Semiconductor substrate and method for production thereof
AssigneeSiltronic AG
InventorsJosef Brunner, Hiroyuki Deai, Atsushi Ikari, Martin Grassl, Atsuki Matsumura, Wilfried von Ammon
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Abstract
Hetero-semiconductor structures possessing an SOI structure containing a silicon-germanium mixed crystal are produced at a low cost and high productivity. The semiconductor substrates comprise a first layer formed of silicon having germanium added thereto, a second layer formed of an oxide and adjoined to the first layer, and a third layer derived from the same source as the first layer, but having an enriched content of germanium as a result of thermal oxidation and thinning of the third layer.
Claims20
A method for the production of a semiconductor substrate, comprising
- a) providing a wafer processed from a germanium doped silicon single crystal ingot having a first concentration of germanium;
- b) implanting oxygen ions into said wafer by ion implantation and heat treating to form a buried oxide film, said buried oxide film separating said wafer into a first germanium doped layer below said buried oxide film, a second layer comprising said buried oxide film, and a third germanium doped layer above said buried oxide film containing a second concentration of germanium;
- and
- c) thinning said third layer by thermal oxidation in an oxidizing atmosphere to enrich the concentration of germanium in said third layer to a germanium concentration higher than said second concentration.
Dependencies are inferred from the claim text.