Pulsed gas plasma doping method and apparatus

摘要

A method and apparatus for doping a surface of a substrate with a dopant, with the dopant being for example phosphine or arsine. The doping is performed with a plasma formed primarily of an inert gas such as helium or argon, with a low concentration of the dopant. To provide conformal doping, preferably to form a monolayer of the dopant, the gas flow introduction location is switched during the doping process, with the gas mixture primarily introduced through a center top port in the process chamber during a first period of time followed by introduction of the gas mixture primarily through peripheral or edge injection ports for a second period of time, with the switching continuing in an alternating fashion as the plasma process.

主权项

1. A method for plasma processing comprising:
loading a substrate into a plasma processing chamber and placing the substrate on a substrate holder, the plasma processing chamber having a top wall opposing the substrate holder, and a peripheral wall surrounding the substrate holder; forming a plasma in the plasma processing chamber; introducing a first gas mixture, for a first time period, at a first flow rate, into the plasma processing chamber, from at least one gas injection port located in a top central region of the plasma processing chamber, the first gas mixture comprising a dopant species; following the introduction of the first gas mixture, introducing a second gas mixture, for a second time period, at a second flow rate, into the plasma processing chamber, from at least one gas injection port located in a peripheral region of the plasma processing chamber, the second gas mixture comprising the dopant species, wherein during at least a portion of the second time period the second flow rate is at least 80% of a total flow rate from both the at least one gas injection port located in the top central region and the at least one injection port located in the peripheral region; repeating the steps of introducing the first gas mixture and introducing the second gas mixture, to form a layer of dopant species on structures on the substrate.