Positive ion current to a spherical electrode in a negative ion plasma

Abstract

Critical parameters for the development of the plasma-source ion implantation process are the ion implantation current and the sheath expansion characteristics. Recently, Xia and Chan [J. Appl. Phys. 73, 3651 (1993)] have investigated these parameters for small spherical electrodes inserted in a two component positive ion-electron plasma. This investigation is extended to a plasma that consists of three components: positive ions, negative ions, and electrons.