평판형 글로우 방전 플라즈마 공정에서의 미립자 오염에 관한 연구

목차

I. 서론

II. 용량결합형 RF 여기 CH4 플라즈마를 이용한 DLC (Diamond-like-Carbon)막 증착 공정 중의 미립자 발생 및 행동양식.

III. 플라즈마-미립자간의 상호작용에 의한 RF 방전특성의 변화.

IV. 방전 후의 미립자 운동양식의 관측.

V. CF4/H2 플라즈마를 이용한 RIE(Reactive Ion Etching) 공정에서의 미립자 발생에 미치는 공정 변수의 영향과 RF on-off 변조(modulation)의 영향.

VI. 직류 평판 Diode형 Al 스퍼터링 공정에서의 미립자 거동과 Ring 전극 첨가가 미립자 거동에 미치는 영향.

VII. 결론.

본문내용

The onset time was dependent on the substrate material and the measured onset time with a Si wafer was relatively smaller than that with a SiO2 wafer. The onset time decreases with the increase of the RF power very rapidly and shows a threshold behavior with the increase of the hydrogen percentage and the RF power. The decrease of the LLS peak intensity was apparantly seen with the square wave modulation process of RF power. The change of the etch rate and the LLS peak intensity according to the change of the duty ratio shows that the optimal process condition which satisfies the high selectivity, the high etch rate and the low particulate growth level can be obtained with the RF modulation method. In RF modulation process, both the increase of the off-period and the decrease of the on-period resulted in the decrease of the LLS signal in the particulate trap. It was observed that the change of the off-period has more important role in the change of LLS signal intensity. The trajectories of particulates in the RF modulated discharge is calculated using a simplified model and the typical plasma parameters. It is confirmed from the calculated and the experimental results that the particulate displacement from trap is dependent on the duty ratio and the particulate size.
The effect of an electrically biased ring electrode on the dynamics of the particulate cloud was examined in a DC diode sputtering process of Al. In this process, the particulate cloud of a ring type was observed below the grounded electrode. Without ring electrode, the particulate cloud drifted to the grounded electrode by the thermophoretic force in the afterglow. Although the particulates is known to have negative charge in plasma, the DC bias of the ring electrode does not show a large effect on the particulate motion when the particulates are immersed in plasma. In order to reduce the electron flux to the ring electrode and satisfy the quasi-netrality condition plasma potential shifted to the higher value as bias voltage is applied to the ring electrode and the potential gradient at the position where the particulate cloud is observed does not direct to the ring electrode. When the plasma is turned off with some decay time, the particulates shows drift motion to the positively biased ring electrode. When the decay time is short and the discharge is rapidly turned off, the particulates may lose its negative charge and the DC bias can not influence on the particulate motion any more. But, when the discharge decay time is large enough, the particulate can keep its negative charge until its motion to the biased ring is completed so that all the particulates can move to the ring electrode.
Key Words : Particulate Contamination, Plasma Processes, Chemical Vapor Deposition, Dry Etching, Sputter Deposition, Particulate Contamination Control, RF Power Modulation, Triode Discharge System, Ring Electrode Discharge, Plasma Property Variation as a result of the Particulate Contamination

키워드

평판형,   플라즈마,   미립자,   직류 평판,   Diode형,   미립자 거동