Si-Ge系エピタキシャル成長による超高濃度不純物半導体の形成とその物性

• Project/Area Number: 11875001
• Research Category: Grant-in-Aid for Exploratory Research
• Allocation Type: Single-year Grants
• Research Field: Applied materials science/Crystal engineering
• Research Institution: Tohoku University
• Principal Investigator: 室田 淳一 東北大学, 電気通信研究所, 教授 (70182144)
• Co-Investigator(Kenkyū-buntansha): 櫻庭 政夫 東北大学, 電気通信研究所, 助手 (30271993) ; 松浦 孝 東北大学, 電気通信研究所, 助教授 (60181690)
• Project Period (FY): 1999 – 2000
• Project Status: Completed (Fiscal Year 2000)
• Budget Amount: ¥2,100,000 (Direct Cost: ¥2,100,000); Fiscal Year 2000: ¥900,000 (Direct Cost: ¥900,000); Fiscal Year 1999: ¥1,200,000 (Direct Cost: ¥1,200,000)
• Keywords: ドーピング / エピタキシャル / シリコン / ゲルマニウム / リン / ボロン / ラングミュア型 / 原子層 / ヘテロデバイス

Research Abstract

高性能超微細ヘテロデバイスを実現するために、高品質Si-Ge系ヘテロエピタキシャル薄膜の膜厚や不純物ドーピング濃度の精密な制御、不純物の拡散抑制と同時に、電極との超低抵抗コンタクトのために超高濃度ドーピングが不可欠である。平成11年度までに高清浄CVDを用いたSi-Ge系薄膜へのP及びBのin-situドーピング特性を明らかにした。本年度はSiH_4-GeH_4-PH_3,-B_2H_6系にCH_3SiH_3を添加して、Si-Ge-C系低温エピタキシャル膜のP及びBのin-situドーピング特性を調べた。その結果、P及びBのSi-Ge-C系薄膜へのドーピング特性は、Si-Ge系と同様に広い濃度範囲にわたってラングミュア型の吸着・反応を仮定することにより説明できることを明らかにした。また、C比率が1%以上のSi-Ge-C系薄膜では、P及びBが電気的に不活性になる傾向がある事を明らかにした。
一方、PH_3によりSi表面上にPを原子層形成し、その上にSiH_4によりSiを形成した原子層ドーピング構造を多重積層した超高濃度PドープSi単結晶の形成についても研究した。450℃において平均P濃度が6x10^<20>cm^<-3>のPとSiの多重積層膜を形成し、ドープしたPの60%が電気的に活性となり、3x10^<-4>Ωcmという低抵抗率になることを確認した。また、この薄膜を550-750℃で熱処理することにより、キャリア密度が減少し、抵抗率が増加することを確認した。これから低抵抗Si単結晶が450℃という低温でのみ形成できることを明らかにした。
以上のように、Si-Ge-C系薄膜中へのP及びBのIn-situドーピング特性を明らかにする一方で、原子層ドーピングを応用した超低抵抗Si単結晶の実現の見通しを得た。

Research Products

• [Publications] Y.Shimamune et al: "Atomic-Layer Adsorption of P on Si(100) and Ge(100) by PH_3 Using an Ultraclean Low-Pressure Chemical Vapor Deposition"Appl.Surf.Sci.. Vol.162-163. 390-394 (2000)
• [Publications] A.Ichikawa et al: "Epitaxial Growth of Si_<1-x-y>Ge_xC_y Film on Si(100) in a SiH_4-GeH_4-CH_3SiH_3 Reaction"Thin Solid Films. Vol.369,No.1-2. 167-170 (2000)
• [Publications] S.Kobayashi et al: "Segregation and Diffusion of Impurities from Doped Si_<1-x>Ge_x Films into Silicon"Thin Solid Films. Vol.369,No.1-2. 222-225 (2000)
• [Publications] T.Noda et al: "Doping and Electrical Characteristics of in-situ Heavily B-Doped Si_<1-x-y>Ge_xC_y Films Epitaxially Grown Using Ultraclean LPCVD"Thin Solid Films. Vol.380. 57-60 (2000)
• [Publications] Y.Shimamune et al: "Atomic-Layer Doping in Si by Alternately Supplied PH_3 and SiH_4"Thin Solid Films. Vol.380. 134-136 (2000)
• [Publications] 室田淳一 他: "CVD Si_<1-x>Ge_xエピタキシャル成長とドーピング制御"日本結晶成長学会誌. Vol.27,No.4. 171-178 (2000)
• [Publications] D.Lee et al: "In-Situ Impurity Doping in Si_<1-x-y>Ge_<1x>C_<1y> Epitaxial Growth Using Ultraclean LPCVD"Abs.of 2000 International Conf.on Solid State Devices and Materials. 206-207 (2000)
• [Publications] Y.Shimamune et al: "Heavily P-doped Si Films Epitaxially Grown at 450℃ by Alternately Supplied PH_3 and SiH_4"Abs.of 2000 International Symposium on Formation, Physics and Device Application of Quantum Dot Structures. 76 (2000)
• [Publications] J.Murota et al: "Atomically Controlled Processing for Fabrication of Si-based Ultimate-Small Devices"Abs.of Workshop on Selective and Functional Film Deposition Technologies as Applied to ULSI Technology (29th IUVSTA Workshop). 131-134 (2000)
• [Publications] Y.Shimamune et al: "Very Low-Resistive Si Epitaxial Growth at 450℃ by Alternately Supplied PH_3 and SiH_4"Abs.of Workshop on Selective and Functional Film Deposition Technologies as Applied to ULSI Technology (29th IUVSTA Workshop). 266-269 (2000)
• [Publications] Y.Shimamune et al: "Heavy Doping Characteristics in Si Epitaxial Growth at 450℃ by Alternate Supplies of PH_3 and SiH_4"Abs.of First Int.Workshop on New Group IV (Si-Ge-C) Semiconductors. 11-12 (2001)
• [Publications] Y.Shimamune et al: "Epitaxial growth of heavily P-doped Si films at 450℃ by alternately supplied PH_3 and SiH_4"Abs.of the 13th European Conference on Chemical Vapor Deposition. (accepted). (2001)
• [Publications] J.Murota: "Atomically Controlled Processing for Group IV Semiconductors"Abs.of the 9th European Conference on Applications of Surface and Interface Analysis. (invited). (2001)
• [Publications] S.Kobayashi, et al.: "Segregation and Diffusion of Phosphorus from Doped Si_<1-x>Ge_x Films into Silicon"J. Appl. Phys. 86,10. 5480-5483 (1999)
• [Publications] Y.Shimamune, et al.: "Atomic-Layer adsorption of P on Si(100) and Ge(100) by PH_3 Using an Ultraclean Low-Pressure Chemical Vapor Deposition"Appl. Surf. Sci.. (in press). (2000)
• [Publications] A.Ichikawa, et al.: "Epitaxial Growth of Si_<1-x-y>Ge_xC_y Film on Si(100) in a SiH_4-GeH_4-CH_3-SiH_3 Reaction"Thin Solid Films. (accepted).
• [Publications] S.Kobayashi, et al.: "Diffusion and segregation of Impurities from Doped Si_<1-x>Ge_x Films into Silicon"Thin Solid Films. (accepted).
• [Publications] J.Murota, et al.: "Higy Quality Si_<1-x>Ge_x Epitaxial Growth by CVD"Proc. of the Third International Symposium on Defects in Silicon. PV99-1. 189-202 (1999)
• [Publications] J.Murota, et al.: "Atomic Order Adsorption and Reaction of CVD Hydride Gases on the Si and Ge Surfaces"Abs. of the 5th International Conference on Atomically Controlled Surfaces, Interfaces and Nanostructures. P19 (1999)
• [Publications] T.Takatsuka, et al.: "Atomic-Order Surface Reaction of CH_3SiH_3 on Ge(100) and Si(100)"Abs. of the 5th International Conference on Atomically Controlled Surfaces, Interfaces and Nanostructures. P20 (1999)
• [Publications] Y.Shimamune, et al.: "Atomic-Layer Adsorption of P on Si(100) and Ge(100) by PH_3 Using an Ultraclean Low-Pressure Chemical Vapor Deposition"Abs. of the 5th International Conference on Atomically Controlled Surfaces, Interfaces and Nanosructures. P37 (1999)
• [Publications] J.Murota, et al.: "CDV Si_<1-x>Ge_x Epitaxial Growth and Its Application to MOS Devices"Proc. of the SPIE Conference on Microelectoronic Device Technology III. 3881. 33-45 (1999)
• [Publications] T.Kanetsuna, et al.: "Surface Adsorption and Reaction of Chlorine on Impurity Doped Si Using an ECR Plasma"Abs. of 197th Meeting of the Electrochemical Society. (accepted). (2000)
• [Publications] Y.Shimamune, et al.: "Atomic-Layer Doping in Si by alternately Supplied PH_3 and SiH_4"Abs. of 2000 Spring Meeting, The European Materials Research Society. (accepted). (2000)
• [Publications] T.Noda, et al.: "Doping and Electrical Characteristics of In Situ Heavily B-Doped Si_<1-x-y>Ge_xC_y Films Epitaxially Grown Using Ultraclean LPCVD"Abs. of 2000 Spring Meeting, The European Materials Research Society. (accepted). (2000)