Semiconductor Device Having Contact Trenches Extending from Opposite Sides of a Semiconductor Body

Abstract

A semiconductor device includes a semiconductor body having first and second opposing sides. Contact trenches extend, from the first and second sides, through a dielectric and into the semiconductor body. The contact trenches include conductive material electrically connected to the semiconductor body via sidewalls. The contact trenches include a first contact trench extending through a first dielectric and into the semiconductor body at the first side, the first contact trench including a first conductive material electrically connected to the semiconductor body adjoining the first contact trench, a second contact trench extending through a second dielectric and into the semiconductor body at the second side, the second contact trench including a second conductive material, a first contact pattern surrounded by the first dielectric at the first side, and a second contact pattern surrounded by the second dielectric at the second side.

What is claimed is: 
     
         1 . A semiconductor device, comprising:
 a semiconductor body including a first side and a second side opposite to the first side;   contact trenches extending, from the first and second sides, through a dielectric and into the semiconductor body, the contact trenches including conductive material electrically connected to the semiconductor body via sidewalls, wherein the contact trenches include:   a first contact trench extending through a first dielectric and into the semiconductor body at the first side, wherein the first contact trench includes a first conductive material electrically connected to the semiconductor body adjoining the first contact trench;   a second contact trench extending through a second dielectric and into the semiconductor body at the second side, wherein the second contact trench includes a second conductive material;   a first contact pattern surrounded by the first dielectric at the first side; and   a second contact pattern surrounded by the second dielectric at the second side,   wherein the first conductive material is electrically coupled to a first semiconductor region of a first conductivity type via a sidewall of the first contact trench,   wherein the first conductive material is electrically coupled to a second semiconductor region of a second conductivity type via a bottom side of the first contact trench, the second conductivity type being complementary to the first conductivity type.   
     
     
         2 . The semiconductor device of  claim 1 , wherein the second conductive material is electrically coupled to a third semiconductor region of the first conductivity type via a sidewall of the second contact trench; and the second conductive material is electrically coupled to a fourth semiconductor region of the second conductivity type via a bottom side of the second contact trench. 
     
     
         3 . The semiconductor device of  claim 1 , wherein the second conductive material is electrically coupled to a third semiconductor region of the second conductivity type via a sidewall of the second contact trench; and the second conductive material is electrically coupled to a fourth semiconductor region of the first conductivity type via a bottom side of the second contact trench. 
     
     
         4 . The semiconductor device of  claim 1 , wherein the second contact pattern and the second conductive material are formed of a continuous and same material. 
     
     
         5 . The semiconductor device of  claim 1 , wherein a part of the second contact pattern is in contact with a surface of the semiconductor body at the second side. 
     
     
         6 . The semiconductor device of  claim 1 , wherein a part of the second contact pattern is in contact with the second conductive material. 
     
     
         7 . The semiconductor device of  claim 1 , wherein the second dielectric is sandwiched between the semiconductor body and a part of a third wiring pattern. 
     
     
         8 . The semiconductor device of  claim 1 , wherein the first conductive material and the second conductive material are electrically decoupled by a pn junction in the semiconductor body. 
     
     
         9 . The semiconductor device of  claim 1 , wherein the semiconductor device is a vertical semiconductor device including a first device terminal at the first side and a second device terminal at the second side. 
     
     
         10 . The semiconductor device of  claim 1 , further comprising at least one of a planar gate FET and a trench gate FET in the semiconductor body at the first side, wherein the first conductive material is electrically coupled to a source region and to a body region of the at least one of a planar gate FET and a trench gate FET. 
     
     
         11 . The semiconductor device of  claim 1 , wherein a width of the second contact trench ranges between 0.1 μm and 10 μm. 
     
     
         12 . The semiconductor device of  claim 1 , wherein a depth of the second contact trench ranges between 0.1 μm and 50 μm. 
     
     
         13 . The semiconductor device of  claim 1 , wherein the first and second conductive materials include one or a combination of Ti, TiN, W, TiW, Ta, Cu, Al, AlSiCu, and AlCu. 
     
     
         14 . The semiconductor device of  claim 1 , wherein at least one of the first and second contact trenches is at least partly filled with a metal or metal alloy configured to induce a compressive strain in the semiconductor body surrounding the second contact trench. 
     
     
         15 . The semiconductor device of  claim 1 , wherein the semiconductor body is a silicon semiconductor body and at least one of the first and second conductive materials includes one of Cu, a combination of W and Cu, and a combination of a diffusion barrier, W, and Cu. 
     
     
         16 . The semiconductor device of  claim 1 , wherein an angle between a sidewall of the second contact trench and a direction perpendicular to the second side ranges between 0° and 44°. 
     
     
         17 . The semiconductor device of  claim 1 , further comprising a plurality of the second contact trenches, wherein the plurality of second contact trenches differ by at least one of shape, layout, and depth. 
     
     
         18 . The semiconductor device of  claim 1 , wherein a plurality of the second contact trenches includes a first number of the second contact trenches in a cell array and a second number of the second trenches in an edge area surrounding the cell array; and wherein a percentage of area of the second number of the second contact trenches in the edge area is higher than a percentage of area of the second number of the second contact trenches in the edge area. 
     
     
         19 . The semiconductor device of  claim 1 , wherein a thickness of the semiconductor body between the first side and the second side ranges between 5 μm and 50 μm. 
     
     
         20 . The semiconductor device of  claim 1 , wherein the second contact pattern, the second conductive material, and a third wiring pattern on the second dielectric are formed of a same material.