Impurity doping apparatus

Claim 1

An impurity doping apparatus comprising: a vacuum chamber for receiving a semiconductor substrate: evacuation means for evacuating said vacuum chamber; heating means for heating the semiconductor substrate placed in said vacuum chamber; a gas supply source for supplying at least one gas species to said vacuum chamber; regulating valve means disposed between said vacuum chamber and said gas supply source for selecting a gas species to be supplied and for regulating the amount of the selected gas species supplied to said chamber; analyzing means communicating with said vacuum chamber and having an output connected to said controlling means for analyzing an exhaust component evacuated from said vacuum chamber; and controlling means operative according to a given sequence of first, second, third and fourth procedures to control said evacuation means, said heating means and said regulating means, said controlling means being operative according to the first procedure to evacuate said vacuum chamber, said controlling means being operative according to the second procedure to effect heating of the semiconductor substrate to a given temperature for a given time interval to activate a surface of the semiconductor substrate, said controlling means being operative according to the third procedure to effect delivery of a given amount of a gas species containing an impurity component into said vacuum chamber while heating the substrate to deposit an impurity adsorption film on the activated surface, wherein said controlling means includes means operative according to the second procedure to detect an end point of activation of the substrate surface based on analyzed results fed from said analyzing means, and said controlling means being operative according to the fourth procedure to effect annealing of the semiconductor substrate at a given temperature for a given time interval to diffuse the impurity component from the impurity adsorption film into the semiconductor substrate.