Defect-free junction formation using octadecaborane self-amorphizing implants

Abstract

A method and apparatus for implanting a semiconductor substrate with boron clusters. A substrate is implanted with octadecaborane by plasma immersion or ion beam implantation. The substrate surface is then annealed to completely dissociate and activate the boron clusters. The annealing may take place by melting the implanted regions or by a sub-melt annealing process.

1 . A method of treating a substrate, comprising:
 disposing the substrate in a processing chamber;   forming a plasma from a vapor of boron macromolecules and a carrier gas in the processing chamber;   immersing the substrate in the plasma;   implanting boron from the plasma into a surface of the substrate; and   subjecting the implanted surface to a melt anneal process.   
     
     
         2 . The method of  claim 1 , wherein the boron macromolecules comprise clusters containing at least sixteen boron atoms. 
     
     
         3 . The method of  claim 1 , wherein forming a plasma from the vapor of boron macromolecules and the carrier gas comprises coupling RF power between about 100 W and about 500 W into the vapor of boron macromolecules and the carrier gas. 
     
     
         4 . The method of  claim 3 , wherein implanting the boron from the plasma into the surface of the substrate comprises applying an electrical bias to the substrate between about 100 V and about 300 V. 
     
     
         5 . The method of  claim 3 , wherein flowing the vapor of boron macromolecules through the processing chamber comprises pulsing the vapor into the processing chamber. 
     
     
         6 . The method of  claim 1 , wherein forming the plasma from the vapor of boron macromolecules and the carrier gas comprises pulsing the vapor of boron macromolecules into the carrier gas. 
     
     
         7 . The method of  claim 1 , wherein the melt anneal process is a pulsed laser process. 
     
     
         8 . The method of  claim 7 , wherein the melt anneal process comprises crystallizing the melted portion of the substrate surface. 
     
     
         9 . A method of treating a substrate, comprising:
 forming a plasma of a gas mixture comprising a carrier gas and boron macromolecules inside a processing chamber;   exposing the substrate to the plasma inside the processing chamber; and then   annealing successive portions of the substrate in a laser annealing process.   
     
     
         10 . The method of  claim 9 , wherein the boron macromolecules comprise octadecaborane. 
     
     
         11 . The method of  claim 9 , wherein the plasma is an inductive plasma. 
     
     
         12 . The method of  claim 11 , wherein forming the plasma comprises applying electrical energy to the gas mixture at a power level above a level that ionizes the boron macromolecules and below a level that fragments the boron macromolecules. 
     
     
         13 . The method of  claim 11 , wherein the gas mixture is formed by pulsing the boron macromolecules into the carrier gas. 
     
     
         14 . The method of  claim 9 , wherein annealing successive portions of the substrate comprises melting and recrystallizing each successive portion of the substrate. 
     
     
         15 . The method of  claim 14 , wherein the boron macromolecules comprise octadecaborane and the plasma is an inductive plasma. 
     
     
         16 . The method of  claim 15 , wherein forming the plasma comprises applying electrical energy to the gas mixture at a power level above a level that ionizes the boron macromolecules and below a level that fragments the boron macromolecules, and exposing the substrate to the plasma comprises applying an electrical bias to the substrate. 
     
     
         17 . The method of  claim 16 , wherein the laser annealing process is a pulsed laser process.