Surface barrier diode having a hypersensitive n region forming a hypersensitive voltage variable capacitor

Abstract

Abstract A method of making a surface barrier diode, also known as a Schottky diode, having a hypersensitive voltage variable capacitance, is disclosed. The surface barrier diode structure comprises a silicon wafer of n conductivity having an n-type epitaxial layer which is oxidized on its outer surface to form a silicon oxide layer overlaying the epitaxial n-region of the wafer. The silicon oxide coating is relatively thin, as of less than 5000 A, and is formed relatively quickly, i.e., in less than 20 minutes at a temperature within the range of 1150* to 1250* C in order to produce a hypersensitive n impurity accumulation layer immediately adjacent to and underlying the oxide coating. A hole is then opened through the silicon oxide layer and a metal electrode, as of chromium, is deposited directly upon the hypersensitive n region to form the rectifying junction of the diode. The surface barrier diode (Schottky diode) exhibits a hypersensitive voltage variable capacitance effect where ''''hypersensitive voltage variable capacitance'''' means that the capacitance is approximately inversely proportional to the first power of the applied voltage as contrasted with normal voltage variable capacitance effects in PN junction devices wherein the capacitance is approximately inversely proportional to the 1/2 or 1/3 power of the applied voltage.

Inventors

• 👤 John Heer

Bibliographic Details