Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
A trench-forming process is provided which uses a lift-off technique with a non-erodible material to form a mask having vertical sidewalls which may be used for reactive ion etching to produce a narrow trench in a semiconductor substrate, e.g., silicon. The process may be better understood by referring to Figs. 1 through 4 wherein a semiconductor substrate 10 has formed thereon successive layers of grown silicon dioxide 12, silicon nitride 14 and pyrolytically deposited silicon dioxide 16. Each of the layers 12 and 14 may have a thickness of approximately 850 angstroms, and layer 16 may have a thickness of 0.64 micrometer. Over layer 16 there is deposited a layer of photoresist which is patterned as segment 18 to define a trench location.