Patent ID: 7542195
Filing Date: 2009-06-02
Classification: B81C,G02B,H01L

Abstract:
1. A method of aligning multiple substrates, the method comprising: providing a handle substrate; providing a silicon spacer substrate, forming a plurality of first alignment marks on a first surface of the handle substrate; forming a plurality of self-limiting alignment marks on a first surface of the spacer substrate, the self-limiting alignment marks being formed using a wet etching process that preferentially etches the <100> and <110> planes of silicon at a faster rate than the <111> plane of silicon; forming a plurality of openings in the spacer substrate, each of the plurality of openings surrounded by standoff regions; aligning the first surface of the handle substrate and the first surface of the spacer substrate using the first alignment marks and the self-limiting alignment marks; and bonding the handle substrate to the spacer substrate to form a composite substrate structure.