Method and apparatus for plasma doping

Abstract

A method for impurity implantation, in which a substrate is positioned on a table provided within a chamber in which a vacuum will be introduced and also an implantation impurity is supplied. A first high frequency electric power is applied to a plasma generating element to thereby generate a plasma so that the impurity in the chamber is implanted in the substrate. Also, a second high frequency electric power is applied to the table. Detected are a condition of the plasma in the chamber and a voltage or current in the table. A controller controls at least one of the first and second high frequency electric power sources according to the detected condition of the plasma and/or the detected voltage or current, thereby controlling an implantation concentration of the impurity to be implanted.

1 . A plasma doping apparatus, comprising: 
 a vacuum container defining a vacuum chamber therein;    a gas supply for supplying a gas into the vacuum chamber;    a vacuum generator for generating a vacuum in the vacuum chamber;    a pressure control valve for controlling a pressure of the vacuum chamber;    a substrate electrode provided within the vacuum chamber for supporting a substrate;    a monitoring conductor provided around the substrate electrode;    a power source for supplying an electric power to the substrate electrode and the monitoring conductor;    a coil provided outside the vacuum container;    a plasma gas source for supplying a plasma gas into the vacuum chamber;    a high frequency power supply for supplying a high frequency power to the coil;    a first monitor for monitoring a condition of plasma; and    a second monitor for monitoring an electric voltage or an electric direct current at the monitoring conductor;    wherein the substrate electrode and the monitoring conductor are electrically connected to each other through a capacitor or a resistance, and the substrate electrode is grounded through the coil, a current detector, and the resistance.    
   
   
       2 . A plasma doping apparatus, comprising: 
 a vacuum container defining a vacuum chamber therein;    a gas supply for supplying a gas into the vacuum chamber;    a vacuum generator for generating a vacuum in the vacuum chamber;    a pressure control valve for controlling a pressure of the vacuum chamber;    a substrate electrode provided within the vacuum chamber for supporting a substrate;    a monitoring conductor provided around the substrate electrode;    a power source for supplying an electric power to the substrate electrode and the monitoring conductor;    a plasma gas source;    a high frequency power supply for supply a high-frequency power to the plasma gas source;    a first monitor for monitoring a condition of plasma; and    a second monitor for monitoring an electric voltage or an electric direct current at the monitoring conductor;    wherein the substrate electrode and the monitoring conductor are electrically connected to each other through a capacitor or a resistance, and the substrate electrode is grounded through a coil, a current detector, and the resistance.