Etching method with less waste gases

Abstract

An etching method with less waste gases. Firstly, provide a substrate covered by a dielectric layer, and put both the substrate and the dielectric layer into a chamber that is coupled with a power source and a C 3 F 8 reactive gases source. Next, provide a plasma inside the chamber under an environment with a low RF power, and a low pressure. Finally, terminate the existence of the plasma and move both the substrate and the etched dielectric later out the chamber.

What is claimed is:  
     
         1 . A method of etching with less waste gases, comprising: 
 providing a substrate, said substrate being covered by a dielectric layer;    putting said substrate inside a chamber, said chamber being coupled with a power source and a C 3 F 8  reactive gases source;    forming a plasma inside said chamber under an environment having a low RF power and a low pressure;    etching said dielectric layer by said plasma, and    terminating the existence of said plasma and moving said substrate out said chamber.    
     
     
         2 . The method of  claim 1 , further comprising the step of forming said plasma under an amended environment having a low C 3 F 8  flow rate, a low RF power and a low pressure.  
     
     
         3 . The method of  claim 1 , further comprising the step of covering a pattern mask on said dielectric layer before said dielectric layer being etched by said plasma, whereby said plasma only etch partial said dielectric layer which is not covered by said pattern mask.  
     
     
         4 . The method of  claim 3 , further comprising the step of etching said pattern mask by said plasma.  
     
     
         5 . The method of  claim 2 , further comprising the step of covering a pattern mask on said dielectric layer before said dielectric layer being etched by said plasma, whereby said plasma only etch partial said dielectric layer which is not covered by said pattern mask.  
     
     
         6 . The method of  claim 5 , further comprising the step of etching said pattern mask by said plasma.  
     
     
         7 . The method of  claim 1 , wherein the material of said dielectric layer is chosen from a group consisting of SiO 2 , SiN and SiO x N y , both X and Y being positive integers.  
     
     
         8 . The method of  claim 1 , said low RF power being about from 900 W to 1300 W.  
     
     
         9 . The method of  claim 1 , the pressure of said environment being smaller than about 3 torrs.  
     
     
         10 . The method of  claim 2 , said low C 3 F 8  flow rate being smaller than about 150 sccm.  
     
     
         11 . The method of  claim 1 , said plasma further comprising one of the following elements: He, Ar, N 2 O, O, and NO 2 ,  
     
     
         12 . A method of etching with less waste gases, comprising: 
 forming a dielectric layer on a substrate; and    applying a plasma on said dielectric layer to let at least partial said dielectric layer be etched by said plasma under an environment having a low RF power and a low pressure, wherein the main material of said plasma is the fluorocarbon which could produce a plurality of CF2* radials under said environment which has low RF power and low pressure environment.    
     
     
         13 . The method of  claim 12 , said fluorocarbon producing more CF2* radials than CF4 under said environment, said fluorocarbon also producing more CF2* radials than C2F6 under said environment.  
     
     
         14 . The method of  claim 12 , further comprising the step of lowering the flow rate of said fluorocarbon during both the formation of said plasma and the existence of said plasma.  
     
     
         15 . The method of  claim 12 , said low RF power being about from 900 W to 1300 W.  
     
     
         16 . The method of  claim 12 , the pressure of said environment being smaller than about 3 torrs.  
     
     
         17 . The method of  claim 14 , said low C 3 F 8  flow rate being smaller than about 150 sccm.  
     
     
         18 . A method of cleaning the chamber with less waste gases, comprising: 
 providing a chamber to be cleaned, said chamber being coupled with a power source and a C 3 F 8  reactive gases source, a dielectric layer being located on the sidewall of said chamber and on a wafer holder;    forming a plasma inside said chamber under an environment having a low RF power and a low pressure;    treating said dielectric layer by said plasma; and    terminating the existence of said plasma.    
     
     
         19 . The method of  claim 18 , further comprising the step of lowering the flow rate of said C 3 F 8  during both the formation of said plasma and the existence of said plasma.  
     
     
         20 . The method of  claim 18 , said dielectric layer being located on a partial surface of said wafer holder, wherein said partial surface is not covered by a wafer while said wafer being treated by said chamber.