Method Of Improving Ion Beam Quality In A Non-Mass-Analyzed Ion Implantation System

Abstract

A method of processing a workpiece is disclosed, where the plasma chamber is first coated using a conditioning gas and optionally, a co-gas. The conditioning gas, which is disposed within a conditioning gas container may comprise a hydride of the desired dopant species and a filler gas, where the filler gas is a hydride of a Group 4 or Group 5 element. The remainder of the conditioning gas container may comprise hydrogen gas. Following this conditioning process, a feedgas, which comprises fluorine and the desired dopant species, is introduced to the plasma chamber and ionized. Ions are then extracted from the plasma chamber and accelerated toward the workpiece, where they are implanted without being first mass analyzed. In some embodiments, the desired dopant species may be boron.

What is claimed is: 
     
         1 . An apparatus for processing workpieces, comprising:
 an ion source having a plasma chamber defined by a dielectric window, a plurality of plasma chamber walls and an aperture;   an RF antenna disposed outside the plasma chamber proximate the dielectric window;   a feedgas gas container, containing fluorine and a desired dopant species, in communication with the plasma chamber; and   a conditioning gas container, containing a conditioning gas, the conditioning gas comprising a hydride containing the desired dopant species and a filler gas, the filler gas comprising a hydride of a Group 4 element or a hydride of a species having an opposite conductivity of the desired dopant species.   
     
     
         2 . The apparatus of  claim 1 , further comprising a coating disposed on the plasma chamber walls. 
     
     
         3 . The apparatus of  claim 2 , wherein the coating is formed by ionizing the conditioning gas in the plasma chamber. 
     
     
         4 . The apparatus of  claim 2 , wherein the coating comprises the desired dopant species. 
     
     
         5 . The apparatus of  claim 4 , wherein the coating further comprises the Group 4 element or the species having an opposite conductivity of the desired dopant species. 
     
     
         6 . The apparatus of  claim 1 , wherein the desired dopant species comprises boron. 
     
     
         7 . The apparatus of  claim 6 , wherein the filler gas comprises a hydride of a Group 5 element. 
     
     
         8 . The apparatus of  claim 1 , wherein the conditioning gas disposed in the conditioning gas container further comprises hydrogen gas. 
     
     
         9 . The apparatus of  claim 8 , wherein less than 50% of the conditioning gas disposed in the conditioning gas container comprises hydrogen gas. 
     
     
         10 . The apparatus of  claim 1 , further comprising a third gas container in communication with the plasma chamber, containing a co-gas, wherein the co-gas comprises a noble gas, a hydride of a Group 4 element or a hydride of a species having an opposite conductivity of the desired dopant species. 
     
     
         11 . The apparatus of  claim 1 , further comprising an electrode disposed outside the aperture to extract and focus positively charged ions from within the plasma chamber through the aperture and toward a workpiece. 
     
     
         12 . An apparatus for processing workpieces, comprising:
 an ion source having a plasma chamber defined by a dielectric window, a plurality of plasma chamber walls and an aperture;   an RF antenna disposed outside the plasma chamber proximate the dielectric window; and   a coating disposed on the plasma chamber walls, wherein the coating comprises a desired dopant species.   
     
     
         13 . The apparatus of  claim 12 , wherein the coating further comprises a Group 4 element or a species having an opposite conductivity of the desired dopant species. 
     
     
         14 . The apparatus of  claim 12 , wherein the desired dopant species comprises boron. 
     
     
         15 . The apparatus of  claim 14 , wherein the coating comprises boron and at least one of arsenic, phosphorus, silicon, and germanium. 
     
     
         16 . The apparatus of  claim 12 , further comprising an electrode disposed outside the aperture to extract and focus positively charged ions from within the plasma chamber through the aperture and toward a workpiece. 
     
     
         17 . The apparatus of  claim 12 , further comprising a feedgas gas container, containing fluorine and the desired dopant species, in communication with the plasma chamber. 
     
     
         18 . The apparatus of  claim 12 , further comprising a conditioning gas container, containing a conditioning gas, the conditioning gas comprising a hydride containing the desired dopant species and a filler gas, the filler gas comprising a hydride of a Group 4 element or a hydride of a species having an opposite conductivity of a desired dopant species. 
     
     
         19 . The apparatus of  claim 18 , wherein the desired dopant species is a Group 3 element and the filler gas comprises a hydride of a Group 5 element. 
     
     
         20 . The apparatus of  claim 18 , wherein the conditioning gas disposed in the conditioning gas container further comprises hydrogen gas. 
     
     
         21 . The apparatus of  claim 20 , wherein less than 50% of the conditioning gas disposed in the conditioning gas container comprises hydrogen gas. 
     
     
         22 . The apparatus of  claim 18 , further comprising a third gas container in communication with the plasma chamber, containing a co-gas, wherein the co-gas comprises a noble gas, a hydride of a Group 4 element or a hydride of a species having an opposite conductivity of the desired dopant species.