Multiple bonding layers for thin-wafer handling

Abstract

Multiple bonding layer schemes that temporarily join semiconductor substrates are provided. In the inventive bonding scheme, at least one of the layers is directly in contact with the semiconductor substrate and at least two layers within the scheme are in direct contact with one another. The present invention provides several processing options as the different layers within the multilayer structure perform specific functions. More importantly, it will improve performance of the thin-wafer handling solution by providing higher thermal stability, greater compatibility with harsh backside processing steps, protection of bumps on the front side of the wafer by encapsulation, lower stress in the debonding step, and fewer defects on the front side.

Having described the invention, the following is claimed: 
     
         1 . A method for separating a stack of substrates wherein a first substrate and a second substrate are temporarily bonded together by a first bonding layer and a second bonding layer, the method comprising the step of:
 mechanically disrupting or destroying an outer periphery of the first bonding layer and/or the second bonding layer using at least one of the following:
 laser ablation, 
 plasma etching, 
 water jetting, or 
 other high-energy techniques that effectively etch or decompose the first bonding layer and/or the second bonding layer. 
   
     
     
         2 . The method of  claim 1 , wherein the method further includes a step of:
 applying a force to the first substrate and/or the second substrate to separate the first substrate and the second substrate from each other.   
     
     
         3 . A method for separating a stack of substrates wherein a first substrate and a second substrate are temporarily bonded together by a first bonding layer and a second bonding layer, the method comprising the step of:
 sawing or cutting through or cleaving the first bonding layer and/or the second bonding layer.   
     
     
         4 . The method of  claim 3 , wherein the method further includes a step of:
 applying a force to the first substrate and/or the second substrate to separate the first substrate and the second substrate from each other.