HgCdTe Junction Characteristics after the Junction Annealing Process

열처리 조건에 따른 HgCdTe의 접합 특성

  • Jeong, Hi-Chan (Dept. of Elec. Eng., Korea Advanced Institute of Science and Technology) ;
  • Kim, Kwan (Dept. of Elec. Eng., Korea Advanced Institute of Science and Technology) ;
  • Lee, Hee-Chul (Dept. of Elec. Eng., Korea Advanced Institute of Science and Technology) ;
  • Kim, Hong-Kook (Agency for Defence Development) ;
  • Kim, Jae-Mook (Agency for Defence Development)
  • 정희찬 (한국과학기술원 전기 및 전자공학과) ;
  • 김관 (한국과학기술원 전기 및 전자공학과) ;
  • 이희철 (한국과학기술원 전기 및 전자공학과) ;
  • 김홍국 (국방과학연구소) ;
  • 김재묵 (국방과학연구소)
  • Published : 1995.02.01

Abstract

The structure of boron ion-implanted pn junctio in the vacancy-doped p-type HgCdTe was investigated with the differential Hall measurement. The as-implanted junction showed the electron concentration as high as 1${\times}10^{18}/cm^{3}$ and the junction depth of 0.6.mu.m. When the HgCdTe junction was heated in oven, the electron concentration near the junction decreased and the junction depth increased as the annealing temperature and time increased. The junction structure after the thermal annealing was n$^{+}$/n$^{-}$/p. For the 200.deg. C 20min annealed sample, the electron mobility was 10$^{4}cm^{2}/V{\cdot}$s near the surface(n$^{+}$), and was larger thatn 10$^{5}cm^{2}/V{\cdot}$s near the junction(n$^{+}$). The junction formation mechanism is conjectured as follows. When HgCdTe is ion-implanted, the ion energy generates crystal defecis and displaced Hg atoms HgCdTe is ion-implanted, the ion energy generates crystal defecis and displaced Hg atoms near the surface. The displaced Hg vacancies diffuse in easily by the thernal treatment and a fill the Hg vacancies in the p-HgCdTe substrate. With the Hg vacancies filled completely, the GfCdTe substrate becomes n-type because of the residual n-type impurity which was added during the wafer growing. Therefore, the n$^{+}$/n$^{-}$/p regions are formed by crystal defects, residual impurities, and Hg vacancies, respectively.

Keywords