Paper PS2-ThM8
In-Situ Wafer-Based Plasma Sensor Analysis in Inductively Coupled Plasmas

Thursday, October 18, 2007, 10:20 am, Room 607

In-situ, wafer-based plasma sensors are currently being explored to attack plasma process control and process development challenges. One such commercially available sensor tool is the PlasmaTemp^TM sensor wafer, developed by KLA-Tencor. PlasmaTemp^TM includes an on-board electronics module, coupled with wireless communication, which allows data storage of 30 temperature sensors embedded onto the wafer at different radial positions. In the present work, we focus on molecular gas (e.g. O₂) inductively coupled plasmas (ICPs). Wafer heating mechanisms in molecular gas plasmas can involve effects in addition to those identified in atomic gas plasmas (i.e. ion bombardment and ion-electron recombination). These mechanisms include thermal conduction from the neutral gas, when bulk temperatures are in excess of ~1000K, and atom recombination on the wafer surface. We report a combination of plasma diagnostics and modeling, sensor wafer modeling, and experimental measurements for a variety of conditions in an Ar/O₂ inductively coupled plasma for wafer temperature measurements as well as for other plasma characteristics such as plasma density, ion flux and optical emission intensity.