Bulk/surface micromachined polymems test chip for the characterization of electrical, mechanical and thermal properties

Abstract

In this work we present the design and fabrication of a test chip to be used for the characterization of the main electrical, mechanical and thermal properties of the structural materials involved in the development of polysilicon-based electrothermal actuators. With this combined bulk/surface micromachined chip, parameters such as Young's modulus (E), stretching or compression stresses (±σ), stress gradients (± Δε), electrical resistivity (ρe), doping level (n+), thermal conductivity (κ), and thermal capacitance (C) can be obtained. This test chip was fabricated using the PolyMEMS-INAOE fabrication process, in which the main materials involved are silicon oxide, silicon nitride, phosphosilicate glass, aluminum, mono-and polycrystalline silicon. In this combined micromachining technology, the polysilicon film is the main structural material and it is used to build the mechanical actuators.

A modular and generic monolithic integrated MEMS fabrication process

“…The PolyMEMS ® technology [8,9] uses polysilicon films as structural material, and it is featured by a surface micromachining sub-module developed for the fabrication of electrostatic and electrothermal sensors and actuators. Such sub-module offers two structural levels, phospho-silicate glass (PSG) films as sacrifice material, and aluminum films for interconnections [6].…”