Low-doped etch stopping for micromechanical device production

摘要

Abstract: This paper describes significant advancements to a lowdoped etch-stop technique which increases thedifferential etch rate of high doped to low dopedsilicon (R$-h/l$/) by a factor of 4 or greater, to avalue of up to R$-h/l$/ $APEQ 50:1. The objective ofthe research was to achieve this increase in thedifferential etch rate by decreasing the etch rate ofthe low doped silicon epilayer, resulting in thedevelopment of an exceptional technique for rapid,safe, and high-quality etching of complexmicro-structures. The technique has been confirmed bythe production of devices. These include both 10 $mu@mthick diaphragms and a complete accelerometerstructure, created fom n on n$PLU epitaxial samples. !5