CN104952708A - 碳化硅半导体装置的制造方法 - Google Patents
碳化硅半导体装置的制造方法 Download PDFInfo
- Publication number
- CN104952708A CN104952708A CN201510131777.6A CN201510131777A CN104952708A CN 104952708 A CN104952708 A CN 104952708A CN 201510131777 A CN201510131777 A CN 201510131777A CN 104952708 A CN104952708 A CN 104952708A
- Authority
- CN
- China
- Prior art keywords
- silicon carbide
- semiconductor device
- substrate
- rate
- etch
- 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.)
- Granted
Links
- 229910010271 silicon carbide Inorganic materials 0.000 title claims abstract description 71
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 title claims abstract description 69
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 30
- 239000004065 semiconductor Substances 0.000 title claims abstract description 18
- 238000000034 method Methods 0.000 title claims abstract description 16
- 239000000758 substrate Substances 0.000 claims abstract description 53
- 229910021421 monocrystalline silicon Inorganic materials 0.000 claims description 27
- 239000007789 gas Substances 0.000 claims description 17
- 230000003628 erosive effect Effects 0.000 claims description 13
- 239000001257 hydrogen Substances 0.000 claims description 5
- 229910052739 hydrogen Inorganic materials 0.000 claims description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 4
- 238000002360 preparation method Methods 0.000 claims description 3
- 239000013078 crystal Substances 0.000 abstract description 14
- 238000005530 etching Methods 0.000 abstract description 8
- NJPPVKZQTLUDBO-UHFFFAOYSA-N novaluron Chemical compound C1=C(Cl)C(OC(F)(F)C(OC(F)(F)F)F)=CC=C1NC(=O)NC(=O)C1=C(F)C=CC=C1F NJPPVKZQTLUDBO-UHFFFAOYSA-N 0.000 description 20
- 239000000428 dust Substances 0.000 description 19
- 238000000137 annealing Methods 0.000 description 10
- 230000007547 defect Effects 0.000 description 10
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 4
- 238000004581 coalescence Methods 0.000 description 3
- 238000000227 grinding Methods 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-N Fluorane Chemical compound F KRHYYFGTRYWZRS-UHFFFAOYSA-N 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 125000004429 atom Chemical group 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 230000015556 catabolic process Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000005684 electric field Effects 0.000 description 2
- 230000006698 induction Effects 0.000 description 2
- 238000009413 insulation Methods 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- 238000006722 reduction reaction Methods 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 244000000626 Daucus carota Species 0.000 description 1
- 235000002767 Daucus carota Nutrition 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 235000011114 ammonium hydroxide Nutrition 0.000 description 1
- 239000003708 ampul Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 125000004432 carbon atom Chemical group C* 0.000 description 1
- 239000012159 carrier gas Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000002050 diffraction method Methods 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000004570 mortar (masonry) Substances 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 125000002524 organometallic group Chemical group 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 238000000859 sublimation Methods 0.000 description 1
- 230000008022 sublimation Effects 0.000 description 1
- 238000002230 thermal chemical vapour deposition Methods 0.000 description 1
- 238000004506 ultrasonic cleaning Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- 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
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/12—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/24—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed including, apart from doping materials or other impurities, only semiconductor materials not provided for in groups H01L29/16, H01L29/18, H01L29/20, H01L29/22
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
- C30B25/02—Epitaxial-layer growth
- C30B25/18—Epitaxial-layer growth characterised by the substrate
- C30B25/186—Epitaxial-layer growth characterised by the substrate being specially pre-treated by, e.g. chemical or physical means
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/36—Carbides
-
- 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
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02367—Substrates
- H01L21/0237—Materials
- H01L21/02373—Group 14 semiconducting materials
- H01L21/02378—Silicon carbide
-
- 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
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02367—Substrates
- H01L21/02428—Structure
-
- 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
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02367—Substrates
- H01L21/02428—Structure
- H01L21/0243—Surface structure
-
- 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
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02518—Deposited layers
- H01L21/02521—Materials
- H01L21/02524—Group 14 semiconducting materials
- H01L21/02529—Silicon carbide
-
- 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
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02518—Deposited layers
- H01L21/0257—Doping during depositing
- H01L21/02573—Conductivity type
- H01L21/02576—N-type
-
- 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
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02518—Deposited layers
- H01L21/02587—Structure
- H01L21/0259—Microstructure
- H01L21/02598—Microstructure monocrystalline
-
- 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
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02612—Formation types
- H01L21/02617—Deposition types
- H01L21/0262—Reduction or decomposition of gaseous compounds, e.g. 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
- H01L21/02104—Forming layers
- H01L21/02365—Forming inorganic semiconducting materials on a substrate
- H01L21/02656—Special treatments
- H01L21/02658—Pretreatments
-
- 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
- H01L21/30604—Chemical etching
-
- 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
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/12—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed
- H01L29/16—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by the materials of which they are formed including, apart from doping materials or other impurities, only elements of Group IV of the Periodic Table
Landscapes
- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Crystallography & Structural Chemistry (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Ceramic Engineering (AREA)
- Recrystallisation Techniques (AREA)
Abstract
本发明得到一种能够提高产品的可靠性的碳化硅半导体装置的制造方法。首先,准备具有平均粗糙度小于或等于0.2nm的平坦性的碳化硅单晶衬底(1)。然后,将碳化硅单晶衬底(1)的表面在还原性气体气氛中进行气蚀。在进行气蚀之后,使碳化硅膜(6)在碳化硅单晶衬底(1)的表面上进行外延生长。在这里,将气蚀的蚀刻速率设为大于或等于0.5μm/h而小于或等于2.0μm/h。
Description
技术领域
本发明涉及一种在将碳化硅单晶衬底的表面气蚀之后形成外延生长层的碳化硅半导体装置的制造方法。
背景技术
近些年,与硅相比,带隙、绝缘破坏电场强度、饱和漂移速度、热导率均相对较大的碳化硅(SiC)主要作为电力控制用功率器件的材料而受到关注。事实上,使用该碳化硅而构成的功率器件(碳化硅半导体装置)能够大幅度降低电力损耗、实现小型化等,还能够实现电源电力转换时的节能化,因此,成为用于电动车的高性能化、太阳能电池系统等的高功能化等实现低碳社会中的关键器件。
在制造碳化硅半导体装置的情况下,大多在碳化硅单晶衬底(SiC大块单晶衬底)上,预先通过热CVD法(热化学气相沉积法)等,使成为碳化硅半导体装置的激活区的碳化硅膜进行外延生长。在这里,激活区是包含晶体中的掺杂浓度以及膜厚受到了精密地控制的生长方向轴的截面区域。在碳化硅单晶衬底的基础上还需要如上所述的碳化硅膜的理由在于,根据器件的规格已经大致决定出掺杂浓度以及膜厚,通常情况下,要求其精度比大块单晶衬底的高。
下面,将在碳化硅单晶衬底上使碳化硅膜进行外延生长而得到的晶片称为外延片。对外延片实施各种加工而制造出碳化硅半导体装置。因此,可以从一张外延片制作出具有期望特性的器件的个数的比率即元件成品率较强地依赖于外延生长层的电气特性的均一性。在外延片面内,如果存在与其他区域相比绝缘破坏电场较小的局部区域,或者说在施加了一定的电压时会流动相对较大的电流的局部区域,则包含该区域的器件的特性例如耐电压特性发生劣化。由此,即使在相对较小的施加电压下,也会产生流动所谓漏电流的问题。换言之,可以限制元件成品率的首要要素是外延片的晶体学上的均一性。作为妨碍该均一性的主要原因,已知的是由于外延生长时的问题而出现的各种所谓的电流泄漏缺陷。
上述的晶体缺陷的共同特征是,晶体中的原子排列的周期性沿晶体生长方向在局部变得不完整。作为随着碳化硅的外延生长而产生的缺陷,根据其表面形状的特征,已知被称为锥形(carrot)缺陷、三角缺陷等的电流泄漏缺陷。其中,作为产生三角缺陷的主要原因,除了残留在衬底表面的研磨损伤、异种的多型(poly type)晶核等以外,还有一个原因是附着在衬底表面的SiC尘埃成为缺陷的起点。作为该SiC尘埃,具有下述状况等所产生的SiC尘埃,即:在碳化硅单晶衬底的制造时附着的SiC尘埃,即,在SiC大块单晶生长之后,在经过磨削、研磨工序等而加工出碳化硅单晶衬底的期间附着的SiC尘埃;以及当通过热CVD法在碳化硅单晶衬底上进行外延生长时,从在反应炉内部堆积的碳化硅膜中脱离的SiC尘埃。
此外,提出了对碳化硅单晶衬底进行氢蚀刻而使衬底表面平坦化的技术(例如,参照专利文献1)。但是,在准备了具有平均粗糙度小于或等于0.2nm的平坦性的碳化硅单晶衬底的情况下,不考虑进行如上所述的平坦化。
专利文献1:日本特开2001-77030号公报
使用形成有这些三角缺陷的碳化硅膜而制造出的碳化硅半导体装置的耐电压特性等器件特性和成品率有所降低。因此,存在产品的可靠性降低的问题。
发明内容
本发明就是为了解决上述的课题而提出的,其目的在于得到一种能够提高产品可靠性的碳化硅半导体装置的制造方法。
本发明所涉及的碳化硅半导体装置的制造方法的特征在于,具有:准备工序,在该工序中,准备具有平均粗糙度小于或等于0.2nm的平坦性的碳化硅单晶衬底;气蚀工序,在该工序中,将所述碳化硅单晶衬底的表面在还原性气体气氛中进行气蚀;以及外延生长工序,在该工序中,在气蚀之后,使碳化硅膜在所述碳化硅单晶衬底的表面上进行外延生长,将所述气蚀的蚀刻速率设为大于或等于0.5μm/h而小于或等于2.0μm/h。
发明的效果
在本发明中,在将具有平均粗糙度小于或等于0.2nm的平坦性的碳化硅单晶衬底的表面在还原性气体气氛中进行蚀刻速率大于或等于0.5μm/h而小于或等于2.0μm/h的气蚀之后,使碳化硅膜进行外延生长。由此,能够得到晶体缺陷较少的高品质的碳化硅膜,因此,能够提高产品的可靠性。
附图说明
图1是用于说明本发明的实施方式所涉及的碳化硅半导体装置的制造方法的图。
图2是用于说明本发明的实施方式所涉及的碳化硅半导体装置的制造方法的图。
图3是蚀刻速率和设定温度的阿伦尼乌斯曲线图。
图4是表示蚀刻速率与三角缺陷数密度的关系的图。
图5是表示以SiC尘埃作为起点的三角缺陷的例子的图。
图6是示意地表示以SiC尘埃作为起点的三角缺陷的俯视图。
图7是示意地表示以SiC尘埃作为起点的三角缺陷的剖面图。
标号的说明
1碳化硅单晶衬底,2反应炉,3a基座上部,3b基座下部,3c基座台,4石英管,5感应线圈,6碳化硅膜
具体实施方式
图1以及图2是用于说明本发明的实施方式所涉及的碳化硅半导体装置的制造方法的图。首先,准备具有平均粗糙度小于或等于0.2nm的平坦性的碳化硅单晶衬底1。具体地说,首先,通过机械研磨以及使用呈酸性或者碱性的药液的化学机械研磨,对4H-SiC大块单晶衬底进行平坦化处理,该4H-SiC大块单晶衬底相对于作为主面的(0001)面(C面)的、朝向<11-20>方向的倾斜角是4度。然后,使用丙酮实施超声波清洗而将有机物去除。然后,进行所谓的RCA清洗。即,在加热至75℃(±5℃)的氨水和双氧水的混合液(1:9)中浸泡10分钟,然后,浸入加热至75℃(±5℃)的盐酸和双氧水(1:9)中。然后,浸入至包含体积比率是5%左右的氢氟酸的水溶液中,随后,通过纯水实施置换处理,从而对衬底进行表面清洗。通过上述的工序,形成碳化硅单晶衬底1。在这里,平均粗糙度是使用原子力显微镜(AFM)测量碳化硅单晶衬底1的表面的5μm×5μm的四方区域并计算出算术平均粗糙度Ra而得到的值。
此外,碳化硅单晶衬底1的倾斜角不限定于4度,只要是2度~10度左右的范围内,通过化学机械研磨实施平坦化处理使得平均粗糙度小于或等于0.2nm即可,更优选通过微分干涉显微镜进行表面观察,确认没有擦伤。
图1是本实施方式中的CVD装置的反应炉2的结构图。反应炉2是横向的热壁型的反应炉,具有基座上部3a、基座下部3b、以及基座台3c,该基座上部3a、基座下部3b、以及基座台3c由涂有SiC的高纯度石墨构成。在该基座台3c上设置碳化硅单晶衬底1。然后,在反应炉2内,作为还原性气体例如导入氢气。该氢气兼作为载气。然后,控制压力,使得反应炉2的真空度保持恒定,例如5kPa左右。然后,通过向卷绕在石英管4的周围的感应线圈5导入交流电流,通过感应过热而将基座上部3a、基座下部3b、以及基座台3c加热至1650℃左右为止,在还原性气体气氛中实施退火工序。由此,将碳化硅单晶衬底1的表面在还原性气体气氛中进行气蚀。此时,还原性气体气氛仅是氢气。例如,衬底表面的蚀刻速率是1.0μm/h,退火时间是15分钟。
然后,如图2所示,通过向反应炉2内供给原料气体,从而使在碳化硅单晶衬底1的表面上外延生长出膜厚10μm的碳化硅膜6。例如,作为Si原子的供给源而供给500sccm流量的硅烷气体(SiH4),作为C原子的供给源而供给200sccm流量的丙烷气体(C3H8)。作为N型掺杂而使用氮气。另外,作为N型掺杂,以下述方式供给氮气,即,使得在衬底界面处的载流子浓度是1×1017/cm3,在激活区的载流子浓度是8×1015/cm3。
然后,停止原料气体的供给,降温至室温。如果使用共焦光学系统扫描型显微镜的表面检查装置(例如,“レーザーテック社”生产的SICA6X)测量该外延片的三角缺陷的数量,则缺陷密度是0.06/cm2,是极低的密度。能够通过在该衬底上制作器件,从而得到高成品率且高品质的碳化硅半导体装置。
在这里,本发明的发明人发现了下述情况,即,在碳化硅膜6的成膜之前实施的在还原性气体气氛中的退火工序对于降低三角缺陷是重要的。并且,还发现了下述情况,即,能够通过适当地控制退火工序中的衬底表面的蚀刻速率,从而制作出缺陷密度极低的外延片。衬底表面的蚀刻速率主要由衬底表面温度和反应炉内的压力进行控制,按照下面的还原反应方程式执行蚀刻。
2SiC+H2→2Si+C2H2 (方程式1)
如果将衬底表面温度即反应炉2内的基座上部3a、基座下部3b、以及基座台3c的设定温度设定得较高,则按照阿伦尼乌斯公式,蚀刻速率呈指数函数的方式增长。图3是蚀刻速率和设定温度的阿伦尼乌斯曲线图。能够通过确定反应炉2的设定温度,从而适当地使蚀刻速率发生变化。另外,蚀刻速率还随着反应炉的压力而变化,如果压力下降,升华压力也降低,因此,蚀刻受到促进。如图3所示,通过使反应炉2内的压力变化,也能够与设定温度相同地使蚀刻速率变化。
如上所述,通过认真反复进行外延生长试验,其结果,发现蚀刻速率与三角缺陷数密度存在特殊的关系,其中,在该外延生长试验中使在还原性气体气氛中进行的退火工序中的SiC衬底表面的蚀刻速率变化。图4是表示蚀刻速率与三角缺陷数密度的关系的图。图5是表示以SiC尘埃为起点的三角缺陷的例子的图。在蚀刻速率低于0.5μm/h的情况下,观察到大量如图5所示的以SiC尘埃为起点的三角缺陷。另一方面,可知下述情况,即,通过将蚀刻速率设为大于或等于0.5μm/h,从而使得三角缺陷密度为小于或等于0.1/cm2的极低密度。
图6和图7是示意地表示以SiC尘埃为起点的三角缺陷的俯视图和剖面图。三角缺陷以附着于衬底的SiC尘埃、或者在外延生长之前落在衬底表面的SiC尘埃为起点,随着步骤流程的推进而进行生长。即,将SiC尘埃作为三角形的顶点,一边在保持相似形状的状态下将面积扩大,一边进行生长,因此,越是在生长初期产生出的三角缺陷,尺寸越大,另外,外延生长的厚度越厚,尺寸越大。为了防止如上所述的三角缺陷的产生,必须在外延生长之前将SiC尘埃去除。在这里,考虑到下述情况,即,在蚀刻速率较低的情况下,未能将附着在衬底表面的SiC尘埃在退火工序中通过蚀刻去除,就形成了碳化硅膜6,通过将蚀刻速率设为大于或等于0.5μm/h,从而能够在碳化硅膜6成膜之前将SiC尘埃有效地去除。
另一方面,可知下述情况,即,在将蚀刻速率设为2.2μm/h的情况下,三角缺陷密度激增至0.6/cm2。推测其原因在于,如果蚀刻速率过高,则促进堆积在基座上部3a、基座下部3b、以及基座台3c的碳化硅膜的脱离,特别是,会增大从基座上部3a落到衬底上的SiC尘埃的量。并且,根据方程式1,推测出下述情况,即,由于Si过量脱离引起在衬底表面形成Si滴,导致形成异常生长核,使三角缺陷的起点增大。另外,还通过试验明确出下述情况,即,在蚀刻速率高达2.2μm/h的情况下,即使将蚀刻时间设为一半左右,以形成与得到低缺陷密度的蚀刻速率是1.0μm/h的条件相同的蚀刻量,也同样是以大于或等于0.5/cm2的高密度产生三角缺陷。该情况显示出,单纯地控制衬底表面的蚀刻量无法将三角缺陷密度抑制在低密度。由此,需要将气蚀的蚀刻速率设为大于或等于0.5μm/h而小于或等于2.0μm/h。
在本实施方式中,在将具有平均粗糙度小于或等于0.2nm的平坦性的碳化硅单晶衬底1的表面在还原性气体气氛中进行蚀刻速率大于或等于0.5μm/h而小于或等于2.0μm/h的气蚀之后,使碳化硅膜6进行外延生长。由此,能够得到晶体缺陷较少的高品质的碳化硅膜6。由此,由于使耐电压特性等器件特性和成品率提高,因此,能够提高产品的可靠性。
此外,在碳化硅膜6成膜时,也可以根据需要,供给包含Al、B、Be的有机金属材料用于P型掺杂。另外,为了实现生长的高速化,也可以同时使用包含氯的气体。另外,能够通过适当改变原料气体流量,从而使碳化硅膜6的生长速度发生变化,无论生长速度是1μm/h,还是10μm/h,都具有相同的效果。
另外,在本实施方式中,将气蚀中的退火时间设为15分钟,但是,如果退火时间超过1小时,则易于产生以螺旋坑为起点的台阶聚并。所谓螺旋坑指的是,在存在于碳化硅单晶衬底1的螺旋位错部分中,由于蚀刻而形成研钵状的凹部。在退火过程中,在碳化硅单晶衬底1的表面进行的原子的表面重构的过程中,以螺旋坑为起点而产生台阶聚并。由于该台阶聚并在碳化硅膜6的成膜时会对其形态造成拖拽,因此,有时会使成膜后的衬底表面的平坦性发生恶化。因此,优选气蚀的时间是1小时以内,如果还考虑到生产性,则更优选是30分钟以内。但是,最适当的蚀刻速率、退火时间依赖于反应炉2内的成膜状况。因此,可以想到该条件不是由单一要素决定的,还要依赖于CVD装置的炉内结构、构造等。在各自的情况下决定出适当的条件。
Claims (3)
1.一种碳化硅半导体装置的制造方法,其特征在于,具有:
准备工序,在该工序中,准备具有平均粗糙度小于或等于0.2nm的平坦性的碳化硅单晶衬底;
气蚀工序,在该工序中,将所述碳化硅单晶衬底的表面在还原性气体气氛中进行气蚀;以及
外延生长工序,在该工序中,在气蚀之后,使碳化硅膜在所述碳化硅单晶衬底的表面上进行外延生长,
将所述气蚀的蚀刻速率设为大于或等于0.5μm/h而小于或等于2.0μm/h。
2.根据权利要求1所述的碳化硅半导体装置的制造方法,其特征在于,
所述还原性气体是氢气。
3.根据权利要求1或2所述的碳化硅半导体装置的制造方法,其特征在于,
所述气蚀的时间是1小时以内。
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014059990A JP6311384B2 (ja) | 2014-03-24 | 2014-03-24 | 炭化珪素半導体装置の製造方法 |
JP2014-059990 | 2014-03-24 |
Publications (2)
Publication Number | Publication Date |
---|---|
CN104952708A true CN104952708A (zh) | 2015-09-30 |
CN104952708B CN104952708B (zh) | 2018-09-18 |
Family
ID=54053821
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CN201510131777.6A Active CN104952708B (zh) | 2014-03-24 | 2015-03-24 | 外延晶圆、半导体装置以及碳化硅半导体装置的制造方法 |
Country Status (5)
Country | Link |
---|---|
US (1) | US9957638B2 (zh) |
JP (1) | JP6311384B2 (zh) |
KR (1) | KR101727544B1 (zh) |
CN (1) | CN104952708B (zh) |
DE (1) | DE102015202131B4 (zh) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105632901A (zh) * | 2016-02-02 | 2016-06-01 | 北京华进创威电子有限公司 | 一种采用干式刻蚀方法获得碳化硅衬底的方法 |
CN110797746A (zh) * | 2018-08-03 | 2020-02-14 | 株式会社日立电力解决方案 | 单晶碳化硅基板、其制造方法以及半导体激光器 |
CN111771259A (zh) * | 2018-02-28 | 2020-10-13 | Abb电网瑞士股份公司 | 通过Al/Be共注入p型掺杂碳化硅的方法 |
CN111799321A (zh) * | 2019-04-05 | 2020-10-20 | 三菱电机株式会社 | 碳化硅外延晶片、碳化硅外延晶片的制造方法、电力变换装置 |
Families Citing this family (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6524233B2 (ja) * | 2015-07-29 | 2019-06-05 | 昭和電工株式会社 | エピタキシャル炭化珪素単結晶ウェハの製造方法 |
JP6635579B2 (ja) * | 2015-08-28 | 2020-01-29 | 昭和電工株式会社 | SiCエピタキシャルウェハ |
JP2017055086A (ja) * | 2015-09-11 | 2017-03-16 | 昭和電工株式会社 | SiCエピタキシャルウェハの製造方法及びSiCエピタキシャルウェハの製造装置 |
US20170275779A1 (en) * | 2015-10-07 | 2017-09-28 | Sumitomo Electric Industries, Ltd. | Silicon carbide epitaxial substrate and method for manufacturing silicon carbide semiconductor device |
JP6862781B2 (ja) * | 2016-11-16 | 2021-04-21 | 富士電機株式会社 | 炭化珪素半導体素子および炭化珪素半導体素子の製造方法 |
JP6748572B2 (ja) * | 2016-12-28 | 2020-09-02 | 昭和電工株式会社 | p型SiCエピタキシャルウェハ及びその製造方法 |
JP6762484B2 (ja) * | 2017-01-10 | 2020-09-30 | 昭和電工株式会社 | SiCエピタキシャルウェハ及びその製造方法 |
WO2018142744A1 (ja) * | 2017-01-31 | 2018-08-09 | 住友電気工業株式会社 | 炭化珪素エピタキシャル基板および炭化珪素半導体装置の製造方法 |
US10964785B2 (en) * | 2017-05-17 | 2021-03-30 | Mitsubishi Electric Corporation | SiC epitaxial wafer and manufacturing method of the same |
JP2022020995A (ja) * | 2020-07-21 | 2022-02-02 | 三菱電機株式会社 | 炭化珪素エピタキシャルウエハの製造方法 |
WO2024018924A1 (ja) * | 2022-07-20 | 2024-01-25 | 住友電気工業株式会社 | 炭化珪素エピタキシャル基板および炭化珪素半導体装置の製造方法 |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006032655A (ja) * | 2004-07-16 | 2006-02-02 | Kyoto Univ | 炭化珪素基板の製造方法 |
CN1892984A (zh) * | 2005-05-25 | 2007-01-10 | 硅电子股份公司 | 半导体层结构及制造半导体层结构的方法 |
JP2008004888A (ja) * | 2006-06-26 | 2008-01-10 | Hitachi Metals Ltd | 炭化珪素半導体エピタキシャル基板の製造方法。 |
CN102576666A (zh) * | 2009-08-28 | 2012-07-11 | 昭和电工株式会社 | SiC外延晶片及其制造方法 |
CN103649385A (zh) * | 2011-07-19 | 2014-03-19 | 昭和电工株式会社 | SiC外延晶片及其制造方法、以及SiC外延晶片的制造装置 |
Family Cites Families (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5230A (en) | 1975-06-20 | 1977-01-05 | Noda Plywood Mfg Co Ltd | Set of joint plate and its assembly method |
JP2001077030A (ja) * | 1999-08-31 | 2001-03-23 | Sanyo Electric Co Ltd | 炭化珪素半導体装置の製造方法 |
JP2001332508A (ja) * | 2000-05-23 | 2001-11-30 | Matsushita Electric Ind Co Ltd | 半導体素子の製造方法 |
JP2004075493A (ja) * | 2002-08-22 | 2004-03-11 | Tokai Carbon Co Ltd | CVD−SiC被覆黒鉛材及びその製造方法 |
JP4437394B2 (ja) * | 2003-10-01 | 2010-03-24 | 芝浦メカトロニクス株式会社 | 真空処理装置 |
JP5285202B2 (ja) * | 2004-03-26 | 2013-09-11 | 一般財団法人電力中央研究所 | バイポーラ型半導体装置およびその製造方法 |
US20070290211A1 (en) | 2004-03-26 | 2007-12-20 | The Kansai Electric Power Co., Inc. | Bipolar Semiconductor Device and Process for Producing the Same |
JP2010111540A (ja) * | 2008-11-06 | 2010-05-20 | Showa Denko Kk | 炭化珪素単結晶の結晶成長方法、種結晶及び炭化珪素単結晶 |
JP4887418B2 (ja) | 2009-12-14 | 2012-02-29 | 昭和電工株式会社 | SiCエピタキシャルウェハの製造方法 |
DE112011101625B4 (de) | 2010-05-10 | 2016-03-10 | Mitsubishi Electric Corporation | Epitaktische Siliciumcarbid-Wafer und Herstellungsverfahren für diese, Siliciumcarbid-Massensubstrat für epitaktisches Wachstum und Herstellungsverfahren für dieses |
JP5786759B2 (ja) | 2012-02-21 | 2015-09-30 | 新日鐵住金株式会社 | エピタキシャル炭化珪素ウエハの製造方法 |
KR101926694B1 (ko) * | 2012-05-30 | 2018-12-07 | 엘지이노텍 주식회사 | 탄화규소 에피 웨이퍼 및 이의 제조 방법 |
-
2014
- 2014-03-24 JP JP2014059990A patent/JP6311384B2/ja active Active
- 2014-12-29 US US14/584,076 patent/US9957638B2/en active Active
-
2015
- 2015-02-06 DE DE102015202131.9A patent/DE102015202131B4/de active Active
- 2015-03-13 KR KR1020150034734A patent/KR101727544B1/ko active IP Right Grant
- 2015-03-24 CN CN201510131777.6A patent/CN104952708B/zh active Active
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2006032655A (ja) * | 2004-07-16 | 2006-02-02 | Kyoto Univ | 炭化珪素基板の製造方法 |
CN1892984A (zh) * | 2005-05-25 | 2007-01-10 | 硅电子股份公司 | 半导体层结构及制造半导体层结构的方法 |
JP2008004888A (ja) * | 2006-06-26 | 2008-01-10 | Hitachi Metals Ltd | 炭化珪素半導体エピタキシャル基板の製造方法。 |
CN102576666A (zh) * | 2009-08-28 | 2012-07-11 | 昭和电工株式会社 | SiC外延晶片及其制造方法 |
CN103649385A (zh) * | 2011-07-19 | 2014-03-19 | 昭和电工株式会社 | SiC外延晶片及其制造方法、以及SiC外延晶片的制造装置 |
Non-Patent Citations (1)
Title |
---|
YOICHIRO MITANI ET AL.: "《Demonstration of high quality 4H-SiC epitaxy by using the two-step growth method》", 《SILICON CARBIDE AND RELATED MATERIALS 2013》 * |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN105632901A (zh) * | 2016-02-02 | 2016-06-01 | 北京华进创威电子有限公司 | 一种采用干式刻蚀方法获得碳化硅衬底的方法 |
CN111771259A (zh) * | 2018-02-28 | 2020-10-13 | Abb电网瑞士股份公司 | 通过Al/Be共注入p型掺杂碳化硅的方法 |
CN111771259B (zh) * | 2018-02-28 | 2021-07-02 | Abb电网瑞士股份公司 | 通过Al/Be共注入p型掺杂碳化硅的方法 |
US11211248B2 (en) | 2018-02-28 | 2021-12-28 | Abb Power Grids Switzerland Ag | SiC electronic device fabricated by Al/Be co-implantation |
CN110797746A (zh) * | 2018-08-03 | 2020-02-14 | 株式会社日立电力解决方案 | 单晶碳化硅基板、其制造方法以及半导体激光器 |
CN111799321A (zh) * | 2019-04-05 | 2020-10-20 | 三菱电机株式会社 | 碳化硅外延晶片、碳化硅外延晶片的制造方法、电力变换装置 |
Also Published As
Publication number | Publication date |
---|---|
CN104952708B (zh) | 2018-09-18 |
KR20150110339A (ko) | 2015-10-02 |
US9957638B2 (en) | 2018-05-01 |
US20150267320A1 (en) | 2015-09-24 |
DE102015202131A1 (de) | 2015-09-24 |
KR101727544B1 (ko) | 2017-04-17 |
DE102015202131B4 (de) | 2018-12-20 |
JP6311384B2 (ja) | 2018-04-18 |
JP2015185653A (ja) | 2015-10-22 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
CN104952708A (zh) | 碳化硅半导体装置的制造方法 | |
JP5152435B2 (ja) | エピタキシャル炭化珪素単結晶基板の製造方法 | |
TWI424476B (zh) | 磊晶塗覆的矽晶圓及製造磊晶塗覆的矽晶圓的方法 | |
KR20130014566A (ko) | 탄화규소 에피택셜 웨이퍼 및 그 제조 방법, 에피택셜 성장용 탄화규소 벌크 기판 및 그 제조 방법 및 열처리 장치 | |
US9752254B2 (en) | Method for manufacturing a single-crystal 4H—SiC substrate | |
KR20180016585A (ko) | 에피택셜 탄화규소 단결정 웨이퍼의 제조 방법 | |
WO2014125550A1 (ja) | SiCエピタキシャルウエハの製造方法 | |
KR101947926B1 (ko) | 에피택셜 탄화규소 웨이퍼의 제조 방법 | |
JP2007182330A (ja) | 炭化ケイ素単結晶ウェハ及びその製造方法 | |
TWI725910B (zh) | 晶圓、磊晶晶圓以及其製造方法 | |
WO2016140051A1 (ja) | SiCエピタキシャルウェハ、SiCエピタキシャルウェハの製造方法 | |
JP5786759B2 (ja) | エピタキシャル炭化珪素ウエハの製造方法 | |
JP2015044727A (ja) | SiCエピタキシャルウエハの製造方法 | |
JP2008222509A (ja) | SiCエピタキシャル膜付き単結晶基板の製造方法 | |
JP5996406B2 (ja) | 炭化珪素エピタキシャルウェハの製造方法 | |
JP2018067736A (ja) | 炭化珪素半導体装置及びその製造方法 | |
JP2008028277A (ja) | 半導体基板の製造方法 | |
JP2018022853A (ja) | 炭化珪素半導体基板および炭化珪素半導体基板の製造方法 | |
JP2014027028A (ja) | SiCエピタキシャル基板製造装置、SiCエピタキシャル基板の製造方法、SiCエピタキシャル基板 | |
JP6399171B2 (ja) | シリコン部材及びシリコン部材の製造方法 | |
JP2009239103A (ja) | 平坦化処理方法 | |
JP6927429B2 (ja) | SiCエピタキシャル基板の製造方法 | |
US9269572B2 (en) | Method for manufacturing silicon carbide semiconductor substrate | |
JP2017122047A (ja) | 単結晶4H−SiC基板及びその製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
C06 | Publication | ||
PB01 | Publication | ||
C10 | Entry into substantive examination | ||
SE01 | Entry into force of request for substantive examination | ||
GR01 | Patent grant | ||
GR01 | Patent grant |