Method of producing homogeneously doped HgCdTe which contains a fast diffusing dopant impurity
US4501625A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1983 |
| Grant date | Feb 26, 1985 |
| Priority date | — |
| Expiry date | Dec 23, 2003 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC30B29/48
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The disclosure relates to a method for making extrinsically doped HgCdTe alloys containing Cu, Ag, or Au or other dopant impurity whereby the excess tellurium in the core is annihilated (stoichiometrically compensated by excess in-diffusing Hg) and the dopant impurities are then permitted to randomly move through the slab to provide for homogeneity thereof. A post-annealing step of much greater than normal temperature-time length than was provided in the prior art is used. A standard post-annealing step in a saturated mercury vapor atomosphere leaves second phase tellurium (and gettered impurities) at the center of the slab, and longer term post-annealing negates this situation by annihilating the second phase tellurium in the slab and thus permitting the impurities to randomly travel by solid state diffusion throughout the slab to ultimately be distributed therein in a homogeneous manner. The additional time required for the post-annealing step following the normal prior art post-annealing step varies based upon slice or slab thickness, the metal-Te stoichiometry, and second post-annealing step temperature and, in general, will be longer but in the same range as that used in the p…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.