WO2017133145A1 - 金属氧化物薄膜晶体管及其制造方法 - Google Patents
金属氧化物薄膜晶体管及其制造方法 Download PDFInfo
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- WO2017133145A1 WO2017133145A1 PCT/CN2016/083536 CN2016083536W WO2017133145A1 WO 2017133145 A1 WO2017133145 A1 WO 2017133145A1 CN 2016083536 W CN2016083536 W CN 2016083536W WO 2017133145 A1 WO2017133145 A1 WO 2017133145A1
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- 239000010409 thin film Substances 0.000 title claims abstract description 59
- 229910044991 metal oxide Inorganic materials 0.000 title claims abstract description 44
- 150000004706 metal oxides Chemical class 0.000 title claims abstract description 44
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 28
- 238000000034 method Methods 0.000 title claims abstract description 19
- 239000000463 material Substances 0.000 claims abstract description 17
- 239000000758 substrate Substances 0.000 claims abstract description 14
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 13
- 229910052814 silicon oxide Inorganic materials 0.000 claims abstract description 13
- 229910052751 metal Inorganic materials 0.000 claims description 38
- 239000002184 metal Substances 0.000 claims description 38
- 239000010408 film Substances 0.000 claims description 11
- 238000005224 laser annealing Methods 0.000 claims description 4
- 229910004205 SiNX Inorganic materials 0.000 abstract description 6
- 229910052739 hydrogen Inorganic materials 0.000 abstract description 5
- 239000001257 hydrogen Substances 0.000 abstract description 5
- -1 hydrogen ions Chemical class 0.000 abstract description 5
- GPRLSGONYQIRFK-UHFFFAOYSA-N hydron Chemical compound [H+] GPRLSGONYQIRFK-UHFFFAOYSA-N 0.000 abstract description 5
- 239000010410 layer Substances 0.000 description 169
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 6
- 238000000206 photolithography Methods 0.000 description 5
- GYHNNYVSQQEPJS-UHFFFAOYSA-N Gallium Chemical compound [Ga] GYHNNYVSQQEPJS-UHFFFAOYSA-N 0.000 description 3
- 239000004020 conductor Substances 0.000 description 3
- 238000005530 etching Methods 0.000 description 3
- 229910052733 gallium Inorganic materials 0.000 description 3
- 229910052738 indium Inorganic materials 0.000 description 3
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 3
- 239000004973 liquid crystal related substance Substances 0.000 description 3
- 238000000059 patterning Methods 0.000 description 3
- 239000011787 zinc oxide Substances 0.000 description 3
- 229910021417 amorphous silicon Inorganic materials 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000000137 annealing Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 229910021420 polycrystalline silicon Inorganic materials 0.000 description 1
- 229920005591 polysilicon Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000004043 responsiveness Effects 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
- H01L29/76—Unipolar devices, e.g. field effect transistors
- H01L29/772—Field effect transistors
- H01L29/78—Field effect transistors with field effect produced by an insulated gate
- H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/68—Types of semiconductor device ; Multistep manufacturing processes therefor controllable by only the electric current supplied, or only the electric potential applied, to an electrode which does not carry the current to be rectified, amplified or switched
- H01L29/76—Unipolar devices, e.g. field effect transistors
- H01L29/772—Field effect transistors
- H01L29/78—Field effect transistors with field effect produced by an insulated gate
- H01L29/786—Thin film transistors, i.e. transistors with a channel being at least partly a thin film
- H01L29/7869—Thin film transistors, i.e. transistors with a channel being at least partly a thin film having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/40—Electrodes ; Multistep manufacturing processes therefor
- H01L29/43—Electrodes ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/49—Metal-insulator-semiconductor electrodes, e.g. gates of MOSFET
- H01L29/4908—Metal-insulator-semiconductor electrodes, e.g. gates of MOSFET for thin film semiconductor, e.g. gate of TFT
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/34—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies not provided for in groups H01L21/0405, H01L21/0445, H01L21/06, H01L21/16 and H01L21/18 with or without impurities, e.g. doping materials
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/40—Electrodes ; Multistep manufacturing processes therefor
- H01L29/43—Electrodes ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/49—Metal-insulator-semiconductor electrodes, e.g. gates of MOSFET
- H01L29/51—Insulating materials associated therewith
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/66—Types of semiconductor device ; Multistep manufacturing processes therefor
- H01L29/66007—Multistep manufacturing processes
- H01L29/66969—Multistep manufacturing processes of devices having semiconductor bodies not comprising group 14 or group 13/15 materials
Definitions
- the present invention relates to the field of wafer fabrication and display technology, and in particular to a metal oxide thin film transistor and a method of fabricating the same.
- a thin film transistor liquid crystal flat panel display is a type of active matrix liquid crystal display device. Each liquid crystal pixel on the display screen is driven by a thin film transistor integrated behind the pixel, and a thin film transistor (TFT, Thin Film Transistor) The responsiveness of the display and the trueness of the color have an important influence and are an important part of this type of display.
- TFT Thin Film Transistor
- Common thin film transistors are mainly amorphous silicon thin film transistors (a-Si TFTs), low temperature polysilicon thin film transistors (LTPS TFTs), metal oxide thin film transistors, and the like.
- TFT technology using metal oxide as a channel layer material is currently a research hotspot in the field of panel technology, especially using TFT technology of Indium Gallium Zinc Oxide, which can be used for display screens.
- the power consumption is close to OLED, the thickness is only 25% higher than OLED, and the resolution can reach full HD (1920 ⁇ 1080P) or even Ultra HD (Ultra Definition) 4K*2k, but the cost is relatively higher. low.
- the mass-produced IGZO TFT mainly adopts a bottom gate structure, and the gate is disposed at the bottom of the TFT, and the preparation process thereof is relatively complicated and relatively high in cost.
- an IGZO TFT using a top gate structure has been proposed.
- the dielectric layer ILD, Inter Layer Dielectric
- the dielectric layer is made of SiN, and the dielectric layer is in contact with the IGZO layer, and the IGZO layer is doped to partially deform the conductor to form a source.
- the pole and drain structures, while the source and drain lines can be directly mounted on the source and gate, thereby producing a TFT structure.
- the H content in the dielectric layer is high, so when the dielectric layer is in contact with the IGZO layer and doped, H diffuses laterally in the IGZO layer, which easily diffuses to the channel layer, thereby causing The leakage is too large, and even the switching characteristics of the TFT are lost. Therefore, it is necessary to optimize and improve the IGZO TFT of the top gate structure to eliminate the above defects.
- an object of the present invention is to provide a metal oxide thin film crystal The tube and the method of manufacturing the same, to reduce the risk of excessive leakage of the metal oxide thin film transistor of the top gate structure and loss of switching characteristics of the thin film transistor.
- the present invention includes two aspects.
- a metal oxide thin film transistor comprising:
- the material of the dielectric layer being SiOx.
- the gate insulating layer and the gate are respectively patterned the gate insulating layer and the patterned gate, and the gate The pole insulating layer and the gate are made of the same mask.
- the source and the drain are formed by using the gate as a light shielding layer and the active exposed to the outside of the gate The layer is subjected to laser irradiation such that the active layers exposed outside the gate are formed as the source and the drain, respectively.
- laser irradiation of the active layer exposed outside the gate is performed by an Excimer Laser Anneal (ELA) on an active layer exposed outside the gate. deal with.
- ELA Excimer Laser Anneal
- the dielectric layer is formed on the buffer layer, the source, and the drain while being formed over the gate, the gate, The gate insulating layer, the source, the drain, and the active layer are all coated in the dielectric layer.
- the metal oxide thin film transistor further includes a source metal layer and a drain metal layer, respectively, corresponding to the source and the drain region on the dielectric layer a source contact hole exposing the source portion and a drain contact hole exposing the drain portion, the source metal layer contacting the source through the source contact hole, the drain a metal layer passing through the drain A contact hole is in contact with the drain.
- the active layer is the patterned active layer.
- the active layer is an IGZO film layer.
- the IGZO film layer refers to Indium Gallium Zinc Oxide.
- the present invention also provides a method of fabricating a metal oxide thin film transistor, comprising the steps of:
- a dielectric layer is formed on the gate, and the material of the dielectric layer is SiOx.
- the same mask is used.
- the gate insulating layer and the gate are photolithographically etched to obtain the patterned gate insulating layer and the patterned gate.
- the steps of forming a source and a drain respectively on both sides of the active layer are: using the gate as a light shielding layer, and exposing the gate to the gate
- the external active layer is subjected to laser irradiation such that an active layer exposed outside the gate becomes the source and the drain, respectively.
- laser irradiation of the active layer exposed outside the gate is performed by an Excimer Laser Anneal (ELA) on an active layer exposed outside the gate. deal with.
- ELA Excimer Laser Anneal
- the dielectric layer is also formed on the buffer layer, the source, and the drain, so that the gate, the A gate insulating layer, the source, the drain, and the active layer are all coated in the dielectric layer.
- the method further includes the step of: corresponding to the source and the drain region on the dielectric layer Forming a source contact hole exposing the source portion and a drain contact hole exposing the drain portion, respectively; the metal oxide thin film transistor of the present invention further forms a source metal layer and a drain metal layer The source metal layer is in contact with the source through the source contact hole, and the drain metal layer is in contact with the drain through the drain contact hole.
- the active layer is the patterned active layer.
- the active layer is processed by photolithography and etching to obtain the patterned active layer.
- the active layer is an IGZO film layer.
- the IGZO film layer refers to Indium Gallium Zinc Oxide.
- the material used for the dielectric layer is SiOx instead of SiNx.
- SiNx is used as a dielectric layer material in which a hydrogen ion content is high, and these hydrogen ions are in contact with the active layer in the dielectric layer, and the active layer is doped. In the impurity process, it will spread laterally in the active layer, resulting in excessive leakage and even loss of switching characteristics of the thin film transistor.
- the SiOx material is used in the dielectric layer of the present invention, the hydrogen ion content in the material is much lower than that of the SiNx, so that the problem that the active layer leaks more due to diffusion of hydrogen ions in the active layer can be effectively reduced. Improve the electrical properties of metal oxide thin film transistors.
- the gate and the gate insulating layer are patterned by the same mask, instead of patterning each of the gate and the gate insulating layer with a mask, respectively, and the two-layer structure can be seen.
- the use of a reticle treatment can save the reticle, save manufacturing processes, simplify the process, and effectively reduce production costs.
- the gate electrode at the top end is skillfully utilized as a light shielding layer, and the active layer underneath is subjected to laser irradiation treatment, and the active layer exposed outside the light shielding layer is subjected to high temperature annealing by laser irradiation.
- the electrical properties of the active layer exposed outside the light shielding layer are changed to become conductors, that is, the source and the drain are formed.
- the metal layer is not separately deposited and subjected to photolithography or the like to form the source and the drain, but on the basis of the formed edge layer structure.
- the edge layer exposed to the outside of the gate is subjected to laser irradiation treatment to form a source and a drain. This process step also simplifies the complexity of the design of the thin film transistor structure and the complexity of its manufacturing process.
- 1 to 8 are process flows of a method of fabricating a metal oxide thin film transistor according to an embodiment of the present invention.
- the embodiment provides a method for manufacturing a metal oxide thin film transistor, and the manufacturing method includes the following steps:
- a substrate 1 is prepared, and a buffer layer 2 is deposited on the glass substrate 1.
- an IGZO film layer is deposited as an active layer 3 over the buffer layer 2, and the active layer 3 is photolithographically and etched to obtain a patterned active layer 3.
- a gate insulating layer 4 and a gate electrode 5 are sequentially deposited over the patterned active layer 3, and the gate insulating layer 4 and the gate electrode 5 are formed by the same photomask (not shown).
- a photolithography and etching process is performed to obtain a patterned gate insulating layer 4 and a gate electrode 5.
- the gate 5 is not completely covered over the active layer 3, so that some of the left and right sides of the active layer 3 are exposed outside the gate-covered position.
- the gate insulating layer and the gate are patterned, only one mask is used, which saves the mask and saves the photolithography step, which simplifies the whole manufacturing method and the thin film transistor. Production costs are reduced and production efficiency is improved.
- the active layer 3 exposed to the coverage area of the gate 5 is irradiated with laser light by an excimer laser annealing method using the gate electrode 5 as a light shielding layer, as shown in FIG.
- the active layer of the left region outside the gate forms the source 61
- the active layer exposed to the right region outside the gate forms the drain 62.
- a partial region thereof is converted into a source and a drain, thereby simplifying design complexity and simplifying the design of the thin film transistor. Manufacturing steps.
- a dielectric layer 7 is formed on the buffer layer 2, the source 61, the drain 62, and the gate 5, and the dielectric layer 7 has a source 61, a drain 62, a gate 5, and a gate. Both the insulating layer 4 and the active layer 3 are coated inside.
- the material of the dielectric layer is made of SiOx instead of SiNx, and the low hydrogen ion content of the SiOx material is used to reduce the leakage of hydrogen ions in the active layer, thereby causing a large amount of leakage of the active layer. Even the ultimate thin film transistor loses the risk of switching characteristics.
- a source contact hole 81 capable of partially exposing the source 61 is formed in a region of the dielectric layer 7 corresponding to the source 61, and a region corresponding to the drain 62 in the dielectric layer 7 can be formed.
- the drain 62 is partially exposed by a drain contact hole 82.
- a source metal layer 91 is deposited in the source contact hole 81, the source metal layer 91 is brought into contact with the source 61, and a drain metal layer 92 is deposited in the drain contact hole 82 to make the drain Metal layer 92 is in contact with drain 62.
- deposition, photolithography, etching, and excimer laser annealing are all common processes in the art for fabricating thin film transistors, and the steps and steps employed in the present invention are applied.
- the relevant parameter conditions are all common steps and parameter conditions in the art, so the above process methods will not be described in detail in the present invention.
- the present embodiment further provides a metal oxide thin film transistor obtained by the above manufacturing method, as shown in FIG. 8, which is a schematic cross-sectional structure of the metal oxide thin film transistor, including:
- a source 61 adjacent thereto is formed on the left side of the active layer 3, and a drain 62 adjacent thereto is formed on the right side of the active layer 3;
- a dielectric layer 7 is formed on the gate 5, and the dielectric layer 7 is also formed on the buffer layer 2, the source 61, and the gate 62, so that the gate 5, the gate insulating layer 4, and the source 61
- the drain electrode 62 and the active layer 3 are both coated in the dielectric layer 7;
- a source contact hole 81 partially exposing the source 61 is further disposed in a left side region of the dielectric layer 7 corresponding to the source 61, and the dielectric layer 7 is further provided in a right side region corresponding to the drain 62.
- a source metal layer 91 is formed in the source contact hole 81, and the source metal layer 91 is in contact with the source.
- the hole 81 is in contact with the source 61, and a drain metal layer 92 is formed in the drain contact hole 82, and the drain metal layer 92 is in contact with the drain electrode 62 through the drain contact hole 82.
- the material used for the dielectric layer is SiOx instead of SiNx. Since the SiOx material is relatively lower than the hydrogen ion content in the SiOx material, it is applied to the dielectric layer of the present embodiment, which can reduce a large amount of leakage of the active layer due to diffusion of hydrogen ions in the active layer. Even the ultimate thin film transistor loses the risk of switching characteristics.
- the patterned gate active layer and the gate are made by the same mask, which is different from the previous process of patterning a layer structure using a mask, and the two layers adopt a mask. It can reduce the number of masks used, and can effectively simplify the process steps and save production costs.
- the source and the drain respectively disposed on the left and right sides of the active layer are obtained by the following manufacturing method: using the gate as a light shielding layer, using an excimer laser annealing method for the active layer exposed outside the gate The laser irradiation causes the active layer exposed outside the gate to be converted into a conductor, that is, a source is formed on the left side of the active layer, and a drain is formed on the right side.
- the metal oxide thin film transistor may further include other conventional functional structures, which will not be further described in the present invention.
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Abstract
一种金属氧化物薄膜晶体管及其制造方法,该薄膜晶体管包括基板(1)、形成于基板上的缓冲层(2)以及形成于缓冲层上的有源层(3),还包括分别形成于有源层两侧的源极(61)和漏极(62)、形成于有源层上的栅极绝缘层(4)、形成于栅极绝缘层上的栅极(5)以及形成于栅极上的介电层(7),且介电层的材料为SiOx。由于介电层中采用SiOx材料,此材料中的氢离子含量远低于SiNx,因此可以有效地降低因氢离子扩散在有源层中导致有源层漏电较多的问题,由此来改善金属氧化物薄膜晶体管的电学性能。
Description
本发明涉及晶圆制造领域及显示技术领域,具体是一种金属氧化物薄膜晶体管及其制造方法。
薄膜晶体管液晶平板显示器是一类有源矩阵液晶显示设备,该类显示屏上的每个液晶像素点都是由集成在像素点后面的薄膜晶体管来驱动,薄膜晶体管(TFT,Thin Film Transistor)对于显示器的响应度及色彩真实度等具有重要影响,是该类显示器中的重要组成部分。常见的薄膜晶体管主要有非晶硅薄膜晶体管(a-Si TFT)、低温多晶硅薄膜晶体管(LTPS TFT)、金属氧化物薄膜晶体管等。其中,采用金属氧化物作为沟道层材料的TFT技术是目前在面板技术领域的研究热点,尤其采用铟镓锌氧化物(IGZO,Indium Gallium Zinc Oxide)的TFT技术,使用该技术可以使显示屏功耗接近OLED,厚度仅比OLED高出25%,且分辨率可以达到全高清(full HD,1920*1080P)乃至超高清(Ultra Definition,分辨率4k*2k)级别程度,而成本却相对更低。
目前已经量产的IGZO TFT主要是采用底栅结构,将栅极设置在TFT的底部,其制备工艺相对复杂,成本相对较高。为降低生产成本,有人提出一种采用顶栅结构的IGZO TFT。在这种IGZO TFT的结构中,介电层(ILD,Inter Layer Dielectric)采用的材料为SiN,并将介电层与IGZO层接触,通过对IGZO层进行掺杂将部分IGZO变形导体,形成源极和漏极结构,而源极和漏极金属线则可以直接搭载源极和栅极上,由此制得TFT结构。在这种结构中,介电层中的H含量较高,因此介电层与IGZO层接触并进行掺杂时,H会在IGZO层中进行横向扩散,其容易扩散至沟道层,从而导致漏电过大,甚至丧失TFT的开关特性。因此实有必要对顶栅结构的IGZO TFT进行优化改善,以消除上述缺陷问题。
发明内容
为克服现有技术的不足,本发明的目的在于提供一种金属氧化物薄膜晶体
管及其制造方法,以降低顶栅式结构的金属氧化物薄膜晶体管出现漏电过大、薄膜晶体管失去开关特性的风险。
本发明包括两个方面,第一个方面,本发明提供一种金属氧化物薄膜晶体管,包括:
基板;
形成于所述基板上的缓冲层;
形成于所述缓冲层上的有源层;
分别形成于所述有源层两侧的源极和漏极;
形成于所述有源层上的栅极绝缘层;
形成于所述栅极绝缘层上的栅极;
形成于所述栅极上的介电层,所述介电层的材料为SiOx。
【GI/GE采用同一道mask】作为一种实施方式,所述栅极绝缘层和所述栅极分别为图形化的所述栅极绝缘层和图形化的所述栅极,且所述栅极绝缘层和所述栅极采用同一道光罩制得。
【S/D形成方法】作为一种实施方式,所述源极和所述漏极是通过以下步骤形成的:以所述栅极为遮光层,对暴露在所述栅极外部的所述有源层进行激光照射,使暴露在所述栅极外部的所述有源层分别形成为所述源极和所述漏极。
进一步地,对暴露在所述栅极外部的所述有源层进行激光照射是采用受激准分子激光退火方法(Excimer Laser Anneal,简称ELA)对暴露在所述栅极外部的有源层进行处理。
【介电层-具体】进一步地,所述介电层在形成于所述栅极上方的同时,也形成于所述缓冲层、所述源极、所述漏极上,所述栅极、所述栅极绝缘层、所述源极、所述漏极、所述有源层均包覆在所述介电层内。
【源漏金属层】进一步地,所述金属氧化物薄膜晶体管还包括源极金属层和漏极金属层,在所述介电层上对应于所述源极和所述漏极区域中分别设有使所述源极部分暴露的源极接触孔和使所述漏极部分暴露的漏极接触孔,所述源极金属层通过所述源极接触孔与所述源极接触,所述漏极金属层通过所述漏极
接触孔与所述漏极接触。
进一步地,所述有源层为图形化的所述有源层。
进一步地,所述有源层为IGZO膜层。
其中,IGZO膜层是指铟镓锌氧化物(Indium Gallium Zinc Oxide)。
第二个方面,本发明还提供一种金属氧化物薄膜晶体管的制造方法,包括以下步骤:
提供一基板;
在所述基板上形成缓冲层;
在所述缓冲层上形成有源层;
在所述有源层上形成栅极绝缘层;
在所述栅极绝缘层上形成栅极;
在所述有源层两侧分别形成源极和漏极;
在所述栅极上形成介电层,所述介电层的材料为SiOx。
作为一种实施方式,在本发明所述的制造方法中,在所述有源层上形成所述栅极绝缘层、在所述栅极绝缘层上形成所述栅极后,采用同一道光罩对所述栅极绝缘层和所述栅极进行光刻、刻蚀,得到图形化的所述栅极绝缘层和图形化的所述栅极。
作为一种实施方式,在本发明所述的制造方法中,在所述有源层两侧分别形成源极和漏极的步骤为:利用所述栅极为遮光层,对暴露在所述栅极外部的所述有源层进行激光照射,使暴露在所述栅极外部的有源层分别变为所述源极和所述漏极。
进一步地,对暴露在所述栅极外部的所述有源层进行激光照射是采用受激准分子激光退火方法(Excimer Laser Anneal,简称ELA)对暴露在所述栅极外部的有源层进行处理。
进一步地,在所述栅极上形成所述介电层时,所述介电层也形成于所述缓冲层、所述源极、所述漏极的上方,使所述栅极、所述栅极绝缘层、所述源极、所述漏极、所述有源层均包覆在所述介电层内。
进一步地,在本发明所述的制造方法中,在所述栅极上形成介电层后,还包括以下步骤:在所述介电层上对应于所述源极和所述漏极区域中分别形成使所述源极部分暴露的源极接触孔、使所述漏极部分暴露的漏极接触孔;本发明的所述金属氧化物薄膜晶体管还形成有源极金属层和漏极金属层,所述源极金属层通过所述源极接触孔与所述源极接触,所述漏极金属层通过所述漏极接触孔与所述漏极接触。
进一步地,在本发明所述的制造方法中,所述有源层为图形化的所述有源层。
进一步地,所述有源层通过光刻、刻蚀工艺处理后得到图形化的所述有源层。
进一步地,所述有源层为IGZO膜层。
其中,IGZO膜层是指铟镓锌氧化物(Indium Gallium Zinc Oxide)。
与现有技术相比,本发明的有益效果如下:
首先,在本发明的金属氧化物薄膜晶体管中,介电层采用的材料为SiOx,而不是SiNx。现有技术中采用顶栅结构的金属氧化物薄膜晶体管中,使用SiNx作为介电层材料,其中氢离子含量较多,这些氢离子在介电层与有源层接触、对有源层进行掺杂的过程中,会在有源层中横向扩散,导致漏电过大、甚至丧失薄膜晶体管开关特性的问题。由于本发明介电层中采用SiOx材料,此材料中的氢离子含量远低于SiNx,因此可以有效地降低因氢离子扩散在有源层中导致有源层漏电较多的问题,由此来改善金属氧化物薄膜晶体管的电学性能。
其次,在本发明中,栅极和栅极绝缘层采用同一道光罩进行图形化处理,而不是分别对栅极和栅极绝缘层各采用一道光罩进行图形化处理,可见这种两层结构采用一道光罩的处理方式能够节省光罩、节约制造工序、简化工艺流程、有效降低生产成本。
最后,在本发明中,巧妙地利用位于顶端的栅极作为遮光层,对于位于其下方的有源层进行激光照射处理,利用激光照射对暴露在遮光层之外的有源层进行高温退火,从而使暴露在遮光层以外这部分有源层的电性发生改变,使其变成导体,即形成了源极和漏极。由此可见,本发明中,未单独沉积金属层并对其进行光刻等工序以形成源极和漏极,而是在已形成的有缘层结构的基础上,
对暴露在栅极外部的该有缘层进行激光照射处理,形成源极和漏极。这种工艺步骤同时简化了薄膜晶体管结构设计的复杂性和其制造工艺的复杂性。
图1至图8是本发明实施例金属氧化物薄膜晶体管的制造方法的工艺流程。
实施例
本实施例提供一种金属氧化物薄膜晶体管的制造方法,该制造方法包括以下步骤:
如图1所示,准备一基板1,并在玻璃基板1上沉积形成缓冲层2。
如图2所示,在缓冲层2上方沉积形成IGZO膜层作为有源层3,并对该有源层3进行光刻、刻蚀工艺,得到图形化的有源层3。
如图3所示,在已图形化的有源层3上方依次沉积形成栅极绝缘层4、栅极5,并利用同一道光罩(图未示)对栅极绝缘层4和栅极5进行光刻、刻蚀工艺,得到图形化的栅极绝缘层4和栅极5。从图3中可以看出,经过图形化之后,栅极5并未完全覆盖于有源层3的上方,使得有源层3左右两侧各有部分区域暴露在栅极覆盖的位置之外。在本实施例中,对栅极绝缘层和栅极进行图形化处理时,仅使用了一道光罩,既节约了光罩,又节省了光刻步骤,使整个制造方法更加简化、薄膜晶体管的生产成本降低、生产效率提升。
如图4所示,以栅极5作为遮光层,利用受激准分子激光退火方法对暴露在栅极5覆盖区域之外的有源层3进行激光照射,如图5所示,使暴露在栅极外部的左侧区域的有源层形成源极61,使暴露在栅极外部的右侧区域的有源层形成漏极62。在本实施例中,在已经形成的有源层结构的基础上,通过对其进行激光照射,使其部分区域转变成为源极和漏极,由此简化了薄膜晶体管的设计复杂性、简化了制造步骤。
如图6所示,在缓冲层2、源极61、漏极62、栅极5上沉积形成介电层7,该介电层7将源极61、漏极62、栅极5、栅极绝缘层4、有源层3均包覆在其内部。本实施例中介电层的材料选用SiOx而非SiNx,利用SiOx材料中氢离子含量更低的特点,来降低由于氢离子在有源层中的扩散而导致有源层大量漏电、
甚至最终薄膜晶体管丧失开关特性的风险。
如图7所示,在介电层7中对应于源极61的区域形成能够使源极61部分暴露的源极接触孔81,在介电层7中对应于漏极62的区域形成能够使漏极62部分暴露的漏极接触孔82。
如图8所示,在源极接触孔81中沉积源极金属层91,使源极金属层91与源极61相接触,在漏极接触孔82中沉积漏极金属层92,使漏极金属层92与漏极62相接触。
在本发明中,沉积、光刻、刻蚀、受激准分子激光退火方法都是本领域在制造薄膜晶体管过程中的常用工艺方法,在本发明中应用上述工艺方法时,所采用的步骤和相关参数条件均为本领域中常用步骤和参数条件,故对于上述工艺方法,在本发明中不再赘述。
进一步地,本实施例还提供一种利用上述制造方法得到的金属氧化物薄膜晶体管,如图8所示,为该金属氧化物薄膜晶体管的剖面结构示意图,包括:
一基板1;
形成于玻璃基板上的缓冲层2;
形成于缓冲层2上的图形化的有源层3,该有源层为IGZO膜层;
在该有源层3的左侧形成有与其相邻的源极61,在该有源层3的右侧形成有与其相邻的漏极62;
在该有源层3上形成有图形化的栅极绝缘层4;
在栅极绝缘层4上形成有图形化的栅极5;
在栅极5上形成有介电层7,该介电层7同时还形成在缓冲层2、源极61、栅极62上,使所述栅极5、栅极绝缘层4、源极61、漏极62、有源层3均包覆在该介电层7内;
在该介电层7对应于源极61的左侧区域中还设有使源极61部分暴露的源极接触孔81,该介电层7对应于漏极62的右侧区域中还设有使漏极62部分暴露的漏极接触孔82;
在源极接触孔81中形成有源极金属层91,该源极金属层91通过源极接触
孔81与源极61相接触,在漏极接触孔82中形成有漏极金属层92,该漏极金属层92通过漏极接触孔82与漏极62相接触。
在本实施例的金属氧化物薄膜晶体管中,介电层所采用的材料为SiOx而非SiNx。由于利用SiOx材料比SiOx材料中的氢离子含量相对要低很多,将其应用于本实施例的介电层中,可降低由于氢离子在有源层中的扩散而导致有源层大量漏电、甚至最终薄膜晶体管丧失开关特性的风险。
另外,具有图形化的栅极有源层和栅极是采用同一道光罩制得的,这不同与以往使用一道光罩对一层结构进行图形化处理的工艺步骤,两层结构采用一道光罩,既能减少使用光罩的数量,又能有效简化工艺步骤,节省生产成本。
另外,分别设置在有源层左右两侧的源极和漏极是通过以下制造方法得到的:以栅极为遮光层,使用受激准分子激光退火方法对于暴露在栅极外部的有源层进行激光照射,使暴露在栅极外部的有源层转变为导体,即有源层左侧形成了源极,右侧形成了漏极。
可以理解的是,以上仅对金属氧化物薄膜晶体管的主体结构进行了说明,该金属氧化物薄膜晶体管还可以包括其它常规的功能结构,在本发明中不再一一赘述。
以上所述为本发明的具体实施方式,其目的是为了清楚说明本发明而作的举例,并非是对本发明的实施方式的限定。对于所属领域的普通技术人员来说,在上述说明的基础上还可以做出其它不同形式的变化或变动。这里无需也无法对所有的实施方式予以穷举。凡在本发明的精神和原则之内所作的任何修改、等同替换和改进等,均应包含在本发明权利要求的保护范围之内。
Claims (18)
- 一种金属氧化物薄膜晶体管,包括基板、形成于所述基板上的缓冲层以及形成于所述缓冲层上的有源层,其中:所述金属氧化物薄膜晶体管还包括:分别形成于所述有源层两侧的源极和漏极;形成于所述有源层上的栅极绝缘层;形成于所述栅极绝缘层上的栅极;形成于所述栅极上的介电层,所述介电层的材料为SiOx。
- 如权利要求1所述的金属氧化物薄膜晶体管,其中:所述栅极绝缘层和所述栅极分别为图形化的所述栅极绝缘层和图形化的所述栅极,且所述栅极绝缘层和所述栅极采用同一道光罩制得。
- 如权利要求1所述的金属氧化物薄膜晶体管,其中:所述源极和所述漏极是通过以下步骤形成的:以所述栅极为遮光层,对暴露在所述栅极外部的所述有源层进行激光照射,使暴露在所述栅极外部的所述有源层分别形成为所述源极和所述漏极。
- 如权利要求3所述的金属氧化物薄膜晶体管,其中:对暴露在所述栅极外部的所述有源层进行激光照射是采用受激准分子激光退火方法对暴露在所述栅极外部的有源层进行处理。
- 如权利要求1所述的金属氧化物薄膜晶体管,其中:所述介电层在形成于所述栅极上方的同时,也形成于所述缓冲层、所述源极、所述漏极上,所述栅极、所述栅极绝缘层、所述源极、所述漏极、所述有源层均包覆在所述介电层内。
- 如权利要求1所述的金属氧化物薄膜晶体管,其中:所述金属氧化物薄膜晶体管还包括源极金属层和漏极金属层,在所述介电层上对应于所述源极和所述漏极区域中分别设有使所述源极部分暴露的源极接触孔和使所述漏极部分暴露的漏极接触孔,所述源极金属层通过所述源极接触孔与所述源极接触,所述漏极金属层通过所述漏极接触孔与所述漏极接触。
- 如权利要求2所述的金属氧化物薄膜晶体管,其中:所述金属氧化物薄膜晶体管还包括源极金属层和漏极金属层,在所述介电层上对应于所述源极和 所述漏极区域中分别设有使所述源极部分暴露的源极接触孔和使所述漏极部分暴露的漏极接触孔,所述源极金属层通过所述源极接触孔与所述源极接触,所述漏极金属层通过所述漏极接触孔与所述漏极接触。
- 如权利要求3所述的金属氧化物薄膜晶体管,其中:所述金属氧化物薄膜晶体管还包括源极金属层和漏极金属层,在所述介电层上对应于所述源极和所述漏极区域中分别设有使所述源极部分暴露的源极接触孔和使所述漏极部分暴露的漏极接触孔,所述源极金属层通过所述源极接触孔与所述源极接触,所述漏极金属层通过所述漏极接触孔与所述漏极接触。
- 如权利要求4所述的金属氧化物薄膜晶体管,其中:所述金属氧化物薄膜晶体管还包括源极金属层和漏极金属层,在所述介电层上对应于所述源极和所述漏极区域中分别设有使所述源极部分暴露的源极接触孔和使所述漏极部分暴露的漏极接触孔,所述源极金属层通过所述源极接触孔与所述源极接触,所述漏极金属层通过所述漏极接触孔与所述漏极接触。
- 如权利要求5所述的金属氧化物薄膜晶体管,其中:所述金属氧化物薄膜晶体管还包括源极金属层和漏极金属层,在所述介电层上对应于所述源极和所述漏极区域中分别设有使所述源极部分暴露的源极接触孔和使所述漏极部分暴露的漏极接触孔,所述源极金属层通过所述源极接触孔与所述源极接触,所述漏极金属层通过所述漏极接触孔与所述漏极接触。
- 如权利要求1所述的金属氧化物薄膜晶体管,其中:所述有源层为IGZO膜层。
- 如权利要求2所述的金属氧化物薄膜晶体管,其中:所述有源层为IGZO膜层。
- 如权利要求3所述的金属氧化物薄膜晶体管,其中:所述有源层为IGZO膜层。
- 如权利要求4所述的金属氧化物薄膜晶体管,其中:所述有源层为IGZO膜层。
- 如权利要求5所述的金属氧化物薄膜晶体管,其中:所述有源层为IGZO膜层。
- 一种金属氧化物薄膜晶体管的制造方法,其中,所述制造方法包括以 下步骤:提供一基板;在所述基板上形成缓冲层;在所述缓冲层上形成有源层;在所述有源层上形成栅极绝缘层;在所述栅极绝缘层上形成栅极;在所述有源层两侧分别形成源极和漏极;在所述栅极上形成介电层,所述介电层的材料为SiOx。
- 如权利要求16所述的制造方法,其中:在所述有源层上形成所述栅极绝缘层、在所述栅极绝缘层上形成所述栅极后,采用同一道光罩对所述栅极绝缘层和所述栅极进行光刻、刻蚀,得到图形化的所述栅极绝缘层和图形化的所述栅极。
- 如权利要求16所述的制造方法,其中:在所述有源层两侧分别形成源极和漏极的步骤为:利用所述栅极为遮光层,对暴露在所述栅极外部的所述有源层进行激光照射,使暴露在所述栅极外部的有源层分别变为所述源极和所述漏极。
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CN106129122B (zh) | 2016-08-31 | 2018-12-11 | 京东方科技集团股份有限公司 | 氧化物薄膜晶体管及其制备方法、阵列基板、显示装置 |
CN106935549B (zh) * | 2017-03-20 | 2019-11-29 | 昆山工研院新型平板显示技术中心有限公司 | 薄膜晶体管阵列基板的制作方法及薄膜晶体管阵列基板 |
CN107910375A (zh) * | 2017-11-02 | 2018-04-13 | 京东方科技集团股份有限公司 | 一种薄膜晶体管及其制备方法、阵列基板和显示装置 |
CN109037076A (zh) * | 2018-08-16 | 2018-12-18 | 北京大学深圳研究生院 | 金属氧化物薄膜晶体管制备的方法 |
CN110190031B (zh) * | 2019-05-17 | 2021-07-23 | 深圳市华星光电半导体显示技术有限公司 | 一种薄膜晶体管基板的制备方法 |
CN110718467B (zh) * | 2019-09-24 | 2021-12-03 | Tcl华星光电技术有限公司 | 一种tft阵列基板的制作方法 |
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