Method of Removing Nitride Overhang Ledge by Differential Etch Technique
Original Publication Date: 1978-Sep-01
Included in the Prior Art Database: 2005-Feb-21
In the semiconductor industry, Schottky barrier diodes are normally formed on silicon bodies using double-layer insulators, such as silicon dioxide coated with silicon nitride. The etching of the underlying silicon dioxide, through an opening in the silicon nitride, to define the diode area on the surface of the silicon body causes undercutting of the silicon nitride, such that when metal is deposited through the defined nitride area, there remains a region of exposed silicon surface around the metallurgy and under the overhanging silicon nitride layer. This exposed silicon surface can collect surface charges, leading to instabilities in the device during operation.