Journal of the Korean Crystal Growth and Crystal Technology (한국결정성장학회지)

The Korea Association of Crystal Growth (한국결정성장학회)
권호 표지

Utilization of the surface damage as gettering sink in the silicon wafers useful for the solar cell fabrication

태양전지용 규소 기판에 존재하는 기계적 손상의 gettering 공정에의 활용

  • Kim, Dae-Il (Department of Material Science & Engineering, University of Incheon) ;
  • Kim, Young-Kwan (Department of Material Science & Engineering, University of Incheon)
  • 김대일 (인천대학교 신소재공학과) ;
  • 김영관 (인천대학교 신소재공학과)
  • Published : 2006.04.30
Download PDF
⟨ Previous Next ⟩

Abstract

Various kind of structural defects are observed to be present on the oxidized surface of the silicon crystal which was previously damaged mechanically. The formation of such defects was found to depend on the amount of damage induced and the temperature of thermal oxidation. It was confirmed by the measurement of minority carrier life time that gettering capability decreases as the size of the defects increase. The strained layer which is formed due to smaller amount of damage or lower oxidation temperature believed to has higher capability of gettering over defects like dislocation loops or stacking faults.

실리콘웨이퍼 표면에 기계적인 손상을 가한 후 산화 열처리 공정을 실시하면 온도와 기계적인 손상의 크기에 따라 여러 가지 결정 결함이 발생된다. 기계적인 손상이 크고 열처리 온도가 증가함에 따라 dislocation loop 등의 대형 결함들이 발생되고 열처리 온도가 낮거나 손상의 크기가 작을수록 OISF(Oxidation Induced Stacking Faults)등의 소형 결함들이 많이 발생된다. Minority carrier lifetime을 측정하여본 결과 결함의 크기가 작을수록 minority carrier lifetime이 높은 것으로 밝혀졌다. 더욱이 dislocation loop 등의 결정 결함보다는 결함 발생 이전 단계인 strained layer등이 금속불순물에 대한 gettering의 효과가 더욱 높음을 알 수 있었다.

Keywords

References

  1. L. Baldi, G. Cerofolini and G. Ferla, 'Heavy metal gettering in silicon device processing', J. Electrochem. Soc. 127 (1980) 164 https://doi.org/10.1149/1.2129609
  2. I. Perichaud, 'Gettering of impurities in solar silicon', Solar Energy Materials & Solar Cells. 72 (2002) 345
  3. L. Kazmerski, 'Polycrystalline silicon: Impurity incorporation and passivation', Proc. 6th European Photovoltaic Solar Energy Conf. London (1985) 83
  4. N. Khedher, A. Ben Jaballah, M. Hassen, M. Hajji, H. Ezzaouia, B. Bessais, A. Selmi and R. Bennaceur, 'Gettering by heat thermal processing: application in crystalline silicon solar cells', Materials Science Semiconductor Processing 7 (2004) 439 https://doi.org/10.1016/j.mssp.2004.09.006
  5. H. Tsuya and F. Shimura, 'Transient behavior of instrinsic gettering in CZ silicon wafers', Phys. Status Solidi. 79 (1983) 199 https://doi.org/10.1002/pssa.2210790122
  6. J.E. Lawrence, 'Metallographic analysis of getterd silicon', Trans. Metall. Soc. 242 (1968) 484
  7. M.W. Jenkins, 'A new preferential etch for defects in silicon crystals', J. Electrochem. Soc. 124 (1977) 757 https://doi.org/10.1149/1.2133401
  8. D.I. Kim, J.B. Kim and Y.K. Kim, 'The influence of mechanical damage on the formation of structural defects on the silicon surface during oxidation', Journal of the Korean Growth and Crystal Technology 15 (2005) 45
  9. C.-Y Choi, J.-H. Lee and S.-H. Cho, 'Characterization of mechanical damage on structural and electrical properties of silicon wafers', Solid-State Electronics. 43 (1999) 2011 https://doi.org/10.1016/S0038-1101(99)00158-6
  10. J.M. Kim and Y.K. Kim, 'Saw damage induced structural defects on the surface of silicon crystals', Journal of Electrochemical Society 152 (2005) 189 https://doi.org/10.1149/1.1859815
  11. F. Secco d'Aragona, 'Dislocation etch for (100) planes in silicon', J. Electrochem. Soc. 119 (1972) 948 https://doi.org/10.1149/1.2404374