Self-aligned pattern over a reflective layer

摘要

An opening in an insulator on a substrate is self-aligned to a reflective region on the substrate. The opening is formed by shining blanket radiation on photoresist on the insulator and developing to open the resist and insulator. The resist region that is above the reflective region absorbs both incident and reflected radiation, a larger total dose of radiation than is absorbed by resist above non-reflective regions. The incident dose is adjusted to provide a below threshold dose everywhere except to those regions of resist that are above highly reflective regions.