Polysilicon Gate Field Effect Transistors With Self Registering Metal Contacts To Both Polysilicon And Diffused Silicon Regions
Original Publication Date: 1979-Feb-01
Included in the Prior Art Database: 2005-Feb-19
This article describes a method for fabricating polysilicon gate MOSFETs (metal oxide semiconductor field effect transistors) with self registering metal contacts to both polysilicon and diffused regions. Such "borderless" contacts yield higher device packing density through the reduction of registration tolerances related to mask to mask misalignment and over etching of contact vias. Disclosed here is a process in which there are no etched contact vias; contact areas to N+ diffused and polysilicon regions are defined by nitride patterns. A thermal oxidation step creates an insulation oxide around the contact areas.