Single mask technique for making positive and negative micromachined features on a substrate

摘要

Methods for making a micromachined device (e.g. an microoptical submount) having positive features (extending up from a device surface) and negative features (extending into the device surface). The present techniques locate the positive feature and negative features according to a single mask step. In one embodiment, a hard mask is patterned on top of the device layer of an SOI wafer. Then, RIE is used to vertically etch to the etch stop layer, forming the positive feature. Then, the positive feature is masked, and metal or hard mask is deposited on the exposed areas of the etch stop layer. Then, portions of the device layer are removed, leaving the patterned metal layer on the etch stop layer. Then, the etch stop layer is removed in an exposed area, uncovering the handle layer. Then, the handle layer is etched in an exposed area to form the negative feature.