摘要 |
A silicon-on-insulator material is formed by a method which includes the steps of forming a p-type silicon epitaxial layer, doped with boron and a higher concentration of germanium, on the surface of a semiconductor silicon substrate, forming an additional silicon epitaxial layer on the p-type silicon epitaxial layer, forming an oxide layer on the additional silicon epitaxial layer, forming an oxide layer on another semiconductor silicon substrate, forming a laminate by bringing into contact, at room temperature, the oxide layers thereby bonding together the substrates, etching the silicon substrate provided with the silicon epitaxial layers, with an isotropic etch to remove most of this silicon substrate, exposing the laminate to an anisotropic etch for this silicon substrate until the remainder of this silicon substrate is removed but only a part of the p-type epitaxial layer is removed and then exposing the resultant structure to an additional isotropic etch for the p-type epitaxial layer for a time sufficient only to remove only the remainder of the p-type epitaxial layer.
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