Low surface roughness substrate having a via and methods of making the same

Abstract

Methods of forming a via in substrates include etching a damage region extending through a thickness of a stack of a plurality of substrates removably bonded together. Each of the substrates in the stack has at least one surface removably bonded to a surface of another substrate in the stack, wherein when the substrates in the stack are debonded, each substrate has at least one surface that has a surface roughness (Ra) of less than or equal to about 0.6 nm.

What is claimed is: 
     
         1 . A method of forming substrates with a via, the method comprising:
 etching a damage region in a stack to form a via in the stack,   wherein the stack comprises a plurality of substrates including a first substrate and at least one additional substrate,   wherein each of the plurality of substrates has at least one surface removably bonded to a surface of another of the plurality of substrates,   wherein the damage region extends through the entire thickness of the at least one additional substrate, and the etching forms a through via in the at least one additional substrate,   wherein the etching forms a blind via in the first substrate, and   the at least one surface of each of the plurality of substrates removably bonded to the surface of another of the plurality of substrates has a surface roughness (Ra) of less than or equal to about 0.6 nm upon debonding the plurality of substrates.   
     
     
         2 . The method of  claim 1 , wherein the damage region of the first substrate extends through only a portion of the first substrate. 
     
     
         3 . The method of  claim 1 , wherein the damage region of the first substrate extends through the first substrate and only a portion of the damage region is etched to form the blind via. 
     
     
         4 . The method of  claim 1 , further comprising debonding the plurality of substrates from one another. 
     
     
         5 . The method of  claim 1 , further comprising creating at least one damage region extending through the thickness of the stack prior to etching. 
     
     
         6 . The method of  claim 5 , wherein creating at least one damage region within the stack comprises applying a laser pulse to the bonded wafer pair to create the at least one damage region. 
     
     
         7 . The method of  claim 1 , wherein the plurality of substrates is bonded together using Van der Waals forces. 
     
     
         8 . The method of  claim 1 , further comprising:
 creating at least one damage region extending through a portion of a thickness of the first substrate; and   creating at least one damage region extending through the entire thickness of the at least one additional substrate disposed;   wherein when the first substrate and the at least one additional substrate are removably bonded together, the at least one damage region in the first substrate is aligned with the at least one damage region in the at least one additional substrate.   
     
     
         9 . The method of  claim 1 , wherein the plurality of substrates is selected from a group consisting of glass, glass-ceramic, ceramic, and combinations thereof. 
     
     
         10 . The method of  claim 1 , wherein the damage region of the stack is etched with an etching solution comprising hydrofluoric acid. 
     
     
         11 . The method of  claim 1 , wherein the stack comprises two or more substrates removably bonded together. 
     
     
         12 . A stack, comprising:
 a plurality of substrates including a first substrate and at least one additional substrate;   at least one blind via in the first substrate; and   at least one through via in the at least one additional substrate,   wherein each of the plurality of substrates has a surface removably bonded to a surface of another one of the plurality of substrates, and   wherein the surface of each of the plurality of substrates removably bonded to a surface of another one of the plurality of substrates has a surface roughness (R a ) of less than or equal to about 0.6 nm upon debonding the plurality of substrates.   
     
     
         13 . The stack of  claim 12 , wherein the stacks comprises 2 or more substrates removably bonded together. 
     
     
         14 . The stack of  claim 12 , wherein the plurality of substrates is bonded together using Van der Waals forces.