02-04-2015 дата публикации
Номер: US20150091140A1
Принадлежит:
A multiple silicon trenches forming method and an etching mask structure, the method comprises: step S, providing a MEMS sealing cap silicon substrate (); step S, forming n stacked mask layers () on the MEMS sealing cap silicon substrate (), after forming each mask layer, photolithographing and etching the mask layer and all other mask layers beneath the same to form a plurality of etching windows (D, D, D); step S, etching the MEMS sealing cap silicon substrate by using the current uppermost mask layer and a layer of mask material beneath the same as a mask; step S, removing the current uppermost mask layer; step S, repeating the step S and the step S until all the n mask layers are removed. The present invention can form a plurality of deep trenches with high aspect ratio on the MEMS sealing cap silicon substrate using conventional semiconductor processes, avoiding the problem that the conventional spin coating cannot be conducted on a sealing cap wafer with deep trenches using photoresist. 1. A multiple silicon trenches forming method for MEMS sealing cap wafer , characterized in comprising:{'b': '11', 'step S, providing a MEMS sealing cap silicon substrate;'}{'b': '12', 'step S, forming n stacked mask layers on the MEMS sealing cap silicon substrate, after forming each mask layer, photolithographing and etching the mask layer and all other mask layers beneath the same to form multiple etching windows, wherein n is a positive integer greater than or equal to 2, and any two adjacent mask layers are made of different materials;'}{'b': '13', 'step S, etching the MEMS sealing cap silicon substrate by using a current uppermost mask layer in the n mask layers as a mask, with an etching selectivity ratio of the MEMS sealing cap silicon substrate to the current uppermost mask layer greater than or equal to 10:1;'}{'b': '14', 'step S, removing the current uppermost mask layer;'}{'b': 15', '13', '14, 'step S, repeating the step S and the step S until all the n mask layers ...
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