Patent ID: 9556021
Date: 2017-01-31
CPC Classifications: B81C

Claim:
1. A method of creating MEMS structures by selectively etching a silicon wafer that is patterned by using masking layers for defining structural features of a MEMS device, the method comprising: a) depositing and patterning a first mask on the silicon wafer in order to define desired first areas on the silicon wafer to be etched into first trenches in a first trench etching and to indirectly define desired second areas to be etched in a second trench etching by protecting said second areas not to be etched in said first trench etching; b) etching the first trenches on parts of the silicon wafer not covered by the first mask in the first trench etching; c) filling the first trenches with a deposit layer; d) removing a part of the deposit layer on the desired second areas to be etched in the second trench etching and leaving a remainder on areas to function as a second mask in order to define final structures; e) etching parts of the silicon wafer on the desired second areas in the second trench etching, wherein dimensions of final structures are indirectly defined by said first mask; and f) removing said second mask.