Patent ID: 9334160
Filing Date: 2016-05-10
CPC Classification: B81C

Claim Text:
1. A method of creating MEMS structures by selectively etching a silicon wafer that is patterned by using masking layers for defining the structural features of a MEMS device, the method comprising: a) depositing and patterning a first mask on a silicon wafer in order to define desired first areas on the wafer to be etched in a first trench etching and to define desired second areas to be etched in a second trench etching; b) depositing and patterning a first intermediate mask on top of the first mask, the first intermediate mask defining desired areas on the wafer to be recessed by etching to a first defined depth; c) etching recession trenches on the parts of the wafer not covered by the first intermediate mask nor the first mask in a recession trench etching; d) removing said first intermediate mask; e) etching first trenches and further etching the recession trenches on the parts of the wafer not covered by the first mask in a first trench etching; f) filling the first trenches and the recession trenches with a deposit layer; g) 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 other than the second areas to function as a second mask in order to define final structures; h) etching parts of the wafer on the desired second areas in the second trench etching; and i) removing said second mask.