CN102339775A - 砷化镓表面自体氧化物清洗、纯化及淀积Al2O3介质的方法 - Google Patents
砷化镓表面自体氧化物清洗、纯化及淀积Al2O3介质的方法 Download PDFInfo
- Publication number
- CN102339775A CN102339775A CN2011102856770A CN201110285677A CN102339775A CN 102339775 A CN102339775 A CN 102339775A CN 2011102856770 A CN2011102856770 A CN 2011102856770A CN 201110285677 A CN201110285677 A CN 201110285677A CN 102339775 A CN102339775 A CN 102339775A
- Authority
- CN
- China
- Prior art keywords
- gaas
- reaction
- passivation
- oxide
- sample
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910001218 Gallium arsenide Inorganic materials 0.000 title claims abstract description 106
- JBRZTFJDHDCESZ-UHFFFAOYSA-N AsGa Chemical compound [As]#[Ga] JBRZTFJDHDCESZ-UHFFFAOYSA-N 0.000 title claims abstract description 105
- 238000000034 method Methods 0.000 title claims abstract description 35
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 title claims abstract 8
- 238000000151 deposition Methods 0.000 title abstract description 7
- 229910052593 corundum Inorganic materials 0.000 title abstract 5
- 229910001845 yogo sapphire Inorganic materials 0.000 title abstract 5
- 238000005406 washing Methods 0.000 title abstract 4
- 238000002161 passivation Methods 0.000 claims abstract description 53
- 238000006243 chemical reaction Methods 0.000 claims abstract description 48
- 238000000231 atomic layer deposition Methods 0.000 claims abstract description 34
- JLTRXTDYQLMHGR-UHFFFAOYSA-N trimethylaluminium Chemical compound C[Al](C)C JLTRXTDYQLMHGR-UHFFFAOYSA-N 0.000 claims abstract description 30
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 claims abstract description 18
- 229910052717 sulfur Inorganic materials 0.000 claims abstract description 18
- 239000011593 sulfur Substances 0.000 claims abstract description 18
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 18
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 17
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 16
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 16
- 238000010926 purge Methods 0.000 claims description 16
- 239000008367 deionised water Substances 0.000 claims description 14
- 229910021641 deionized water Inorganic materials 0.000 claims description 14
- 238000004140 cleaning Methods 0.000 claims description 13
- 239000007789 gas Substances 0.000 claims description 11
- 235000011114 ammonium hydroxide Nutrition 0.000 claims description 9
- 239000003989 dielectric material Substances 0.000 claims description 9
- 239000000126 substance Substances 0.000 claims description 8
- YUKQRDCYNOVPGJ-UHFFFAOYSA-N thioacetamide Chemical compound CC(N)=S YUKQRDCYNOVPGJ-UHFFFAOYSA-N 0.000 claims description 8
- DLFVBJFMPXGRIB-UHFFFAOYSA-N thioacetamide Natural products CC(N)=O DLFVBJFMPXGRIB-UHFFFAOYSA-N 0.000 claims description 8
- 239000010409 thin film Substances 0.000 claims description 6
- 238000012856 packing Methods 0.000 claims description 3
- 230000035484 reaction time Effects 0.000 claims description 3
- 230000001105 regulatory effect Effects 0.000 claims description 2
- 239000000463 material Substances 0.000 abstract description 18
- UCKMPCXJQFINFW-UHFFFAOYSA-N Sulphide Chemical compound [S-2] UCKMPCXJQFINFW-UHFFFAOYSA-N 0.000 abstract description 11
- 239000004065 semiconductor Substances 0.000 abstract description 6
- 239000003795 chemical substances by application Substances 0.000 abstract description 3
- 230000008021 deposition Effects 0.000 abstract description 2
- 230000002349 favourable effect Effects 0.000 abstract description 2
- 238000002360 preparation method Methods 0.000 abstract description 2
- 238000010405 reoxidation reaction Methods 0.000 abstract 1
- 239000000243 solution Substances 0.000 description 15
- 239000010408 film Substances 0.000 description 10
- 239000000758 substrate Substances 0.000 description 7
- 229910052785 arsenic Inorganic materials 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 6
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 5
- 235000019441 ethanol Nutrition 0.000 description 5
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 4
- HIVLDXAAFGCOFU-UHFFFAOYSA-N ammonium hydrosulfide Chemical compound [NH4+].[SH-] HIVLDXAAFGCOFU-UHFFFAOYSA-N 0.000 description 4
- 229910004298 SiO 2 Inorganic materials 0.000 description 3
- 230000007062 hydrolysis Effects 0.000 description 3
- 238000006460 hydrolysis reaction Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 229910052710 silicon Inorganic materials 0.000 description 3
- 239000010703 silicon Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- XSTXAVWGXDQKEL-UHFFFAOYSA-N Trichloroethylene Chemical group ClC=C(Cl)Cl XSTXAVWGXDQKEL-UHFFFAOYSA-N 0.000 description 2
- 239000002800 charge carrier Substances 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 150000002500 ions Chemical class 0.000 description 2
- 238000004377 microelectronic Methods 0.000 description 2
- 239000011259 mixed solution Substances 0.000 description 2
- 239000013307 optical fiber Substances 0.000 description 2
- 230000003647 oxidation Effects 0.000 description 2
- 238000007254 oxidation reaction Methods 0.000 description 2
- 238000001420 photoelectron spectroscopy Methods 0.000 description 2
- UBOXGVDOUJQMTN-UHFFFAOYSA-N trichloroethylene Natural products ClCC(Cl)Cl UBOXGVDOUJQMTN-UHFFFAOYSA-N 0.000 description 2
- 230000005641 tunneling Effects 0.000 description 2
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 1
- FKNQFGJONOIPTF-UHFFFAOYSA-N Sodium cation Chemical compound [Na+] FKNQFGJONOIPTF-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000001476 alcoholic effect Effects 0.000 description 1
- 239000003513 alkali Substances 0.000 description 1
- 230000003321 amplification Effects 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 239000003990 capacitor Substances 0.000 description 1
- 230000015556 catabolic process Effects 0.000 description 1
- 238000006388 chemical passivation reaction Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000007850 degeneration Effects 0.000 description 1
- 238000000280 densification Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 229910052733 gallium Inorganic materials 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 238000004020 luminiscence type Methods 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000013386 optimize process Methods 0.000 description 1
- 230000005693 optoelectronics Effects 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052698 phosphorus Inorganic materials 0.000 description 1
- 239000011574 phosphorus Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 239000000047 product Substances 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000004151 rapid thermal annealing Methods 0.000 description 1
- 230000036632 reaction speed Effects 0.000 description 1
- 230000006798 recombination Effects 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910001415 sodium ion Inorganic materials 0.000 description 1
Images
Classifications
-
- 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
- H01L21/0226—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process
- H01L21/02263—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase
- H01L21/02271—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition
- H01L21/0228—Forming insulating materials on a substrate characterised by the process for the formation of the insulating layer formation by a deposition process deposition from the gas or vapour phase deposition by decomposition or reaction of gaseous or vapour phase compounds, i.e. chemical vapour deposition deposition by cyclic CVD, e.g. ALD, ALE, pulsed CVD
-
- 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
- H01L21/02041—Cleaning
- H01L21/02043—Cleaning before device manufacture, i.e. Begin-Of-Line process
- H01L21/02052—Wet cleaning only
-
- 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
- H01L21/02296—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer
- H01L21/02299—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer pre-treatment
- H01L21/02301—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer pre-treatment in-situ cleaning
-
- 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
- H01L21/02296—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer
- H01L21/02299—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer pre-treatment
- H01L21/02312—Forming insulating materials on a substrate characterised by the treatment performed before or after the formation of the layer pre-treatment treatment by exposure to a gas or vapour
-
- 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
- H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
- H01L21/306—Chemical or electrical treatment, e.g. electrolytic etching
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Manufacturing & Machinery (AREA)
- Computer Hardware Design (AREA)
- Physics & Mathematics (AREA)
- Power Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Formation Of Insulating Films (AREA)
- Cleaning Or Drying Semiconductors (AREA)
- Insulated Gate Type Field-Effect Transistor (AREA)
Abstract
本发明属于半导体材料技术领域,具体为一种砷化镓表面自体氧化物清洗、纯化及淀积Al2O3介质的方法。该方法包括:使用新型的硫钝化剂,与砷化镓表面的自体氧化物发生反应而清洗,并生成硫化物钝化膜使砷化镓和外界隔绝,从而防止了砷化镓的再次氧化;利用ALD淀积Al2O3的反应源三甲基铝与砷化镓表面进行的预处理反应,进一步清洗GaAs表面的残留自体氧化物和硫化物等,然后采用ALD淀积高质量Al2O3介质作为栅介质,Al2O3介质层将GaAs和外界环境很好地隔离开来。本发明工艺简单,效果良好,为进一步制备GaAs的器件提供了前提条件。
Description
技术领域
本发明属于半导体材料技术领域,具体涉及一种砷化镓表面自体氧化物的清洗和进一步淀积Al2O3介质的方法。
背景技术
随着微电子产业和光电子产业的高速发展,对GaAs等Ⅲ-Ⅴ族化合物半导体材料制备的半导体激光器、光纤通信光接收组件、高速和高频半导体器件的需求越来越大,所以GaAs等Ⅲ-Ⅴ族化合物半导体材料的研究一直是学术界和工业界关注的重点。GaAs本征材料由于具有很高的电子迁移率、较大的禁带宽度(1.43eV)和较低载流子浓度,因而在高速器件和高温环境中获得广泛运用。GaAs被认为是后硅时代 (Post-Silicon)中非常有可能取代硅(Si)作为CMOS器件的沟道材料。但是,由于GaAs暴露在空气中很容易被氧化生成一系列复杂的氧化物和砷单质,这使得GaAs材料的表面缺陷很多,无法直接用于和微电子器件和光电子器件中。无法制备出清洁表面的GaAs和缺少合适的钝化GaAs表面的介质材料是长期以来是阻碍GaAs材料大规模应用的最大的问题。
上世纪六、七十年代,借鉴Si氧化后能生成高质量的SiO2薄膜的思路,科研人员曾花费大量精力研究GaAs的自体氧化物作为钝化介质,但最后都以失败告终。深入的研究发现,砷的氧化物是不稳定的,自体氧化层与GaAs之间有很高的界面态密度,它们对载流子起着散射中心和非辐射复合中心的作用,减小载流子的迁移率,并引起费米能级钉扎,因而严重影响到器件的电学和光学特性。
采用常规的GaAs清洗流程后,GaAs表面自体氧化物并不能完全清除,而且清洗过程结束后的GaAs样品到下一步的工艺步骤之间无法避免在空气中暴露。清洁的GaAs表面具有很活泼的化学性质,GaAs样品的表面会和空气中的氧气发生如下的一系列反应:
3O2+2GaAs=As2O3+Ga2O3 (1)
4O2+2GaAs=As2O5+Ga2O3 (2)
As2O3+2GaAs=Ga2O3+4As (3)
3As2O5+10GaAs=5Ga2O3+16As (4)
从而在GaAs表面生成了Ga2O3、As2O3和As等成分。
1987年sandroff等首先提出了硫化物水溶液钝化GaAs表面的硫钝化方法。他们使用Na2S·9H2O溶液来钝化AlxGa1-xAs/GaAs异质结双极晶体管(HBT)器件,使HBT的小电流放大系数提高达60倍,钝化后样品的光致发光(PL)强度增加了250倍。湿法硫钝化的机理是通过溶液中的S2-离子和GaAs的自体氧化物以及砷单质的化学反应,生成以GaxSy和AsxSy为主的致密的钝化层。硫钝化方法有效地去除表面不稳定氧化物,生成硫化物层,并且能抑制表面再次被氧化,使表面态密度下降,表面复合速率下降。基本达到了降低表面态密度(电子学钝化)和提高稳定性(化学钝化)的效果。近些年来,有关GaAs材料的各种硫钝化方法不断被发明和采用,极大地改善了GaAs的表面特性。
通常GaAs采用的是(NH4)2S钝化液,(NH4)2S水解能够产生大量S2- 和HS-离子,由于反应速度很快,会使得GaAs表面腐蚀比较严重,产生较多的凹坑。而且溶液中的水会导致GaAs在有氧环境中被再次氧化,生成的硫化物厚度较薄,这对后续工艺而言来说是很不利的。获得清洁的无氧GaAs衬底表面是生长高质量薄膜的先决条件,为此这里采用了CH3CSNH2、乙醇和氨水的混合液缓慢水解形成HS-和S2-离子来钝化GaAs表面,生成更为致密且更厚的硫化物,这层硫化物将GaAs和外界环境隔绝开来。由于醇溶液的相对介电系数比水要低很多,HS-、S2-离子和GaAs表面的静电吸附能力增强,氨水 (PH>7)的碱性环境促进水解产生HS-和S2-离子,从而有利于S与GaAs表面原子形成共价键,其钝化的GaAs表面具有较低的界面态密度、腐蚀的凹坑数目较少。
硫钝化虽然消除了GaAs表面大部分的自体氧化物和单质砷,但是钝化形成的硫化物,尤其是As-S仍然会在GaAs禁带中形成新的缺陷能级,因此GaAs表面的费米能级钉扎仍然无法消除。As-S键在350℃左右的温度下,会分解而脱离GaAs表面,而Ga-S键在460℃的温度下仍然具有稳定性。另一方面,在原子层淀积(ALD)工艺中,反应源和淀积的衬底表面发生的自清洗现象逐渐被认识和利用,它是指吸附在衬底表面的反应源会和衬底上的氧化物等发生反应,这样衬底上的氧化物等会被清洗干净。本发明利用三甲基铝(TMA)和AsxSy GaxSy、AsxOy、GaxOy、As等之间发生的化学反应,以及ALD工艺中的热效应使GaAs上残留的硫化物和自体氧化物挥发而脱离GaAs表面,从而在淀积Al2O3薄膜介质之前能够获得清洁的衬底表面。
根据摩尔定律,器件的尺寸不断缩小,工作速度越来越快,功耗也越来越小。器件尺寸不断缩小的的趋势也体现在金属-氧化物-半导体场效应晶体管(MOSFETs)的栅氧化层厚度(Tox)的减薄上。由量子隧穿效应导致的栅极泄漏电流随栅极氧化层厚度的减小而指数上升,当栅氧化层厚度小于2nm时,量子隧穿效应带来栅极泄漏电流急速增加,最终导致器件性能的退化。
由平行板电容器电容公式 可知,为了增大栅极电容的电容密度,可以采用介电常数更高的材料(高k材料)替代常规的SiO2作为栅介质。不难理解,为了获得相同的栅极电容,使用SiO2和高k材料相应的厚度符合如下关系:
在众多高k材料中,从材料特性和电学特性而言,Al2O3是一种很优良的介质材料。Al2O3有很高的禁带宽度(~9eV),高的击穿电场强度(5-10 MV/cm),良好的热稳定性,高温工艺处理后仍能保持非晶态。Al2O3和Si、GaAs等材料具有很稳定的界面,Al2O3 对钠离子,硼,磷等具有较好的阻挡作用,抗辐射能力强。因此Al2O3常被用来作为钝化薄膜和介质材料,有助于提高和改善器件的性能和可靠性。
发明内容
本发明的目的在于提供一种工艺简单、效果优异的砷化镓表面自体氧化物清洗、纯化方法,并进一步提供在其上淀积Al2O3介质的方法。
本发明内容包括:
1.使用新型的硫钝化剂,与砷化镓表面的自体氧化物发生反应而清洗,并生成硫化物钝化膜使砷化镓和外界隔绝,从而防止了砷化镓的再次氧化。
2.利用原子层淀积 (ALD) Al2O3的反应源三甲基铝(TMA)与砷化镓表面进行的预处理反应,进一步清洗GaAs表面的残留自体氧化物和硫化物等,获得非常清洁的GaAs表面。采用ALD方法淀积高质量Al2O3介质作为栅介质,Al2O3介质层将GaAs和外界环境很好地隔离开来,为进一步制备GaAs的器件提供了前提条件。
本发明方法的具体步骤为:
(1)砷化镓样品经过常规的化学清洗后,立即放入事先配置好的硫钝化溶液中,硫钝化溶液由1-5g硫代乙酰胺(CH3CSNH2)、1-4ml无水乙醇(CH3COOH)和1-4ml氨水(NH3.H2O)所组成,钝化反应的温度25℃-60℃,钝化时间为5-30min。
(2)钝化结束后,再用去离子水漂洗砷化镓样品10-60秒,然后用高纯的氮气吹洗样品5-15秒后,立刻装入原子层淀积(ALD)反应腔中。
(3)在生长氧化铝(Al2O3)薄膜介质之前,先进行砷化镓样品的三甲基铝(TMA)的预处理反应,目的是为了进一步去除GaAs表面的硫化物和残留的自体氧化物,从而得到清洁的砷化镓表面。预处理的条件包括:三甲基铝气体通入原子层淀积反应腔中2-8分钟,氮气吹洗10-60秒钟;
(4)用原子层淀积的方法生长需要的高质量的Al2O3薄膜介质。反应源分别为三甲基铝(TMA)和去离子水,淀积反应的温度为250-350℃,反应腔气压小于15托,氧化物薄膜的厚度可以通过控制原子层反应循环次数调节。单个反应周期包括1-5秒的三甲基铝气体通入,2-10秒钟的氮气吹洗,1-5秒的去离子水蒸汽通入,2-10秒的氮气吹洗。
本发明中,优化的工艺条件为:
硫钝化溶液为:2g硫代乙酰胺、4ml无水乙醇和1ml氨水所组成,钝化反应的温度25℃,钝化时间为10min。
钝化结束后,去离子水漂洗砷化镓样品10秒,然后用高纯的氮气吹洗样品10秒后,立刻装入原子层淀积(ALD)反应腔中。
三甲基铝(TMA)和砷化镓的预处理条件包括:三甲基铝气体通入原子层淀积反应腔中5分钟,氮气吹洗30秒钟;
原子层淀积的方法生长Al2O3薄膜介质,反应源分别为三甲基铝(TMA)和去离子水,淀积反应的温度为300℃,反应腔气压为5托,。单个反应周期包括1.5秒的三甲基铝气体通入,3秒钟的氮气吹洗,1秒的去离子水蒸汽通入3秒的氮气吹洗。
本发明方法可以用于GaAs的MES(金属-半导体)结构和MOS(金属-氧化物-半导体)结构的GaAs表面清洗和氧化物的淀积。
本发明方法的进一步的具体操作流程为:
(1)先将GaAs样品依次放入三氯乙烯、丙酮、酒精和去离子水中超声清洗4--8分钟;
(2)取出GaAs样品后,放入HF溶液(HF/H2O=1/50)中清洗2-3分钟,除去GaAs衬底表面的氧化层;
(3)再将GaAs样品放入浓度为10%氨水中清洗4--6分钟,除去残余的HF溶液和GaAs表面的氧化层;
(4)把GaAs取出后,立即放入CH3CSNH2、乙醇和氨水的混合液中钝化5--30分钟,清除GaAs的氧化物并生成硫钝化层;
(5)钝化结束后,用去离子水漂洗GaAs样品8--15秒钟,然后用高纯的N2枪将样品吹干;
(6)将硫钝化好的GaAs样品装入ALD的反应腔中,开启原子层淀积设备。达到工艺条件后,往ALD反应腔中通入三甲基铝气体2-8分钟,然后关闭三甲基铝气体,再向ALD反应腔中通入10--60秒的氮气吹洗预处理反应的生成物和残余物;
(7)三甲基铝和GaAs样品的预处理结束后,开始Al2O3介质的淀积,通过控制工艺条件来生长所需的薄膜厚度;
(8)Al2O3介质淀积结束后,将Al2O3/GaAs样品进行快速热退火, 300-600℃温度下N2气氛退火1-5分钟,可以提高Al2O3介质层的质量和改善 Al2O3/GaAs的界面特性。
本发明使用硫钝化剂与砷化镓表面的自体氧化物的反应进行化学清洗,以及使用原子层淀积方法的反应源与砷化镓的预处理反应进一步清洗砷化镓(GaAs)表面,生成的高质量Al2O3介质将GaAs和外界环境很好的隔离开来,为进一步制备GaAs的器件提供了很好的条件。
附图说明
图1为本发明工艺流程图示。其中,(1)-GaAs的硫钝化,(2)-TMA预处理GaAs, (3)-ALD Al2O3介质。
图2为GaAs样品在ALD反应腔中淀积Al2O3介质工艺图示。其中,上图为淀积工艺流程控制;下图为GaAs样品上淀积的Al2O3介质图示。
图3为原子层淀积方法淀积60个周期Al2O3介质后的样品A(硫代乙酰胺钝化)和样品B(硫铵钝化)的光电子能谱图(XPS)。其中,左图为样品A的As 3d XPS峰,右图为样品B的As 3d XPS峰。
图4为样品A(硫代乙酰胺钝化) (左图)和样品B(硫铵钝化) (右图)的Ga 2p XPS峰。
具体实施方式
以下结合具体的实施例对本发明做进一步的说明。
实施例1
实验采用Si掺杂的n型(100)晶向GaAs样品,掺杂浓度约为1.0×1017cm-3。将GaAs样品解理成小块的样品后,依次放入三氯乙烯、丙酮、酒精和去离子水中超声清洗5分钟,以除去表面的油脂、有机物等。随即将GaAs样品放入浓度为2%的稀HF溶液中,清洗2分钟后用去离子水漂洗多余的HF溶液,这一步是为了清洗掉GaAs表面的氧化物。然后再用浓度为10%的氨水,浸泡5分钟,利用碱可以和GaAs的自体氧化物反应而将其清除,此外这一步骤还可以中和之前的HF溶液。
以2g的CH3CSNH2、4ml的无水乙醇和1ml氨水的比例配置混合溶液,用干净的镊子将GaAs样品取出后,立即放入混合溶液中钝化10分钟,清除GaAs表面的氧化物并生成致密硫钝化层,处理过的样品标记为样品A。作为对照,我们还配置含有乙醇的(NH4)2S钝化液,具体为将浓度为10%的(NH4)2S和的无水乙醇以1:1的体积比混合,同样将上一步清洗后的GaAs样品钝化10分钟,处理过的样品标记为样品B。
硫钝化结束后,样品A和B用去离子水漂洗10秒,然后再用干燥的N2将吹干。迅速将样品A和B装入ALD反应腔中,开启原子层淀积设备。达到工艺条件后,往ALD反应腔中通入三甲基铝气体5分钟,然后关闭三甲基铝气体,再向ALD反应腔中通入30秒的氮气吹洗三甲基铝和GaAs的反应生成物。三甲基铝和GaAs样品的预处理结束后,开始Al2O3介质的淀积。采用三甲基铝和水作为反应源,通过改变淀积的周期数来控制生长所需的薄膜厚度。具体工艺条件为反应腔温度300℃,反应腔的气压< 15torr。如图2所示,每个周期包括通入1.5秒的三甲基铝气体脉冲(5)和3秒氮气吹洗时间(6),以及1秒的水汽通入时间(7)和3秒的3秒氮气吹洗时间(8)。利用原子层淀积方法可以获得原子级平整的表面,淀积的薄膜的均匀性和可重复性好,并且可以非常精确地控制薄膜的厚度。图2中,10为反应源和氮气通入管道,11为反应源和生成排出管道,12为GaAs样品,13为淀积的Al2O3介质。
材料结果分析
图3为原子层淀积方法淀积60个周期Al2O3介质后的样品A(硫代乙酰胺钝化)和样品B(硫铵钝化)的光电子能谱图(XPS)。表1为样品A(上表)和B(下表)As 3d XPS峰拟合结果
拟合峰 | As-Ga | As-As |
中心峰位(eV) | 41.3 | 42.1 |
面积所占比例 | 89.13% | 10.87% |
拟合峰 | As-Ga | As-As |
中心峰位(eV) | 41.2 | 42.0 |
面积所占的比例 | 86.24% | 13.76% |
表1
从图3和表1可以看出,样品A和样品B相比, As-As(As单质)的相对比例减小了,这说明硫代乙酰胺钝化过的样品的单质砷含量比硫铵钝化过的样品低。
图4为样品A(左图)和B(右图)的Ga 2p XPS峰。表2为样品A(上表)和B(下表)Ga 2p XPS峰拟合结果
拟合峰 | Ga-As | Ga-S | Ga-O |
中心峰位(eV) | 1117.1 | 1117.7 | 1118.5 |
面积所占比例 | 89.95% | 5.54% | 4.50% |
拟合峰 | Ga-As | Ga-S | Ga-O |
中心峰位(eV) | 1117.1 | 1117.7 | 1118.5 |
面积所占的比例 | 82.68% | 13.10% | 4.22% |
表2
从图4和表2可以看出,样品A和样品B相比, Ga-S键的相对比例减小了很多,我们期望的Ga-AS键的组分含量更大。这说明硫代乙酰胺钝化过的样品的界面成分主要以Ga-As为主,符合减小界面态密度和消除费米能级钉扎的要求。
Claims (2)
1.一种砷化镓表面自体氧化物清洗、纯化及淀积Al2O3介质的方法,其特征在于具体步骤为:
(1)砷化镓样品经过常规的化学清洗后,立即放入事先配置好的硫钝化溶液中,硫钝化溶液由1-5g硫代乙酰胺、1-4ml无水乙醇和1-4ml氨水所组成,钝化反应的温度25℃-60℃,钝化时间为5-30min;
(2)钝化结束后,再用去离子水漂洗砷化镓样品10-60秒,然后用高纯的氮气吹洗样品5-15秒,然后立刻装入原子层淀积反应腔中;
(3)在生长氧化铝薄膜介质之前,先进行砷化镓样品的三甲基铝的预处理反应,预处理的条件为:三甲基铝气体通入原子层淀积反应腔中2-8分钟,氮气吹洗10-60秒钟;
(4)用原子层淀积的方法生长需要的高质量的Al2O3薄膜介质,反应源分别为三甲基铝和去离子水,淀积反应的温度为250-350℃,反应腔气压小于15托,氧化物薄膜的厚度通过控制原子层反应循环周期次数调节。
2.根据权利要求1所述方法,其特征在于步骤(4)中单个反应周期依次为:1-5秒的三甲基铝气体通入,2-10秒钟的氮气吹洗,1-5秒的去离子水蒸汽通入,2-10秒的氮气吹洗。
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2011102856770A CN102339775A (zh) | 2011-09-23 | 2011-09-23 | 砷化镓表面自体氧化物清洗、纯化及淀积Al2O3介质的方法 |
US13/528,509 US8455372B2 (en) | 2011-09-23 | 2012-06-20 | Method for cleaning and passivating gallium arsenide surface autologous oxide and depositing AL203 dielectric |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
CN2011102856770A CN102339775A (zh) | 2011-09-23 | 2011-09-23 | 砷化镓表面自体氧化物清洗、纯化及淀积Al2O3介质的方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
CN102339775A true CN102339775A (zh) | 2012-02-01 |
Family
ID=45515423
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN2011102856770A Pending CN102339775A (zh) | 2011-09-23 | 2011-09-23 | 砷化镓表面自体氧化物清洗、纯化及淀积Al2O3介质的方法 |
Country Status (2)
Country | Link |
---|---|
US (1) | US8455372B2 (zh) |
CN (1) | CN102339775A (zh) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102610714A (zh) * | 2012-03-27 | 2012-07-25 | 中国科学院半导体研究所 | 同步实现阻止GaAs盖层氧化和提高氧化层热稳定性的方法 |
CN106601587A (zh) * | 2016-11-29 | 2017-04-26 | 东莞市广信知识产权服务有限公司 | 一种Ge基MOS器件结构 |
TWI635531B (zh) * | 2013-09-27 | 2018-09-11 | 愛美科公司 | Iii-v族半導體之層沈積 |
Families Citing this family (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US9673038B2 (en) | 2014-07-10 | 2017-06-06 | Tokyo Electron Limited | Gas phase oxide removal and passivation of germanium-containing semiconductors and compound semiconductors |
US10943780B2 (en) | 2017-11-19 | 2021-03-09 | Applied Materials, Inc. | Methods for ALD of metal oxides on metal surfaces |
KR102569299B1 (ko) * | 2018-04-05 | 2023-08-22 | 어플라이드 머티어리얼스, 인코포레이티드 | 금속 산화물들의 저온 ald를 위한 방법들 |
SG11202106864TA (en) * | 2018-12-25 | 2021-07-29 | Showa Denko Kk | Adhesion removal method and film-forming method |
CN112831777A (zh) * | 2020-10-16 | 2021-05-25 | 扬州工业职业技术学院 | GaAs基高功率半导体激光器腔面钝化处理方法及其钝化液 |
CN113000476B (zh) * | 2021-01-26 | 2023-03-24 | 威科赛乐微电子股份有限公司 | 一种砷化镓物料的清洗工艺 |
US11869806B2 (en) * | 2021-05-07 | 2024-01-09 | Applied Materials, Inc. | Methods of forming molybdenum contacts |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1146632A (zh) * | 1996-06-19 | 1997-04-02 | 复旦大学 | 砷化镓表面微波放电钝化膜的自体生长方法 |
CN1241019A (zh) * | 1998-07-01 | 2000-01-12 | 中国科学技术大学 | 一种ⅲa-ⅴa族化合物半导体表面硫钝化方法 |
CN102005380A (zh) * | 2010-10-12 | 2011-04-06 | 复旦大学 | 一种采用原子层淀积AlN/高k栅介质双层结构的方法 |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5616947A (en) * | 1994-02-01 | 1997-04-01 | Matsushita Electric Industrial Co., Ltd. | Semiconductor device having an MIS structure |
US5799028A (en) * | 1996-07-18 | 1998-08-25 | Sdl, Inc. | Passivation and protection of a semiconductor surface |
US20040099889A1 (en) * | 2002-11-27 | 2004-05-27 | Agere Systems, Inc. | Process for fabricating a semiconductor device having an insulating layer formed over a semiconductor substrate |
CN102191483B (zh) * | 2003-04-23 | 2012-10-03 | 艾克斯特朗公司 | 瞬时增强原子层沉积 |
-
2011
- 2011-09-23 CN CN2011102856770A patent/CN102339775A/zh active Pending
-
2012
- 2012-06-20 US US13/528,509 patent/US8455372B2/en not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN1146632A (zh) * | 1996-06-19 | 1997-04-02 | 复旦大学 | 砷化镓表面微波放电钝化膜的自体生长方法 |
CN1241019A (zh) * | 1998-07-01 | 2000-01-12 | 中国科学技术大学 | 一种ⅲa-ⅴa族化合物半导体表面硫钝化方法 |
CN102005380A (zh) * | 2010-10-12 | 2011-04-06 | 复旦大学 | 一种采用原子层淀积AlN/高k栅介质双层结构的方法 |
Non-Patent Citations (2)
Title |
---|
GE-MING TAN: "improvement of atomic-layer-deposited AL2O3/GaAs inderface quality through a novel sulfuration method", 《ADVANCED MATERIALS RESEARCH》, vol. 287290, 4 July 2011 (2011-07-04), pages 2327 - 2331 * |
徐敏 等: "si衬底上原子层淀积Al2O3薄膜的界面一致", 《第六届全国表面工程学术会议》, 31 August 2006 (2006-08-31), pages 474 - 476 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN102610714A (zh) * | 2012-03-27 | 2012-07-25 | 中国科学院半导体研究所 | 同步实现阻止GaAs盖层氧化和提高氧化层热稳定性的方法 |
TWI635531B (zh) * | 2013-09-27 | 2018-09-11 | 愛美科公司 | Iii-v族半導體之層沈積 |
CN106601587A (zh) * | 2016-11-29 | 2017-04-26 | 东莞市广信知识产权服务有限公司 | 一种Ge基MOS器件结构 |
Also Published As
Publication number | Publication date |
---|---|
US20130078819A1 (en) | 2013-03-28 |
US8455372B2 (en) | 2013-06-04 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN102339775A (zh) | 砷化镓表面自体氧化物清洗、纯化及淀积Al2O3介质的方法 | |
EP2426233B1 (en) | Use of dialkyl monoalkoxy aluminum for the growth of Al2O3 thin films for photovoltaic applications | |
Naghavi et al. | Buffer layers and transparent conducting oxides for chalcopyrite Cu (In, Ga)(S, Se) 2 based thin film photovoltaics: present status and current developments | |
US9685322B2 (en) | Layer deposition on III-V semiconductors | |
CN107946176B (zh) | Ga2O3薄膜晶体管的制备方法 | |
Werner et al. | Oxidation as key mechanism for efficient interface passivation in Cu (In, Ga) Se 2 thin-film solar cells | |
CN113611756A (zh) | 一种N型TOPCon电池及其制备方法 | |
Banerjee et al. | A review of Al2O3 as surface passivation material with relevant process technologies on c-Si solar cell | |
Shishiyanu et al. | Photoluminescence of chemical bath deposited ZnO: Al films treated by rapid thermal annealing | |
Jamarkattel et al. | Improving CdSeTe Devices With a Back Buffer Layer of Cu x AlO y | |
CN103668108A (zh) | 一种氧化物介质的原子层沉积方法 | |
Li et al. | Hydrogen induced interface passivation in atomic layer deposited Al2O3 films and Al2O3/SiO2 stacks | |
CN101393852B (zh) | 一种半导体硅片的清洗方法 | |
SG175830A1 (en) | Process and apparatus for removal of contaminating material from substrates | |
CN102024707A (zh) | 一种GaAs基MOS器件的制备方法 | |
JP2015111658A (ja) | カルコゲニド層を洗浄およびパッシベーションする方法 | |
Buffière et al. | Recombination stability in polycrystalline Cu 2 ZnSnSe 4 thin films | |
MX2011007413A (es) | Solucion para aumentar la resistencia de la hoja de lamina y/o elevar la densidad de energia de la celda fotovoltaica. | |
CN105513948B (zh) | 一种砷化镓材料表面的改性方法 | |
Wang et al. | Chemical depositing of CdS/ZnS composition nanostructure modified TiO2 thin film | |
Hildebrandt et al. | Fast chemical bath deposition process at room temperature of ZnS-based materials for buffer application in high-efficiency Cu (In, Ga) Se 2-based solar cells | |
Chen et al. | Oxygen backed silicon hydride in correlation with the photoluminescence of silicon nano-crystals | |
CN102517171A (zh) | 一种太阳能电池硅片清洗液及其使用方法 | |
Lucovsky et al. | Remote Plasma Enhanced Chemical Deposition of Non-Crystalline GeO2 on Ge and Si Substrates | |
Shih et al. | Photocatalytic study of zinc oxide with different bismuth doping |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
C10 | Entry into substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
WD01 | Invention patent application deemed withdrawn after publication |
Application publication date: 20120201 |