Self-aligned polysilicon MEMS-reduced mask count surface micromachining

摘要

A self-aligned reduced mask count micromachined polysilicon on nitride (SAMPSON) surface micromachining process is introduced. The self-alignment fabrication concept enables rapid fabrication, improves yields, and reduces parasitic capacitance of MEM devices. For many MEM devices the SAMPSON process results in a one mask savings over more conventional approaches. As a demonstration of the fabrication technique a burst-proof surface micromachined polysilicon resonant pressure sensor is fabricated using the SAMPSON process. This pressure sensor does not require a sealed cavity. It is also insensitive to mechanical property variations of the structural material, rendering its response essentially temperature independent.