IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Plasma Science Thursday Sessions
       Session PS-ThP

Paper PS-ThP8
Electron-Temperature Control in 915 MHz ECR Plasma

Thursday, November 1, 2001, 5:30 pm, Room 134/135

Session: Plasma Etching Poster Session
Presenter: N. Itagaki, Kyushu University, Japan
Authors: N. Itagaki, Kyushu University, Japan
S. Kawakami, Tokyo Electron Co. Ltd., Japan
N. Ishii, Tokyo Electron Co. Ltd., Japan
Y. Kawai, Kyushu University, Japan
Correspondent: Click to Email
In semiconductor processing, it is required to control the electron temperature in plasma for progress of microelectronic devices and minimization of substrate damage. Since the reactive processes occurred strongly depend on the electron temperature, this control is also necessary to find the best conditions for various plasma processings. An electron cyclotron resonance (ECR) plasma source has attracted much attention for its high electron density (10@super 17@-10@super 18@ m@super -3@) that can be achieved at low gas pressure (10@super -4@-10@super -3@ Torr). However, in a conventional ECR plasma produced by 2.45 GHz microwave, the electron temperature is relatively high, and it is quite hard to control the electron temperature in a wide range. Recently, we succeeded in production of a low-electron-temperature ECR plasma with high electron density using 915 MHz microwave. Furthermore, it was found that the electron temperature depends on the external conditions such as incident microwave power, gas pressure and magnetic field configuration. In this report, we measured the electron temperature of 915 MHz ECR plasma in detail and attempted to control the electron temperature by changing the external conditions. As a result, it was found that the electron temperature of the 915 MHz ECR plasma can be easily controlled by changing the incident microwave power in the case that the magnetic field configuration is flat. Especially, at the gas pressure of 8.5 mTorr, the electron temperature decreased nearly from 7 eV to 1.6 eV as the microwave power was decreased from 2.5 kW to 0.5 kW. In addition, we have tried to investigate the mechanism of a low-electron-temperature plasma production with 915 MHz microwave by measuring the spatial profile of the plasma parameters and wave patterns.