Defect density reduction of n/sup +/p and p/sup +/n InP structures fabricated by closed ampoule thermal diffusion

Author

Faur, M. ; Faur, M. ; Goradia, C. ; Ghalla, M. ; Weinberg, I.

Author_Institution

Dept. of Electr. Eng., Cleveland State Univ., OH, USA

fYear

1992

fDate

21-24 April 1992

Firstpage

322

Lastpage

325

Abstract

A significant reduction of defect densities of n/sup +/p and p/sup +/n InP structures fabricated by closed-ampoule thermal diffusion was obtained after optimizing the diffusion process. For n/sup +/p structures, the lowest etch pit density (EPD) of 6*10/sup 5/ cm/sup -2/ was achieved after S diffusion into InP:Cd (N/sub A/=1.2*10/sup 16/ cm/sup -3/) substrates using a thin In(PO/sub 3/)/sub 3/-rich anodic oxide diffusion cap layer at a diffusion temperature of 660 degrees C, while the lowest EPD after S diffusion into InP:Zn (N/sub A/ approximately 2*10/sup 16/ cm/sup -3/) under similar diffusion conditions was 8*10/sup 6/ cm/sup -2/. For p/sup +/n structures, surface EPD values as low as 4*10/sup 2/ cm/sup -2/ were achieved in the case of Cd diffusion into InP:S (N/sub D/=3.5*10/sup 16/ cm/sup -3/) substrates at a diffusion temperature of 560 degrees C using a thin In(PO/sub 3/)/sub 3/-rich chemical oxide diffusion cap layer, while the lowest EPD in the case of Zn diffusion was 3*10/sup 5/ cm/sup -2/. The differences are explained by the large number of In/sub 2/S/sub 3/, InS, and Zn/sub 3/P/sub 2/ surface and deep precipitates detected in the case of n/sup +/-p(S, Zn) and p/sup +/-n (Zn, S)InP structures.<>

Keywords

III-V semiconductors; cadmium; chemical interdiffusion; crystal defects; dislocation etching; indium compounds; semiconductor doping; sulphur; surface diffusion; thermal diffusivity; zinc; 560 degC; 660 degC; InP:Cd, S; InP:Zn, S; chemical oxide diffusion cap layer; closed-ampoule thermal diffusion; deep precipitates; defect densities; etch pit density; semiconductors; Chemicals; Doping; Etching; Fabrication; Indium phosphide; NASA; Photovoltaic cells; Substrates; Temperature; Zinc;

fLanguage

English

Publisher

ieee

Conference_Titel

Indium Phosphide and Related Materials, 1992., Fourth International Conference on

Conference_Location

Newport, RI, USA

Print_ISBN

0-7803-0522-1

Type

conf

DOI

10.1109/ICIPRM.1992.235688

Filename

235688