Epitaxial structure of gallium nitride series semiconductor device and process of manufacturing the same

Abstract

An epitaxial stricture of a gallium nitride series semiconductor device and a process of forming the same are described. A first buffer layer of gallium nitride is epitaxially formed on a substrate at a first temperature. A second buffer layer of indium gallium nitride is formed on the first buffer layer at a second temperature. The second temperature increases up to a third temperature, during which precursors including In(CH 3 ) 3 and NH 3 are used for surface treatment. A high-temperature gallium nitride is formed at the third temperature. The buffer layer and the way to form such a buffer layer allow improved crystal configuration and lowered defect density, thereby increasing the performance and service life of a semiconductor device.

1 - 11 . (canceled)  
   
   
       12 . A process of forming an epitaxial structure of a gallium nitride series semiconductor, comprising: 
 providing a substrate;    forming a first buffer layer of gallium nitride on the substrate at a first temperature;    forming a second buffer layer of indium gallium nitride on the first buffer layer;    increasing temperature up to a third temperature, during which precursors including In(CH3)3 and NH3 are used for surface treatment; and    growing a high-temperature an epitaxial layer of gallium nitride at the third temperature;    wherein the first temperature is less than the second temperature, and the second temperature is less than the third temperature.    
   
   
       13 . The process of  claim 12 , wherein the first temperature is about 400° C. to 800° C.  
   
   
       14 . The process of  claim 12 , wherein the second temperature is about 800° C. to 830° C.  
   
   
       15 . The process of  claim 12 , further comprising growing a gallium nitride series epitaxial layer on the gallium nitride epitaxial layer.  
   
   
       16 . The process of  claim 12 , wherein the step of forming the first buffer layer at the first temperature includes forming a low-temperature gallium nitride buffer layer on the substrate at the first temperature, and increasing the first temperature to form crystal cores on the low-temperature gallium nitride buffer layer, thereby forming a high-temperature gallium nitride buffer layer.  
   
   
       17 . The process of  claim 16 , wherein a difference between the first temperature and a temperature for forming the high-temperature gallium nitride buffer layer is more than 300° C.