Plasma and Fusion Research

Volume 3, 028 (2008)

Letters


Temporal Analysis of Electrostatic Chuck Characteristics in Inductively Coupled Plasma
Gyu Il SHIM and Hideo SUGAI1)
Department of Electrical Engineering and Computer Science, Nagoya University, Nagoya 464-8603, Japan
1)
Department of Electronics and Information Engineering, Chubu University, Kasugai 487-8501, Japan
(Received 11 April 2008 / Accepted 30 April 2008 / Published 30 May 2008)

Abstract

Johnsen-Rahbek electrostatic chuck (ESC) for holding a silicon wafer in semiconductor processing is investigated in inductively coupled plasma (ICP). Bi-layer model of the ESC consisting of a thick bulk layer and a thin interface layer is proposed. The resistance of each layer is obtained by measuring the ESC voltage-current (V-I) characteristic with and without the wafer in ICP, along with the voltage effectively applied to the interface layer. Surface charges stored in the interface layer capacitance are found by the time-integration of current in a turn-on phase of a ramped voltage. On the other hand, the chuck holding force is in situ obtained in a turn-off phase of slowly ramped voltage, from the critical conditions of helium gas pressurization for wafer de-chuck. The electrostatic force predicted on a basis of equivalent circuit in the bi-layer model coincides with the mechanical force obtained in the wafer de-touch experiments.


Keywords

electrostatic chuck, Johnsen-Rahbek, inductively coupled plasma, Bi-layer model

DOI: 10.1585/pfr.3.028


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This paper may be cited as follows:

Gyu Il SHIM and Hideo SUGAI, Plasma Fusion Res. 3, 028 (2008).