WO2006066962A2 - Selective oxidation and selective etching of allnn layers for manufacturing group iii nitride semiconductor devices - Google Patents
Selective oxidation and selective etching of allnn layers for manufacturing group iii nitride semiconductor devices Download PDFInfo
- Publication number
- WO2006066962A2 WO2006066962A2 PCT/EP2005/013966 EP2005013966W WO2006066962A2 WO 2006066962 A2 WO2006066962 A2 WO 2006066962A2 EP 2005013966 W EP2005013966 W EP 2005013966W WO 2006066962 A2 WO2006066962 A2 WO 2006066962A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- group iii
- layer
- iii nitride
- layers
- oxidized
- Prior art date
Links
- 150000004767 nitrides Chemical class 0.000 title claims description 41
- 230000003647 oxidation Effects 0.000 title claims description 32
- 238000007254 oxidation reaction Methods 0.000 title claims description 32
- 239000004065 semiconductor Substances 0.000 title claims description 16
- 238000004519 manufacturing process Methods 0.000 title description 6
- 238000005530 etching Methods 0.000 title description 5
- 238000000034 method Methods 0.000 claims abstract description 36
- 239000002243 precursor Substances 0.000 claims abstract description 31
- 239000000758 substrate Substances 0.000 claims abstract description 10
- 230000001590 oxidative effect Effects 0.000 claims abstract description 8
- 229910045601 alloy Inorganic materials 0.000 claims description 3
- 239000000956 alloy Substances 0.000 claims description 3
- 238000000137 annealing Methods 0.000 claims description 3
- 239000010410 layer Substances 0.000 description 76
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 8
- 230000008569 process Effects 0.000 description 8
- 229910001218 Gallium arsenide Inorganic materials 0.000 description 5
- 229910052681 coesite Inorganic materials 0.000 description 4
- 229910052906 cristobalite Inorganic materials 0.000 description 4
- 229910052738 indium Inorganic materials 0.000 description 4
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 description 4
- 238000003780 insertion Methods 0.000 description 4
- 230000037431 insertion Effects 0.000 description 4
- 239000000377 silicon dioxide Substances 0.000 description 4
- 229910052682 stishovite Inorganic materials 0.000 description 4
- 229910052905 tridymite Inorganic materials 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 230000008859 change Effects 0.000 description 3
- 239000003792 electrolyte Substances 0.000 description 3
- 230000005693 optoelectronics Effects 0.000 description 3
- 229910052594 sapphire Inorganic materials 0.000 description 3
- 239000010980 sapphire Substances 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- 239000010409 thin film Substances 0.000 description 3
- 229910002704 AlGaN Inorganic materials 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 238000006731 degradation reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000008151 electrolyte solution Substances 0.000 description 2
- 230000005669 field effect Effects 0.000 description 2
- 238000005286 illumination Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- MGFYIUFZLHCRTH-UHFFFAOYSA-N nitrilotriacetic acid Chemical compound OC(=O)CN(CC(O)=O)CC(O)=O MGFYIUFZLHCRTH-UHFFFAOYSA-N 0.000 description 2
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 229910017107 AlOx Inorganic materials 0.000 description 1
- 229910000980 Aluminium gallium arsenide Inorganic materials 0.000 description 1
- -1 Nitride compounds Chemical class 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- 230000004913 activation Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 238000010835 comparative analysis Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000000866 electrolytic etching Methods 0.000 description 1
- 238000005566 electron beam evaporation Methods 0.000 description 1
- 238000006056 electrooxidation reaction Methods 0.000 description 1
- 239000011229 interlayer Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000000879 optical micrograph Methods 0.000 description 1
- 238000000206 photolithography Methods 0.000 description 1
- 238000001020 plasma etching Methods 0.000 description 1
- 229910052697 platinum Inorganic materials 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000000750 progressive effect Effects 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 238000007669 thermal treatment Methods 0.000 description 1
- 230000009466 transformation Effects 0.000 description 1
- 238000000927 vapour-phase epitaxy Methods 0.000 description 1
- 238000001039 wet etching Methods 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L33/00—Semiconductor devices having potential barriers specially adapted for light emission; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
- H01L33/005—Processes
- H01L33/0062—Processes for devices with an active region comprising only III-V compounds
- H01L33/0066—Processes for devices with an active region comprising only III-V compounds with a substrate not being a III-V compound
- H01L33/007—Processes for devices with an active region comprising only III-V compounds with a substrate not being a III-V compound comprising nitride compounds
-
- 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
- H01L21/18—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 comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/31—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers
- H01L21/32—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to form insulating layers thereon, e.g. for masking or by using photolithographic techniques; After treatment of these layers; Selection of materials for these layers using masks
-
- 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
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02109—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates
- H01L21/02112—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer
- H01L21/02172—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing at least one metal element, e.g. metal oxides, metal nitrides, metal oxynitrides or metal carbides
- H01L21/02175—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing at least one metal element, e.g. metal oxides, metal nitrides, metal oxynitrides or metal carbides characterised by the metal
- H01L21/02178—Forming insulating materials on a substrate characterised by the type of layer, e.g. type of material, porous/non-porous, pre-cursors, mixtures or laminates characterised by the material of the layer the material containing at least one metal element, e.g. metal oxides, metal nitrides, metal oxynitrides or metal carbides characterised by the metal the material containing aluminium, e.g. Al2O3
-
- 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
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02225—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer
- H01L21/02227—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a process other than a deposition process
- H01L21/0223—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a process other than a deposition process formation by oxidation, e.g. oxidation of the substrate
- H01L21/02233—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a process other than a deposition process formation by oxidation, e.g. oxidation of the substrate of the semiconductor substrate or a semiconductor layer
-
- 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
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02225—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer
- H01L21/02227—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a process other than a deposition process
- H01L21/0223—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a process other than a deposition process formation by oxidation, e.g. oxidation of the substrate
- H01L21/02233—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a process other than a deposition process formation by oxidation, e.g. oxidation of the substrate of the semiconductor substrate or a semiconductor layer
- H01L21/02241—III-V semiconductor
-
- 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
- H01L21/02104—Forming layers
- H01L21/02107—Forming insulating materials on a substrate
- H01L21/02225—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer
- H01L21/02227—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a process other than a deposition process
- H01L21/02258—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a process other than a deposition process formation by anodic treatment, e.g. anodic oxidation
Definitions
- This invention relates to methods for manufacturing Group III nitride devices for optoelectronic and electronic applications.
- Nitride compounds emerged in recent years as the leading III-V materials for blue to near ultraviolet optoelectronics, as well as for high power electronics. Nitride compounds exhibit an enhanced hardness and chemical inertness compared to other III-V semiconductors, which represents a unique advantage for high temperature operation and device reliability, but also introduces new processing challenges.
- Selective oxidation is a widely used technique in the AlAs/GaAs system, as it allows, for instance, successful current confinement schemes in GaAs-based vertical cavity surface emitting lasers (VCSELs), high reflectivity distributed Bragg reflectors (DBRs) with broad stop- bands suitable for VCSEL applications, improved light confinement in planar waveguides, or insulating buffer layers for field effect transistors (FETs).
- VCSELs vertical cavity surface emitting lasers
- DBRs distributed Bragg reflectors
- FETs field effect transistors
- the selective oxidation technique consists in the insertion of pure AlAs or Al-rich AlGaAs layers in the device during the epitaxial growth, which do not affect the structural quality of the device, since AlAs is nearly lattice-matched to GaAs. Trenches or mesas are then etched in order to give access to the layers from the sidewalls.
- AlAs layers are oxidized in wet atmosphere at ⁇ 450 °C and converted into "AlO x " oxide, while other layers are left unaffected.
- the oxidation depth of such laterally oxidized layers can be precisely controlled.
- the main properties of these oxidized layers are their electrically insulating behavior and their much lower refractive index (less than 1.8) as compared with AlAs ( ⁇ 2.9 at 1.4 eV, 300 K).
- AlN, and Al-rich AlGaN alloys exhibit a significant lattice mismatch to GaN and induce tensile strain in the structure, which prevents their use as sacrificial layers for selective oxidation.
- a method for including an oxide region in a layered structure being grown epitaxially on a substrate such as a group III-V, Si or sapphire substrate is provided which method comprises the steps of epitaxially forming a group III nitride precursor layer and selectively oxidizing the precursor layer, thereby forming the oxide region.
- the inventive method permits selective oxidation of a group III nitride layer that is inserted as a group III nitride precursor layer such as AlInN for example into a multilayer structure during its growth. Subsequently the precursor layer is transformed selectively into a layer including oxidized regions such as AlInO x . The transformation can be achieved without noticeable change in volume. Moreover, the insertion of the precursor layer e.g. in a Group III nitride heterostructure can be performed without a degradation of structural quality. After the group III nitride precursor layer device-quality layers can be obtained by subsequent growth steps.
- the layer including selectively oxidized regions may be used, for example, for a current confinement in group III nitride semiconductor devices. According to one preferred embodiment the selective oxidizing is controlled in depth.
- the method includes a step of selectively dissolving the oxidized region.
- a step of selectively dissolving the oxidized region By removing and particularly by etching oxidized regions air-gap structures such as free-standing GaAs membranes can be obtained. This permits to obtain well-defined structures including undercuts of a well-defined depth.
- a step of annealing the oxide region is provided if the oxide is to remain in the structure. The annealing step improves the optical and electrical properties of the structure.
- the step of selectively oxidizing the Group III precursor layer includes an electrochemical selective oxidation for example by means of an electrolytic solution.
- this step permits to perform oxidation of the Group III precursor layer by a room temperature electrochemical process. Any additional processing such as additional illumination of the structure is not necessary.
- this oxidation does not involve any noticeable change in volume in the structure.
- the electro-chemical selective oxidation may include an electrolyte comprising an amino- polycarboxylic acid and in particular nitrilotriacetic acid (NTA).
- NTA nitrilotriacetic acid
- the electro-chemical selective oxidation process is carried out by applying a small current density to the sample. Since the process is highly selective surrounding layers are not affected.
- the method includes adapting the electrolytic solution so that the oxide is dissolved or etched during the electrochemical oxidation step. Thereby, a direct electrolytic etching is performed which is still selective.
- the group III nitride precursor layer comprises AlInN, in particular Al(I -x) In x N with 0.25>x>0.1, or this alloy with adjunction of Ga.
- This composition provides layers with a lattice constant near to the lattice constant of GaN and which are moderately strained, the lattice mismatch being within [-1%....1%].
- Some strain may however be present in the AlInN precursor layer, by adjusting its indium content, in order to improve its oxidation rate.
- some difference in strain / indium content can be used to provide oxidation selectivity between the AlInN precursor layer and other AlInN layers possibly present in the layered structure.
- the growth of all layers may be performed by metalorganic vapor phase epitaxy (MOVPE) or other known semiconductor growth techniques such as MBE.
- MOVPE metalorganic vapor phase epitaxy
- the method includes the formation of a superlat- tice and in particular of a Group III nitride superlattice.
- a Group III nitride pre- cursor layer of AlInN can be replaced by a short period superlattice of AlInN / GaN having a layer thickness of for example 2nm.
- the method may include according to a further preferred embodiment the insertion of a composition-graded Group III nitride layer such as a layer of (Ali.yIn y )i -x Ga x N having a varying Ga content x as a function of the layer thickness.
- This layer can be provided at least at one of the interfaces between the Group III nitride layer and Group III nitride precursor layer.
- the method may include a step of entirely oxidizing and dissolving or etching the Group III nitride precursor layer.
- the Group III nitride precursor layer can serve as a sacrificial layer which after its removal permits to separate a substrate from a thin-film device such as a LED.
- a layered semiconductor structure including a GaN compatible substrate such as a group IH-V, Si or sapphire substrate, at least one layer of Group III nitride such as GaN and a Group III nitride precursor layer including a selectively oxidized region or selectively etched region.
- the Group III nitride precursor layer can be partially or entirely oxidized or etched.
- a partially oxidized or etched Group III nitride precursor layer can be used in group III nitride semiconductor devices such as VCSELs and LEDs for providing a lateral current confinement.
- An oxidized Group III nitride precursor layer can also be used in high contrast DBRs and waveguides e.g.
- VCSELs and RCLEDs can include an oxidized DBR or a DBR having an air-gap or may additionally comprise an oxidized layer to improve current confinement.
- an oxidized layer according to the invention can be used as a highly resistive buffer layer in HEMTs or FETs to achieve better insulating properties such as a higher electrical resistivity and to avoid leakage currents.
- group III nitride MOEMs the inventive method can be used to form air-gap structures by oxidizing and dissolving or etching oxidized regions.
- the layered structure can include a Group III quantum well structure such as an InGaN/GaN quantum well structure.
- the structure includes a superlattice and in particular a short period Group III nitride precursor / Group III nitride superlattice such as a short period superlattice of AlInN / GaN.
- the layer thickness may comprise for example 2nm.
- the structure includes a composition-graded Group III nitride layer such as a layer of (Al 1-y In y )i -x Ga x N comprising a varying x-value over its thickness at least at one the interfaces between the Group III nitride and Group III nitride precursor layer.
- the composition-graded layer permits to achieve a better current confinement. Furthermore, the mechanical strength of the layer including the oxide region or oxidized region can be improved.
- the structure does not comprise a substrate.
- This type of structure can be advantageous for instance for thin-film LEDs and can be achieved by removing a previously grown thin-film III-N structure.
- the layered structure according to the invention may be part of a semiconductor device such as a LED (light emitting device), VCSEL (vertical cavity surface emitting laser), RCLED (resonant cavity LED), HEMT (high electron mobility transistor) or FET (field effect transistor) or a MOEM (micro-opto-electro mechanical) device or part of a waveguide or DBR.
- a semiconductor device such as a LED (light emitting device), VCSEL (vertical cavity surface emitting laser), RCLED (resonant cavity LED), HEMT (high electron mobility transistor) or FET (field effect transistor) or a MOEM (micro-opto-electro mechanical) device or part of a waveguide or DBR.
- Fig. 1 shows an example of a layered structure including the semiconductor structure according to one embodiment of the present invention
- Fig. 2 shows a schematic view of the oxidation setup according to one embodiment
- Fig. 3a-f show examples of oxidized and non-oxidized LED structures according to one embodiment of the invention; wherein (a) and (b) are taken after the oxidation step, (c) and (d) are taken at the end of the processing, and (e) and (f) with an operating current of about 0.5 mA; and Fig. 4 shows I-V characteristics of a non-oxidized LED, a fully oxidized LED and a
- FIG. 1 shows a schematic cross section of the structure used according to one embodiment.
- a 50 nm thick Al O g 2 In O i 8 N layer 1 is introduced above the «-doped region 3 of an InGaN/GaN quantum well (QW) based LED grown on a 2 inch sapphire substrate 5.
- QW quantum well
- the AlInN layer 1 is non intentionally doped but its donor concentration measured by C-V analysis is estimated to 10 18 cm "3 due to high residual doping.
- the «-doped GaN region 3 is 2 ⁇ m thick with a Si doping level of ⁇ 3 xlO 18 cm “3
- the p-doped GaN region 7 is 200 nm thick with a hole concentration of ⁇ 2 ⁇ l ⁇ 17 cm “3 after a Mg activation thermal treatment of 10 minutes at 800 0 C under N 2 atmosphere.
- the active region features a single 3 nm thick InGaN QW 9, grown 10 nm above the AlInN layer 1, without any AlGaN electron blocking layer. This basic design was chosen to limit the amount of tensile strain generated in the cap layer, which could otherwise induce strain issues during the oxidation process and possibly damage the device.
- a 400 nm SiO 2 mask 11 is deposited on the wafer by standard photolithography techniques and square mesas of various sizes (28-400 ⁇ m) are etched by Cl 2 / Ar reactive ion etching to give access to the n-GaN bottom layer 3 and the AlInN layer 1 side- wall.
- the SiO 2 cap layer 1 1 can be removed or possibly kept in place to protect the top surface of the mesa and avoid oxidation of the AlInN layer 1 from the surface through defects.
- a small piece of indium 13 is alloyed to the tt-GaN layer 3.
- the preparation of the electrolyte 23 is done by adjusting a 0.1 M solution of ni- trilotriacetic acid (NTA) by addition of potassium hydroxyde to a pH-value between 8 and 12 depending on the layer stack and the respecting doping levels.
- Another way of preparation of the electrolyte 23 is to dissolute nitrilotriacetic acid (NTA) in a 0.3 M solution of potassium hydroxide in order to reach a pH value of 8.5.
- the anodic oxidation is performed at room temperature without illumination in a small beaker 15 fitted with a platinum cathode 17, as described in Fig. 2.
- Typical oxidation rates of the AlInN layer 1 vary between 5 and 20 ⁇ m per hour and depend on the applied current density, composition/strain of the AlInN layer, crystalline quality and doping levels in the structure. The process is highly selective and the surrounding GaN layers 3, are kept unaffected. Besides, no significant change in the volume of the oxidized AlInN layer 1 was detected.
- the oxidation extends laterally 22 ⁇ m inside the structure, leaving 70 ⁇ m ⁇ 70 ⁇ m mesas with a 26 ⁇ m ⁇ 26 ⁇ m square opening, whereas 28 ⁇ m ⁇ 28 ⁇ m mesas are fully oxidized.
- the oxidation time was reduced and, as a result, the oxidation front extends only 10.5 ⁇ m within the structure leaving a small circular aperture at the center of 28 ⁇ m ⁇ 28 ⁇ m mesas (see Fig. 3).
- the aperture diameter is about 5-7 ⁇ m which is the diameter needed for current confinement in nitride VCSELs.
- the third area was left non-oxidized for the sake of comparison.
- the processing of the LEDs involved the following steps: removal of both the indium contact 13 and the protective SiO 2 cap layer 1 1 by wet etching in a HF solution, deposition of a Ti/Al/Ni/Au (10/300/10/200 nm) ⁇ -contact (not shown) by electron beam evaporation and of a semitransparent Ni/ Au (10/10 nm) />-contact (not shown) that is further oxidized during 5 min at 550 °C in an O 2 atmosphere.
- An insulating SiO 2 dielectric layer (not shown) is deposited on the layer and eventually opened to deposit large Ti/Au (10/300 nm) contact pads.
- Figure 3 shows a comparison of optical microscope images of an oxidized 28 ⁇ m ⁇ 28 ⁇ m LED device and a nonoxidized one at different stages of the process. Images (a) and (b) are taken just after the oxidation step, (c) and (d) at the end of the processing, while (e) and (f) show the LEDs operating with an injected current of about 0.5 mA.
- the effect of the oxidation aperture is clearly seen on these pictures: for the oxidized device, carriers are confined within the 5 ⁇ m aperture and light is emitted only in this area (guided light is also noticed on the mesa sides). On the other hand, light is emitted over the full mesa for the nonoxidized device due to lateral diffusion of the carriers below the top contact. The insulating behavior of the oxide layer is also observed on the electrical characteristics of the devices. The reduction of the current aperture leads to an increase in the differential resistance of the LEDs.
- the anodically formed oxide material is insulating and permits to provide a current confinement scheme in a LED device. This technique is useful for several applications in nitride optoelectronics and electronics.
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Formation Of Insulating Films (AREA)
- Led Devices (AREA)
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US63902604P | 2004-12-24 | 2004-12-24 | |
US60/639,026 | 2004-12-24 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2006066962A2 true WO2006066962A2 (en) | 2006-06-29 |
WO2006066962A3 WO2006066962A3 (en) | 2007-03-29 |
Family
ID=36602113
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/EP2005/013966 WO2006066962A2 (en) | 2004-12-24 | 2005-12-23 | Selective oxidation and selective etching of allnn layers for manufacturing group iii nitride semiconductor devices |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO2006066962A2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2454655A (en) * | 2007-11-09 | 2009-05-20 | Sharp Kk | Nitride structures with AlInN current confinement layers |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1235279A2 (en) * | 2001-02-27 | 2002-08-28 | Matsushita Electric Industrial Co., Ltd. | Semiconductor device using nitride compound and method for fabricating the same |
US20040188693A1 (en) * | 2003-03-25 | 2004-09-30 | Matsushita Electric Industrial Co., Ltd. | Semiconductor device and method for fabricating the same |
-
2005
- 2005-12-23 WO PCT/EP2005/013966 patent/WO2006066962A2/en active Application Filing
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP1235279A2 (en) * | 2001-02-27 | 2002-08-28 | Matsushita Electric Industrial Co., Ltd. | Semiconductor device using nitride compound and method for fabricating the same |
US20040188693A1 (en) * | 2003-03-25 | 2004-09-30 | Matsushita Electric Industrial Co., Ltd. | Semiconductor device and method for fabricating the same |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2454655A (en) * | 2007-11-09 | 2009-05-20 | Sharp Kk | Nitride structures with AlInN current confinement layers |
Also Published As
Publication number | Publication date |
---|---|
WO2006066962A3 (en) | 2007-03-29 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US11133652B2 (en) | Optical devices and methods of manufacture and operation | |
US20230105367A1 (en) | Method for electrochemically etching a semiconductor structure | |
US8541869B2 (en) | Cleaved facet (Ga,Al,In)N edge-emitting laser diodes grown on semipolar bulk gallium nitride substrates | |
CN107078190B (en) | Method for GaN vertical microcavity surface emitting laser (VCSEL) | |
JP5280439B2 (en) | Semiconductor layer structure | |
CN101272037B (en) | Method for manufacturing semiconductor optical device | |
JP4272239B2 (en) | Semiconductor optical device manufacturing method | |
KR20160065178A (en) | Heterostructure including anodic aluminum oxide layer | |
US7964424B2 (en) | Method for manufacturing nitride semiconductor light-emitting element | |
WO2007138656A1 (en) | Nitride semiconductor light emitting element | |
EP3413412B1 (en) | Electron beam pumped non-c-plane uv emitters | |
JPH10215034A (en) | Compound semiconductor element and manufacture thereof | |
US7611916B2 (en) | Method of manufacturing semiconductor optical element | |
US7751456B2 (en) | Method for manufacturing semiconductor optical device | |
JP2006279023A (en) | Semiconductor device and fabrication method therefor | |
WO2006066962A2 (en) | Selective oxidation and selective etching of allnn layers for manufacturing group iii nitride semiconductor devices | |
US20050249253A1 (en) | Semiconductor light-emitting device and a method of manufacture thereof | |
JP3552642B2 (en) | Semiconductor light emitting device and method of manufacturing the same | |
JP2006295056A (en) | Semiconductor laser device and its manufacturing method | |
WO2002069466A1 (en) | Iii group nitride semiconductor element and iii group nitride semiconductor substrate | |
Zhang | Nanoporous GaN and Its Application in Vertical-Cavity Surface-Emitting Lasers | |
JP2004014747A (en) | Face light-emitting semiconductor laser device | |
JP2005347609A (en) | Manufacturing method for semiconductor layer and for semiconductor light emitting element | |
JP2008282836A (en) | Semiconductor laser device and manufacturing method of nitride semiconductor device | |
JP2001044573A (en) | Nitride semiconductor element and nitride light-emitting element |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A2 Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KM KN KP KR KZ LC LK LR LS LT LU LV LY MA MD MG MK MN MW MX MZ NA NG NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW |
|
AL | Designated countries for regional patents |
Kind code of ref document: A2 Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU LV MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
32PN | Ep: public notification in the ep bulletin as address of the adressee cannot be established |
Free format text: COMMUNICATION PURSUANT TO RULE 69(1) EPC (FORM 1205A OF 31.08.07) |
|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 05826463 Country of ref document: EP Kind code of ref document: A2 |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 05826463 Country of ref document: EP Kind code of ref document: A2 |