Semiconductor elevated temp. treatment with getter screening - from foreign matter in oven, improving charge carrier lifetime

摘要

In elevated temp. treatment of semiconductors, the semiconductor (I) is screened from the oven by a material (II) which does not cover its surface and getters foreign atoms from the oven. This can be achieved by placing (I) in a vessel with protective coating(s) of (II) or Si and (II) on the outsides. The coatings pref. consist of Si and Ga or Al; or phosphorus glass and opt. Si. It is also possible to use a Si vessel with a Ga or Al coating. The coating should be removed and replaced after one or more processes. The vessel can be sealed or open a the ends extending from the oven. Used for doping (I) by diffusion; preventing diffusion of heavy metal atoms into (I); and for the prodn. of (I) devices with high charge carrier lifetime. The process gives improved charge carrier lifetime (ca. 18 mu s) and saves the use of costly getter processes and thus reduces prodn. costs with a simultaneous improvement in quality.