III-Nitride Transistor with Solderable Front Metal

Abstract

Some exemplary embodiments of a III-nitride power device including a HEMT with multiple interconnect metal layers and a solderable front metal structure using solder bars for external circuit connections have been disclosed. The solderable front metal structure may comprise a tri-metal such as TiNiAg, and may be configured to expose source and drain contacts of the HEMT as alternating elongated digits or bars. Additionally, a single package may integrate multiple such HEMTs wherein the front metal structures expose alternating interdigitated source and drain contacts, which may be advantageous for DC-DC power conversion circuit designs using III-nitride devices. By using solder bars for external circuit connections, lateral conduction is enabled, thereby advantageously reducing device Rdson.

1 - 60 . (canceled) 
     
     
         61 . A III-nitride semiconductor device comprising:
 a source and a drain over a III-nitride layer;   a first metal layer over said III-nitride layer, said first metal layer including a source contact over said source;   a via connecting said source contact to a second metal layer situated over said first metal layer;   a solderable front metal over said second metal layer.   
     
     
         62 . The III-nitride semiconductor device of  claim 61 , wherein said first metal layer includes a drain contact over said drain. 
     
     
         63 . The III-nitride semiconductor device of  claim 62 , wherein said solderable front metal comprises spaced elongated digits configured for external circuit connection. 
     
     
         64 . The III-nitride semiconductor device of  claim 61 , wherein said solderable front metal comprises solder bars. 
     
     
         65 . The III-nitride semiconductor device of  claim 61 , wherein said III-nitride semiconductor device is a high electron mobility transistor (HEMT). 
     
     
         66 . The III-nitride semiconductor device of  claim 63 , wherein said spaced elongated digits alternately expose said source contact and said drain contact. 
     
     
         67 . The III-nitride semiconductor device of  claim 63 , comprising a first transistor and a second transistor, wherein said solderable front metal exposes alternating interdigitated source and drain contacts of said first and second transistors. 
     
     
         68 . The III-nitride semiconductor device of  claim 61 , further comprising a passivation on said top metal layer, said passivation surrounding said solderable front metal. 
     
     
         69 . The III-nitride semiconductor device of  claim 61 , further comprising a passivation on said top metal layer, said passivation selected from the group consisting of epoxy, polyamide, and silicon oxide. 
     
     
         70 . The III-nitride semiconductor device of  claim 61 , wherein said III-nitride layer comprises AlGaN. 
     
     
         71 . The III-nitride semiconductor device of  claim 61 , wherein said solderable front metal comprises Titanium-Nickel-Silver (TiNiAg) tri-metal. 
     
     
         72 . The III-nitride semiconductor device of  claim 61 , wherein said III-nitride layer is situated over a silicon substrate. 
     
     
         73 . The III-nitride semiconductor device of  claim 61 , wherein said solderable front metal is soldered with solder bars to conductive traces of a circuit board for external circuit connection. 
     
     
         74 . The III-nitride semiconductor device of  claim 61 , wherein said solderable front metal is soldered with solder bars to conductive traces of a circuit board for implementing a DC-DC conversion circuit. 
     
     
         75 . A III-nitride semiconductor device comprising:
 a first high electron mobility transistor (HEMT) including a solderable front metal, said solderable front metal exposing a source contact and a drain contact of said first HEMT, wherein said solderable front metal is configured for external circuit connection.   
     
     
         76 . The III-nitride semiconductor device of  claim 75 , further comprising a second HEMT, wherein said solderable front metal of said first HEMT and a solderable front metal of said second HEMT expose alternating interdigitated source and drain contacts. 
     
     
         77 . The III-nitride semiconductor device of  claim 75 , further comprising a passivation on said top metal layer, said passivation selected from the group consisting of epoxy, polyamide, and silicon oxide. 
     
     
         78 . The III-nitride semiconductor device of  claim 75 , wherein said first HEMT is an AlGaN/GaN HEMT. 
     
     
         79 . The III-nitride semiconductor device of  claim 75 , wherein said solderable front metal comprises Titanium-Nickel-Silver (TiNiAg) tri-metal. 
     
     
         80 . The III-nitride semiconductor device of  claim 75 , wherein said first HEMT is disposed on a silicon substrate.