Semiconductor apparatus

Abstract

A semiconductor apparatus invention includes a substrate ( 1 ), an epitaxial layer ( 2 ) formed on the substrate ( 1 ), agate electrode ( 3 ), a source electrode ( 4 ), and a drain electrode ( 5 ) that are formed on the epitaxial layer. The source electrode ( 4 ) and the drain electrode ( 5 ) each include at least two first divided electrodes that are formed to extend in parallel to each other in a first direction, inter-electrode distances Ps and Pd between the first divided electrodes are greater than or equal to a radius of an abnormal growth portion formed on a surface of the epitaxial layer ( 2 ), and widths of the first divided electrodes are less than or equal to the radius of the abnormal growth portion.

1 . A semiconductor apparatus comprising:
 a substrate;   an epitaxial layer formed on the substrate, the epitaxial layer comprising an operating region having its width in a first direction in a plan view, the operating region extending in a second direction in the plan view, the second direction crossing the first direction;   a gate electrode disposed in the operating region, the gate electrode extending in the first direction;   a source electrode disposed on one side of the gate electrode in the operating region, the source electrode comprising a first divided source electrode and a second divided source electrode extending in the first direction; and   a drain electrode disposed on the other side of the gate electrode in the operating region, the drain electrode comprising a first divided drain electrode and a second divided drain electrode extending in the first direction, wherein   an inter-electrode distance between the first and second divided source electrodes is greater than or equal to a radius of an abnormal growth portion formed on a surface of the epitaxial layer, and a width of each of the first and second divided source electrodes is less than or equal to the radius of the abnormal growth portion.   
     
     
         2 . The semiconductor apparatus according to  claim 1 , wherein
 an inter-electrode distance between the first and second divided drain electrodes is greater than or equal to the radius of the abnormal growth portion formed on the surface of the epitaxial layer, and a width of each of the first and second divided drain electrodes is less than or equal to the radius of the abnormal growth portion.   
     
     
         3 . The semiconductor apparatus according to  claim 1 , further comprising:
 a gate electrode pad, a source electrode pad, and a drain electrode pad disposed outside the operating region, wherein   the gate electrode pad is connected to the gate electrode,   the source electrode pad is connected to the first and second divided source electrodes, and   the drain electrode pad is connected to the first and second divided drain electrodes.   
     
     
         4 . The semiconductor apparatus according to  claim 1 , wherein
 the source electrode further comprises third and fourth divided source electrodes formed to extend in parallel to each other in the second direction,   the drain electrode further comprises third and fourth divided drain electrodes formed to extend in parallel to each other in the second direction,   an inter-electrode distance between the third and fourth divided source electrodes is greater than or equal to the radius of the abnormal growth portion, and a width of each of the third and fourth divided source electrodes is less than or equal to the radius of the abnormal growth portion, and   at least one of the inter-electrode distance between the first and second divided source electrodes and the inter-electrode distance between the third and fourth divided source electrodes is greater than or equal to a diameter of the abnormal growth portion.   
     
     
         5 . The semiconductor apparatus according to  claim 1 , wherein
 the source electrode further comprises third and fourth divided source electrodes formed to extend in parallel to each other in the second direction,   the drain electrode further comprises third and fourth divided drain electrodes formed to extend in parallel to each other in the second direction,   an inter-electrode distance between the third and fourth divided source electrodes is greater than or equal to the radius of the abnormal growth portion, and a width of each of the third and fourth divided source electrodes is less than or equal to the radius of the abnormal growth portion,   at least one of the inter-electrode distance between the first and second divided source electrodes and the inter-electrode distance between the third and fourth divided source electrodes is greater than or equal to a diameter of the abnormal growth portion,   an inter-electrode distance between the third and fourth divided drain electrodes is greater than or equal to the radius of the abnormal growth portion, and a width of each of the third and fourth divided drain electrodes is less than or equal to the radius of the abnormal growth portion, and   at least one of the inter-electrode distance between the first and second divided drain electrodes and the inter-electrode distance between the third and fourth divided drain electrodes is greater than or equal to the diameter of the abnormal growth portion,   
     
     
         6 . The semiconductor apparatus according to  claim 1 , wherein the abnormal growth portion has a hexagon shape on the surface of the epitaxial layer, and the radius of the abnormal growth portion is a radius of a circle to which the hexagon shape is approximated. 
     
     
         7 . The semiconductor apparatus according to  claim 1 , wherein the epitaxial layer contains GaN. 
     
     
         8 . The semiconductor apparatus according to  claim 1 , wherein the substrate is any one of an SiC substrate, a sapphire substrate, an Si substrate, a GaN substrate, and a GaAs substrate. 
     
     
         9 . The semiconductor apparatus according to  claim 1 , wherein the radius of the abnormal growth portion is 20 μm or greater. 
     
     
         10 . The semiconductor apparatus according to  claim 1 , wherein a plurality of electrode sets are arranged in parallel, each of the plurality of electrode sets including the gate electrode, and the source electrode and the drain electrode that sandwich the gate electrode. 
     
     
         11 . The semiconductor apparatus according to  claim 1 , wherein the inter-electrode distance between the first and second divided source electrodes is greater than or equal to ¾ of the diameter of the abnormal growth portion, and the inter-electrode distance between the first and second divided drain electrodes is greater than or equal to ¾ of the diameter of the abnormal growth portion 
     
     
         12 . The semiconductor apparatus according to  claim 1 , wherein the inter-electrode distance between the third and fourth divided source electrodes is greater than or equal to ¾ of the diameter of the abnormal growth portion, and the inter-electrode distance between the third and fourth divided drain electrodes is greater than or equal to ¾ of the diameter of the abnormal growth portion. 
     
     
         13 . The semiconductor apparatus according to  claim 1 , wherein
 the epitaxial layer comprises:
 a channel layer; 
 a barrier layer that is formed on the channel layer and supplies electrons to the channel layer; and 
 a two-dimensional electron gas layer that is formed by heterojunction of the channel layer and the barrier layer, 
   the source electrode and the drain electrode are formed to come into ohmic contact with the barrier layer, and   the gate electrode is formed to come into Schottky contact with the barrier layer.   
     
     
         14 . The semiconductor apparatus according to  claim 13 , wherein the channel layer is made from i-GaN, and the barrier layer is made from i-Al x Ga 1-x N (x=0.1 to 0.4). 
     
     
         15 . A semiconductor apparatus comprising:
 a substrate;   an epitaxial layer formed on the substrate, and including an operating region having its width in a first direction and extending in a second direction which is perpendicular to the first direction in a plan view;   a first gate electrode and a second gate electrode extending in the first direction disposed in the operating region; and   a first divided source electrode and a second divided source electrode each extending in the first direction disposed in the operating region;   wherein the first gate electrode is adjacent to the second gate electrode,   wherein the first divided source electrode and the second divided source electrode are arranged between the first gate electrode and the second gate electrode, and   wherein a first inter-electrode distance between the first and second divided source electrodes is greater than or equal to a radius of an abnormal growth portion formed on a surface of the epitaxial layer.   
     
     
         16 . The semiconductor apparatus according to  claim 15 , further comprising:
 a first divided drain electrode and a second divided drain electrode,   wherein the first divided source electrode is disposed at one side of the first gate electrode and the first divided drain electrode is disposed at the other side of the first gate electrode, and   wherein the second divided source electrode is disposed at one side of the second gate electrode and the second divided drain electrode is disposed at the other side of the second gate electrode.   
     
     
         17 . The semiconductor apparatus according to  claim 15 ,
 wherein a first width of each of the first and second divided source electrodes is less than or equal to the radius of the abnormal growth portion   
     
     
         18 . The semiconductor apparatus according to  claim 16 , wherein
 a second inter-electrode distance between the first and second divided drain electrodes is greater than or equal to the radius of the abnormal growth portion formed on the surface of the epitaxial layer, and a second width of each of the first and second divided drain electrodes is less than or equal to the radius of the abnormal growth portion.   
     
     
         19 . The semiconductor apparatus according to  claim 16 , further comprising:
 agate electrode pad disposed outside of the operating region and connected to the first and second gate electrodes,   a source electrode pad disposed outside of the operating region and connected to the first and second divided source electrodes, and   a drain electrode pad disposed outside of the operating region and connected to the first and second divided drain electrodes.