Semiconductor Device with Breakdown Preventing Layer

Abstract

A semiconductor device with a breakdown preventing layer is provided. The breakdown preventing layer can be located in a high-voltage surface region of the device. The breakdown preventing layer can include an insulating film with conducting elements embedded therein. The conducting elements can be arranged along a lateral length of the insulating film. The conducting elements can be configured to split a high electric field spike otherwise present in the high-voltage surface region during operation of the device into multiple much smaller spikes.

What is claimed is: 
     
         1 . A lateral semiconductor device comprising:
 a device channel;   a first contact on a first end of the device channel;   a second contact on a second end of the device channel, wherein the second end is opposite the first end, and wherein the first and second contacts are located on a first side of the device channel; and   a breakdown preventing layer located on the first side of the device channel in at least a portion of a spacing between the first contact and the second contact, wherein the breakdown preventing layer comprises:
 an insulating film; and 
 a plurality of conducting elements embedded in the insulating film, wherein the plurality of conducting elements are arranged along a lateral length of the insulating film and are electrically isolated from the first contact and the second contact. 
   
     
     
         2 . The device of  claim 1 , wherein each of the plurality of conducting elements has a rectangular shape extending substantially all of a lateral width of the insulating film and having a shorter side aligned with a direction of surface lateral electrical field lines present during operation of the device. 
     
     
         3 . The device of  claim 1 , wherein each of the plurality of conducting elements comprises an isolated element, and wherein the plurality of conducting elements are further arranged along a lateral width of the insulating film. 
     
     
         4 . The device of  claim 1 , wherein a lateral spacing between two adjacent conducting elements is approximately equal to a characteristic size of a lateral edge field spike around an edge of each conducting element. 
     
     
         5 . The device of  claim 4 , wherein the lateral spacing between two adjacent conducting elements is at least twice a lateral length of each of the two adjacent conducting elements. 
     
     
         6 . The device of  claim 1 , wherein a vertical spacing between a conducting element and a device surface channel is approximately equal to a characteristic size of a vertical fringing field spread for the conducting element. 
     
     
         7 . The device of  claim 6 , wherein a vertical thickness of the insulating film is at least two times the vertical spacing between the conducting element and the device surface channel. 
     
     
         8 . The device of  claim 1 , wherein the insulating film has a non-uniform vertical thickness, and wherein a vertical thickness of the insulating film in a first location is greater than a vertical thickness of the insulating film in a second location having a electric field relatively lower than an electric field of the first location. 
     
     
         9 . The device of  claim 1 , further comprising a gate located between the first contact and the second contact, wherein the breakdown preventing layer is located in a region between the gate and the second contact. 
     
     
         10 . The device of  claim 9 , wherein the breakdown preventing layer is further located in a region between the gate and the first contact. 
     
     
         11 . The device of  claim 1 , wherein at least one of the first contact or the second contact includes a field plate. 
     
     
         12 . The device of  claim 1 , wherein the insulating film is formed of a layer of low conducting material, wherein the low conducting material has a sheet resistance between approximately 10 3  Ohm per square and approximately 10 7  Ohm per square. 
     
     
         13 . The device of  claim 1 , wherein the plurality of conducting elements are further arranged along a vertical height of the insulating film. 
     
     
         14 . A field effect transistor comprising:
 a device channel;   a source contact on a first end of the device channel;   a drain contact on a second end of the device channel, wherein the second end is opposite the first end, and wherein the source and drain contacts are located on a first side of the device channel;   a gate located on the first side of the device channel between the source contact and the drain contact; and   a breakdown preventing layer located on the first side of the device channel in at least a portion of at least one of: a spacing between the source contact and the gate or a spacing between the drain contact and the gate, wherein the breakdown preventing layer comprises:
 an insulating film; and 
 a plurality of conducting elements embedded in the insulating film, wherein the plurality of conducting elements are arranged along a lateral length of the insulating film and are electrically isolated from the source contact, the drain contact, and the gate. 
   
     
     
         15 . The transistor of  claim 14 , wherein each of the plurality of conducting elements comprises an isolated element, and wherein the plurality of conducting elements are further arranged along a lateral width of the insulating film. 
     
     
         16 . The transistor of  claim 14 , wherein a lateral spacing between two adjacent conducting elements is approximately equal to a characteristic size of a lateral edge field spike around an edge of each conducting element, and wherein the lateral spacing between two adjacent conducting elements is at least twice a lateral length of each of the two adjacent conducting elements. 
     
     
         17 . The transistor of  claim 14 , wherein a vertical spacing between a conducting element and a device surface channel is approximately equal to a characteristic size of a vertical fringing field spread for the conducting element, and wherein a vertical thickness of the insulating film is at least two times the vertical spacing between the conducting element and the device surface channel. 
     
     
         18 . A method comprising:
 creating a design for a lateral semiconductor device, wherein the design for the lateral semiconductor device defines a device including:
 a device channel; 
 a first contact on a first end of the device channel; 
 a second contact on a second end of the device channel, wherein the second end is opposite the first end, and wherein the first and second contacts are located on a first side of the device channel; and 
 a breakdown preventing layer located on the first side of the device channel in at least a portion of a spacing between the first contact and the second contact, wherein the breakdown preventing layer comprises:
 an insulating film; and 
 a plurality of conducting elements embedded in the insulating film, wherein the plurality of conducting elements are arranged along a lateral length of the insulating film and are electrically isolated from the first contact and the second contact; and 
 
   fabricating the lateral semiconductor device according to the design.   
     
     
         19 . The method of  claim 18 , wherein the designing includes arranging a lateral spacing of the plurality of conducting elements based on a characteristic size of a lateral edge field spike around an edge of each conducting element. 
     
     
         20 . The method of  claim 18 , wherein the designing includes selecting a vertical spacing between a conducting element and a device surface channel based on a characteristic size of a vertical fringing field spread for the conducting element.