Semiconductor structure with gallium arsenide and tantalum nitride

Abstract

Disclosed are structures and methods related to metallization of a gallium arsenide (GaAs) layer. In some embodiments, a tantalum nitride (TaN) layer can be formed on a doped GaAs layer, and a metal layer can be formed on the TaN layer. Such a structure can be included in a Schottky diode. In some embodiments, such a Schottky diode can be fabricated utilizing heterojunction bipolar transistor (HBT) processes.

1 . (canceled) 
     
     
         2 . A semiconductor structure comprising:
 a gallium arsenide substrate;   a sub-collector layer over the gallium arsenide substrate;   a collector layer over and in physical contact with the sub-collector layer; and   a tantalum nitride layer including a surface that is planar, an entirety of the surface being in physical contact with the collector layer.   
     
     
         3 . The semiconductor structure of  claim 2  wherein the collector layer includes n− gallium arsenide and the sub-collector layer includes n+ gallium arsenide. 
     
     
         4 . The semiconductor structure of  claim 2  wherein the gallium arsenide substrate includes semi-insulating gallium arsenide. 
     
     
         5 . The semiconductor structure of  claim 2  further comprising an electrical contact in physical contact with the sub-collector layer on opposing sides of the tantalum nitride layer. 
     
     
         6 . The semiconductor structure of  claim 2  further comprising an isolation implant having a surface that is co-planar with a surface of the sub-collector layer. 
     
     
         7 . A Schottky diode comprising:
 a first doped gallium arsenide layer;   a second doped gallium arsenide layer over and in physical contact with the first doped gallium arsenide layer;   a tantalum nitride layer including a surface that is planar, an entirety of the surface being in physical contact with the second doped gallium arsenide layer; and   electrical contacts including a first contact on the tantalum nitride layer and a second contact on the first doped gallium arsenide layer, the Schottky diode having a turn-on voltage.   
     
     
         8 . The Schottky diode of  claim 7  wherein the turn-on voltage is 0.45 Volts or less. 
     
     
         9 . The Schottky diode of  claim 7  wherein the turn-on voltage is about 0.42 Volts. 
     
     
         10 . The Schottky diode of  claim 7  wherein the first contact is arranged as an anode of the Schottky diode, and the second contact is arranged as a cathode of the Schottky diode. 
     
     
         11 . The Schottky diode of  claim 7  wherein the second contact is in physical contact with the first doped gallium arsenide layer on opposing sides of the tantalum nitride layer. 
     
     
         12 . The Schottky diode of  claim 11  wherein the second contact has an inverted-U shaped footprint. 
     
     
         13 . The Schottky diode of  claim 7  wherein the first doped gallium arsenide layer includes n+ gallium arsenide and the second doped gallium arsenide layer includes n− gallium arsenide. 
     
     
         14 . The Schottky diode of  claim 7  wherein a doping concentration of the first doped gallium arsenide layer is greater than a doping concentration of the second doped gallium arsenide layer. 
     
     
         15 . The Schottky diode of  claim 7  further comprising a passivation structure, the tantalum nitride layer and a passivation structure being in physical contact with and fully covering the second doped gallium arsenide layer. 
     
     
         16 . An electronic module comprising:
 a packaging substrate; and   a semiconductor device on the packaging substrate, the semiconductor device including a first doped gallium arsenide layer, a second doped gallium arsenide layer over and in physical contact with the first doped gallium arsenide layer, and a tantalum nitride layer including a surface that is planar, an entirety of the surface of the tantalum nitride layer being in physical contact with the second doped gallium arsenide layer.   
     
     
         17 . The electronic module of  claim 16  further comprising an overmold over the semiconductor device. 
     
     
         18 . The electronic module of  claim 16  wherein the semiconductor device is a radio frequency power detector. 
     
     
         19 . The electronic module of  claim 16  wherein the semiconductor device is a photoelectric cell. 
     
     
         20 . The electronic module of  claim 16  wherein the semiconductor device is a radio frequency mixer. 
     
     
         21 . The electronic module of  claim 16  wherein the semiconductor device further includes a heterojunction bipolar transistor on a gallium arsenide substrate, and the first doped gallium arsenide layer is positioned on the gallium arsenide substrate.