Patent ID: 7547586
Filing Date: 2009-06-16
Classification: H01L

Abstract:
1. A method of making a self aligned ion implanted gate structure for use in a static induction transistor, comprising the steps of: providing a semiconductor body having a plurality of epitaxially grown layers of a first conductivity type on a substrate, with a top one of said layers having a dopant concentration greater than that the next adjacent said layer; forming a thick oxide arrangement on the top of said top layer; depositing a mask having a plurality of metallic strips, on the top of said oxide arrangement, with said strips being parallel to one another; etching away said oxide arrangement which is between said strips down to said next adjacent layer to form an array of parallel pillars each having sidewalls and each having at the base thereof the remainder of said top layer after said etching; removing said mask; subjecting the resulting structure to an oxidation process to grow an oxide skirt around said base of each said pillar and to consume the edges of said remainder of said top layer; subjecting the resulting structure to an ion implantation to form gate regions of a second conductivity type between said oxide skirts; removing any remaining oxide to form a structure to which electrical contacts may be made to each said remainder of said top layer, each defining a source, to said gate regions and to said substrate forming a drain.