title claims abstract description 233
- 239000002184 metal Substances 0.000 title claims abstract description 233
- 239000003990 capacitor Substances 0.000 title claims abstract description 66
- 229910052707 ruthenium Inorganic materials 0.000 claims abstract description 45
- 229910052703 rhodium Inorganic materials 0.000 claims abstract description 31
- 229910052762 osmium Inorganic materials 0.000 claims abstract description 29
- 229910052741 iridium Inorganic materials 0.000 claims abstract description 27
- 229910052697 platinum Inorganic materials 0.000 claims abstract description 19
- 230000001590 oxidative effect Effects 0.000 claims abstract 2
- 239000000758 substrate Substances 0.000 claims description 38
- 150000004706 metal oxides Chemical class 0.000 claims description 24
- 229910044991 metal oxide Inorganic materials 0.000 claims description 23
- 239000000463 material Substances 0.000 claims description 19
- 229910052763 palladium Inorganic materials 0.000 claims description 15
- 229910000510 noble metal Inorganic materials 0.000 claims description 12
- 150000002739 metals Chemical class 0.000 claims description 6
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 5
- PBCFLUZVCVVTBY-UHFFFAOYSA-N tantalum pentoxide Inorganic materials O=[Ta](=O)O[Ta](=O)=O PBCFLUZVCVVTBY-UHFFFAOYSA-N 0.000 claims description 4
- 229910020279 Pb(Zr, Ti)O3 Inorganic materials 0.000 claims description 2
- 229910003781 PbTiO3 Inorganic materials 0.000 claims description 2
- 229910002370 SrTiO3 Inorganic materials 0.000 claims description 2
- 229910010252 TiO3 Inorganic materials 0.000 claims description 2
- 229910002113 barium titanate Inorganic materials 0.000 claims description 2
- 229910052746 lanthanum Inorganic materials 0.000 claims description 2
- 229910052745 lead Inorganic materials 0.000 claims description 2
- 229910052726 zirconium Inorganic materials 0.000 claims description 2
- 238000010438 heat treatment Methods 0.000 abstract description 42
- 239000012299 nitrogen atmosphere Substances 0.000 abstract description 25
- 239000013078 crystal Substances 0.000 abstract description 24
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 abstract description 16
- 239000001301 oxygen Substances 0.000 abstract description 16
- 229910052760 oxygen Inorganic materials 0.000 abstract description 16
- 230000015572 biosynthetic process Effects 0.000 abstract description 10
- 230000001965 increasing effect Effects 0.000 abstract description 8
- 239000010410 layer Substances 0.000 description 312
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- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 18
- 238000000034 method Methods 0.000 description 15
- 239000007789 gas Substances 0.000 description 10
- 238000004519 manufacturing process Methods 0.000 description 10
- 239000012298 atmosphere Substances 0.000 description 8
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 230000001939 inductive effect Effects 0.000 description 5
- 239000004065 semiconductor Substances 0.000 description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 3
- 230000004888 barrier function Effects 0.000 description 3
- 238000000151 deposition Methods 0.000 description 3
- 238000009832 plasma treatment Methods 0.000 description 3
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 3
- 229920005591 polysilicon Polymers 0.000 description 3
- 229910021417 amorphous silicon Inorganic materials 0.000 description 2
- 238000002425 crystallisation Methods 0.000 description 2
- 230000008025 crystallization Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- -1 Pt Ru Inorganic materials 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 230000000295 complement effect Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 239000003989 dielectric material Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 235000012054 meals Nutrition 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
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Images
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
- H01L27/02—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers
- H01L27/04—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components specially adapted for rectifying, oscillating, amplifying or switching and having potential barriers; including integrated passive circuit elements having potential barriers the substrate being a semiconductor body
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
- H01L28/40—Capacitors
- H01L28/60—Electrodes
- H01L28/82—Electrodes with an enlarged surface, e.g. formed by texturisation
- H01L28/84—Electrodes with an enlarged surface, e.g. formed by texturisation being a rough surface, e.g. using hemispherical grains
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
- H01L28/40—Capacitors
- H01L28/55—Capacitors with a dielectric comprising a perovskite structure material
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
- H01L28/40—Capacitors
- H01L28/60—Electrodes
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L28/00—Passive two-terminal components without a potential-jump or surface barrier for integrated circuits; Details thereof; Multistep manufacturing processes therefor
- H01L28/40—Capacitors
- H01L28/60—Electrodes
- H01L28/82—Electrodes with an enlarged surface, e.g. formed by texturisation
- H01L28/90—Electrodes with an enlarged surface, e.g. formed by texturisation having vertical extensions
Definitions
- the present invention relates to integrated circuit capacitors and methods for manufacturing the same, and more particular to Metal-Insulator-Metal (MIM) capacitors and methods for manufacturing the same
- MIM Metal-Insulator-Metal
- MIM capacitors are widely used in integrated circuit devices. As is well known to those having skill in the art, a MIM capacitor comprises spaced apart first (lower) and second (upper) metal layers (electrodes) and a dielectric layer therebetween. As the integration density of integrated circuit devices continues to increase, the area occupied by an individual device may continue to decrease. Thus, in MIM capacitors, it may be desirable to increase the capacitance by increasing the effective area of the capacitor, by forming a thin dielectric layer and/or by forming the dielectric layer of a material having high dielectric constant. Unfortunately, a thin film dielectric may produce decreased reliability and high dielectric constant dielectrics may require new manufacturing processes.
- the capacitor may be formed to have a three-dimensional structure, such as a fin structure, a cylinder structure and/or a trench structure.
- a metal-insulator-semiconductor (MIS) capacitor hemispherical grain (HSG) silicon lumps may be formed of doped polysilicon on the surface of a lower electrode, thereby increasing the effective area of the MIS capacitor.
- polysilicon may be deposited on the surface of an amorphous silicon layer and may be heat-treated in a high vacuum. Silicon atoms around the surface of the amorphous silicon layer may move toward the surface of the polysilicon layer, and thus the HSG lumps may be formed.
- the lower electrode of an MIM capacitor may be formed of noble metals, such as Au, Ag, Pd, Pt Ru, Ir, Rh, Hg or Os, and/or their conductive oxides. Since Ru, in particular, can be easily etched by plasma containing oxygen and can form conductive oxides, Ru often may be used in forming the lower electrode of a MIM capacitor.
- the lower electrode of a MIM capacitor may be formed to have a three-dimensional structure, such as a cylinder structure, a pin structure and/or a trench structure. However, an area increase effect induced by the formation of the HSG lumps in the MIS capacitor may not be obtained in the MIM structure because the lower electrode of the MIM structure is formed of metal rather than silicon.
- the dielectric layer may be crystallized after forming the dielectric layer and/or the MIM capacitor may be cured by heat-treating the MIM capacitor after forming the upper electrode.
- the dielectric layer may crack due to heat treatment.
- there may be limitations in the heat treatment and the characteristics of a capacitor may be degraded due to the heat treatment.
- Embodiments of the present invention provide integrated circuit MIM capacitors having a lower electrode that includes a metal layer on an integrated circuit substrate and hemispherical grain lumps that protrude from the metal layer.
- the metal layer comprises a metal that is capable of inducing growth of crystal grains using a heat treatment.
- the metal layer comprises a noble metal.
- the metal layer comprises at least one of the noble metals Pt, Ru, Rh, Ir, Os, and Pd.
- the metal layer is heat-treated in a nitrogen atmosphere. The metal layer may be heat-treated at between about 500° C. to about 800° C. (for example, about 700° C.).
- the metal layer and the hemispherical grain lumps both comprise at least one of Pt, Ru, Rh, Os, Ir, and Pd. In other embodiments, the metal layer and the hemispherical grain lumps both comprise the same material.
- a metal layer is formed of an oxidizable metal.
- the metal layer may comprise at least one of Ru, Rh, Os, and Pd.
- the metal layer is heat-treated in an oxygen atmosphere at about 500° C.
- hemispherical grain lumps are formed of a metal oxide on the surface of the metal layer.
- the metal layer is exposed to plasma containing O 2 gas, N 2 O gas, a mixed gas of He and O 2 , NO gas and/or a mixed gas of O 2 and N 2 so that the hemispherical grain lumps can be uniformly formed of the metal oxide.
- a lower electrode having hemispherical grain lumps includes a metal layer comprised of a first portion and a second portion.
- the first and second portions of the metal layer comprise different metals.
- the hemispherical grain lumps protrude from the second portion of the metal layer.
- the material of the first portion may comprise TiN, Ti, or TaN which is used as a barrier layer.
- the second portion may be formed of a metal, which is capable of inducing growth of crystal grains using a heat treatment.
- the second portion may comprise at least one of Pt, Ru, Rh, Os, Ir, and Pd.
- the second portion may be formed of an oxidizable metal.
- the second portion may comprise at least one of Ru, Rh, Os, Ir, and Pd.
- a lower electrode having hemispherical grain lumps includes a metal layer comprised of a first portion and a second portion.
- the first and second portions of the metal layer comprise different metals.
- the hemispherical grain lumps protrude from the second portion of the metal layer.
- the surface of the first portion is treated such that the morphology of the surface of the first portion is retained during subsequent heat treatments that are performed after the formation of the first portion.
- the subsequent heat treatments may include a process for forming the hemispherical grain lumps to protrude from the second portion, a process for crystallizing a dielectric layer, and/or a process for curing a capacitor after forming an upper electrode.
- a metal layer used to form the first portion is formed on an integrated circuit substrate and then is exposed to plasma containing argon (Ar), oxygen (O 2 ) and/or nitrogen (N 2 ).
- a metal layer used to form the first portion and a capping layer are sequentially formed on an integrated circuit substrate. Then, the metal layer covered with the capping layer is heat-treated in a nitrogen atmosphere at about 500° C. to about 800° C. (for example, about 700° C.), and the capping layer is removed. Next, the metal layer is exposed to plasma containing argon (Ar), oxygen (O 2 ) and/or nitrogen (N 2 ).
- a lower electrode having hemispherical grain lumps is formed by sequentially forming a metal layer and a metal oxide layer on an integrated circuit substrate and heat-treating the metal oxide layer in a nitrogen atmosphere. As a result of the heat treatment in a nitrogen atmosphere, the hemispherical grain lumps are formed to protrude from the metal oxide layer.
- the metal layer can be prevented from being thermally deformed by the metal oxide layer.
- a lower electrode having hemispherical grain lumps includes a metal layer on an integrated circuit substrate.
- the hemispherical grain lumps are formed between the metal layer and the substrate.
- the metal layer is thin and conformal, to maintain the profile of the hemispherical grain lumps protruding above the substrate.
- the hemispherical grain lumps may comprise metal or metal oxide.
- Pt, Ru, Rh, Os and/or Pd is deposited on the substrate and then is heat-treated in a nitrogen atmosphere at about 500° to about 800° C. (for example, about 700° C). The crystal grains of the metal grow on the substrate to form hemispherical grain lumps.
- an oxidizable metal for example Ru, Rh, Os, Ir and/or Pd is deposited on the substrate and then is heat-treated in an oxygen atmosphere at about 500° C. to about 800° C. (for example, about 500° C.). Then, the surface of the metal layer is oxidized, thus forming hemispherical grain lumps of a metal oxide.
- a capping layer (such as an oxide layer) is formed on the metal layer.
- the metal layer covered with the capping layer is heat-treated in a nitrogen atmosphere at about 700° C. and then the capping layer is removed. Hemispherical grain lumps can be formed to protrude from a dielectric layer on the substrate according to these embodiments.
- predetermined portions of the surface of the substrate may be exposed between the hemispherical grain lumps.
- a thin metal layer may cover the predetermined portions of the surface of the substrate that are exposed between the hemispherical grain lumps as well as the hemispherical grain lumps. Accordingly, dielectric layers to be formed on the lower electrode can be prevented from being connected to the semiconductor substrate and/or a contact plug on the substrate.
- the thin metal layer may comprise a metal which has good interfacial characteristics with a dielectric layer.
- the material of the thin metal layer is not restricted to noble metals.
- the size of the hemispherical grain lumps may vary depending on the thickness of the metal layer and the time duration and/or temperature of the heat treatment.
- a metal layer used to form a lower electrode is deposited on a substrate and then is heat-treated in a nitrogen and/or oxygen atmosphere to form hemispherical grain lumps before forming a dielectric layer.
- the surface of the metal layer is deformed before the formation of the dielectric layer. Accordingly, the deformation of the lower electrode caused by heat treatments subsequent to the formation of the lower electrode and the dielectric layer can be reduced or prevented, and thus cracks in the dielectric layer can be reduced or eliminated.
- FIGS. 1A and 1B are cross-sectional views illustrating hemispherical grain lumps formed on a ruthenium layer by a heat treatment under a nitrogen atmosphere, according to embodiments of the present invention.
- FIGS. 2A through 2D are cross-sectional views illustrating growth of ruthenium crystal grains undergoing the heat treatment according to the thickness of an electrode according to embodiments of the present invention.
- FIG. 3 is a cross-sectional view illustrating a capacitor using a ruthenium layer, on which hemispherical grain lumps shown in FIGS. 1A and 1B are formed as a lower electrode according to embodiments of the present invention.
- FIG. 4 is a cross-sectional view illustrating another capacitor using a ruthenium layer as a lower electrode according to embodiments of the present invention.
- FIG. 5 is a cross-sectional view illustrating another capacitor using a ruthenium layer as a lower electrode according to embodiments of the present invention.
- FIGS. 6A through 6C are cross-sectional views illustrating methods for forming the capacitor of FIG. 3 according to embodiments of the present invention.
- FIGS. 7A and 7B, 8 A and 8 B, 9 A through 9 C, and 10 A and 10 B are cross-sectional views illustrating methods for forming capacitors of FIG. 4 according to the present invention.
- FIGS. 1A through 11C are cross-sectional views illustrating methods for forming capacitors of FIG. 5 according to the present invention.
- Lower and/or upper electrodes of an MIM capacitor may be formed of noble metals including Au, Ag, Hg, Ru, Rh, Os, Pt, Ir and/or Pd, and/or their oxides.
- the lower and/or upper electrodes may be formed of Ru, Rh, Os, Pt, Ir and/or Pd, and/or their oxides.
- a noble metal layer for example, a ruthenium layer 10 is heat-treated in a nitrogen atmosphere, ruthenium atoms move so as to reduce the surface energy or crystal grain boundary energy of the ruthenium layer 10 .
- the crystal grains of the ruthenium layer 10 grow or ruthenium atoms at the surface of the ruthenium layer 10 agglomerate.
- crystal grains 12 a, 12 b, and, 12 c growing on the surface of the ruthenium layer 10 or agglomerate grains 14 are formed.
- the size of such crystal grains or agglomerate grains may be varied depending on the thickness of a metal layer when heat-treating the metal layer in a nitrogen atmosphere, as will be described with reference to FIGS. 2A through 2D.
- Ruthenium layers are each deposited to thicknesses of 50 ⁇ , 100 ⁇ , 150 ⁇ , and 200 ⁇ on an integrated substrate, such as a semiconductor substrate or a dielectric layer 20 a, 20 b, 20 c, and 20 d, respectively, and are heat-treated in a nitrogen atmosphere for about thirty minutes.
- the size and/or height of hemispherical grain lumps 22 , 24 , 26 , and 28 increase.
- the hemispherical grain lumps 22 and 24 formed on ruthenium layers having a thickness no greater than 200 ⁇ are discontinuous and expose predetermined portions of the semiconductor substrate or the dielectric layers 20 a and 20 b.
- the size and/or height of hemispherical grain lumps may be increased or decreased by heat treatment conditions, such as heat treatment temperature and/or heat treatment time, as well as the thickness of the ruthenium layer. For example, if the heat treatment of a ruthenium layer is performed for a longer time or at a higher temperature, the growth of crystal grains can be accelerated.
- MIM capacitors including lower electrodes, each of which has hemispherical grain lumps formed through heat treatment of a metal layer in a nitrogen atmosphere according to embodiments of the invention are illustrated in FIGS. 3 through 5.
- Various embodiments for manufacturing such capacitors are illustrated in FIGS. 6A and 6B, 7 A and 7 B, 8 A and 8 B, 9 A through 9 C, 10 A and 10 B, and 11 A through 11 C.
- FIGS. 2A through 2D in some embodiments, if the thickness of a metal layer exceeds a predetermined level, hemispherical grain lumps are formed such that the surface of an underlying layer is not exposed. Thus, it is possible to form a lower electrode having an increased effective area. A capacitor including such a lower electrode is illustrated in FIG. 3.
- a first interlayer dielectric layer 400 includes a contact plug 410 on an integrated circuit substrate (not shown).
- a second interlayer dielectric layer 420 includes an opening on the first interlayer dielectric layer 400 such that the contact plug 410 is exposed through the opening.
- a first metal layer 432 is provided on the sidewalls and floor of the opening of the second interlayer dielectric layer 420 .
- Hemispherical grain lumps 435 protrude from the first metal layer 432 .
- the hemispherical grain lumps 435 are formed of the same metal as the first metal layer 432 .
- the first metal layer 432 and the hemispherical grain lumps 435 form a lower electrode 430 .
- a dielectric layer 450 is provided on the hemispherical grain lumps 435 and the second interlayer dielectric layer 420 .
- the dielectric layer 450 may comprise Ta 2 O 5 , SrTiO 3 (STO), (Ba, Sr)TiO 3 (BST), PbTiO 3 , Pb(Zr, Ti)O 3 (PZT), SrBi 2 Ta 2 O 5 (SBT), (Pb, La)(Zr, Ti)O 3 , Bi 4 Ti 3 O 12 , and/or BaTiO 3 (BTO).
- a second metal layer 460 which corresponds to an upper electrode of a capacitor, is provided on the dielectric layer 450 .
- the first metal layer 432 of the lower electrode 430 , the hemispherical grain lumps 435 , and the upper electrode 460 comprise Ru, Rh, Pt, Os and/or Pd.
- a metal layer on which hemispherical grain lumps will be formed if the thickness of a metal layer on which hemispherical grain lumps will be formed, is no greater than a predetermined level, the hemispherical grain lumps may be nonuniformly formed on the metal layer, and thus the surface of an underlying layer, that is, the surface of the dielectric layer 20 a or 20 b, may be exposed.
- a metal layer may be provided as a double layer such that a dielectric layer formed on the metal layer can be prevented from contacting layers under the metal layer.
- the metal layer is not restricted to a double layer but may be three- or more-layered.
- the uppermost metal layer constituting the multilayered metal layer should have characteristics that if the uppermost metal layer is heat-treated, crystal grains grow from the uppermost metal layer of the metal layer.
- a capacitor formed through this method is illustrated in FIG. 4.
- a lower electrode 530 includes a first metal layer 532 , a second metal layer 534 , and hemispherical grain lumps 536 protruding from the second metal layer 534 .
- the hemispherical grain lumps 536 may be formed of the same metal as the second metal layer 534 or its metal oxides.
- the first and second metal layers 532 and 534 may be formed of the same material or different materials.
- the second metal layer 534 may not appear in a finished lower electrode depending on processing conditions. For example, if the second metal layer 534 is very thin and is heat-treated at a high temperature and/or for a long time, the entire second metal layer 534 may be transformed into hemispherical grain lumps 536 , thereby forming a lower electrode consisting of the first metal layer 532 and the hemispherical grain lumps 536 .
- the first and second metal layers 532 and 534 are formed of the same material and the hemispherical grain lumps 536 are formed of metal, the first and second metal layers 532 and 534 may be formed of a metal that is capable of inducing growth of crystal grains, for example, Pt, Ru, Rh, Ir, Os, or Pd.
- a lower electrode by replacing the second metal layer 534 with a conductive layer formed of an oxide of a metal forming the first metal layer 532 , such as an oxide of Ru, Rh, Os, Ir, or Pd.
- a conductive layer formed of an oxide of a metal forming the first metal layer 532 such as an oxide of Ru, Rh, Os, Ir, or Pd.
- hemispherical grain lumps 536 may be formed of a metal oxide through growth of crystal grains caused by a heat treatment in a nitrogen atmosphere.
- the first metal layer 532 may comprise any metal.
- TiN, Ti, or TaN which generally acts as a barrier layer, may be used to form the first metal layer 532 , which can improve the characteristics of an interface between an oxide dielectric layer and the first metal layer.
- the second metal layer 534 may be formed of a metal that is capable of inducing growth of crystal grains during a subsequent heat treatment, such as Pt, Ru, Rh, Os, Ir, or Pd.
- the first and second metal layers 532 and 534 comprise different materials and the hemispherical grain lumps 536 comprise a metal oxide
- the first metal layer 532 is may comprise metal which is resistant to oxidation, such as Pt.
- the second metal layer 534 may comprise Ru, Rh, Os, Ir and/or Pd.
- Reference numerals 500 , 510 , 540 , and 550 which have not been mentioned yet, refer to a first interlayer dielectric layer formed on a substrate (not shown), a contact plug, a dielectric layer, and an upper electrode, respectively.
- Embodiments of capacitors formed by forming a thin metal layer between an underlying layer including hemispherical gain lumps and a dielectric layer while the hemispherical grain lumps are directly on the underlying layer are illustrated in FIG. 5.
- a lower electrode 630 includes hemispherical grain lumps 632 directly on a first interlayer dielectric layer 620 , a dielectric layer 600 , and a contact plug 610 , and a first metal layer 634 covering the underlying layers including the hemispherical grain lumps 632 .
- the hemispherical grain lumps 632 may be formed of a metal or a metal oxide.
- the hemispherical grain lumps 632 comprise metal
- Pt, Ru, Rh, Os, Ir and/or Pd may be used.
- a metal which can form an oxide when heat-treated, such as Ru, Rh, Os, Ir, or Pd may be used.
- Reference numerals 600 , 640 , and 650 which have not been mentioned yet, refer to a first interlayer dielectric layer, a dielectric layer, and an upper electrode, respectively.
- FIGS. 6A through 6C are cross-sectional views illustrating methods for manufacturing capacitors shown in FIG. 3. The conventional steps of forming a dielectric layer and an upper electrode after a step of forming a lower electrode are not illustrated in FIGS. 6A through 6C.
- a contact plug 710 is formed in a first interlayer dielectric layer 700 .
- a second interlayer dielectric layer 720 is formed to have an opening on the first interlayer dielectric layer 700 including the contact plug 710 formed therein such that the contact plug 710 is exposed through the opening of the second interlayer dielectric layer 720 .
- a metal layer 730 is formed at the sides and floor of the opening and on the second interlayer dielectric layer 720 .
- the metal layer 730 is heat-treated in a nitrogen atmosphere, as shown in FIG. 6B, hemispherical grain lumps are formed.
- the metal layer 730 and the hemispherical grain lumps are polished until the top surface of the second interlayer dielectric layer 720 is exposed, thereby forming a lower electrode L 1 including a metal layer 732 and hemispherical grain lumps 734 .
- the metal layer 732 shown in FIG. 6B is formed by heat-treating and polishing the metal layer 730 .
- the metal layer 730 is heat-treated in a nitrogen atmosphere at a temperature higher than the crystallization temperature of a dielectric layer or the temperature of curing a capacitor, i.e., about 500° to about 800° C. for about ten minutes to about three hours, for example, at about 700° C. for about thirty minutes, crystal grains grow from the surface of the metal layer 730 such that the hemispherical grain lumps 734 formed of the same metal as the metal layer 730 are formed.
- Pt, Ru, Rh, Os, Ir and/or Pd may be used.
- the hemispherical grain lumps 734 may be formed by heat-treating the metal layer 730 in an oxygen atmosphere.
- the metal layer 730 is exposed to plasma containing oxygen, for example, O 2 gas, N 2 O gas, a mixed gas of He and O 2 , NO gas and/or a mixed gas of O 2 and N 2 , during the heat-treatment, thereby uniformly forming metal oxide, i.e., the hemispherical grain lumps 734 at the surface of the metal layer 730 .
- the metal layer may be formed of Ru, Rh, Os, Ir, or Pd.
- FIGS. 7A and 7B, 8 A and 8 B, 9 A through 9 C, and 10 A and 10 B are cross-sectional views illustrating methods for manufacturing the capacitor shown in FIG. 4 according to embodiments of the invention. For the sake of brevity, manufacturing steps after forming a lower electrode are not illustrated in these figures.
- steps of preparing a first interlayer dielectric layer 800 including a contact plug 810 and forming a second interlayer dielectric layer 820 having an opening through which the contact plug 810 is exposed can be the same as described above with reference to FIG. 6A.
- a first metal layer 830 and a second metal layer 835 are sequentially formed of different metals at the sides and floor of the opening and on the second interlayer dielectric layer 820 .
- the first metal layer 830 may be formed of any kind of metal, such as TiN, Ti, or TaN, which is used as a barrier layer.
- the first metal layer 830 and second metal layer 835 are polished until the surface of the second interlayer dielectric layer 820 is exposed.
- the second metal layer 835 a that is polished is heat-treated in an oxygen atmosphere and/or a nitrogen atmosphere, thereby forming hemispherical grain lumps 837 to protrude from the surface of the second metal layer 835 a.
- Predetermined portions or all of the second metal layer 835 a may be transformed into the hemispherical grain lumps 837 depending on heat treatment conditions.
- the second, metal layer 835 a is only partially transformed into the hemispherical grain lumps 837 .
- a lower electrode L 2 includes a first metal layer 830 a, portions of the second metal layer 835 a not transformed into the hemispherical grain lumps 837 , and the hemispherical grain lumps 837 .
- the effective area of the lower electrode L 2 is increased due to the hemispherical grain lumps 837 .
- the hemispherical grain lumps 837 formed by heat-treating the second metal layer 835 in a nitrogen atmosphere at about 500° C. to about 800° C. may be formed of the same metal as the second metal layer 835 , such as Pt, Ru, Rh, Os, Ir, or Pd.
- a first metal layer 930 is formed at the sides and bottom of an opening, through which a contact plug 910 is exposed, on a second interlayer dielectric layer 920 and then is exposed to plasma containing N 2 , O 2 and/or argon (Ar).
- the plasma treatment can be replaced by any treatment that is capable of accelerating charged particles and then inducing a collision between the charged particles and the first metal layer 930 .
- a second metal layer 935 is formed of the same material as the first metal layer 930 on the plasma-treated first metal layer 930 .
- the first and second metal layers 930 and 935 are polished until the top surface of the second interlayer dielectric layer 920 is exposed.
- the second metal layer 935 is heat-treated in a nitrogen atmosphere.
- hemispherical grain lumps 936 are formed on the second metal layer 935 .
- predetermined portions or all of the second metal layer 935 may be transformed into the hemispherical grain lumps 936 .
- the second metal layer 935 is only partially transformed into the hemispherical grain lumps 936 .
- a lower electrode L 3 includes a first metal layer 930 a, the second metal layer 935 , and the hemispherical grain lumps 936 .
- the first metal layer 930 may be prevented from being rapidly deformed by a subsequent heat treatment, i.e., the heat treatment of the second metal layer 935 .
- a subsequent heat treatment i.e., the heat treatment of the second metal layer 935 .
- hemispherical grain lumps 936 may be formed at the surface of the second metal layer 935 such that a contact area between the hemispherical grain lumps and a dielectric layer to be formed on the hemispherical grain lumps increases.
- Reference numeral 900 which has not been mentioned yet, refers to a first dielectric layer formed on a substrate (not shown).
- the first metal layer 930 is formed at the sides and bottom of the opening, through which the contact plug 910 is exposed, and on the second interlayer dielectric layer 920 .
- a capping layer 950 is formed of a material that does not react significantly with the first metal layer 930 , such as an oxide layer.
- the first metal layer 930 and the capping layer 950 are preheat-treated in a nitrogen atmosphere at about 500° C. to about 800° C., thereby growing the crystal grains of the first metal layer 930 .
- the first metal layer 930 is exposed by removing the capping layer 950 .
- the exposed first metal layer 930 is plasma-treated.
- the plasma treatment of the first metal layer 930 can be the same as that of the first metal layer 930 described above with reference to FIG. 8A.
- a second metal layer 970 is formed on a first metal layer 930 b, which has been plasma-treated, and then the first and second metal layers 930 and 970 are polished until the top surface of the second interlayer dielectric layer 920 is exposed.
- the second metal layer 970 is heat-treated in a nitrogen atmosphere so as to form hemispherical grain lumps 975 protruding from the second metal layer 970 .
- predetermined portions or all of the second metal layer 970 may be transformed into the hemispherical grain lumps 975 .
- the second metal layer 970 is partially transformed into the hemispherical grain lumps 975 .
- a lower electrode L 4 including the first metal layer 930 c, which has been plasma-treated, portions of the second metal layer 970 not transformed into the hemispherical grain lumps 975 , and the hemispherical grain lumps 975 protruding from the top surface of the second metal layer 970 is provided.
- the surface of the first metal layer 930 can be prevented from being deformed by a subsequent heat treatment, i.e., the heat-treatment of the second metal layer 970 .
- a subsequent heat treatment i.e., the heat-treatment of the second metal layer 970 .
- crystal grains grow or oxides are formed at the surface of the second metal layer 970 due to a heat treatment subsequent to the formation of the second metal layer, and thus the hemispherical grain lumps 975 are formed.
- the materials of the hemispherical grain lumps 936 formed in an oxygen or nitrogen atmosphere and the second metal layer 935 can be the same as described above with reference to FIGS. 6A and 6B, and 7 A and 7 B, and thus their description will not be repeated.
- a first metal layer 1130 and a metal oxide layer 1150 are sequentially formed at the sides and floor of an opening, through which a contact plug 1110 is exposed, and on the top surface of a second interlayer dielectric layer 1120 .
- the first metal layer 1130 and the metal oxide layer 1150 are polished until the top surface of the second interlayer dielectric layer 1120 is exposed.
- a substrate including the metal oxide layer 1150 is heat-treated in a nitrogen atmosphere.
- the temperature of the heat treatment is higher than the crystallization temperature of a dielectric layer or the temperature of curing a capacitor, for example, between about 500° C. and about 800° C.
- the heat treatment is performed at about 700° C. for about thirty minutes.
- metal oxide crystal grains grow on the surface of the metal oxide layer 1150 , and thus hemispherical grain lumps 1170 are formed.
- a lower electrode L 5 includes a first metal layer 1130 a, a metal oxide layer 1150 , and the hemispherical grain lumps 1170 formed of a metal oxide.
- FIGS. 11A through 11C are cross-sectional views illustrating methods for manufacturing capacitors shown in FIG. 5. Only the manufacturing steps performed until a lower electrode is formed are illustrated in these figures.
- a first metal layer 1230 is formed at the sides and floor of an opening, through which a contact plug 1210 is exposed, and on the top surface of a second interlayer dielectric layer 1220 .
- the first metal layer 1230 is heat-treated in an oxygen and/or nitrogen atmosphere, thereby forming hemispherical grain lumps 1230 a. Since the first metal layer 1230 is very thin, as described above with reference to FIGS. 2A through 2D (particularly, FIGS.
- first interlayer dielectric layer 1200 the second interlayer dielectric layer 1220 , and the contact plug 1210 are partially exposed between the hemispherical grain lumps 1230 a that are nonuniformly formed.
- a capping layer 1250 is formed of a material that does not react significantly with the first metal layer 1230 , such as an oxide layer, between the step of depositing the first metal layer 1230 on the substrate including the second interlayer dielectric layer 1220 and the step of heat-treating the first metal layer 1230 .
- the first metal layer 1230 is heat-treated to grow crystal grains, thus forming hemispherical grain lumps.
- the capping layer 1250 is removed.
- a second metal layer 1240 is conformally deposited along the shape of the hemispherical grain lumps formed through one of the embodiments described above so as to cover the underlying layers including the hemispherical grain lumps 1230 a.
- the hemispherical grain lumps and the second metal layer are polished until the top surface of the second interlayer dielectric layer 1220 is exposed, thereby forming a lower electrode including hemispherical grain lumps 1230 a and a second metal layer 1240 .
- the second metal layer 1240 may be formed of a metal that is stable in processes subsequent to the formation of the lower electrode L 6 and has superior interfacial characteristics with respect to a dielectric layer.
- the second metal layer 1240 may be formed of noble metals including Pt, Rh, Os, Ir, and Pd.
- the materials of the hemispherical grain lumps 1230 a and the second metal layer 1240 can be the same as described above with reference to FIGS. 6A and 6B, and 7 A and 7 B, and thus their description will not be repeated.
- a dielectric layer is crystallized after a lower electrode and a dielectric layer are formed, and a capacitor is cured through heat treatment after an upper electrode is formed.
- the dielectric layer may slightly crack due to the heat treatment, there may be a limit in performing the heat-treatment after the formation of the lower electrode and the dielectric layer.
- the metal layer used for a lower electrode can be primarily heat-treated during the formation of the lower electrode such that the surface of the metal layer is changed. Then, a second heat treatment is performed after the deposition of a dielectric layer.
- the metal layer that is subjected to the primary heat treatment may be changed less in the second heat treatment compared, to a metal layer that is subjected to only the second heat treatment subsequent to the deposition of a dielectric layer.
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Abstract
The effective area of a MIM capacitor is increased by forming a lower electrode that includes hemispherical grain lumps. The hemispherical grain lumps are formed by heat-treating a metal layer in an oxygen and/or nitrogen atmosphere, thus oxidizing the surface of the metal layer or growing the crystal grains of the metal layer. The MIM capacitor may be formed of Pt, Ru, Rh, Os, Ir, or Pd, and the hemispherical grain lumps may be formed of Pt, Ru, Rh, Os, Ir, or Pd. Since the metal layer is primarily heat-treated during the formation of the lower electrode, it is possible to reduce the degree to which the surface morphology of the lower electrode is rapidly changed due to a heat treatment subsequent to forming a dielectric layer and an upper electrode.
Description
- This application is a divisional of application Ser. No. 10/180,277, filed Jun. 26, 2002, entitled Methods for Manufacturing Integrated Circuit Metal-Insulator-Metal Capacitors Including Hemispherical Grain Lumps, assigned to the assignee of the present invention, the disclosure of which is hereby incorporated herein by reference in its entirety as if set forth fully herein. This application also claims the benefit of Korean Patent Application No. 2001-36584, filed Jun. 26, 2001, the disclosure of which is hereby incorporated herein by reference in its entirety as if set forth fully herein.
- The present invention relates to integrated circuit capacitors and methods for manufacturing the same, and more particular to Metal-Insulator-Metal (MIM) capacitors and methods for manufacturing the same
- MIM capacitors are widely used in integrated circuit devices. As is well known to those having skill in the art, a MIM capacitor comprises spaced apart first (lower) and second (upper) metal layers (electrodes) and a dielectric layer therebetween. As the integration density of integrated circuit devices continues to increase, the area occupied by an individual device may continue to decrease. Thus, in MIM capacitors, it may be desirable to increase the capacitance by increasing the effective area of the capacitor, by forming a thin dielectric layer and/or by forming the dielectric layer of a material having high dielectric constant. Unfortunately, a thin film dielectric may produce decreased reliability and high dielectric constant dielectrics may require new manufacturing processes.
- In order to increase the effective area of a capacitor, the capacitor may be formed to have a three-dimensional structure, such as a fin structure, a cylinder structure and/or a trench structure. In particular, in the case of a metal-insulator-semiconductor (MIS) capacitor, hemispherical grain (HSG) silicon lumps may be formed of doped polysilicon on the surface of a lower electrode, thereby increasing the effective area of the MIS capacitor. Specifically, polysilicon may be deposited on the surface of an amorphous silicon layer and may be heat-treated in a high vacuum. Silicon atoms around the surface of the amorphous silicon layer may move toward the surface of the polysilicon layer, and thus the HSG lumps may be formed.
- The lower electrode of an MIM capacitor may be formed of noble metals, such as Au, Ag, Pd, Pt Ru, Ir, Rh, Hg or Os, and/or their conductive oxides. Since Ru, in particular, can be easily etched by plasma containing oxygen and can form conductive oxides, Ru often may be used in forming the lower electrode of a MIM capacitor. The lower electrode of a MIM capacitor may be formed to have a three-dimensional structure, such as a cylinder structure, a pin structure and/or a trench structure. However, an area increase effect induced by the formation of the HSG lumps in the MIS capacitor may not be obtained in the MIM structure because the lower electrode of the MIM structure is formed of metal rather than silicon.
- Moreover, in order to obtain a high dielectric constant from the MIM capacitor, the dielectric layer may be crystallized after forming the dielectric layer and/or the MIM capacitor may be cured by heat-treating the MIM capacitor after forming the upper electrode. However, the dielectric layer may crack due to heat treatment. Thus, there may be limitations in the heat treatment, and the characteristics of a capacitor may be degraded due to the heat treatment.
- Embodiments of the present invention provide integrated circuit MIM capacitors having a lower electrode that includes a metal layer on an integrated circuit substrate and hemispherical grain lumps that protrude from the metal layer. In some embodiments, the metal layer comprises a metal that is capable of inducing growth of crystal grains using a heat treatment. For example, in some embodiments, the metal layer comprises a noble metal. In other embodiments, the metal layer comprises at least one of the noble metals Pt, Ru, Rh, Ir, Os, and Pd. In some embodiments, the metal layer is heat-treated in a nitrogen atmosphere. The metal layer may be heat-treated at between about 500° C. to about 800° C. (for example, about 700° C.). In some embodiments, as a result of the heat treatment in a nitrogen atmosphere, crystal grains are grown on the surface of the metal layer, and the crystal grains form hemispherical grain lumps. Accordingly, in some embodiments, the metal layer and the hemispherical grain lumps both comprise at least one of Pt, Ru, Rh, Os, Ir, and Pd. In other embodiments, the metal layer and the hemispherical grain lumps both comprise the same material.
- In other embodiments of the present invention, a metal layer is formed of an oxidizable metal. For example, the metal layer may comprise at least one of Ru, Rh, Os, and Pd. The metal layer is heat-treated in an oxygen atmosphere at about 500° C. As a result of the heat treatment in an oxygen atmosphere, hemispherical grain lumps are formed of a metal oxide on the surface of the metal layer. In some embodiments, before heat-treating the metal layer in an oxygen atmosphere, the metal layer is exposed to plasma containing O2 gas, N2O gas, a mixed gas of He and O2, NO gas and/or a mixed gas of O2 and N2 so that the hemispherical grain lumps can be uniformly formed of the metal oxide.
- According to other embodiments of the present invention, a lower electrode having hemispherical grain lumps includes a metal layer comprised of a first portion and a second portion. In these embodiments, the first and second portions of the metal layer comprise different metals. The hemispherical grain lumps protrude from the second portion of the metal layer. There may be no limitation in the material of the first portion. For example, the first portion may comprise TiN, Ti, or TaN which is used as a barrier layer. The second portion may be formed of a metal, which is capable of inducing growth of crystal grains using a heat treatment. For example, the second portion may comprise at least one of Pt, Ru, Rh, Os, Ir, and Pd. In some embodiments where the first portion is formed of a metal which is not readily oxidized, such as a Pt-based material, the second portion may be formed of an oxidizable metal. For example, the second portion may comprise at least one of Ru, Rh, Os, Ir, and Pd.
- According to other embodiments of the present invention, a lower electrode having hemispherical grain lumps includes a metal layer comprised of a first portion and a second portion. In these embodiments, the first and second portions of the metal layer comprise different metals. The hemispherical grain lumps protrude from the second portion of the metal layer. In some embodiments, the surface of the first portion is treated such that the morphology of the surface of the first portion is retained during subsequent heat treatments that are performed after the formation of the first portion. The subsequent heat treatments may include a process for forming the hemispherical grain lumps to protrude from the second portion, a process for crystallizing a dielectric layer, and/or a process for curing a capacitor after forming an upper electrode.
- Various embodiments of the present invention can retain the morphology of the first portion. In some embodiments, a metal layer used to form the first portion is formed on an integrated circuit substrate and then is exposed to plasma containing argon (Ar), oxygen (O2) and/or nitrogen (N2). In other embodiments, a metal layer used to form the first portion and a capping layer are sequentially formed on an integrated circuit substrate. Then, the metal layer covered with the capping layer is heat-treated in a nitrogen atmosphere at about 500° C. to about 800° C. (for example, about 700° C.), and the capping layer is removed. Next, the metal layer is exposed to plasma containing argon (Ar), oxygen (O2) and/or nitrogen (N2).
- According to other embodiments of the present invention, a lower electrode having hemispherical grain lumps is formed by sequentially forming a metal layer and a metal oxide layer on an integrated circuit substrate and heat-treating the metal oxide layer in a nitrogen atmosphere. As a result of the heat treatment in a nitrogen atmosphere, the hemispherical grain lumps are formed to protrude from the metal oxide layer. In some embodiments, the metal layer can be prevented from being thermally deformed by the metal oxide layer.
- According to other embodiments of the present invention, a lower electrode having hemispherical grain lumps includes a metal layer on an integrated circuit substrate. The hemispherical grain lumps are formed between the metal layer and the substrate. The metal layer is thin and conformal, to maintain the profile of the hemispherical grain lumps protruding above the substrate.
- In these embodiments, the hemispherical grain lumps may comprise metal or metal oxide. In some embodiments, Pt, Ru, Rh, Os and/or Pd is deposited on the substrate and then is heat-treated in a nitrogen atmosphere at about 500° to about 800° C. (for example, about 700° C). The crystal grains of the metal grow on the substrate to form hemispherical grain lumps. Alternatively, an oxidizable metal, for example Ru, Rh, Os, Ir and/or Pd is deposited on the substrate and then is heat-treated in an oxygen atmosphere at about 500° C. to about 800° C. (for example, about 500° C.). Then, the surface of the metal layer is oxidized, thus forming hemispherical grain lumps of a metal oxide.
- Before the heat treatment in a nitrogen or oxygen atmosphere, a capping layer (such as an oxide layer) is formed on the metal layer. Next, the metal layer covered with the capping layer is heat-treated in a nitrogen atmosphere at about 700° C. and then the capping layer is removed. Hemispherical grain lumps can be formed to protrude from a dielectric layer on the substrate according to these embodiments.
- In some embodiments of the present invention, predetermined portions of the surface of the substrate may be exposed between the hemispherical grain lumps. In other embodiments, a thin metal layer may cover the predetermined portions of the surface of the substrate that are exposed between the hemispherical grain lumps as well as the hemispherical grain lumps. Accordingly, dielectric layers to be formed on the lower electrode can be prevented from being connected to the semiconductor substrate and/or a contact plug on the substrate. The thin metal layer may comprise a metal which has good interfacial characteristics with a dielectric layer. The material of the thin metal layer is not restricted to noble metals. The size of the hemispherical grain lumps may vary depending on the thickness of the metal layer and the time duration and/or temperature of the heat treatment.
- As described above, since a lower electrode of a MIM capacitor includes hemispherical grain lumps protruding toward a dielectric layer, the effective area of the MIM capacitor may increase, and thus it is possible to increase the capacitance of the MIM capacitor, according to embodiments of the present invention. Moreover, in some embodiments of the present invention, a metal layer used to form a lower electrode is deposited on a substrate and then is heat-treated in a nitrogen and/or oxygen atmosphere to form hemispherical grain lumps before forming a dielectric layer. In other words, in these embodiments, the surface of the metal layer is deformed before the formation of the dielectric layer. Accordingly, the deformation of the lower electrode caused by heat treatments subsequent to the formation of the lower electrode and the dielectric layer can be reduced or prevented, and thus cracks in the dielectric layer can be reduced or eliminated.
- FIGS. 1A and 1B are cross-sectional views illustrating hemispherical grain lumps formed on a ruthenium layer by a heat treatment under a nitrogen atmosphere, according to embodiments of the present invention.
- FIGS. 2A through 2D are cross-sectional views illustrating growth of ruthenium crystal grains undergoing the heat treatment according to the thickness of an electrode according to embodiments of the present invention.
- FIG. 3 is a cross-sectional view illustrating a capacitor using a ruthenium layer, on which hemispherical grain lumps shown in FIGS. 1A and 1B are formed as a lower electrode according to embodiments of the present invention.
- FIG. 4 is a cross-sectional view illustrating another capacitor using a ruthenium layer as a lower electrode according to embodiments of the present invention.
- FIG. 5 is a cross-sectional view illustrating another capacitor using a ruthenium layer as a lower electrode according to embodiments of the present invention.
- FIGS. 6A through 6C are cross-sectional views illustrating methods for forming the capacitor of FIG. 3 according to embodiments of the present invention.
- FIGS. 7A and 7B,8A and 8B, 9A through 9C, and 10A and 10B are cross-sectional views illustrating methods for forming capacitors of FIG. 4 according to the present invention.
- FIGS. 1A through 11C are cross-sectional views illustrating methods for forming capacitors of FIG. 5 according to the present invention.
- The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the relative sizes of regions may be exaggerated for clarity. It will be understood that when an element such as a layer, region or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present. Moreover, each embodiment described and illustrated herein includes its complementary conductivity type embodiment as well.
- Lower and/or upper electrodes of an MIM capacitor may be formed of noble metals including Au, Ag, Hg, Ru, Rh, Os, Pt, Ir and/or Pd, and/or their oxides. In some embodiments, the lower and/or upper electrodes may be formed of Ru, Rh, Os, Pt, Ir and/or Pd, and/or their oxides.
- Hereinafter, increasing the surface area of a lower electrode by forming hemispherical grain lumps of noble metal or noble metal oxide, according to embodiments of the invention, will be described. Although all the above noble meals may have similar characteristics in that if heat is applied, crystal grains grow or the noble metals form oxides, only ruthenium will be described here for the sake of brevity.
- Referring to FIGS. 1A and 1B; if a noble metal layer, for example, a
ruthenium layer 10 is heat-treated in a nitrogen atmosphere, ruthenium atoms move so as to reduce the surface energy or crystal grain boundary energy of theruthenium layer 10. As a result, the crystal grains of theruthenium layer 10 grow or ruthenium atoms at the surface of theruthenium layer 10 agglomerate. In other words,crystal grains ruthenium layer 10 oragglomerate grains 14 are formed. - The size of such crystal grains or agglomerate grains may be varied depending on the thickness of a metal layer when heat-treating the metal layer in a nitrogen atmosphere, as will be described with reference to FIGS. 2A through 2D. Ruthenium layers are each deposited to thicknesses of 50 Å, 100 Å, 150 Å, and 200 Å on an integrated substrate, such as a semiconductor substrate or a
dielectric layer dielectric layers dielectric layers - The size and/or height of hemispherical grain lumps may be increased or decreased by heat treatment conditions, such as heat treatment temperature and/or heat treatment time, as well as the thickness of the ruthenium layer. For example, if the heat treatment of a ruthenium layer is performed for a longer time or at a higher temperature, the growth of crystal grains can be accelerated.
- MIM capacitors including lower electrodes, each of which has hemispherical grain lumps formed through heat treatment of a metal layer in a nitrogen atmosphere according to embodiments of the invention, are illustrated in FIGS. 3 through 5. Various embodiments for manufacturing such capacitors are illustrated in FIGS. 6A and 6B,7A and 7B, 8A and 8B, 9A through 9C, 10A and 10B, and 11A through 11C.
- As shown in FIGS. 2A through 2D, in some embodiments, if the thickness of a metal layer exceeds a predetermined level, hemispherical grain lumps are formed such that the surface of an underlying layer is not exposed. Thus, it is possible to form a lower electrode having an increased effective area. A capacitor including such a lower electrode is illustrated in FIG. 3.
- Referring to FIG. 3, a first
interlayer dielectric layer 400 includes acontact plug 410 on an integrated circuit substrate (not shown). A secondinterlayer dielectric layer 420 includes an opening on the firstinterlayer dielectric layer 400 such that thecontact plug 410 is exposed through the opening. A first metal layer 432 is provided on the sidewalls and floor of the opening of the secondinterlayer dielectric layer 420. Hemispherical grain lumps 435 protrude from the first metal layer 432. In these embodiments, the hemispherical grain lumps 435 are formed of the same metal as the first metal layer 432. The first metal layer 432 and the hemispherical grain lumps 435 form alower electrode 430. Adielectric layer 450 is provided on the hemispherical grain lumps 435 and the secondinterlayer dielectric layer 420. Thedielectric layer 450 may comprise Ta2O5, SrTiO3(STO), (Ba, Sr)TiO3(BST), PbTiO3, Pb(Zr, Ti)O3(PZT), SrBi2Ta2O5(SBT), (Pb, La)(Zr, Ti)O3, Bi4Ti3O12, and/or BaTiO3(BTO). Asecond metal layer 460, which corresponds to an upper electrode of a capacitor, is provided on thedielectric layer 450. - In some embodiments, the first metal layer432 of the
lower electrode 430, the hemispherical grain lumps 435, and theupper electrode 460 comprise Ru, Rh, Pt, Os and/or Pd. - As shown in FIGS. 2A through 2D, if the thickness of a metal layer on which hemispherical grain lumps will be formed, is no greater than a predetermined level, the hemispherical grain lumps may be nonuniformly formed on the metal layer, and thus the surface of an underlying layer, that is, the surface of the
dielectric layer - In order to form the metal layer into a double layer, it is possible to make hemispherical grain lumps directly on a dielectric layer or to form a thin metal layer between an underlying layer including hemispherical grain lumps and a dielectric layer while forming the hemispherical grain lumps directly on the underlying layer.
- When forming a metal layer into a double layer by making hemispherical grain lumps directly on a dielectric layer, the metal layer is not restricted to a double layer but may be three- or more-layered. In this case, the uppermost metal layer constituting the multilayered metal layer should have characteristics that if the uppermost metal layer is heat-treated, crystal grains grow from the uppermost metal layer of the metal layer. A capacitor formed through this method is illustrated in FIG. 4.
- In FIG. 4, a
lower electrode 530 includes afirst metal layer 532, asecond metal layer 534, and hemispherical grain lumps 536 protruding from thesecond metal layer 534. As shown in FIG. 4, the hemispherical grain lumps 536 may be formed of the same metal as thesecond metal layer 534 or its metal oxides. The first andsecond metal layers - The
second metal layer 534 may not appear in a finished lower electrode depending on processing conditions. For example, if thesecond metal layer 534 is very thin and is heat-treated at a high temperature and/or for a long time, the entiresecond metal layer 534 may be transformed into hemispherical grain lumps 536, thereby forming a lower electrode consisting of thefirst metal layer 532 and the hemispherical grain lumps 536. - In other embodiments, the first and
second metal layers second metal layers - In still other embodiments, it is possible to form a lower electrode by replacing the
second metal layer 534 with a conductive layer formed of an oxide of a metal forming thefirst metal layer 532, such as an oxide of Ru, Rh, Os, Ir, or Pd. In these embodiments, however, hemispherical grain lumps 536 may be formed of a metal oxide through growth of crystal grains caused by a heat treatment in a nitrogen atmosphere. - In yet other embodiments, if the first and
second metal layers first metal layer 532 may comprise any metal. For example, TiN, Ti, or TaN, which generally acts as a barrier layer, may be used to form thefirst metal layer 532, which can improve the characteristics of an interface between an oxide dielectric layer and the first metal layer. Thesecond metal layer 534 may be formed of a metal that is capable of inducing growth of crystal grains during a subsequent heat treatment, such as Pt, Ru, Rh, Os, Ir, or Pd. On the other hand, in still other embodiments, if the first andsecond metal layers first metal layer 532 is may comprise metal which is resistant to oxidation, such as Pt. Thesecond metal layer 534 may comprise Ru, Rh, Os, Ir and/or Pd. -
Reference numerals - Embodiments of capacitors formed by forming a thin metal layer between an underlying layer including hemispherical gain lumps and a dielectric layer while the hemispherical grain lumps are directly on the underlying layer are illustrated in FIG. 5.
- In FIG. 5, a
lower electrode 630 includes hemispherical grain lumps 632 directly on a firstinterlayer dielectric layer 620, adielectric layer 600, and acontact plug 610, and afirst metal layer 634 covering the underlying layers including the hemispherical grain lumps 632. Here, the hemispherical grain lumps 632 may be formed of a metal or a metal oxide. In embodiments where the hemispherical grain lumps 632 comprise metal, Pt, Ru, Rh, Os, Ir and/or Pd may be used. In embodiments wherein the hemispherical grain lumps 632 comprise metal oxide, a metal which can form an oxide when heat-treated, such as Ru, Rh, Os, Ir, or Pd may be used. -
Reference numerals - Hereinafter, methods for forming the capacitors shown in FIGS. 3 through 5 will be described.
- FIGS. 6A through 6C are cross-sectional views illustrating methods for manufacturing capacitors shown in FIG. 3. The conventional steps of forming a dielectric layer and an upper electrode after a step of forming a lower electrode are not illustrated in FIGS. 6A through 6C. Referring to FIG. 6A, a
contact plug 710 is formed in a firstinterlayer dielectric layer 700. A secondinterlayer dielectric layer 720 is formed to have an opening on the firstinterlayer dielectric layer 700 including thecontact plug 710 formed therein such that thecontact plug 710 is exposed through the opening of the secondinterlayer dielectric layer 720. Ametal layer 730 is formed at the sides and floor of the opening and on the secondinterlayer dielectric layer 720. Next, if themetal layer 730 is heat-treated in a nitrogen atmosphere, as shown in FIG. 6B, hemispherical grain lumps are formed. Next, themetal layer 730 and the hemispherical grain lumps are polished until the top surface of the secondinterlayer dielectric layer 720 is exposed, thereby forming a lower electrode L1 including ametal layer 732 and hemispherical grain lumps 734. Themetal layer 732 shown in FIG. 6B is formed by heat-treating and polishing themetal layer 730. - If the
metal layer 730 is heat-treated in a nitrogen atmosphere at a temperature higher than the crystallization temperature of a dielectric layer or the temperature of curing a capacitor, i.e., about 500° to about 800° C. for about ten minutes to about three hours, for example, at about 700° C. for about thirty minutes, crystal grains grow from the surface of themetal layer 730 such that the hemispherical grain lumps 734 formed of the same metal as themetal layer 730 are formed. In order to obtain the hemispherical grain lumps 734 from the growth of crystal grains, Pt, Ru, Rh, Os, Ir and/or Pd may be used. - Referring to FIG. 6C, in other embodiments, the hemispherical grain lumps734 may be formed by heat-treating the
metal layer 730 in an oxygen atmosphere. In this case, themetal layer 730 is exposed to plasma containing oxygen, for example, O2 gas, N2O gas, a mixed gas of He and O2, NO gas and/or a mixed gas of O2 and N2, during the heat-treatment, thereby uniformly forming metal oxide, i.e., the hemispherical grain lumps 734 at the surface of themetal layer 730. Here, the metal layer may be formed of Ru, Rh, Os, Ir, or Pd. - FIGS. 7A and 7B,8A and 8B, 9A through 9C, and 10A and 10B are cross-sectional views illustrating methods for manufacturing the capacitor shown in FIG. 4 according to embodiments of the invention. For the sake of brevity, manufacturing steps after forming a lower electrode are not illustrated in these figures.
- Referring to FIG. 7A, steps of preparing a first
interlayer dielectric layer 800 including acontact plug 810 and forming a secondinterlayer dielectric layer 820 having an opening through which thecontact plug 810 is exposed can be the same as described above with reference to FIG. 6A. Afirst metal layer 830 and asecond metal layer 835 are sequentially formed of different metals at the sides and floor of the opening and on the secondinterlayer dielectric layer 820. Thefirst metal layer 830 may be formed of any kind of metal, such as TiN, Ti, or TaN, which is used as a barrier layer. - Referring to FIG. 7B, the
first metal layer 830 andsecond metal layer 835 are polished until the surface of the secondinterlayer dielectric layer 820 is exposed. Thesecond metal layer 835 a that is polished is heat-treated in an oxygen atmosphere and/or a nitrogen atmosphere, thereby forming hemispherical grain lumps 837 to protrude from the surface of thesecond metal layer 835 a. Predetermined portions or all of thesecond metal layer 835 a may be transformed into the hemispherical grain lumps 837 depending on heat treatment conditions. In some embodiments, the second,metal layer 835 a is only partially transformed into the hemispherical grain lumps 837. Accordingly, in these embodiments, a lower electrode L2 includes afirst metal layer 830 a, portions of thesecond metal layer 835 a not transformed into the hemispherical grain lumps 837, and the hemispherical grain lumps 837. The effective area of the lower electrode L2 is increased due to the hemispherical grain lumps 837. - The hemispherical grain lumps837 formed by heat-treating the
second metal layer 835 in a nitrogen atmosphere at about 500° C. to about 800° C. may be formed of the same metal as thesecond metal layer 835, such as Pt, Ru, Rh, Os, Ir, or Pd. - Referring to FIG. 8A, a
first metal layer 930 is formed at the sides and bottom of an opening, through which acontact plug 910 is exposed, on a secondinterlayer dielectric layer 920 and then is exposed to plasma containing N2, O2 and/or argon (Ar). The plasma treatment can be replaced by any treatment that is capable of accelerating charged particles and then inducing a collision between the charged particles and thefirst metal layer 930. - A
second metal layer 935 is formed of the same material as thefirst metal layer 930 on the plasma-treatedfirst metal layer 930. Next, the first andsecond metal layers interlayer dielectric layer 920 is exposed. Next, thesecond metal layer 935 is heat-treated in a nitrogen atmosphere. As a result, hemispherical grain lumps 936 are formed on thesecond metal layer 935. As shown in FIG. 8B, predetermined portions or all of thesecond metal layer 935 may be transformed into the hemispherical grain lumps 936. In the present embodiments, thesecond metal layer 935 is only partially transformed into the hemispherical grain lumps 936. Accordingly, a lower electrode L3 includes afirst metal layer 930 a, thesecond metal layer 935, and the hemispherical grain lumps 936. - As described above, if an activation energy for growing the crystal grains of the first metal layer is increased by damaging the surface of the
first metal layer 930 through the plasma treatment, thefirst metal layer 930 may be prevented from being rapidly deformed by a subsequent heat treatment, i.e., the heat treatment of thesecond metal layer 935. In addition, if thesecond metal layer 935 is heat-treated, hemispherical grain lumps 936 may be formed at the surface of thesecond metal layer 935 such that a contact area between the hemispherical grain lumps and a dielectric layer to be formed on the hemispherical grain lumps increases. - The materials of the hemispherical grain lumps936 formed in an oxygen or nitrogen atmosphere and the
second metal layer 935 can be the same as those described with reference to FIGS. 6A and 6B, and 7A and 7B, and thus their descriptions will not be repeated.Reference numeral 900, which has not been mentioned yet, refers to a first dielectric layer formed on a substrate (not shown). - Referring to FIG. 9A, the
first metal layer 930 is formed at the sides and bottom of the opening, through which thecontact plug 910 is exposed, and on the secondinterlayer dielectric layer 920. Next, acapping layer 950 is formed of a material that does not react significantly with thefirst metal layer 930, such as an oxide layer. Thefirst metal layer 930 and thecapping layer 950 are preheat-treated in a nitrogen atmosphere at about 500° C. to about 800° C., thereby growing the crystal grains of thefirst metal layer 930. - Referring to FIG. 9B, the
first metal layer 930 is exposed by removing thecapping layer 950. The exposedfirst metal layer 930 is plasma-treated. The plasma treatment of thefirst metal layer 930 can be the same as that of thefirst metal layer 930 described above with reference to FIG. 8A. - Referring to FIG. 9C, a
second metal layer 970 is formed on afirst metal layer 930 b, which has been plasma-treated, and then the first andsecond metal layers interlayer dielectric layer 920 is exposed. Next, thesecond metal layer 970 is heat-treated in a nitrogen atmosphere so as to form hemispherical grain lumps 975 protruding from thesecond metal layer 970. As shown in FIGS. 7B and 8B, predetermined portions or all of thesecond metal layer 970 may be transformed into the hemispherical grain lumps 975. However, in some embodiments, thesecond metal layer 970 is partially transformed into the hemispherical grain lumps 975. In other words, as shown in FIG. 9C, a lower electrode L4 including thefirst metal layer 930 c, which has been plasma-treated, portions of thesecond metal layer 970 not transformed into the hemispherical grain lumps 975, and the hemispherical grain lumps 975 protruding from the top surface of thesecond metal layer 970 is provided. - After preliminarily heat-treating and plasma-treating the
first metal layer 930, the surface of thefirst metal layer 930 can be prevented from being deformed by a subsequent heat treatment, i.e., the heat-treatment of thesecond metal layer 970. On the other hand, since thesecond metal layer 970 has never been subject to a preliminary heat treatment, crystal grains grow or oxides are formed at the surface of thesecond metal layer 970 due to a heat treatment subsequent to the formation of the second metal layer, and thus the hemispherical grain lumps 975 are formed. - The materials of the hemispherical grain lumps936 formed in an oxygen or nitrogen atmosphere and the
second metal layer 935 can be the same as described above with reference to FIGS. 6A and 6B, and 7A and 7B, and thus their description will not be repeated. - Referring to FIG. 10A, a
first metal layer 1130 and ametal oxide layer 1150 are sequentially formed at the sides and floor of an opening, through which acontact plug 1110 is exposed, and on the top surface of a secondinterlayer dielectric layer 1120. Next, thefirst metal layer 1130 and themetal oxide layer 1150 are polished until the top surface of the secondinterlayer dielectric layer 1120 is exposed. - Next, as shown in FIG. 10B, a substrate including the
metal oxide layer 1150 is heat-treated in a nitrogen atmosphere. In some embodiments, the temperature of the heat treatment is higher than the crystallization temperature of a dielectric layer or the temperature of curing a capacitor, for example, between about 500° C. and about 800° C. In some embodiments, the heat treatment is performed at about 700° C. for about thirty minutes. As a result of the heat treatment, metal oxide crystal grains grow on the surface of themetal oxide layer 1150, and thushemispherical grain lumps 1170 are formed. Accordingly, as shown in FIG. 10B, a lower electrode L5 includes afirst metal layer 1130 a, ametal oxide layer 1150, and thehemispherical grain lumps 1170 formed of a metal oxide. - FIGS. 11A through 11C are cross-sectional views illustrating methods for manufacturing capacitors shown in FIG. 5. Only the manufacturing steps performed until a lower electrode is formed are illustrated in these figures. Referring to FIG. 11A, a
first metal layer 1230 is formed at the sides and floor of an opening, through which acontact plug 1210 is exposed, and on the top surface of a secondinterlayer dielectric layer 1220. Referring to FIG. 11B, thefirst metal layer 1230 is heat-treated in an oxygen and/or nitrogen atmosphere, thereby forminghemispherical grain lumps 1230 a. Since thefirst metal layer 1230 is very thin, as described above with reference to FIGS. 2A through 2D (particularly, FIGS. 2A and 2B), a substrate (not shown), or a firstinterlayer dielectric layer 1200, the secondinterlayer dielectric layer 1220, and thecontact plug 1210 are partially exposed between thehemispherical grain lumps 1230 a that are nonuniformly formed. - As shown in FIG. 11C, a
capping layer 1250 is formed of a material that does not react significantly with thefirst metal layer 1230, such as an oxide layer, between the step of depositing thefirst metal layer 1230 on the substrate including the secondinterlayer dielectric layer 1220 and the step of heat-treating thefirst metal layer 1230. Next, thefirst metal layer 1230 is heat-treated to grow crystal grains, thus forming hemispherical grain lumps. Next, thecapping layer 1250 is removed. - Referring again to FIG. 11B, a
second metal layer 1240 is conformally deposited along the shape of the hemispherical grain lumps formed through one of the embodiments described above so as to cover the underlying layers including thehemispherical grain lumps 1230 a. Next, the hemispherical grain lumps and the second metal layer are polished until the top surface of the secondinterlayer dielectric layer 1220 is exposed, thereby forming a lower electrode includinghemispherical grain lumps 1230 a and asecond metal layer 1240. Thesecond metal layer 1240 may be formed of a metal that is stable in processes subsequent to the formation of the lower electrode L6 and has superior interfacial characteristics with respect to a dielectric layer. For example, thesecond metal layer 1240 may be formed of noble metals including Pt, Rh, Os, Ir, and Pd. - The materials of the
hemispherical grain lumps 1230 a and thesecond metal layer 1240 can be the same as described above with reference to FIGS. 6A and 6B, and 7A and 7B, and thus their description will not be repeated. - According to embodiments of the present invention, it is possible to form a lower electrode having hemispherical grain lumps without exposing a dielectric layer or a contact plug, and thus it is possible to increase the capacitance of a capacitor without appreciably deteriorating the characteristics of a device.
- In addition, in a conventional MIM structure, a dielectric layer is crystallized after a lower electrode and a dielectric layer are formed, and a capacitor is cured through heat treatment after an upper electrode is formed. However, since the dielectric layer may slightly crack due to the heat treatment, there may be a limit in performing the heat-treatment after the formation of the lower electrode and the dielectric layer. In embodiments of the present invention, the metal layer used for a lower electrode can be primarily heat-treated during the formation of the lower electrode such that the surface of the metal layer is changed. Then, a second heat treatment is performed after the deposition of a dielectric layer. Thus, the metal layer that is subjected to the primary heat treatment may be changed less in the second heat treatment compared, to a metal layer that is subjected to only the second heat treatment subsequent to the deposition of a dielectric layer. Thus, it is possible to reduce or prevent the dielectric layer from being cracked due to the heat treatment subsequent to the formation of the dielectric layer.
- In the drawings and specification, there have been disclosed typical preferred embodiments of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.
Claims (18)
1. An integrated circuit capacitor comprising:
a lower electrode on an integrated circuit substrate, the lower electrode comprising a metal layer on the integrated circuit substrate and hemispherical grain lumps that protrude from the metal layer opposite the integrated circuit substrate;
a dielectric layer on the hemispherical grain lumps opposite the integrated circuit substrate; and
an upper electrode on the dielectric layer opposite the lower electrode;
wherein the metal layer and the hemispherical grain lumps comprise at least one of Pt, Ru, Rh, Os, Ir and Pd.
2. The capacitor of claim 1 , wherein the dielectric layer comprises at least one of Ta2O5, SrTiO3(STO), (Ba, Sr)TiO3(BST), PbTiO3, Pb(Zr, Ti)O3(PZT), SrBi2Ta2O5(SBT), (Pb, La)(Zr, Ti)O3, Bi4Ti3O12, or BaTiO3(BTO).
3. The capacitor of claim 1 , wherein the metal layer comprises a first portion and a second portion on the first portion, and wherein the first and second portions comprise different metals.
4. The capacitor of claim 3 , wherein the first portion comprises at least one of TaN, Ti, and TiN.
5. The capacitor of claim 4 , wherein the second portion comprises at least one of Pt, Ru, Rh, Os, Ir and Pd.
6. The capacitor of claim 4 , wherein the first portion comprises a first material, and wherein the second portion comprises a second material that is more readily oxidized than the first material, under same oxidizing conditions.
7. The capacitor of claim 3i wherein the first portion comprises Pt, and wherein the second portion comprises at least one of Ru, Rh, Os and Pd.
8. The capacitor of claim 1 , wherein the metal layer comprises a first portion and a second portion on the first portion, which both comprise a same metal, and wherein the first portion retains it surface morphology when forming the hemispherical grain lumps.
9. The capacitor of claim 8 , wherein the metal layer comprises at least one of Pt, Ru, Rh, Os, Ir and Pd.
10. The capacitor of claim 1 , wherein the lower electrode further comprises a metal layer on the integrated circuit substrate between the hemispherical grain lumps or the substrate and the metal layer, and the metal layer is sufficiently thin so as to maintain the profile of the hemispherical grain lumps.
11. The capacitor of claim 10 , wherein the hemispherical grain lumps comprise at least one of Pt, Ru, Rh, Os, Ir and Pd.
12. The capacitor of claim 10 wherein the hemispherical grain lumps comprise at least one of Ru, Rh, Os, Ir and Pd.
13. The capacitor of claim 1 , wherein the lower electrode comprises a metal layer on the substrate and a metal oxide layer on the metal layer opposite the substrate, and the hemispherical grain lumps protrude from the metal oxide layer opposite the metal layer.
14. The capacitor of claim 13 , wherein the metal layer comprises at least one of Pt, Ru, Rh, Os, Ir and Pd.
15. An integrated circuit capacitor comprising:
a lower electrode on an integrated circuit substrate, the lower electrode comprising a metal layer on the integrated circuit substrate and hemispherical grain lumps that comprises at least one noble metal and that protrude from the metal layer opposite the integrated circuit substrate;
a dielectric layer on the hemispherical grain lumps that comprise at least one noble metal, opposite the integrated circuit substrate; and
an upper electrode on the dielectric layer opposite the lower electrode.
16. The capacitor of claim 15 , wherein the metal layer comprises a first portion and a second portion on the first portion, and wherein the first and second portions comprise different metals.
17. The capacitor of claim 16 , wherein the first portion comprises at least one of TaN, Ti, and TiN.
18. The capacitor of claim 17 , wherein the second portion comprises at least one of Pt, Ru, Rh, Os, Ir and Pd.
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US10/715,273 US20040070019A1 (en) | 2001-06-26 | 2003-11-17 | Integrated circuit metal-insulator-metal capacitors including hemispherical grain lumps |
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KR2001-36584 | 2001-06-26 | ||
KR10-2001-0036584A KR100425450B1 (en) | 2001-06-26 | 2001-06-26 | Method for manufacturing Metal-Insulator-Metal Capacitor |
US10/180,277 US6677217B2 (en) | 2001-06-26 | 2002-06-26 | Methods for manufacturing integrated circuit metal-insulator-metal capacitors including hemispherical grain lumps |
US10/715,273 US20040070019A1 (en) | 2001-06-26 | 2003-11-17 | Integrated circuit metal-insulator-metal capacitors including hemispherical grain lumps |
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US10/180,277 Division US6677217B2 (en) | 2001-06-26 | 2002-06-26 | Methods for manufacturing integrated circuit metal-insulator-metal capacitors including hemispherical grain lumps |
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US10/180,277 Expired - Fee Related US6677217B2 (en) | 2001-06-26 | 2002-06-26 | Methods for manufacturing integrated circuit metal-insulator-metal capacitors including hemispherical grain lumps |
US10/715,273 Abandoned US20040070019A1 (en) | 2001-06-26 | 2003-11-17 | Integrated circuit metal-insulator-metal capacitors including hemispherical grain lumps |
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CN100464403C (en) * | 2006-01-10 | 2009-02-25 | 财团法人工业技术研究院 | DRAM hollow column capacitor and manufacturing method thereof |
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KR100902870B1 (en) * | 2007-11-07 | 2009-06-16 | 고려대학교 산학협력단 | High k and Low Loss Dielectric Thin Film Materials for Capacitors with Low Processing Temperature |
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US11469294B2 (en) * | 2020-03-13 | 2022-10-11 | United Microelectronics Corp. | Metal-insulator-metal capacitor and method for fabricating the same |
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KR20030000555A (en) | 2003-01-06 |
US6677217B2 (en) | 2004-01-13 |
KR100425450B1 (en) | 2004-03-30 |
US20030011013A1 (en) | 2003-01-16 |
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