Schottky Diodes Including Polysilicon Having Low Barrier Heights

Abstract

Hybrid semiconductor devices including a PIN diode portion and a Schottky diode portion are provided. The PIN diode portion is provided on a semiconductor substrate and has an anode contact on a first surface of the semiconductor substrate. The Schottky diode portion is also provided on the semiconductor substrate and includes a polysilicon layer on the semiconductor substrate and a ohmic contact on the polysilicon layer. Related Schottky diodes are also provided herein.

1 . A Schottky diode, comprising:
 a drift layer on a first surface of a semiconductor substrate;   a polysilicon layer on the drift layer; and   an anode contact on the poly-silicon layer.   
     
     
         2 . The diode of  claim 1 , wherein the drift layer comprises a silicon carbide (SiC) drift layer and the semiconductor substrate comprises a SiC substrate. 
     
     
         3 . The diode of  claim 2 , wherein the polysilicon layer comprises N-type polysilicon. 
     
     
         4 . The diode of  claim 3 , further comprising a cathode contact on a second surface of the semiconductor substrate, opposite the first surface of the substrate. 
     
     
         5 . The diode of  claim 4 , wherein the diode comprises a junction barrier Schottky (JBS) diode and wherein the diode further comprises a plurality P-type regions in the SiC drift layer and wherein the anode contact forms a Schottky junction with the exposed portions of the SiC drift layer and an ohmic contact with the plurality of P-type regions. 
     
     
         6 . The diode of  claim 1 , wherein the drift layer comprises a layer including gallium nitride (GaN) and the semiconductor substrate comprises GaN, the diode further comprising a cathode contact on the layer including GaN that is spaced apart from the polysilicon layer and the anode contact. 
     
     
         7 . The diode of  claim 6 , wherein the layer including GaN comprises aluminum gallium nitride (AlGaN). 
     
     
         8 . A Schottky diode, comprising:
 a drift layer on a first surface of a semiconductor substrate;   a barrier layer on the drift layer; and   an anode contact on the barrier layer, wherein the barrier layer provides a diode having a barrier height of from about 0.2eV to about 0.8eV.   
     
     
         9 . The diode of  claim 8 , where the barrier height is 0.5 eV or less. 
     
     
         10 . The diode of  claim 9 , wherein the barrier height is 0.4 eV or less. 
     
     
         11 . The diode of  claim 10 , wherein the barrier height is 0.3 eV or less. 
     
     
         12 . The diode of  claim 8 , wherein the barrier height is from about 0.2 eV to about 0.5 eV.