Dose control technique for plasma doping in ultra-shallow junction formations

摘要

A method of plasma doping substrates is provided. The substrate is covered with photoresist and placed within a plasma chamber. A doping gas is introduced into the chamber and ionized. A dilutant gas is also introduced to provide better control of the total amount of dosage associated with a given duration of exposure. The dilutant gas is preferably monatomic to reduce, or eliminate, affects associated with pressure variations within the chamber caused by dissociation of elements within the plasma chamber. The dilutant gas preferably contains lighter elements so as to reduce, or eliminate, damage to the photoresist caused by ion impacts. The dilutant gas is preferably neon or helium. The present method provides a means to better control the dosage and reduce photoresist damage and contamination.