| 摘要 |
PROBLEM TO BE SOLVED: To avoid the decrease of an ashing rate even if the number of water 5 for ashing processing is increased and to keep the high ashing rate by setting the distance between a microwave transmission window and a quartz plate at a value higher than the specified fraction of the wavelength of the microwave. SOLUTION: In a plasma generating chamber 12, plasma such as oxygen is generated by the microwave, which is transmitted through a microwave transmitting window 13. At this time, a disk-shaped shower head 15 comprising quartz having many holes 15a is arranged between the plasma generating chamber 12 and an ashing chamber 14. Furthermore, a distance LO between the shower head 15 and the microwave transmission window 13 is set at the value larger than the length of 1/10 of the wavelength of the microwave. Then, even if the number of the wafers under ashing processing is increased, the decrease in ashing rate is not observed. Furthermore, the ashing rate is kept at the high level. |
