2005TCH

黃德昌 (Ter-Chang Huang)

Miniaturization of Micro Pressure Sensor by Combining Dry and Wet Etching

以乾濕複合蝕刻法進行微壓力感測器微小化之研究

In this research, silicon piezo-resistive pressure sensor were fabricated by the combining dry and wet silicon etching method. The combining etching method can reduce the pressure sensor chip size fifty-seven percent. That is to say, the combining silicon etching wafers can yield approximately two times the number of chips than typically silicon wet etched wafers.

The combining silicon etching have two major process. First step, to use the inductively coupled plasma etching equipment etch about eighty percent depth of the wafer thickness. Second step, to put electro-chemical etch stop technology in used. Make sure the sensing diaphragm’s thickness were achieved the goal of the design.

In this study, the chip size after sawing is 1080μm*1080μm*800μm. The sensor sensitivity is 0.324 mv/v/Psi. the sensitivity result is grater than the estimated data by finite elements method about 4.5 percents. The variation of sensitivity resulted largely from the 0.3μm difference of the diaphragm thickness.