Semiconductor device and manufacturing method therefor

Abstract

A semiconductor device is obtained, in which excellent characteristics are achieved, the reliability is improved, and an SiC wafer can also be used for the fabrication. A plurality of Schottky-barrier-diode units 10 is formed on an SiC chip 9 , and each of the units 10 has an external output electrode 4 independently of each other. Bumps 11 (the diameter is from several tens to several hundreds of μm) are formed only on the external output electrodes 4 of non-defective units among the units 10 formed on the SiC chip 9 , meanwhile bumps are not formed on the external output electrodes 4 of defective units in which the withstand voltage is too low, or the leakage current is too much. Because the bumps are not formed on the defective units, Schottky-barrier-side electrodes 3 are connected in parallel to the exterior of the device through the bumps 11 , and a wiring layer 13 and an external lead 13 a of a wiring substrate 12 ; thus, only the external output electrodes 4 of the non-defective units 10 are connected in parallel with each other.

1 . A semiconductor device comprising: 
 a plurality of semiconductor units formed on a semiconductor chip;    external output electrodes formed, independently of each other, on the semiconductor units, each on one of the units;    bumps selectively formed on the external output electrodes of, among the semiconductor units as including non-defective and defective units, the non-defective semiconductor units; and    a wiring substrate provided with a wiring layer electrically connected to the bumps.    
   
   
       2 . A semiconductor device as recited in  claim 1 , wherein the semiconductor units are Schottky diodes fabricated using an SiC wafer, or MOSFET semiconductor devices fabricated using the same.  
   
   
       3 . A semiconductor device as recited in  claim 1 , further comprising: 
 a region apart from the external output electrodes formed on the semiconductor chip; and    bumps for connecting the region with the wiring substrate.    
   
   
       4 . A method of manufacturing a semiconductor device, the method comprising: 
 a step of forming a plurality of semiconductor units on a semiconductor wafer;    a step of determining whether each of the semiconductor units is defective or non-defective;    a step of selectively forming bumps on external output electrodes of, among the non-defective and defective semiconductor units, the non-defective semiconductor units, to obtain a semiconductor wafer member;    a step of segmenting the semiconductor wafer member to obtain a semiconductor chip having a plurality of semiconductor units; and    a step of electrically connecting the bumps with a wiring layer provided on a wiring substrate.    
   
   
       5 . A method of manufacturing a semiconductor device as recited in  claim 4 , wherein the semiconductor units are Schottky diodes fabricated using an SiC wafer, or MOSFET semiconductor devices fabricated using the same.  
   
   
       6 . A method of manufacturing a semiconductor device as recited in  claim 4 , wherein in the bump forming step the bumps are formed selectively, based on test results determining whether each of the semiconductor units is defective or non-defective, by dripping molten metal onto the external output electrodes of the non-defective semiconductor units.  
   
   
       7 . A method of manufacturing a semiconductor device as recited in  claim 4 , wherein in the bump forming step the bumps are formed with a bump bonder selectively, based on test results determining whether each of the semiconductor units is defective or non-defective, onto the external output electrodes of the non-defective semiconductor units.  
   
   
       8 . A method of manufacturing a semiconductor device as recited in  claim 4 , wherein the bump forming step includes, based on test results of determining whether each of the semiconductor units is defective or non-defective: 
 a step, for a photo-reactive resin layer provided on the semiconductor wafer, of selectively and sequentially exposing the photo-reactive resin layer to light so as to form apertures on the external output electrodes of the non-defective semiconductor units; and    a step of forming bumps in the apertures, so as to selectively form the bumps onto the external output electrodes of the non-defective semiconductor units.