Tokyo Electron Limited

Fumitoshi Kumagai

Taichi Hirano

Yoshinobu Hayakawa

Hikoichiro Sasaki

Satoshi Yamada

Junji Ishibashi

Ken Yoshida

A power supply systemincludes high frequency power suppliesandthat supply a high frequency power for plasma generation; a DC power supplythat supplies a DC voltage to be applied to an electrode; and control unitthat controls the high frequency power suppliesandand the DC power supplyincluding a first DC power supply unitthat supplies a first negative DC voltage V, a second DC power supply unitthat supplies a second negative DC voltage Vhaving a higher absolute value than the first negative DC voltage V, and a selecting circuitthat selectively connects the first DC power supply unitand the second DC power supply unitto the electrode; and a discharging circuitconnected with a nodebetween the first DC power supply unitand the selecting circuit

Power supply system

A plasma processing apparatus can efficiently perform a pulse modulation method of switching a high frequency power to be used in a plasma process between a high level and a low level alternately according to a duty ratio of a modulation pulse. In this plasma processing apparatus, when performing a high/low pulse modulation on the high frequency power for plasma generation, if a weighted variable K is set to be 0.5&#x3c;K&#x3c;1, a constant reflection wave power PRis generated on a high frequency transmission line of a plasma generation system even during a pulse-on period T. Meanwhile, during a pulse-off period T, a reflection wave power PRdecreases. By adjusting the value of K, a balance between the reflection wave power PRduring the pulse-on period Tand the reflection wave power PRduring the pulse-off period Tcan be controlled.

Plasma processing apparatus

Power supply system, plasma etching apparatus, and plasma etching method

Growing community of inventors

Miyagi, Japan

Fumitoshi Kumagai