Method of producing semiconductor substrate
AssigneeShin-Etsu Handotai Co., Ltd.
InventorsTakao Abe, Yasuaki Nakazato, Atsuo Uchiyama
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Abstract
The present invention provides a method of making a semiconductor substrate having an SOI structure by temporarily bonding together two wafers having different thermal expansion coefficients to allow thinning of at least one of the wafers by chemical and/or mechanical treatment(s) to reduce the risk of strain, separation, cracks to the wafers followed by one or more heat treating steps to fully bond the wafers together. The method can produce semiconductor substrate having an SOI structure which can provide a silicon layer thin enough to allow various integrated circuits, or TFL-LCD or the like to be formed.
Claims6
A method of producing a semiconductor substrate formed by bonding two wafers having different thermal expansion coefficients together, comprising the steps of:
- polishing and cleaning surfaces of said two wafers to be bonded together;
- placing said two wafers in contact each other;
- applying heat treatment to said two wafers in a first temperature range thereby forming a temporarily heat bonded substrate;
- thinning at least one of said two wafers by chemical treatment;
- and
- applying heat treatment to said temporarily heat bonded substrate in a second temperature range higher than said first temperature range, thereby forming a fully heat bonded substrate.
Dependencies are inferred from the claim text.