Method of forming high stability self-registered field effect transistors

Abstract

Abstract HIGH STABLITY, SELF-REGISTERED FIELD EFFECT TRANSISTORS ARE FORMED BY ETCHING THE METAL GATE ELECTRODE SIMULTANEOUSLY WITH EXPOSURE OF SURFACE ADJACENT AREAS OF A SEMICONDUCTIVE WAFER, GROWING AN ACTIVATOR CONTAINING GLASS ATOP ONLY THE EXPOSED AREAS OF THE WAFER BY PASSING A GASEOUS STREAM CONTAINING A MILD OXIDIZING AGENT AND AN ACTIVATOR IMPURITY ACROSS THE ETCHED FACE OF THE WAFER HEATED TO A TEMPERATURE BETWEEN 700*C. AND 1000*C., AND SUBSEQUENTLY BAKING THE SEMICONDUCTIVE WAFER IN A REDUCING ATMOSPHERE AT TEMPERATURES IN EXCESS OF 1000*C. TO FORM THE SOURCE AND DRAIN REGIONS OF THE SEMICONDUCTIVE WAFER. IN A PARTICULARLY PREFERRED EMBODIMENT, A GASEOUS STREAM CONTAINING 5-10% HYDROGEN AND 90-95% HELIUM OR ARGON IS BUBBLED THROUGH WATER AND ETHYL BORATE SOLUTIONS AT ROOM TEMPERATURE WHEREUPON THE STREAM IS PASSED OVER AN ETCHED WAFER TO FORM A SILICO-BORATE GLASS ATOP THE EXPOSED SILICON SURFACE. THE SEMICONDUCTIV WAFER THEN IS BAKED FOR APPROXIMATELY 4 HOURS AT 1000*C. IN A NITROGEN ATMOSPHERE CONTAINING 5-10% BY VOLUME HYDROGEN TO DRIVE THE ACTIVATOR IMPURITIES INTO THE WAFER. A TECHNIQUE FOR FORMING COMPLEMENTARY PAIRS OF HIGH STABILITY SELF-REGISTERED FIELD EFFECT TRANSISTORS ON A SINGLE SUBSTRATE ALSO IS DISCLOSED.

Inventors

• 👤 James F Burgess
• 👤 Constantine A Neugebauer
• 👤 Reuben E Joynson

Bibliographic Details