Integrating atomic scale processes: ald (atomic layer deposition) and ale (atomic layer etch)

Abstract

Methods are provided for integrating atomic layer etch and atomic layer deposition by performing both processes in the same chamber or reactor. Methods involve sequentially alternating between atomic layer etch and atomic layer deposition processes to prevent feature degradation during etch, improve selectivity, and encapsulate sensitive layers of a semiconductor substrate.

1 - 31 . (canceled) 
     
     
         32 . A method comprising:
 providing a substrate to a chamber, the substrate having a feature with an aspect ratio of at least about 2:1;   exposing the substrate to alternating pulses of an etching gas and a removal gas to etch the substrate layer by layer; and   exposing the substrate to alternating pulses of a first reactant and a second reactant to deposit a film over the substrate.   
     
     
         33 . The method of  claim 32 , wherein a plasma is ignited during at least one of a pulse of the etching gas and a pulse of the removal gas. 
     
     
         34 . The method of  claim 32 , wherein the aspect ratio is at least about 4:1. 
     
     
         35 . The method of  claim 32 , wherein the aspect ratio is at least about 6:1. 
     
     
         36 . The method of  claim 32 , wherein the aspect ratio is at least about 10:1. 
     
     
         37 . The method of  claim 32 , wherein the aspect ratio is at least about 30:1. 
     
     
         38 . The method of  claim 32 , wherein a pulse of the etching gas modifies the substrate to form a modified material and a pulse of the removal gas removes at least some of the modified material. 
     
     
         39 . The method of  claim 32 , wherein etching the substrate layer by layer is performed in a self-limiting manner. 
     
     
         40 . The method of  claim 32 , wherein depositing the film over the substrate is performed in a self-limiting manner. 
     
     
         41 . The method of  claim 32 , wherein exposing the substrate to the alternating pulses of the etching gas and the removal gas comprises applying a bias to the substrate. 
     
     
         42 . The method of  claim 41 , wherein the bias is applied during the pulses of the removal gas but not during the pulses of the etching gas. 
     
     
         43 . The method of  claim 32 , wherein the exposing the substrate to the alternating pulses of the etching gas and the removal gas and the exposing the substrate to the alternating pulses of the first reactant and the second reactant are performed without breaking vacuum. 
     
     
         44 . A method comprising:
 providing a substrate to a chamber, the substrate having a feature with a feature opening of less than about 150 nm;   exposing the substrate to alternating pulses of an etching gas and a removal gas to etch the substrate layer by layer; and   exposing the substrate to alternating pulses of a first reactant and a second reactant to deposit a film over the substrate.   
     
     
         45 . The method of  claim 44 , wherein a plasma is ignited during at least one of a pulse of the etching gas and a pulse of the removal gas. 
     
     
         46 . The method of  claim 44 , wherein a pulse of the etching gas modifies the substrate to form a modified material and a pulse of the removal gas removes at least some of the modified material. 
     
     
         47 . The method of  claim 44 , wherein etching the substrate layer by layer is performed in a self-limiting manner. 
     
     
         48 . The method of  claim 44 , wherein depositing the film over the substrate is performed in a self-limiting manner. 
     
     
         49 . The method of  claim 44 , wherein exposing the substrate to the alternating pulses of the etching gas and the removal gas comprises applying a bias to the substrate. 
     
     
         50 . The method of  claim 49 , wherein the bias is applied during the pulses of the removal gas but not during the pulses of the etching gas. 
     
     
         51 . The method of  claim 44 , wherein the exposing the substrate to the alternating pulses of the etching gas and the removal gas and the exposing the substrate to the alternating pulses of the first reactant and the second reactant are performed without breaking vacuum.