Ex parte IWAMURO - Page 8

          Appeal No. 95-4159                                                          
          Application 08/151,055                                                      

          expected to have lifetime killers in order to operate as a PT               
          device.  Although the examiner attempts to dismiss features of              
          claim 1 as being directed to the process of making the                      
          product, the presence or absence of lifetime killers in the                 
          device is a structural distinction which is known to affect                 
          the performance of the device.  Therefore, Fay’s epitaxial                  
          layers 13 and 14 cannot simply be equated with a single                     
          substrate having the properties recited in claim 1.                         
          Appellant also argues that the collective teachings of                      
          Fay and Laska do not teach or suggest that a third diffused                 
          region of at least 2 microns should be implanted on the                     
          backside of the substrate [brief, pages 7-9].  It is the                    
          examiner’s position that since the P-type collector region of               
          Fay is thicker than 5 microns, if the P-type region of Fay                  
          were created by diffusion as taught by Laska, then this                     
          diffused P-type region would also have a thickness greater                  
          than 5 microns.  Appellant notes that Laska discloses no                    
          dimensions for his third diffused region, and the Laska                     
          teachings of an NPT IGBT would not have been combined with the              
          Fay PT IGBT for determining dimensions of layers in two                     
          disparate devices such as this.  We agree with appellant.                   

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