Browse Prior Art Database

FET High Performance Circuit and Fabrication Technology

IP.com Disclosure Number: IPCOM000076750D
Original Publication Date: 1972-Apr-01
Included in the Prior Art Database: 2005-Feb-24
Document File: 2 page(s) / 39K

Publishing Venue

IBM

Related People

Forbes, L: AUTHOR [+2]

Abstract

Complex logic functions operating at delay times of 15 to 20 nanoseconds can be achieved in metal-oxide semiconductor technology by (1) incorporating enhancement and depletion type devices in the same structure; (2) controlling leakage in the field-insulator region by a surface sandwich of phosphosilicate glass-aluminum trioxideisilicon dioxide, and (3) having a low-diffusion capacitance.

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FET High Performance Circuit and Fabrication Technology

Complex logic functions operating at delay times of 15 to 20 nanoseconds can be achieved in metal-oxide semiconductor technology by (1) incorporating enhancement and depletion type devices in the same structure; (2) controlling leakage in the field-insulator region by a surface sandwich of phosphosilicate glass-aluminum trioxideisilicon dioxide, and (3) having a low-diffusion capacitance.

A depletion mode and enhancement mode circuit and device are shown in Figs. 1 and 2. A P type substrate of the order of 10 ohms-cm, with a crystal orientation of [100] serves as the substrate for the depletion and enhancement mode devices. A silicon dioxide layer serves as an insulator and protects the junctions in the device. An aluminum trioxide layer regulates the surface properties of the P type substrate in the field region of the substrate.

A Phosphosilicate glass layer overlies the aluminum trioxide and serves as a "getter" of ions in the silicon dioxide and aluminum trioxide films. Aluminum or similar metallurgy interconnects the enhancement and depletion mode devices. A high resistivity starting material is required for the depletion load device and also aids in minimizing capacitance due to diffusion.

A thermally grows silicon dioxide layer of approximately 200 angstroms is formed on the substrate. An aluminum trioxide film of approximately 1400 angstroms is formed on top of the silicon dioxide. A phosphosilicate...