| Project/Area Number |
03452157
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
電子材料工学
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| Research Institution | Kaisai University |
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Principal Investigator |
YOKOTA Katsuhiro Kansai University, Faculty of Engineering, Professor, 工学部, 教授 (50067617)
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| Co-Investigator(Kenkyū-buntansha) |
TAMURA Susumu Kansai Uni., Faculty of Eng., Asso.Prof., 工学部, 助教授 (10067754)
横田 勝弘 関西大学, 工学部, 教授 (50067617)
片山 佐一 関西大学, 工学部, 教授 (90067398)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥5,400,000 (Direct Cost: ¥5,400,000)
Fiscal Year 1993: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1992: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1991: ¥4,000,000 (Direct Cost: ¥4,000,000)
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| Keywords | Ion Implantation / Diffusion / Electrical Activity / Silicon / Impurity / 半導体 / RBS / XPS / 拡散 / 電気特性 / ひ素 / ボロン / ラザフォ-ド後方散乱 / 二次イオン質量分析 / 注入不純物の電気的活性化制御 / 転位 |
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| Research Abstract |
Czochralski-silicon, 20 ohm-cm boron-doped (100) wafers were implanted with various combinations of As and B ions. The 45 keV As^+ ions were first implanted in the Si wafers followed by the 9 keV B^+ ions. Their ion energies were of sufficient strength so that their respective projected ranges coincided at a position about 30 nm below the surface. the samples were annealed under neutral ambient (Ar) condition at a temperature of 950ﾟC for 30 and 300 minutes.
As^+ and B^+ ions were implanted in Si at energies such that their respective projected ranges coincide. B atoms concentrated only in the rigion near the surface of the samples to form complex by reacting with As atoms. As a result, the solid solubility limit of the B atoms was improved, the diffusivity was reduced, and the B atom concentration profile followed to a simple analytical solution of the diffusion equation under the condition that the diffusion coefficient is independent of the concentration. The diffusion coefficient of
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the B atoms was decreased with an iuncrease in annealing time according to an equation of D=D_B^iexp(-1.6x10^<-3>t).
In the p-type region in the Si with a high concentration of the B atoms, the concentration profile of the As atoms was similar to that of the B atoms : the diffusivity of the As atoms was reduced by chemically reacting with the B atoms and by forming the As cluster. However, since the As clusters and the p-type complexes such as BAs_2^- decomposed with an increase in annealing time, the As atom concentration in the region decreased, and the As atoms diffused into the deeper side of the Si. The carrier concentration of the p-type region in the annealed sample, thus, decreased with an increase in annealing, and that in the n-type in all samples increased.
RBS results showed that improvement in the substitutional number of As atoms occurred during the high temperature annealing. The binding energy of the B 1s_<1/2> XPS signal on the annealed dual As and B implanted Si became larger than that on the annealed B implanted Si by 1.5 eV.The binding energy of the As 3d_<5/2> XPS signal on the annealed dual As and B implanted Si was lower than that on As doped Si by 0.8 eV.On the annealed dual As and B implanted Si, the chemical shift for the B 1s_<1/2> XPS signal is opposite in sign to that for the As 3d_<5/2> XPS signal. The absolute value of the chemical shift of the B 1s_<1/2> XPS signal then was about two times larger than that of the As 3d_<5/2> XPS signal. That is, we can propose a model whereby one B atom combines with two As atoms : such a complex is As_2B where the B atom occupies the Si vacancy of AS_2V_<Si>. Less
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