Capacitively Coupled Plasma(CCP) have been widely used in the semiconductor manufacturing.(sputtering, chemical vapor deposition, dry etching etc) CCP type plasma sources have good uniformity and low electron temperature. but Plasma density and ion bombardment energy can not be controled independently. Dual Frequency Capacitively Coupled Plasmas(DFCCPs) are designed to offer independent control of the flux and energy of ions impacting on an object immersed in a plasma.
In such discharges, people expected that a low frequency component controls the ion energy, while a high frequency component controls the plasma density. but, clearly this desired behavior is not achieved for arbitrary configurations of the discharge, and in general one expects some unwanted coupling of ion flux and energy.
Objective of this thesis is measuring plasma parameters in a DFCCP chamber and finding physical roles of both frequencies.
All experiments are done under conditions which are operating pressure $\approx 100mTorr$, gas = Argon, driving frequencies = 2 & 27Mhz, maximum power of each frequency < 250W (low power regime), electrode gap distance < 40mm.
본 실험에서는 이중 주파수 축전 결합 플라즈마 장비에서 플라즈마 변수들을 측정하여 실제 높은 주파수와 낮은 주파수가 하는 물리적 역할을 알아보고, 플라즈마 밀도와 이온 충돌 에너지를 독립적으로 제어하기 위한 조건을 찾는데 그 목적을 두고 있다. 실험에 사용된 장비는 2Mhz와 27Mhz를 사용한 이중 주파수 축전결합 플라즈마 장비 이고, 플라즈마 진단을 위해서 RF 보상 랑뮤어 탐침을 사용하였으며, 전체 파워가 350W 미만인 낮은 파워 영역에서 실험이 진행 되었다.
