수직경사응고(VGF)법에 의한 Si 도핑 GaAs 단결정 성장시 $B_{2}O_{3}$ 첨가에 따른 캐리어 농도 변화

Control of carrier concentrations by addition of $B_{2}O_{3}$ in Si-doped vertical gradient freeze (VGF) GaAs single crystal growth

  • 발행 : 2009.04.30

초록

PBN 도가니를 이용하여 Si이 도핑된 GaAs 단결정을 수직경사 응고법으로 성장시켰다. PBN 도가니에 산화막인 $B_{2}O_{3}$의 양을 $0{\sim}0.2wt%$ 범위에서 변화시키면서, 성장 후 캐리어 농도를 측정하였다. $B_{2}O_{3}$ 첨가량이 증가함에 따라, 초기 0.1 정도의 Si 도판트의 편석계수는 0.01 부근까지 급격히 감소하고, 동시에 캐리어 농도도 감소하는 것을 알 수 있었다. 이는 성장도중 도판트인 Si이 $B_{2}O_{3}$과 반응하며 도너인 Si 양을 감소시키며, 동시에 억셉터인 B 양을 증가시키기 때문으로 보인다. 한편 PBN 도가니 내면에 얇은 유리질의 $B_{2}O_{3}$층 형성이 용이한 고온 산화막 처리가 결함감소에 효과적임을 확인하였다.

Si-doped GaAs single crystals were grown by vertical gradient freeze using PBN crucibles. The amount of oxide layer $B_{2}O_{3}$ in PBN crucible was changed($0{\sim}0.2wt%$) and measured the concentration of carriers. The segregation coefficients of Si in GaAs melt decreased rapidly from initial 0.1 to 0.01 as the amount of $B_{2}O_{3}$ increases. At the same time, concentration of carriers was shown to decrease. It is likely that the reaction between dopant Si and $B_{2}O_{3}$ in GaAs melt results in the reduction of Si dopants(donor) while increase in the amount of boron(acceptor). The thin layer of $B_{2}O_{3}$ glass in PBN crucible was proved to be a better way to reduce defect formation rather than the total amount of $B_{2}O_{3}$.

키워드

참고문헌

  1. W.A. Gault, E.M. Monberg and J.E. Clemans, "A novel application of the vertical gradient freeze method to the growth of high quality III-V crystals", J. Crystal Growth 74 (1986) 491 https://doi.org/10.1016/0022-0248(86)90194-6
  2. A.N. Gulluoglu and C.T. Tsai, "Dislocation generation in GaAs crystals grown by the vertical gradient freeze method", J. Materials Processing Technology 102 (2000) 179 https://doi.org/10.1016/S0924-0136(00)00468-4
  3. Amon, J. Hartwig, W. Ludwig and G. Muller, "Analysis of types of residual dislocations in the VGF growth of GaAs with extremely low dislocation density $(EPD << 1000cm^{-2})$", J. Crystal Growth 198/199 (1999) 367 https://doi.org/10.1016/S0022-0248(98)01219-6
  4. E. Buhrig, C. Frank, C. Hannig and B. Hoffmann, "Growth and properties of semi-insulating VGF-GaAs", Materials Science and Engineering B 44 (1997) 248 https://doi.org/10.1016/S0921-5107(97)80007-4
  5. J. Amon, P. Berwian and G. Muller, "Computer-assisted growth of low-EPD GaAs with 3'' diameter by the vertical gradient-freeze technique", J. Crystal Growth 198/199 (1999) 361 https://doi.org/10.1016/S0022-0248(98)01220-2
  6. L. Fischer, U. Lambert, G. Nagel, H. Rufer and E. Tomzig, "Influence of pyrolytic boron nitride crucibles on GaAs crystal growth process and crystal properties", J. Crystal Growth 153 (1995) 90 https://doi.org/10.1016/0022-0248(95)00209-X
  7. S.-H. Hahn, H.-T. Chung, Y.-K. Kim and J.-K. Yoon, "The effect of the system factors on the shape of the S/L interface in GaAs single crystal grown by VGF method", J. Korean Association of Crystal Growth 4[1] (1994) 33
  8. A. Flat, "Silicon incorporation anomaly in LEC grown GaAs", J. Crystal Growth 109 (1991) 224 https://doi.org/10.1016/0022-0248(91)90182-5
  9. I.C. Bassignana, D.A. Macquistan, G.C. Hillier, R. Streater, D. Beckett, A. Majeed and C. Miner, "Variation in the lattice parameter and crystal quality of commercially available Si-doped GaAs substrates", J. Crystal Growth 178 (1997) 445 https://doi.org/10.1016/S0022-0248(97)00009-2
  10. C. Hannig, G. Schwichtenberg, E. Buhrig and G. Gartner, "Study of silicon-doped VGF-GaAs by DSL-etching and LVM spectroscopy and the influence of B2O3 coating", Materials Science and Engineering B66 (1999) 97 https://doi.org/10.1016/S0921-5107(99)00092-6
  11. K. Hashio, S. Sawada, M. Tatsumi, K. Fujita and S. Akai, "Low dislocation density Si-doped GaAs single crystal grown by the vapor-pressure-controlled Czochralski method", J. Crystal Growth 173 (1997) 33 https://doi.org/10.1016/S0022-0248(96)00785-3
  12. P.D. Greene “Growth of GaAs ingots with high free electron concentrations”, J. Crystal Growth 50 (1980) 612 https://doi.org/10.1016/0022-0248(80)90004-4