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

Abstract

A semiconductor device includes a semiconductor body includes a first side and a second side opposite to the first side, a first dielectric disposed on the first side, a second dielectric disposed on the second side, one or more FET devices disposed at the first side, a first contact trench extending through the first dielectric at the first side, a first conductive material disposed in the first contact trench and electrically connected to the semiconductor body, a second contact trench extending through the second dielectric and into the semiconductor body at the second side, and a second conductive material disposed in the second contact trench and electrically connected to the semiconductor body at sidewalls of the second contact trench.

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;   a first dielectric disposed on the first side;   a second dielectric disposed on the second side;   one or more FET devices disposed at the first side;   a first contact trench extending through the first dielectric at the first side;   a first conductive material disposed in the first contact trench and electrically connected to the semiconductor body;   a second contact trench extending through the second dielectric and into the semiconductor body at the second side;   a second conductive material disposed in the second contact trench and electrically connected to the semiconductor body at sidewalls of the second contact trench.   
     
     
         2 . The semiconductor device of  claim 1 , wherein the one or more FET devices comprise a planar FET, the planar FET comprising a first conductivity type source region that extends to the first side, and wherein the first conductive material directly adjoins and is electrically connected to first conductivity type source region. 
     
     
         3 . The semiconductor device of  claim 2 , wherein the semiconductor body further comprises a second conductivity type body region disposed at the second side, and wherein the second conductive material directly adjoins and is electrically connected to the body region at the sidewalls of the second contact trench. 
     
     
         4 . The semiconductor device of  claim 3 , wherein the one or more FET devices further comprise:
 a vertical FET, the vertical FET comprising a first conductivity type source region that extends to the first side and a second conductivity type body region disposed beneath the source region of the vertical FET;   a third contact trench extending through the first dielectric at the first side;   a third conductive material disposed in the third contact trench and electrically connected to the semiconductor body,   wherein the third conductive material directly adjoins and is electrically connected to the source and body regions of the vertical FET at sidewalls of the third contact trench.   
     
     
         5 . The semiconductor device of  claim 4 , further comprising:
 a fourth contact trench extending through the second dielectric at the second side;   a fourth conductive material disposed in the fourth contact trench and electrically connected to the semiconductor body,   wherein the semiconductor body further comprises a further second conductivity type region disposed at the second side, and   wherein the third conductive material directly adjoins and is electrically connected to the further second conductivity type region.   
     
     
         6 . The semiconductor device of  claim 5 , wherein the second contact trench is directly below the planar FET, and wherein the fourth contact trench is directly below the vertical FET. 
     
     
         7 . The semiconductor device of  claim 5 , further comprising:
 a fifth contact trench extending through the second dielectric at the second side; and   a fifth conductive material disposed in the fifth contact trench and electrically connected to the semiconductor body,   wherein the semiconductor body further comprises a first conductivity type region disposed at the second side, the first conductivity type having a higher dopant concentration than immediately adjacent semiconductor material of the semiconductor body, and   wherein the fifth conductive material directly adjoins and is electrically connected to the first conductivity type region.   
     
     
         8 . The semiconductor device of  claim 1 , further comprising 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. 
     
     
         9 . The semiconductor device of  claim 8 , wherein the second contact pattern and the second conductive material are formed of a continuous and same material. 
     
     
         10 . The semiconductor device of  claim 8 , wherein a part of the second contact pattern is in contact with a surface of the semiconductor body at the second side. 
     
     
         11 . The semiconductor device of  claim 8 , wherein a part of the second contact pattern is in contact with the second conductive material. 
     
     
         12 . The semiconductor device of  claim 8 , wherein the second dielectric is sandwiched between the semiconductor body and a part of a third wiring pattern. 
     
     
         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 a width of the second contact trench ranges between 0.1 μm and 10 μm, and wherein a depth of the second contact trench ranges between 0.1 μm and 50 μm. 
     
     
         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 , wherein the semiconductor device comprises 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 the semiconductor device comprises a plurality of the second contact trenches, wherein the 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 first number of the second contact trenches in the cell array. 
     
     
         19 . A semiconductor device, comprising:
 a semiconductor body including a first side and a second side opposite to the first side, the semiconductor body comprising a semiconductor material of a first conductivity type;   a gate formed at the first side;   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 via sidewalls of 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 laterally completely surrounded by the first dielectric at the first side; and   a second contact pattern laterally completely surrounded by the second dielectric at the second side,   wherein lower sidewall portions of the second contact trench that extend between the second side and a bottom side of the contact trench directly interface with the semiconductor body,   wherein the second conductive material is electrically connected to the semiconductor body via the lower sidewall portions of the second contact trench,   wherein the second conductive material is electrically connected to a first semiconductor region of the first conductivity type via the lower sidewall portions of the second contact trench; and wherein the second conductive material is electrically connected to a second semiconductor region of a second conductivity type via the bottom side of the second contact trench.   
     
     
         20 . A semiconductor device, comprising:
 a semiconductor body including a first side and a second side opposite to the first side, the semiconductor body comprising a semiconductor material of a first conductivity type;   a gate formed at the first side;   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 via sidewalls of 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 laterally completely surrounded by the first dielectric at the first side; and   a second contact pattern laterally completely surrounded by the second dielectric at the second side,   wherein lower sidewall portions of the second contact trench that extend between the second side and a bottom side of the contact trench directly interface with the semiconductor body,   wherein the second conductive material is electrically connected to the semiconductor body via the lower sidewall portions of the second contact trench,   wherein the second conductive material is electrically connected to a first semiconductor region of a second conductivity type via the lower sidewall portions of the second contact trench; and the second conductive material is electrically coupled to a second semiconductor region of the first conductivity type via the bottom side of the second contact trench.