Patent ID: 7571698

Claim:
A substrate processing system comprising: a housing defining a process chamber; a substrate holder disposed within the process chamber and configured to support a substrate during substrate processing; a gas-delivery system configured to introduce a gas into the process chamber; a pressure-control system for maintaining a selected pressure within the process chamber; a high-density plasma generating system operatively coupled with the process chamber for forming a plasma having a density greater than 10 11 ions/cm 3 within the process chamber; a radio-frequency bias system electrically coupled with the substrate holder to generate an electrical bias on the substrate at a frequency less than 5 MHz, wherein the radio-frequency bias system comprises a radio-frequency generator electrically coupled with an impedance matching network; and a controller for controlling the gas-delivery system, the pressure-control system, the high-density plasma generating system, and the radio-frequency bias system, the controller having instructions to operate the radio-frequency generator to electronically sweep through a frequency range to determine the frequency that minimizes a power reflected from the process chamber.