Patent ID: 6150275
Filing Date: 2000-11-21
Classification: B81B,B81C,C30B

Abstract:
A micromechanical system fabrication method using (111) single crystalline silicon as a silicon substrate, comprising:(a) a first reactive ion etching step to the front side of the silicon substrate, in which the etching depth is the thickness of microstructures to be separated from the silicon substrate;(b) a passivation step to the side walls of the microstructures which are patterned by the said first reactive ion etching step;(c) a second reactive ion etching step to the front side of the microstructures of which side walls are protected by the said passivation step, in which the etching is performed to the vertical direction of the microstructures and the etching depth is the spacing between the silicon substrate and the microstructures to be released from the silicon substrate; and(d) a selective release etching step in aqueous alkaline solution, in which the etching process is performed in the lateral direction of the spacing parts between the silicon substrate and the microstructures to be released, and in which all parts of the microstructures to be released are released in this single step.