Apparatus and method for focused electric field enhanced plasma-based ion implantation

Abstract

There is disclosed an apparatus and method for focused electric field enhanced plasma-based ion implantation. The apparatus includes an implantation chamber, a vacuum pump for maintaining the pressure in the implantation chamber at a desired level, a sample holder, means for applying a negative potential to the sample holder, and means for supplying a gaseous or vaporized implantation material. The supplying means takes the form of a feed conduit having an exit opening located in the implantation chamber above the sample holder, and when a negative potential is applied to the sample holder the exit opening of the feed conduit is maintained at a potential that is positive relative to the sample holder.

1 . An apparatus comprising:
 an implantation chamber;   an evaporation chamber including a heater and configured to vaporize a solid to thereby form a vapor;   a valve arranged to receive the vapor from the evaporation chamber; and   a conduit located between the valve and the implantation chamber, wherein the conduit includes a conduit exit that opens into the implantation chamber.   
     
     
         2 . The apparatus of  claim 1 , further comprising a valve heater arranged to transfer heat to the valve. 
     
     
         3 . The apparatus of  claim 1 , wherein the evaporation chamber further comprises an opening configured to receive a carrier gas. 
     
     
         4 . The apparatus of  claim 1 , wherein a length of the conduit is at least four times greater than an internal diameter of the conduit. 
     
     
         5 . The apparatus of  claim 1 , further comprising a vacuum chamber including a plasma generator, wherein the implantation chamber is located within the vacuum chamber. 
     
     
         6 . The apparatus of  claim 1 , further comprising a sample holder located within the implantation chamber, wherein:
 a surface of the sample holder opposite the conduit exit includes a cross-sectional area; and   the cross-sectional area of the sample holder is greater than a cross-sectional area of the conduit exit.   
     
     
         7 . The apparatus of  claim 6 , wherein the cross-sectional area of the sample holder is at least six times greater than the cross-sectional area of the conduit exit. 
     
     
         8 . An apparatus comprising:
 an evaporation chamber including a heater and configured to vaporize a solid to thereby form a vapor;   a valve arranged to receive the vapor from the evaporation chamber; and   a first portion of a conduit extending from an implantation chamber, wherein the first portion of the conduit is releasably connected with a second portion of the conduit, and wherein the second portion of the conduit is further connected to the valve.   
     
     
         9 . The apparatus of  claim 8 , wherein the heater comprises a high-frequency heater. 
     
     
         10 . The apparatus of  claim 8 , wherein the evaporation chamber further comprises an opening configured to receive a carrier gas. 
     
     
         11 . The apparatus of  claim 8 , wherein:
 the evaporation chamber comprises a top surface and a neck extending from an opening in the top surface;   the neck is arranged to allow the vapor to escape to the valve; and   a surface area of the top surface of the evaporation chamber is greater than an area of the opening in the top surface.   
     
     
         12 . The apparatus of  claim 11 , wherein the surface area of the top surface of the evaporation chamber is at least four times greater than the area of the opening in the top surface. 
     
     
         13 . The apparatus of  claim 8 , further comprising a valve heater arranged to transfer heat to the valve. 
     
     
         14 . An apparatus comprising:
 a vacuum chamber;   a plasma generator located in an upper region of the vacuum chamber;   an implantation chamber located within the vacuum chamber;   a sample holder located within the implantation chamber and configured to hold a sample; and   a first portion of a conduit extending through the vacuum chamber and including a conduit exit that opens into the implantation chamber.   
     
     
         15 . The apparatus of  claim 14 , further comprising:
 an evaporation chamber; and   a second portion of the conduit;   wherein the evaporation chamber is arranged to provide a vapor to the implantation chamber through the first and second portions of the conduit.   
     
     
         16 . The apparatus of  claim 15 , further comprising a valve configured to adjust a flow of the vapor from the evaporation chamber to the implantation chamber. 
     
     
         17 . The apparatus of  claim 16 , further comprising a valve heater configured to transfer heat to the valve. 
     
     
         18 . The apparatus of  claim 15 , further comprising a flange configured to releasably connect the second portion of the conduit with the first portion of the conduit. 
     
     
         19 . The apparatus of  claim 15 , wherein the evaporation chamber comprises a heater configured to heat a solid to thereby form the vapor. 
     
     
         20 . The apparatus of  claim 15 , wherein the evaporation chamber comprises an inlet to receive a carrier gas.