Fabrication process for bonded wafer precision layer thickness control and its non-destructructive measurement method
AssigneeAsia Pacific Microsystems, Inc.
InventorsHung-Dar Wang, Ruey-Shing Huang, Shih-Chin Gong, Chung-Yang Tseng
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Abstract
A measurement method for the thinned thickness of the silicon wafer, wherein thickness inspection patterns are fabricated onto the silicon wafer substrate by anisotropic etching, and then the wafer is polished with a polisher; thus a wafer with desired thickness can be obtained after the polish is proceeded; the thickness of the upper wafer is determined by the said inspection patterns, then the wafer is sorted by thickness; thus it can be applied to the MEMS micromachined devices that in need of the wafer with such precise thickness.
Claims10
A measurement method for measuring the thickness of the thinned wafer, characterized in that:
- V-grooves are fabricated onto one side of a wafer by composing photolithography and anisotropic etching, so as to determine the thinned wafer whether an precise thickness is achieved;
- the processes comprise the following steps:
- (a) Providing a silicon wafer substrate;
- on a first side of the substrate, a plurality of thickness-inspecting patterns are composed, and then processed by photolithography;
- thus an upper wafer is obtained;
- (b) Etching the said composed patterns on the first side of the upper wafer to form V-grooves by anisotropic etching;
- (c) Bonding the first side of the upper wafer with another wafer;
- (d) Proceeding the second side of the upper wafer with the polishing process;
- (e) Sorting the upper wafers by thickness according to the gaps on the polished wafer are generated or not.
Dependencies are inferred from the claim text.