Process for making a CMOS image sensor

Abstract

An image sensor includes a semi-conducting substrate having a photo-sensitive region and doping for forming a path to a charge-to-voltage mechanism; a dielectric spanning the substrate; and a semi-conducting layer, which is less than approximately 1 micrometer, spanning the dielectric which contains electrodes and circuit elements that control flow of charge.

1 . A method for creating an image sensor comprising the steps of: 
 (a) providing a substrate;    (b) providing the substrate with a dielectric;    (c) providing a single crystal, semi-conducting layer which is approximately 1 micrometer on the dielectric which contains electrodes and circuit elements that control flow of charge; and    (d) implanting through the dielectric and semi-conducting layer into the substrate for forming a photo-sensitive region, a transfer gate channel and charge-to-voltage mechanism.    
   
   
       2 . The method as in  claim 1  further comprising forming an isolation region adjacent the photodiode.  
   
   
       3 . A method for creating an image sensor comprising the steps of: 
 (a) forming a substrate;    (b) covering the substrate with a dielectric;    (c) implanting through the dielectric into the substrate for forming a photodiode, a transfer gate channel and floating diffusion; and    (d) bonding a single crystal, semi-conducting layer which is approximately 1 micrometer onto the dielectric which contains electrodes and circuit elements that control flow of charge.    
   
   
       4 . The method as in  claim 3  further comprising forming an epitaxial layer as a portion of the substrate.  
   
   
       5 . The method as in  claim 1  further comprising forming an epitaxial layer as a portion of the substrate.