| 摘要: | 隨著半導體工業的發展，半導體元件越縮越小，導致半導體在製程上的控制精密度需求上升。在半導體製程中，藉由不同製程技術製造出元件，如:沉積、蝕刻等。其中隨著元件縮小，想要蝕刻出高深寬比之孔洞大都需電漿來輔助製程，而在蝕刻製程時，因內部因素(電漿環境、腔體壁面之溫度)可能造成蝕刻品質的影響，故在設備開發時，必須針對這些影響因素做調整，使其達到最佳製程。 本文將分析目前業界所使用的深反應離子蝕刻系統，其搭載電感耦合式電漿源。在此製程中，為了蝕刻出高深寬比的孔洞，將配合高分子間歇沉積製程，導致高分子粒子在製程中會沉積於腔體壁面上，將造成設備維護上的不便，而藉由提高腔體壁面溫度，可以有效的降低粒子於壁面上的沉積率，所以本文將先針對電漿中的粒子與溫度分佈作模擬分析，再結合腔體熱分析，探討腔體底部不同形式之加熱器對於溫度分佈的影響。在電漿模擬是使用流體式模型來模擬電漿內部的物理現象，並配合有限元素分析軟體做為模型之建立，而本文還配合熱傳及流場與電漿的耦合，可以使模擬更符合實際情況。在腔體熱分析的部分將結合電漿模擬所得之結果，探討腔體壁面與內部遮罩的溫度分佈。由模擬結果可以得知不同壓力與線圈電流對於氬氣電漿內部粒子的分佈及密度與氣體之溫度是有影響存在，其中，隨著壓力與線圈電流上升，激發態氬原子對於電漿的影響越是劇烈，而隨著激發態氬原子離子化比率上升，進而影響電子溫度隨著壓力而下降，且隨著線圈電流變化而導致徑向梯度越來越大。隨著激發態氬原子密度提升，反應時的熱源也隨之上升，導致氣體溫度的提升。在外加晶圓偏壓後對於電漿密度以及氣體溫度都有明顯的影響，但是隨著偏壓上升越趨於穩定。 由腔體熱分析之結果可以得知圓環狀加熱器除了較圓柱狀加熱器有更好的加熱效果外，加熱後的壁面溫度也較均勻。藉由量測結果可以得知本文在溫度分佈模擬的趨勢尚有一定的可靠度存在。 With the development of semiconductor industry, the semiconductor devices are getting smaller, those results in semiconductor fabrication has to precision. In the semiconductor fabrication, devices are manufactured by different fabrication techniques, such as deposition, etching etc. With the devices are getting smaller, want to produce high aspect ratio holes must by enhanced plasma fabrication. In etching process, result in the effects of etching quality by internal reasons (plasma environment or temperature of chamber walls), therefore, in order to achieve optimal fabrication have to adjusted those effect reasons. This article analyze deep reactive ion etcher (DRIE) used by currently industry, and it is carrying inductively coupled plasma source. In DRIE fabrication, with additional intermittent polymer deposition process, it is able to produce high aspect ratio holes, but polymer film is deposited on the chamber walls, those results in the difficulty in equipment maintenance. The situation can be alleviated in an elevated wall temperature, so this article presents the results on distribution of particles and temperature in plasma, and combine with chamber thermal analysis, investigate affected by different types of heaters under the chamber for temperature distribution. In the plasma simulation, we use the fluid model method to simulate physical phenomena in plasma. To make the plasma simulations more close to the reality, we also consider the effects of heat transfer and flow field. In chamber thermal analysis, it is combined with plasma simulation results, and investigated temperature distribution of chamber walls and shields in chamber. In the result of this article, we find out that affect the existence of argon plasma distribution and temperature by pressure and coil current. Besides, argon excitation state has effect about argon plasma with pressure and coil current raised. With pressure raised, the argon excitation state ionize ratio also raised, and result in electron temperature decreased. When wafer holder has self-bias, it is obviously affects plasma density and gas temperature. In the result of chamber thermal analysis, we found out that circular heater has better heating effect and better temperature uniformity than cylindrical heater. By measured results, this article shows reliability for the simulation results. |
