Semiconductor device

Abstract

A technique for expanding an effective area in which a semiconductor structure required for a semiconductor device to function is desired. With the semiconductor device 2 of this invention, a pad 12 to be connected with a conductive wire 14 is sloping with respect to the surface of the semiconductor device 2 around the pad 12 and along a longitudinal direction of the conductive wire 14. Consequently, the length of the pad 12, when projecting the pad 12 onto the surface of the semiconductor device 2, can be shortened. As a result, the area of the pad region 10 can be reduced and the effective area for forming a semiconductor structure can be enlarged.

1 . A semiconductor device comprising:
 a semiconductor substrate;   an oxide film formed on a top surface of the semiconductor substrate;   a pad formed on the oxide film; and   a conductive wire bonded on the pad,   wherein   the oxide film includes a part whose thickness changes along a longitudinal direction of the conductive wire,   the pad includes a surface on which the conductive wire is bonded,   the surface includes a region formed on the part of the oxide film and sloping with respect to the top surface of the semiconductor substrate along the longitudinal direction, and   the oxide film is formed by oxidizing a first surface region of the semiconductor substrate into which ions for slightly increasing an oxidation rate are injected and a second surface region of the semiconductor substrate which is adjacent to the first surface region and into which ions for greatly increasing the oxidation rate are injected.   
     
     
         2 . The semiconductor device as in  claim 1 , wherein
 a distance between the surface of the pad and the top surface of the semiconductor substrate increases toward a side to which an extended portion of the conductive wire is pulled in order to cut the conductive wire connected with the pad.   
     
     
         3 . The semiconductor device as in  claim 2 , wherein
 a drag mark is not formed on the surface of the pad.   
     
     
         4 . A semiconductor device comprising:
 a semiconductor substrate;   an oxide film formed on a top surface of the semiconductor substrate;   a pad formed on the oxide film; and   a conductive wire bonded on the pad,   wherein   the oxide film includes a part whose thickness changes along a longitudinal direction of the conductive wire,   the pad includes a surface on which the conductive wire is bonded,   the surface includes a region formed on the part of the oxide film and sloping with respect to the top surface of the semiconductor substrate along the longitudinal direction, and   the oxide film is formed by oxidizing a first surface region of the semiconductor substrate into which ions for increasing an oxidation rate are injected and a second surface region of the semiconductor substrate which is adjacent to the first surface region and into which ions for increasing the oxidation rate are injected at a higher density than the first surface region.   
     
     
         5 . The semiconductor device as in  claim 4 , wherein
 a distance between the surface of the pad and the top surface of the semiconductor substrate increases toward a side to which an extended portion of the conductive wire is pulled in order to cut the conductive wire connected with the pad.   
     
     
         6 . The semiconductor device as in  claim 5 , wherein
 a drag mark is not formed on the surface of the pad.   
     
     
         7 . (canceled) 
     
     
         8 . A method of manufacturing a semiconductor device,
 the semiconductor device comprising:   a semiconductor substrate;   an oxide film formed on a top surface of the semiconductor substrate;   a pad formed on the oxide film; and   a conductive wire bonded on the pad,   wherein   the oxide film includes a part whose thickness changes along a longitudinal direction of the conductive wire,   the pad includes a surface on which the conductive wire is bonded, and   the surface includes a region formed on the part of the oxide film and sloping with respect to the top surface of the semiconductor substrate along the longitudinal direction,   the method comprising:   injecting ions for slightly increasing an oxidation rate into a first surface region of the semiconductor substrate;   injecting ions for greatly increasing the oxidation rate into a second surface region of the semiconductor substrate which is adjacent to the first surface region of the semiconductor substrate; and   oxidizing the first surface region and the second surface region to form the oxide film.   
     
     
         9 . A method of manufacturing a semiconductor device,
 the semiconductor device comprising:   a semiconductor substrate;   an oxide film formed on a top surface of the semiconductor substrate;   a pad formed on the oxide film; and   a conductive wire bonded on the pad,   wherein   the oxide film includes a part whose thickness changes along a longitudinal direction of the conductive wire,   the pad includes a surface on which the conductive wire is bonded, and   the surface includes a region formed on the part of the oxide film and sloping with respect to the top surface of the semiconductor substrate along the longitudinal direction,   the method comprising:   injecting ions for increasing an oxidation rate into a first surface region of the semiconductor substrate;   injecting ions for increasing the oxidation rate into a second surface region of the semiconductor substrate, which is adjacent to the first surface region of the semiconductor substrate, at a higher density than the first surface region; and   oxidizing the first surface region and the second surface region to form the oxide film.