Removing sacrificial material by thermal decomposition

Abstract

A thermally decomposable sacrificial material is deposited in a void or opening in a dielectric layer on a semiconductor substrate. The thermally decomposable sacrificial material may be removed without damaging or removing the dielectric layer. The thermally decomposable sacrificial material may be a combination of organic and inorganic materials, such as a hydrocarbon-siloxane polymer hybrid.

1 - 15 . (Canceled).  
   
   
       16 . An apparatus comprising: 
 a semiconductor substrate having a conductive layer, a barrier layer over the conductive layer, and a dielectric layer over the barrier layer;    a first opening and a second opening etched into the dielectric layer, at least one of the openings extending through the dielectric layer to the barrier layer; and    a thermally decomposable sacrificial material in at least one of the first and second openings, wherein the first opening is a via and the second opening is a trench in a dual damascene interconnect.    
   
   
       17 . An apparatus comprising: 
 a semiconductor substrate having a conductive layer, a barrier layer over the conductive layer, and a dielectric layer over the barrier layer;    a first opening and a second opening etched into the dielectric layer, at least one of the openings extending through the dielectric layer to the barrier layer; and    a thermally decomposable sacrificial material in at least one of the first and second openings, wherein the dielectric layer has a dielectric constant below 3.9.    
   
   
       18 . The apparatus of  claim 17  wherein the dielectric layer has a dielectric constant in the range of 2.2 to 2.6.  
   
   
       19 . An apparatus comprising: 
 a semiconductor substrate having a conductive layer, a barrier layer over the conductive layer, and a dielectric layer over the barrier layer;    a first opening and a second opening etched into the dielectric layer, at least one of the openings extending through the dielectric layer to the barrier layer; and    a thermally decomposable sacrificial material in at least one of the first and second openings, wherein the thermally decomposable sacrificial material is a hydrocarbon-siloxane polymer hybrid.    
   
   
       20 . An apparatus comprising: 
 a semiconductor substrate having a conductive layer, a barrier layer over the conductive layer, and a dielectric layer over the barrier layer;    a first opening and a second opening etched into the dielectric layer, at least one of the openings extending through the dielectric layer to the barrier layer; and    a thermally decomposable sacrificial material in at least one of the first and second openings, wherein the thermally decomposable sacrificial material is light absorbing.    
   
   
       21 . The apparatus of  claim 16  wherein the dielectric layer has a dielectric constant below 3.9.  
   
   
       22 . The apparatus of  claim 16  wherein the dielectric layer has a dielectric constant in the range of 2.2 to 2.6.  
   
   
       23 . The apparatus of  claim 16  wherein the thermally decomposable sacrificial material is a hydrocarbon-siloxane polymer hybrid.  
   
   
       24 . The apparatus of  claim 16  wherein the thermally decomposable sacrificial material is light absorbing.  
   
   
       25 . The apparatus of  claim 17  wherein the first opening is a via and the second opening is a trench in a dual damascene interconnect.  
   
   
       26 . The apparatus of  claim 19  wherein the first opening is a via and the second opening is a trench in a dual damascene interconnect.  
   
   
       27 . The apparatus of  claim 19  wherein the dielectric layer has a dielectric constant below 3.9.  
   
   
       28 . The apparatus of  claim 20  wherein the first opening is a via and the second opening is a trench in a dual damascene interconnect.  
   
   
       29 . The apparatus of  claim 20  wherein the dielectric layer has a dielectric constant below 3.9.