Development of Protective Coatings for Silicon Devices

Ceramic coatings can be effectively used as a surface protective layer for silicon-based devices due to their inertness and good mechanical properties. One challenge is to avoid the weaknesses that ceramic coatings inherently possess, i.e., low strain tolerance, brittleness, high temperature required to process the film, and difficulty to produce a uniform, dense layer. Therefore, in an attempt to process strain-tolerant ceramic coatings at low temperatures, we develop an aqueous solution precursor processing route. Nanometer scale organic coatings, fabricated by self-assembly processes on the silicon, are used as a ‘template’ to aid the subsequent deposition of hard ceramic coatings (ZrO2 ). The ceramic coatings are deposited by spin coating. The organic self-assembled monolayer (SAM) coating provides temporary strain tolerance for the overlying hard coating upon mechanical and thermomechanical stresses before being decomposed at high temperatures. Molecular level understanding of the coating microstructure and micromechanics involved in the coating processes is systematically approached via experimental tools such as AFM and nanoindenter, as well as numerical simulation.Copyright © 2003 by ASME