Process for obtaining high barrier schottky diode and local interconnect

Abstract

This invention is a silicon bipolar integrated circuit comprising: a high barrier Schottky diode clamp on a bipolar transistor, the diode clamp comprising a self-aligned PtSi layer on a silicon surface; and a TiN local interconnect partially overlying the PtSi layer. It also is a method of manufacturing an integrated circuit comprising: forming a self-aligned PtSi layer on the adjacent base and collector silicon regions, the PtSi serving as a clamp diode on the bipolar transistor; and forming an etch-patterned TiN layer partially overlying the PtSi layer, the etch-patterned TiN layer serving as local interconnects. The invention provides a PtSi Schottky diode on a bipolar transistor in combination with a TiN local interconnect with the advantages of (i) providing a TiN local interconnect which can be etched without also etching the PtSi, (ii) permitting a wide process window for overetching at contacts, (ii) a TiN local interconnect which is an improvement over a polysilicon local interconnect, and (iv) a high barrier Schottky diode for clamping a bipolar transistor.