Methods of thin film process

Abstract

A method for forming a semiconductor structure includes forming a plurality of features across a surface of a substrate, with at least one space being between two adjacent features. A first dielectric layer is formed on the features and within the at least one space. A portion of the first dielectric layer interacts with a reactant derived from a first precursor and a second precursor to form a first solid product. The first solid product is decomposed to substantially remove the portion of the first dielectric layer. A second dielectric layer is formed to substantially fill the at least one space.

1 . A method of fabricating a semiconductor structure, the method comprising:
 providing a substrate having a least one trench between two or more adjacent features;   depositing a first layer comprising silicon oxide within at least a portion of the trench;   reacting at least a portion of the first layer with reactive species from a reactant gas mixture comprising a fluorine-containing gas and a reducing gas, wherein the reaction forms a solid product comprising materials from the first layer and the reactive species;   sublimating the solid product from the substrate to leave a remaining portion of the first layer; and   depositing a second layer comprising a dielectric material on at least a part of the remaining portion of the first layer.   
     
     
         2 . The method of  claim 1 , wherein semiconductor substrate comprises a semiconductor wafer. 
     
     
         3 . The method of  claim 2 , wherein the semiconductor substrate comprises a plurality of semiconductor wafers. 
     
     
         4 . The method of  claim 1 , wherein fluorine-containing gas comprises hydrogen fluoride. 
     
     
         5 . The method of  claim 1 , wherein the fluorine-containing gas comprises nitrogen trifluoride. 
     
     
         6 . The method of  claim 1 , wherein the reducing gas comprises ammonia. 
     
     
         7 . The method of  claim 1 , wherein the solid product comprises an ammonia fluorosilicate. 
     
     
         8 . The method of  claim 7 , wherein the solid product comprises (NF 4 ) 2 SiF 6 . 
     
     
         9 . The method of  claim 1 , wherein the second layer comprises a dielectric material selected from the group consisting of silicon oxide, silicon nitride, silicon oxynitride, a low-κ dielectric material, and an ultra low-κ dielectric material. 
     
     
         10 . The method of  claim 1 , wherein the first layer is deposited by a process selected from the group consisting of a spin-coating process, a high aspect ratio process, an e-HARP process, an APCVD process, a HTUSG process, an HDP-CVD process, an PECVD process, a furnace deposited oxide process, and an atomic layer deposition process. 
     
     
         11 . The method of  claim 1 , wherein the second layer is deposited by a process selected from the group consisting of a spin-coating process, a high aspect ratio process, an e-HARP process, an APCVD process, a HTUSG process, an HDP-CVD process, an PECVD process, a furnace deposited oxide process, and an atomic layer deposition process. 
     
     
         12 . A method of fabricating a semiconductor structure, the method comprising:
 providing one or more wafer substrates each having at least one trench between two or more adjacent features;   depositing a silicon oxide layer within at least a portion of the trench;   etching at least a portion of the silicon oxide layer by sublimating an ammonia fluorosilicate solid product that is formed from the reaction of the silicon oxide with a reactive species generated from a gas mixture comprising hydrogen fluoride and ammonia; and   depositing a dielectric layer on a remaining portion of the silicon oxide layer within the trench.   
     
     
         13 . The method of  claim 12 , wherein the silicon oxide layer is deposited by a high aspect ratio process. 
     
     
         14 . The method of  claim 12 , wherein the remaining portion of the silicon oxide layer forms an angle between slanted sidewalls of the silicon oxide remaining in the trench and the silicon oxide remaining in the bottom of the trench of about 87° or less. 
     
     
         15 . The method of  claim 12 , wherein the dielectric layer comprises silicon oxide deposited by a high aspect ratio process. 
     
     
         16 . A method of processing a semiconductor substrate, the method comprising:
 depositing a first silicon oxide layer on the semiconductor substrate, wherein the substrate has at least one trench formed thereon;   exposing the semiconductor substrate at a first temperature to hydrogen fluoride and ammonia, wherein the hydrogen fluoride and ammonia react with a portion of the silicon oxide layer to form a solid product;   adjusting the substrate to a second temperature greater than the first temperature to remove the solid product and leave a remaining portion of the first silicon oxide layer; and   depositing a second silicon oxide layer on the remaining portion of the first silicon oxide layer, wherein the at least a portion of the second silicon oxide layer is deposited in the trench.   
     
     
         17 . The method of  claim 16 , wherein the first silicon oxide layer is deposited by a high aspect ratio process. 
     
     
         18 . The method of  claim 16 , wherein the second silicon oxide layer is deposited by a high aspect ratio process. 
     
     
         19 . The method of  claim 16 , wherein the solid product comprises an ammonia fluorosilicate. 
     
     
         20 . The method of  claim 16 , wherein the semiconductor substrate comprises a silicon substrate.