Semiconductor device and electric power converter, drive inverter, general-purpose inverter and super-power high-frequency communication equipment using the semiconductor device

Abstract

In a semiconductor device that uses a silicon carbide semiconductor substrate having p type, n type impurity semiconductor regions formed by ion implantation, the electrical characteristics of the end semiconductor device can be improved by decreasing the roughness of the silicon carbide semiconductor substrate surface. The semiconductor device of this invention is a Schottky barrier diode or a p-n type diode comprising at least one of a p type semiconductor region and n type semiconductor region selectively formed in a silicon carbide semiconductor region having an outermost surface layer surface that is a (000-1) surface or a surface inclined at an angle to the (000-1) surface, and a metal electrode formed on the outermost surface layer surface, that controls a direction in which electric current flows in a direction perpendicular to the outermost surface layer surface from application of a voltage to the metal electrode.

1 . A semiconductor device that is a Schottky barrier diode or p-n type diode comprising:
 at least one of a p type semiconductor region and n type semiconductor region selectively formed in a silicon carbide semiconductor region having an outermost surface layer surface that is a (000-1) surface or a surface inclined at an angle to the (000-1) surface; and   and a metal electrode formed on the outermost surface layer surface, that controls a direction in which electric current flows in a direction perpendicular to the outermost surface layer surface from application of a voltage to the metal electrode.   
     
     
         2 . The semiconductor device according to  claim 1 , wherein the silicon carbide semiconductor region is p type or n type. 
     
     
         3 . The semiconductor device according to  claim 1 , wherein formation of the p type semiconductor region or n type semiconductor region by implantation of impurity ions in the silicon carbide semiconductor region is followed by implementation of impurity activation heat treatment for a period of 10 seconds to 10 minutes at a temperature of from 1500° C. to 2000° C. in an inert atmosphere. 
     
     
         4 . The semiconductor device according to  claim 1 , wherein formation of the p type semiconductor region or n type semiconductor region by implantation of impurity ions in the silicon carbide semiconductor region is followed by elevation of a temperature from 1200° C. or below to from 1500° C. to 2000° C. within 1 minute, in an inert atmosphere, and implementation of impurity activation heat treatment for a period of 10 seconds to 10 minutes at that temperature. 
     
     
         5 . The semiconductor device according to  claim 1 , wherein the silicon carbide semiconductor region on a substrate side is 4H-SiC. 
     
     
         6 . An electric power converter comprising the semiconductor device according to  claim 1 . 
     
     
         7 . A drive inverter comprising the semiconductor device according to  claim 1 . 
     
     
         8 . A general-purpose inverter comprising the semiconductor device according to  claim 1 . 
     
     
         9 . A semiconductor device that is a MES type field-effect transistor or junction type field-effect transistor, comprising:
 at least one of a p type semiconductor region and n type semiconductor region selectively formed in a silicon carbide semiconductor region having an outermost surface layer surface that is a (000-1) surface or a surface inclined at an angle to the (000-1) surface;   and a metal electrode formed on the outermost surface layer surface, that, when a voltage is applied to the metal electrode, functions as a switching device that controls electric current flow/interception.   
     
     
         10 . A super-power high-frequency communication apparatus comprising the MES type field-effect transistor according to  claim 9 . 
     
     
         11 . The semiconductor device according to  claim 9 , wherein the silicon carbide semiconductor region is p type or n type. 
     
     
         12 . The semiconductor device according to  claim 9 , wherein formation of the p type semiconductor region or n type semiconductor region by implantation of impurity ions in the silicon carbide semiconductor region is followed by implementation of impurity activation heat treatment for a period of 10 seconds to 10 minutes at a temperature of from 1500° C. to 2000° C. in an inert atmosphere. 
     
     
         13 . The semiconductor device according to  claim 9 , wherein formation of the p type semiconductor region or n type semiconductor region by implantation of impurity ions in the silicon carbide semiconductor region is followed by elevation of a temperature from 1200° C. or below to from 1500° C. to 2000° C. within 1 minute, in an inert atmosphere, and implementation of impurity activation heat treatment for a period of 10 seconds to 10 minutes at that temperature. 
     
     
         14 . The semiconductor device according to  claim 9 , wherein the silicon carbide semiconductor region on a substrate side is 4H-SiC. 
     
     
         15 . An electric power converter comprising the semiconductor device according to  claim 9 . 
     
     
         16 . A drive inverter comprising the semiconductor device according to  claim 9 . 
     
     
         17 . A general-purpose inverter comprising the semiconductor device according to  claim 9 . 
     
     
         18 . A semiconductor device according to  claim 1 , wherein the diode is a p-n type diode comprising;
 at least one of a p-type semiconductor region and n-type semiconductor region selectively formed in a silicon carbide semiconductor region having an outermost surface layer surface that is a (000-1) surface or a surface inclined at an angle to the (000-1) surface and   a gate insulation film formed on the (000-1) surface., wherein the gate insulation film contains hydrogen.   
     
     
         19 . A semiconductor device according to  claim 18 , wherein the gate insulation film contains hydrogen with not less than 1×10 19  cm −3  and not more than 1×10 22  cm −3  in density. 
     
     
         20 . A semiconductor device according to  claim 19 , wherein the gate insulation film has a layer in contact with a silicon carbide substrate and is formed by thermal oxidation of silicon carbide in an atmosphere containing water. 
     
     
         21 . A semiconductor device according to  claim 1 , wherein the diode is a p-n type diode comprising:
 at least one of a p-type semiconductor region and n-type semiconductor region selectively formed in a silicon carbide semiconductor region having an outermost surface layer surface that is a (000-1) surface or a surface inclined at an angle to the (000-1) surface and,   a gate insulation film formed on the (000-1) surface, wherein the gate insulation film contains nitrogen.