自製蘭牟爾探針診斷TE微波模式電子迴旋共振電漿

Electron Cyclotron Resonance Plasma Diagnostics by Using Self-fabricated Langmuir Probe

陳怡珮(Yi-pei Chen)

指導教授 ： 利定東

國立中央大學/工學院/能源工程研究所/碩士(2011年)

摘要

由於各類電漿輔助沉膜設備中，電漿狀態對反應過程有決定性之影響，因此往往需要搭配電漿量測裝置探究該設備電漿生成機制，或藉由對電漿內部粒子密度與其能量分布狀態的了解，輔助製程參數調控達到最佳化。
本實驗中，利用自製蘭牟爾電漿探針量測電子迴旋共振電漿設備，得到電漿內部資訊包含電子溫度、離子密度、電漿電位與浮動電位，並搭配光放射光譜儀量測結果，探討本設備電漿特性與均勻度受外部參數影響之機制。實驗結果得到藉由調高微波功率可有效增加離子密度，而提高製程壓力則明顯降低電子溫度，於主磁圈33A 所對應之共振位置為電子共振吸收能量最大位置，在本實驗參數中主磁圈33A、壓力15mTorr、微波功率1200w輔助下磁場未開啟之條件下得到目前最高電漿密度7x10^17(m^-3)，其電子溫度1.86eV。電漿均勻度方面，降低微波功率與製程壓力對均勻度有小幅改善，而靠近盤面之共振位置皆可得到較佳均勻度，輔助電磁圈的開啟可有
效改變原本TE 微波模式中央密度較高的特性，對均勻度有決定性之影響，外磁圈產生與主磁圈同向之磁場雖提高離子密度，但均勻度卻變差；而內磁圈形成與主磁圈反向之磁場，減低中心離子密度的同時亦有效提高了盤面電漿均勻度，在本實驗中以主磁圈電流33A 之共振位置，調變輔助電磁圈得到外磁圈6A 內磁圈12A 時均勻度最佳。

關鍵字

電子迴旋共振電漿 ； 蘭牟爾探針

並列摘要

Due to the state of plasma is the decisive factor to thin film deposition equipment, it is necessary to investigate the formation mechanism of plasma using plasma measurement techniques or get the plasma information such as density and energy distribution of particles to assist to optimize thin film deposition process. In this work, electron cyclotron resonance plasma is investigated by self-fabricated Langmuir probe. The electron temperature, ion densities, plasma potential and floating potential are studied with the result of optical emission spectroscope(OES) measurement to investigate the characteristics of the ECR system, as well as the relationship between plasma uniformity and process parameters. The experimental results show that ion densities could be increased by raising microwave power and electron temperature could be decreased under higher working pressure. The optimal region for microwave absorption is the resonance position when main coil current is 33A. The highest ion density, , is reached while the electron temperature is 1.86eV when the power is 1200w under 15mTorr.
About the plasma uniformity, decreasing microwave power and processing pressure would slightly improved. And the plasmas show better uniformities when resonance zones are near process chamber. Assistant magnetic coils have decisive affection to plasma uniformity. Mirror field could help to increase ion densities but have worse plasma uniformities, while plasma densities above the center of holder decreasing in Cusp field. Therefore, plasma uniformity can be improved in cusp field. When resonance region is fixed at 33A main coil current, we can get the best uniformity condition by setting outer coil 6A and inner coil 12A.

並列關鍵字

Langmuir probe ； electron cyclotron resonance(ECR) plasma

參考文獻

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