Create a supplemental plasma density near the substrate using low bias voltages in an inductively coupled plasma (ICP) processing chamber

摘要

The substrate is positioned on the substrate support structure within the plasma processing volume of the inductively coupled plasma (ICP) processing chamber. The first RF signal is supplied from a first RF signal generator to a coil disposed outside the plasma processing volume to expose the substrate to generate a plasma. The second RF signal is supplied from the second RF signal generator to an electrode in the substrate support structure. The first RF signal generator and the second RF signal generator are controlled independently of each other. The second RF signal has a frequency of about 27 MHz or more. The second RF signal produces a supplemental plasma density at the level of the substrate in the plasma processing volume, while producing a bias voltage less than about 200 V at the level of the substrate.