Manufacturing process of semiconductor device and semiconductor device

Abstract

After forming a ring-shaped trench penetrating through a semiconductor substrate from a rear surface side thereof and forming an insulating film inside the trench and on the rear surface of the semiconductor substrate, a through hole is formed in the insulating film and semiconductor substrate on an inner side of the ring-shaped trench from the rear surface side, thereby exposing a surface protection insulating film formed on a front surface of the semiconductor substrate at a bottom of the through hole. After removing the surface protection insulating film at the bottom of the through hole to form an opening to expose an element surface electrode, a contact electrode connected to the element surface electrode is formed on inner walls of the through hole and opening, and a pad electrode made of the same layer as the contact electrode is formed on the rear surface of the semiconductor substrate.

1 . A manufacturing process of a semiconductor device comprising the steps of:
 (a) forming a semiconductor element on a first surface of a semiconductor substrate, forming a first insulating film on the semiconductor element, and then forming a first electrode on the first insulating film;   (b) forming a ring-shaped trench penetrating through the semiconductor substrate from a side of a second surface of the semiconductor substrate opposite to the first surface;   (c) forming a second insulating film on the second surface of the semiconductor substrate including an inside of the ring-shaped trench;   (d) forming a through hole in the second insulating film and the semiconductor substrate on an inner side of the ring-shaped trench, from the side of the second surface of the semiconductor substrate;   (e) removing the first insulating film exposed on a bottom surface of the through hole, thereby forming an opening which exposes the first electrode;   (f) forming a seed layer in contact with the first electrode on the second surface of the semiconductor substrate including inner walls of the through hole and the opening;   (g) forming a second electrode on the seed layer formed on the second surface of the semiconductor substrate around the through hole, and simultaneously forming a third electrode on the seed layer formed on the inner walls of the through hole and the opening; and   (h) removing the seed layer in a region other than a region where the second and third electrodes are formed.   
     
     
         2 . The manufacturing process of a semiconductor device according to  claim 1 , further comprising the step of: before the step (b),
 (i) grinding the second surface of the semiconductor substrate so that the semiconductor substrate has a predetermined thickness.   
     
     
         3 . The manufacturing process of a semiconductor device according to  claim 1 , further comprising the step of: after the step (h),
 (j) connecting a bump to the first electrode.   
     
     
         4 . The manufacturing process of a semiconductor device according to  claim 1 ,
 wherein, in the step (e), the first insulating film is removed by dry etching.   
     
     
         5 . The manufacturing process of a semiconductor device according to  claim 1 ,
 wherein, in the step (e), the first insulating film is removed by wet etching.   
     
     
         6 . A manufacturing process of a semiconductor device comprising the steps of:
 (a) forming a semiconductor element on a first surface of a semiconductor substrate, and then forming a first insulating film on the semiconductor element;   (b) forming a plurality of holes reaching the semiconductor substrate in a predetermined region of the first insulating film, and then filling an inside of the plurality of holes with a conductive material, thereby forming a plurality of contact plugs;   (c) forming a first electrode connected to the plurality of contact plugs;   (d) forming a ring-shaped trench penetrating through the semiconductor substrate from a side of a second surface of the semiconductor substrate opposite to the first surface;   (e) forming a second insulating film on the second surface of the semiconductor substrate including an inside of the ring-shaped trench;   (f) forming a through hole in the second insulating film and the semiconductor substrate on an inner side of the ring-shaped trench, from the side of the second surface of the semiconductor substrate;   (g) forming a seed layer connected to the plurality of contact plugs on the second surface of the semiconductor substrate including an inner wall of the through hole;   (h) forming a second electrode on the seed layer formed on the second surface of the semiconductor substrate around the through hole, and simultaneously forming a third electrode on the seed layer formed on the inner wall of the through hole; and   (i) removing the seed layer in a region other than a region where the second and third electrodes are formed.   
     
     
         7 . The manufacturing process of a semiconductor device according to  claim 6 , further comprising the step of: before the step (d),
 (j) grinding the second surface of the semiconductor substrate so that the semiconductor substrate has a predetermined thickness.   
     
     
         8 . The manufacturing process of a semiconductor device according to  claim 6 , further comprising the step of: after the step (i),
 (k) connecting a bump to the first electrode.   
     
     
         9 . A manufacturing process of a semiconductor device comprising the steps of:
 (a) forming a semiconductor element and a fourth electrode on a first surface of a semiconductor substrate, and then forming a first insulating film on the semiconductor element and the fourth electrode;   (b) forming a plurality of holes reaching the fourth electrode in a predetermined region of the first insulating film, and then filling an inside of the plurality of holes with a conductive material, thereby forming a plurality of contact plugs;   (c) forming a first electrode connected to the plurality of contact plugs;   (d) forming a ring-shaped trench penetrating through the semiconductor substrate from a side of a second surface of the semiconductor substrate opposite to the first surface;   (e) forming a second insulating film on the second surface of the semiconductor substrate including an inside of the ring-shaped trench;   (f) forming a through hole in the second insulating film and the semiconductor substrate on an inner side of the ring-shaped trench, from the side of the second surface of the semiconductor substrate;   (g) forming a seed layer connected to the fourth electrode on the second surface of the semiconductor substrate including an inner wall of the through hole;   (h) forming a second electrode on the seed layer formed on the second surface of the semiconductor substrate around the through hole, and simultaneously forming a third electrode on the seed layer formed on the inner wall of the through hole; and   (i) removing the seed layer in a region other than a region where the second and third electrodes are formed.   
     
     
         10 . The manufacturing process of a semiconductor device according to  claim 9 , further comprising the step of: before the step (d),
 (j) grinding the second surface of the semiconductor substrate so that the semiconductor substrate has a predetermined thickness.   
     
     
         11 . The manufacturing process of a semiconductor device according to  claim 9 , further comprising the step of: after the step (i),
 (k) connecting a bump to the first electrode.   
     
     
         12 . The manufacturing process of a semiconductor device according to  claim 1 ,
 wherein the inside of the ring-shaped trench is completely filled with the second insulating film.   
     
     
         13 . The manufacturing process of a semiconductor device according to  claim 1 ,
 wherein a cavity is formed inside the ring-shaped trench.   
     
     
         14 . The manufacturing process of a semiconductor device according to  claim 1 ,
 wherein a width of the ring-shaped trench is 2 to 10 μm.   
     
     
         15 . The manufacturing process of a semiconductor device according to  claim 1 ,
 wherein an inner diameter of the through hole is 5 to 40 μm.   
     
     
         16 . The manufacturing process of a semiconductor device according to  claim 6 ,
 wherein an inner diameter of the plurality of holes is 1 to 2 μm.