McDermott Will & Emery LLP
Plasma doping method and apparatus employed in the same
A plasma doping method and a plasma doping apparatus, having a superior in-plane uniformity of an amorphous layer formed on a sample surface, are provided.In the plasma doping method by which plasma is generated within a vacuum chamber, and impurity ions contained in the plasma are caused to collide with the surface of the sample so as to quality-change the surface of the sample into an amorphous state thereof, a plasma irradiation time is adjusted in order to improve an in-plane uniformity. If the plasma irradiation time becomes excessively short, then a fluctuation of the plasma is transferred to depths of an amorphous layer formed on a silicon substrate, so that the in-plane uniformity is deteriorated. On the other hand, if the irradiation time becomes excessively long, then an effect for sputtering the surface of the silicon substrate by using the plasma becomes dominant, then the in-plane uniformity is deteriorated. While a proper plasma irradiation time present in an intermediate time between the long plasma irradiation time and the short plasma irradiation time is found out, during which the in-plane uniformity becomes better, a plasma doping process is carried out within the intermediate time.
Panasonic Corporation
H H
H01L H01J
inventional inventional
Yuichiro Bunji Hiroyuki Katsumi
Sasaki Mizuno Ito Okashita