Systems and method for ohmic contacts in silicon carbide devices

摘要

A silicon carbide device is presented that includes a gate electrode disposed over a portion of a silicon carbide substrate as well as a dielectric film disposed over the gate electrode. The device has a contact region disposed near the gate electrode and has a layer disposed over the dielectric film and over the contact region. The layer includes nickel in portions disposed over the dielectric film and includes nickel silicide in portions disposed over the contact region. The nickel silicide layer is configured to provide an ohmic contact to the contact region of the silicon carbide device.

主权项

1. A silicon carbide device, comprising
a gate electrode disposed over a portion of a silicon carbide substrate; a dielectric film disposed over the gate electrode; a contact region of the silicon carbide device disposed near the gate electrode, the contact region including a base of a well of the silicon carbide substrate, the base of the well being doped with a first conductivity type, and two regions on opposite sides of the base of the well, the two regions being doped with a second conductivity type opposite the first conductivity type; and a plurality of layers disposed over the contact region of the silicon carbide device, wherein the plurality of layers are configured to provide an ohmic contact to the contact region of the silicon carbide device, wherein the plurality of layers extend over an entirety of an upper surface of the base of the well and directly contacts the upper surface of the base of the well and across at least portions of each of the two regions on opposites sides of the base of the well, wherein the plurality of layers comprise a titanium/aluminum layer disposed on a first portion of the base of the well of the contact region of the silicon carbide device; and wherein the plurality of layers further comprise nickel silicide layers disposed on portions of the two regions and directly contacting an upper surface of a second portion of the base of the well of the contact region of the silicon carbide device.