| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve such a problem of prior art that a discharge unstable region relying upon the microwave power exists because discharge test is performed by changing the power of microwave, and although the process window is narrowed by developing the system while avoiding the discharge unstable region, a wider process window is needed. <P>SOLUTION: By means of a pulse generator 112 attached to a magnetron 106, the plasma 111 is subjected to on/off modulation in the form of a pulse. The on-time peak power value is set larger than a value causing discharge instability in continuous discharge, and the duty ratio of on/off modulation is changed for each wafer thus controlling the average power of microwave. Furthermore, repetition frequency of pulse is controlled so that the off time of the plasma 111 becomes 10 ms or shorter. <P>COPYRIGHT: (C)2013,JPO&INPIT |
