TIME-RESOLVED MEASUREMENTS OF RF PLASMAS USING ELECTROSTATIC-PROBE HAVING COMPENSATION CIRCUITS FOR SPACE POTENTIAL FLUCTUATION

The time-resolved Langmuir probe method using a laser-heated emissive probe to compensate space potential fluctuation is modified to improve the limit of amplitude for compensation and reliability of current de tection in order to experimentally study RF plasma under various condi tions. Time-resolved electron temperatures and electron densities are measured at various input powers and pressures of Ar and He in 13.56 M Hz RF asymmetric discharge. Not only the electron temperature but also the electron density change was synchronized with excitation RF. The period of variation is not the same as second harmonics, but is a fund amental period of 13.56 MHz. The electron temperature and the self-bia s depend on the excitation RF power. Such evidence may indicate that p lasma parameters are closely related with the electron acceleration in the electrode sheath and the plasma caused by the self-bias field.