System and method of determining effective glow discharge lamp current

摘要

The embodiments of the invention include a method for controlling plasma conditions of a glow discharge system using the integrated electron (or ion) pulse area extracted from the total lamp current. The method of using an integrated electron/ion pulse area for controlling plasma conditions allows for controlled analysis of conductive, non-conductive and layered materials without the need for estimation of plasma voltages. The method allows for control of sputter rates and plasma emissions that cannot be achieved using other methods such as capacitive divider calculations where actual thicknesses and dielectric constants are not known or predefined.

主权项

1. A glow discharge lamp system comprising:
a glow discharge lamp for ionizing a sample of a material to be analyzed in a plasma; an RF power supply for supplying RF power to the glow discharge lamp at a power level selected in response to an RF output control signal; a lamp current sensor for sensing a total lamp current and generating a total lamp current signal representative of the total lamp current over time; and a processor for receiving the total lamp current signal from said lamp current sensor and for supplying the RF output control signal to said RF power supply, wherein said processor determines an integrated pulse area of a pulse contained within the total lamp current signal and adjusts the RF power supplied to the glow discharge lamp in response to the integrated pulse area, wherein the pulse is one of an electron pulse and an ion pulse.