Ultra-high speed anisotropic reactive ion etching

Abstract

A system and method for reactive ion etching (RIE) system of a material is provided. The system includes a plasma chamber comprising a plasma source and a gas inlet, a diffusion chamber comprising a substrate holder for supporting a substrate with a surface comprising the material and a gas diffuser, and a source of a processing gas coupled to the gas diffuser. In the system and method, at least one radical of the processing gas is reactive with the material to perform etching of the material, the gas diffuser is configured to introduce the processing gas into the processing region, and the substrate holder comprises an electrode that can be selectively biased to draw ions generated by the plasma source into the processing region to interact with the at least one processing gas to generate the at least one radical at the surface.

What is claimed is: 
     
         1 . A system for reactive ion etching (RIE) system of a material, comprising:
 a plasma chamber comprising a plasma source and a gas inlet; and   a diffusion chamber comprising a substrate holder for supporting a substrate with a surface comprising the material and a gas diffuser; and   a source of at least one processing gas coupled to the gas diffuser,   wherein at least one radical of the at least one processing gas is reactive with the material to perform etching of the material, wherein the substrate holder is configured to support the substrate within a processing region of the diffusion chamber, wherein the gas diffuser is configured to introduce the at least one processing gas into the processing region, and wherein the substrate holder comprises an electrode that can be selectively biased to draw ions generated by the plasma source into the processing region to interact with the at least one processing gas to generate the at least one radical at the surface.   
     
     
         2 . The RIE system of  claim 1 , wherein the plasma source comprises a high density plasma source. 
     
     
         3 . The RIE system of  claim 1 , wherein the high density plasma source comprises one of an inductively coupled plasma source, a capacitively coupled plasma source, magnetically enhanced plasma source, or a helicon plasma source. 
     
     
         4 . The RIE system of  claim 1 , wherein the gas diffuser comprises a diffuser ring. 
     
     
         5 . The RIE system of  claim 1 , wherein the diffuser ring is attached to the substrate holder. 
     
     
         6 . The RIE system of  claim 1 , wherein the gas diffuser comprises a plurality of nozzles. 
     
     
         7 . The RIE system of  claim 1 , wherein the gas inlet is coupled to a first gas delivery system and the gas diffuser is coupled to a second gas delivery system. 
     
     
         8 . The RIE system of  claim 7 , wherein the first gas delivery system is configured for delivering at least one gas comprising at least one of fluorine or chlorine, Ar, O 2 , or any combinations thereof and the second gas delivery system is configured for delivering NF 3 . 
     
     
         9 . The RIE system of  claim 8 , wherein the at least one gas comprising at least one of fluorine or chlorine comprises at least one of SF 6 , C 4 F 8 , CH 4 , or NF 3 . 
     
     
         10 . The RIE system of  claim 8 , wherein the first gas delivery system is configured for delivering Ar and NF 3 . 
     
     
         11 . A method for reactive ion etching, the method comprising:
 forming a plasma at a first location;   introducing at least one processing gas at a second location corresponding to a surface to be etched, wherein at least one radical of the at least one processing gas is reactive with the surface to perform etching of the surface; and   directing ions from the plasma to a substrate at second location to interact with the at least one processing gas to generate the at least one radical at the surface.   
     
     
         12 . The method of  claim 11 , wherein forming the plasma comprises generating the plasma using a high density plasma source. 
     
     
         13 . The method of  claim 12 , wherein the high density plasma source is selected from an inductively coupled plasma source, a capacitively coupled plasma source, magnetically enhanced plasma source, or a helicon plasma source. 
     
     
         14 . The method of  claim 11 , wherein introducing the at least one processing gas comprises providing a gas diffuser configured to direct the at least one processing gas into the second location. 
     
     
         15 . The method of  claim 12 , wherein the gas diffuser comprises a diffuser ring. 
     
     
         16 . The method of  claim 12 , wherein the gas diffuser comprises a plurality of nozzles. 
     
     
         17 . The method of  claim 11 , wherein the forming of the plasma comprises:
 directing at least one other processing gas into a plasma chamber;   generating the plasma by exciting the at least one processing gas in the plasma chamber.   
     
     
         18 . The method of  claim 17 , further comprising selecting the at least one other processing gas to comprise at least one gas comprising at least one of fluorine or chlorine, Ar, O 2 , or any combinations thereof and selecting the at least one processing gas introduced at the second location to comprise NF3. 
     
     
         19 . The method of  claim 18 , wherein the at least one gas comprising at least one of fluorine or chlorine comprises at least one of SF 6 , C 4 F 8 , CH 4 , or NF 3 . 
     
     
         20 . The method of  claim 17 , selecting the at least one other processing gas to comprise Ar and NF 3 .