| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 2002: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 2001: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Research Abstract |
By means of the insulated probe method, it is possible to measure the electron temperature, plasma density, amplitude of plasma potential oscillation, and time-averaged voltage across probe sheath in an RF generated plasma, which is widely used for various industrial processes, even with the existence of reactive species in the plasma. By the use of half-wavelength transmission line in the probe circuitry in order for the probe current detection, the flexibility of geometric design of the probe system is greatly improved and the applicability of the insulated probe method to actual process monitoring has been greatly enhanced.
In order to extend the applicability of the insulated probe method for monitoring practical process, which often use large RF power over kilo-watts, a mew probe system is presented. In this probe system, two probes of the same dimension are used. One probe is a sensing probe and another is a reference probe. The probe voltage is applied only to the sensing probe. The probe current signal of the reference probe is subtracted from that of the sensing probe. By this differential sensing technique, the amplitude of the probe current signal at steady state is suppressed without attenuate the signal of the change in the probe current due to the change in the probe voltage. Consequently, the dynamic range of the probe current signal detection has been improved up to 60dB in an RF plasma at 13.56MHz of frequency. Furthermore, by employing electronic circuits for analyzing the amplitude change and the phase shift in the probe current signal, the dynamic range can be improved up to 80dB
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