Seiichiro Kanno

Wafer-Voltage Measurement in Plasma Processes by Means of a New Probe Method and an Impedance Monitor

A new probe method, which can measure wafer voltage directly from the wafer back-side without fluctuating the plasma, was developed. This method clarified the effect of the bias power, gas pressure and gas component on wafer Vpp, Vdc, and Vdc/Vpp. In addition, current, voltage, and phase shift were measured with an impedance monitor (IM) installed between the matching network and the bias electrode. Furthermore, wafer Vpp was calculated from IM data according to a devised equivalent circuit model. It was found that calculated wafer Vpp agrees with actual wafer Vpp within 3.4% when bias power is ranged from 200 W to 500 W.

A Novel Plasma Etching Tool with RF-Biased Faraday-Shield Technology: Chamber Surface Reaction Control in the Etching of Nonvolatile Materials

A novel electro-magnetically coupled plasma (EMCP) etching tool for nonvolatile materials has been developed. The EMCP etcher is based on inductively coupled plasma generation and has a function for controlling surface reactions by supplying RF bias to a Faraday shield which covers a ceramic discharge dome. We investigated plasma controllability and chamber surface reaction controllability of the EMCP etcher and found that the RF-biased Faraday shield effectively keeps the internal surface of the dome clean in the etching processes of nonvolatile materials. Because of this feature, the EMCP etcher can be applied to the etching processes of various nonvolatile materials such as Pt, Ru, Ir, NiFe, Au, Mo, Ta, Al2O3, HfO2, ZrO2, and indium tin oxide (ITO).