Method of forming through-silicon vias with stress buffer collars and resulting devices

Abstract

A method of forming a via having a stress buffer collar, wherein the stress buffer collar can absorb stress resulting from a mismatch in the coefficients of thermal expansion of the surrounding materials. Other embodiments are described and claimed.

1 - 21 . (canceled) 
   
   
       22 . A device comprising:
 a die comprised of a first material;   a via extending into the die;   a layer of a buffer material disposed in the via; and   a second material disposed over the buffer layer within the via;   wherein the buffer layer is capable of absorbing stress due to a thermal expansion mismatch between the first and second materials.   
   
   
       23 . The device of  claim 22 , wherein the die includes a front side and an opposing back side, and wherein circuitry is formed on the die front side and an interconnect structure is disposed over the die front side. 
   
   
       24 . The device of  claim 23 , wherein the via extends from the die back side to a conductor in the interconnect structure, and wherein the second material comprises a conductive material. 
   
   
       25 . The device of  claim 24 , wherein the conductive material comprises copper and the die comprises silicon. 
   
   
       26 . The device of  claim 24 , wherein the die is bonded to a second die. 
   
   
       27 - 32 . (canceled)