Masking without photolithography during the formation of a semiconductor device

摘要

A method for forming a semiconductor device comprises forming a dielectric layer over a semiconductor wafer substrate assembly having closely-spaced regions, such as a memory transistor array, and widely-spaced regions, such as a periphery. Under conditions specified, the dielectric layer forms to have a first thickness over the closely-spaced regions and a second thickness over the widely-spaced regions. The second thickness is much thinner than the first thickness and dielectric over the widely-spaced regions may be etched away with a blanket etch which leaves the majority of the dielectric layer over the closely-spaced regions.