Patent ID: 9580301
Date: 2017-02-28
CPC Classifications: B81B,B81C

Claim:
1. A MEMS chip, comprising: a silicon substrate layer comprising a front surface for a MEMS process and a rear surface opposite to the front surface, wherein both the front surface and the rear surface are polished surfaces; a first oxidation layer mainly made of SiO a first thin film layer mainly made of silicon nitride formed on a surface of the first oxidation layer; a second oxidation layer formed on the front surface of the silicon substrate layer; a ratio of a thickness of the first oxidation layer to a thickness of the first thin film layer ranges from 3 to 4; wherein the combined stress between the first thin film layer and the first oxidation layer is compensated by the second oxidation layer such that the chip is flat; wherein the first thin film layer and the first oxidation layer are adapted to protect the rear surface of the silicon substrate layer during formation of second oxidation layer and layers applied subsequent to the second oxidation layer.