Patent ID: 8709926
Filing Date: 2014-04-29
Classification: H01J,H01L

Abstract:
1. A plasma doping method for doping impurities into a sample or into a film on the surface of the sample, comprising: a first step of placing said sample on a sample electrode in a vacuum chamber; a second step of evacuating said vacuum chamber with supplying a gas comprising a doping material gas and helium into said vacuum chamber, and supplying a high frequency electric power to a plasma source with controlling the pressure of said vacuum chamber at a first pressure so as to generate plasma in said vacuum chamber; and a third step of controlling the pressure of said vacuum chamber into a second pressure different from said first pressure with maintaining the generation of the plasma, and supplying a high frequency electric power larger than the high frequency electric power in said second step to the plasma source, wherein a pressure just before the high frequency electric power is supplied to the plasma source at the second step is maintained to the first pressure, the pressure of said vacuum chamber is changed into the second pressure different from the first pressure at the third step, and the plasma is composed mainly of helium.