Isolation structure with nitrogen-containing liner and methods of manufacture

Abstract

A semiconductor isolation trench includes a substrate and a trench formed therein. The trench is lined with a nitrogen-containing liner and filled with a dielectric material. The nitrogen-containing liner preferably contacts the active region of a device, such as a transistor, located adjacent to the trench.

1 . An isolation structure comprising: 
 a substrate having a trench with sidewall surfaces and at least one of a top rounded corner and a bottom rounded corner;    a nitrogen-containing liner in contact with at least one of the top rounded corner or the bottom rounded corner; and    a trench-filling material in the trench.    
   
   
       2 . The isolation structure of  claim 1 , wherein the top rounded corner or bottom rounded corner has a radius of curvature in the range of about 5 to about 50 nm.  
   
   
       3 . The isolation structure of  claim 1 , wherein the trench has a trench depth in the range of about 2000 to about 6000 angstroms.  
   
   
       4 . The isolation structure of  claim 1 , wherein the nitrogen-containing liner has a thickness in the range of about 5 to about 200 angstroms.  
   
   
       5 . The isolation structure of  claim 1 , further comprising at least one transistor formed in a portion of the substrate adjacent to the trench.  
   
   
       6 . The isolation structure of  claim 1 , wherein the trench-filling material comprises silicon oxide.  
   
   
       7 . The isolation structure of  claim 1 , wherein the trench-filling material comprises poly-crystalline silicon.  
   
   
       8 . The isolation structure of  claim 1 , wherein the nitrogen-containing liner comprises silicon nitride.  
   
   
       9 . The isolation structure of  claim 1 , wherein the nitrogen containing liner comprises silicon oxynitride.  
   
   
       10 . The isolation structure of  claim 1 , wherein the nitrogen-containing liner has a nitrogen content of about 5 to about 60 percent.  
   
   
       11 . A semiconductor structure comprising: 
 a semiconductor substrate having a trench with a sidewall surface;    a nitrogen-containing liner in contact with the sidewall surface;    a trench-filling material in the trench;    an active area within the semiconductor substrate adjacent the trench, the active area having at least one transistor device formed therein;    an inter-layer dielectric overlying the semiconductor substrate;    a metal line overlying the inter-layer dielectric; and    a conductive contact connecting the metal line to the active area.    
   
   
       12 . The semiconductor structure of  claim 1   1 , wherein the trench has a trench depth in the range of about 2000 to about 6000 angstroms.  
   
   
       13 . The semiconductor structure of  claim 1   1 , wherein the nitrogen-containing liner has a thickness in the range of about 5 to about 200 angstroms.  
   
   
       14 . The semiconductor structure of  claim 11 , wherein the trench-filling material comprises silicon oxide.  
   
   
       15 . The semiconductor structure of  claim 11 , wherein the trench-filling material comprises silicon oxide.  
   
   
       16 . The semiconductor structure of  claim 11 , wherein the trench-filling material comprises poly-crystalline silicon.  
   
   
       17 . The semiconductor structure of  claim 11 , wherein the nitrogen-containing liner comprises silicon nitride.  
   
   
       18 . The semiconductor structure of  claim 11 , wherein the nitrogen-containing liner comprises silicon oxynitride.  
   
   
       19 . The semiconductor structure of  claim 11 , wherein the nitrogen-containing liner has a nitrogen content of about 5 to about 60 percent.  
   
   
       20 . The semiconductor structure of  claim 11 , wherein the inter-layer dielectric comprises silicon oxide.