Fabrication of electron beam physical vapor deposited polysilicon piezoresistive MEMS pressure sensor

•A cost effective and simple fabrication process sequence based on e-beam polysilicon has been described.•In this process, reactive ion etching (RIE) was completely avoided or replaced by suitable wet etching method.•Ti/Au layer was used as both metal interconnection and hard mask for piezoresistors protection during bulk micromachining process. MEMS pressure sensor fabrication introduce a number of challenges to handle the processed wafers in batch fabrication after bulk-micromachining. In this paper, fabrication process sequence was optimized where photolithography steps were reduced after the diaphragm formation. Reactive ion etching (RIE) and low pressure chemical vapor deposition (LPCVD) has been replaced during the modified process. Polysilicon thin film based on electron beam physical vapor deposition (EBPVD) was optimized for required sheet resistivity. MEMS pressure sensor rooted on EBPVD polysilicon piezoresistive sensing element was successfully fabricated and characterized in terms of sensitivity, linearity and repeatability.