Trench diode and power semiconductor device including the same

Abstract

A power semiconductor device includes a source region in an active area, a gate structure in a peripheral area, and a plurality of trench diodes connected in series between the source region and the gate structure. Each of the plurality of trench diodes includes a first trench provided in a substrate material, an insulating layer provided over surfaces of the first trench, a first semiconductor material of a first conductivity type provided within the first trench, and a second semiconductor material of a second conductivity type provided within the first trench and disposed over the first semiconductor material in the first trench.

What is claimed is: 
     
         1 . A power semiconductor device, comprising:
 a source region in an active area;   a gate structure in a peripheral area; and   a plurality of trench diodes connected in series between the source region and the gate structure,   wherein each of the plurality of trench diodes comprises:
 a first trench provided in a substrate material; 
 an insulating layer provided over surfaces of the first trench; 
 a first semiconductor material of a first conductivity type provided within the first trench; and 
 a second semiconductor material of a second conductivity type provided within the first trench and disposed over the first semiconductor material in the first trench. 
   
     
     
         2 . The power semiconductor device of  claim 1 , wherein the first semiconductor material has a doping concentration of at least 1×10 18 /cm 3 , and the second semiconductor material has a doping concentration of at least 1×10 17 /cm 3 . 
     
     
         3 . The power semiconductor device of  claim 1 , wherein the substrate material includes an epi layer and the first trench is provided in the epi layer, and
 wherein the first semiconductor material is polysilicon having the first conductivity type, and the second semiconductor material is polysilicon having the second conductivity type, the second conductivity type being different than the first conductivity type.   
     
     
         4 . The power semiconductor device of  claim 1 , further comprising:
 a third semiconductor material of the second conductivity type provided within the first trench and over the second semiconductor material, the third semiconductor material having a higher doping concentration than that of the second semiconductor material.   
     
     
         5 . The power semiconductor device of  claim 1 , wherein the gate structure is disposed within a second trench defined in the substrate material, the gate structure being formed by the first semiconductor material of the first conductivity type. 
     
     
         6 . The power semiconductor device of  claim 5 , wherein the first trench has a first width that is greater than a second width of the second trench. 
     
     
         7 . The power semiconductor device of  claim 1 , further comprising:
 a first electrode provided over a first side of the substrate material and electrically coupled the source region and a first one of the plurality of trench diodes; and   a second electrode provided over the first side of the substrate material and electrically coupled a second one of the plurality of trench diodes and the gate structure.   
     
     
         8 . The power semiconductor device of  claim 7 , further comprising:
 a third electrode provided over a second side of the substrate material, the second side being in an opposing side of the first side,   wherein the power semiconductor device includes a metal oxide semiconductor field effect transistor device, the first electrode is a source electrode, and the third electrode is a drain electrode.   
     
     
         9 . The power semiconductor device of  claim 1 , wherein the plurality of trench diodes and the gate structure are provided in an electrostatic discharge (ESD) area. 
     
     
         10 . The power semiconductor device of  claim 1 , wherein the plurality of trench diodes and the gate structure have a line type. 
     
     
         11 . A Zener trench diode, comprising:
 a first trench provided in a substrate material;   an insulating layer provided over sidewalls and bottom of the first trench;   a first semiconductor material layer of a first conductivity type provided within the first trench and disposed over the insulating layer, the first semiconductor material layer having a doping concentration of at least 1×10 18 /cm 3 ; and   a second semiconductor material layer of a second conductivity type provided within the first trench and disposed over the first semiconductor material layer in the first trench, the second semiconductor material layer having a doping concentration of at least 1×10 17 /cm 3 .   
     
     
         12 . The Zener trench diode of  claim 11 , wherein the substrate material includes an epi layer and the first trench is provided in the epi layer, and
 wherein the first semiconductor material layer is polysilicon having the first conductivity type, and the second semiconductor material layer is polysilicon having the second conductivity type, the second conductivity type being different than the first conductivity type.   
     
     
         13 . The Zener trench diode of  claim 11 , further comprising:
 a third semiconductor material layer of the second conductivity type provided within the first trench and over the second semiconductor material layer, the third semiconductor material layer having a higher doping concentration than that of the second semiconductor material layer.   
     
     
         14 . The Zener trench diode of  claim 11 , wherein the Zener trench diode is part of a power semiconductor device, and
 wherein the power semiconductor device has a gate structure within a second trench defined in the substrate material, the gate structure being formed by the first semiconductor material layer of the first conductivity type.