Silicon-Germanium Alloys for Infrared Detectors.
Abstract
Silicon-germanium alloys in the range of 10 at .% germanium have been prepared and investigated. The object of the program is to prepare intrinsic Si-Ge with high enough absorption at 1.06 micrometers to be suitable for detectors at that wavelength and to investigate whether the changes in energy levels and optical properties of doped Si-Ge offer advantages for monolithic focal plane array applications over the corresponding doped silicon. The first year's work concentrated mostly on growing intrinsic material. After some attempts to prepare crystals by growing a succession of seeds of increasing Ge content, we found that alloys with greater than 10% Ge could be grown by the Czochralski technique directly from 0.5% (or even 0%) Ge seeds if a suitable growth rate was chosen. The necessary slow growth rate to achieve single crystals necessitated long exposures of the melt to contamination from the crucible, but the use of high-purity synthetic quartz crucibles reduced the uptake of electrically active impurties. Measurements on alloys that were not intentionally doped yielded values for the shift in the energy level of boron from the case of a pure silicon host that were in agreement with the literature.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1979
- Accession Number
- ADA070932
Entities
People
- H. Kimura
- H. Winston
Organizations
- HRL Laboratories