Carbon-controlled ohmic contact layer for backside ohmic contact on a silicon carbide power semiconductor device

Abstract

A semiconductor power device may include a Silicon Carbide (SiC) layer having an active power device formed on a first surface thereof. An Ohmic contact layer may be formed on a second, opposing surface of the SiC layer, the Ohmic contact layer including Nickel Silicide (NiSix) with a first silicide region containing a first precipitate of non-reacted carbon disposed between the SiC layer and a second silicide region. The second silicide region may be disposed between the first silicide region and a third silicide region, and may include a mixture of a first precipitate of refractory metal carbide and a second precipitate of non-reacted carbon. The third silicide region may contain a second precipitate of refractory metal carbide. A solder metal layer may be formed on the Ohmic contact layer, with the third silicide region disposed between the second silicide region and the solder metal layer.