此研究動機起因於半導體製程在世界競爭下，晶圓尺寸來到十二吋，而十二吋晶圓的良率即是代表企業生存能力的一個指標。良率高低可看三方面，一是生產管理面、二是製程能力面、三是機台設備面，新製程要取得客戶認證，缺陷檢測極嚴格，藉此提高產品認證可靠度，而變壓耦合式電漿蝕刻為半導體蝕刻大量運用，研究電漿蝕刻微粒子汙染，已經是刻不容緩。
此研究範圍針對二十奈米乾蝕刻製程中，蝕刻Poly層時，微粒子殘留現象造成晶圓汙染，若未及時掃描攔截，晶圓持續後面製程，會造成其製程設備汙染及良率下降。研究分析資料找出電漿蝕刻晶圓時，從反應爐內部ESC (Electric Static Chuck)靜電吸附和排斥晶圓動作中發現ESC產生之電子隨者ESC時數增加(老化)及Poly製程會蝕刻數片晶圓後再執行WAC(Wafer Auto Clean)方式，使得ESC表面排斥不良而形成電子大量殘留並會傳導至晶圓表面直接吸引反應爐中游離分子團及反應後離子，而附著於晶圓表面邊緣，當製程電漿產生，此時晶圓邊緣薄膜上所吸附的電子會和電漿反應而被帶走，但邊緣上的游離分子團及反應後離子(微粒子)會留在晶圓上。
此研究目的，期望能一步一步找出根本解決方法。第一步，分析電漿
特性及微粒子滯留之過程。 第二步，用田口法建立電漿蝕刻Poly製程過程的實驗模型，研究電漿、電荷殘留與微粒子滯留現象之原因，電漿蝕刻機台參數有電漿功率、偏壓功率、壓力、氣體流量、吸附電壓、氦氣壓力、氦氣流量和晶圓偏移偵測，找出方法；實驗設計為找出蝕刻製程因電子殘留在晶圓邊緣薄膜表面為目標。第三步，對蝕刻Poly製程既有機台，透過實驗結果擬定方法，進行改善及調整，為此研究目的。
本研究對象為半導體電漿蝕刻機台，欲解決微粒子殘留晶圓邊緣薄膜上問題，找出原因並擬出根本解決之道，降低此類微粒子汙染數及造成缺陷而停機之機台目標數降為零，以驗證本研究的想法與可行性。

Based on the competition of semiconductor in the world up to the twelve inch wafer, the yield of the wafer is an indicator of the enterprise viability in career, which inspires the study motivation of the thesis. Yield rate can be observed in three areas: the production management, processing ability and machine equipment. The new process needs to obtain the customer certification and the strict defect detection could enhance the reliability of the product certification. The transformer coupled plasma etching is extensively used in semiconductor etching processes. It is imperative to study on the fine particle pollution of the plasma etching.
This study area is focused on the twenty nanometers dry etching process. During the poly layer etching process, the fine particle residual phenomenon would cause wafer contamination. If it cannot be intercepted by the in-time scanning, it would contaminate the following process equipment and decline the yield.
During the plasma etching, the chamber ESC (Electrostatic Chuck) executes the electrostatic attraction and repulsion actions to the wafer. As the RF (Radio Frequency) time increases and the ratio of the number of wafer going through the poly etching process to the execution number of WAC (wafer auto clean) process deceases, the induced electrons are raised. This would lead to the poor surface repulsion and the formation of large number residual electrons. The electrons are transmitted directly to the wafer surface, which would attract the free molecules in the reactor and the ions after the reaction. The molecules and ions are attached to the edge surface of the wafer. When the plasma is produced in the process, the absorbed electrons on the wafer, reacted with the plasma, are taken away, but the free molecules and reacted ions (fine particles) remain on the wafer.

The study purpose is to find a fundamental solution using the following steps. Step 1 is to analyze the plasma characteristics and the detention process of fine particles. Step 2 is to establish an experimental model of poly plasma etching process using the Taguchi method to study the interaction among plasma, fine particles and residual charges. The operating parameters of the plasma etching equipment are plasma power, bias power, pressure and gas flow rate of helium, adsorption voltage, pressure and flow rate of helium, detection of wafer location deviation. The target of the experimental design is to find out the residual electrons. Step 3 is to improve the etching process by adjusting the operating parameters through the study of the established experimental model. This is the primary purpose of the thesis.

[1]R. Patrick, S. Baldwin, N. Williams, “Application of direct bias control in high-density inductively coupled plasma etching equipment＂, J. Vac. Sci. Technol. A 18(2).,pp.17-18, 2000
[2]Carter Jr, Tsvetkov, V.F., Glass, R.C., Henshall, D.,Brady, M., StG,M.,Kordina, O.,Irvine, K.,Edmond, J.A.,Kong, H.S. and Singh, R.,Process in Si:from “material growth to commercial device development, Materials Science and Engineering＂:B, vol.63,pp.1-8,1999.
[3]Christopher D Himmel and Gary S.Mary, “Advantages of Plasma Etch Modeling Using Neural Network Over Statistical Techniques＂ ,IEEE Trans. Semicond. Manuf, VOl.6, NO.2, pp 103-111, May 1993
[4]Lambrecht, W.R.,Limpijumnong, S., Rashkeev, S.N.and Segall, B., “Electronic band structure of SiC polytypes:a discussion of theory and experiment＂, Physica Status Solidi(B),vol.102,pp. 3-13,1997.
[5]Byungwhan Kim and Gary S.Mary, “An optimal neural network process model for plasma etching＂ ,IEEE Trans. Semicond. Manuf, VOl.7, NO.1, pp 12-21,February .,pp.23-26,1994
[6]ANSYS Structural Analysis Guide ,Release 12.0 ANSYS ,Inc .,pp. 55-56,2009.
[7] R.A.Stewart, P.Vitello, and D.B.Graves, “Two-dimensional fluid model of ligh density inductively coupled plasma source＂, 1994 J.Vac.Sci.Technol.B, 12, p487-485
[8] Peter L.G. Ventzek, Robert J. Hoekstra, and Mark J.kushner, “Two-dimensional modeling of high plasma density inductively coupled source for materials processing＂,pp.39-41, 1994 J. Vac. Sci. Technol. B.12(1)
[9] Gary S.Mary,Jiahua Huang,Costas J.Spanos, “Statisical Experimental Design in Plasma Etch Modeling＂,IEEE Trans. Semicond. Manuf, VOl.4, NO.2, pp83-97, May 1991
[10] Tairov,Y.M., “Growth of bulk Si＂Materials Science and Engineering:B, vol.29,pp.83-89,1995
[11] Herro,Z.G.,Epelbaum,B.M.,Bickermann, M.,Masri,P. and Winnacker,A., “Effective increase of Electronic Static＂Journal of Crystal Growth, vol.362, pp 114-118,2004.
[12] David Stokes and Gary S.May, “Real-time Control of Reactive Ion Etching Using Neural Networks ＂ ,IEEE Trans. Semicond. Manuf, VOl.3, NO.4, pp 469 - 480 November 2000
[13] Yan,J.Y.,Chen,Q.S.,Jiang,Y.N.,and Zhang, H., “Improvent of the thermal design in the poly process,＂Journal of Crystal Growth, vol.325,pp. 41-43,2014.
[14] H. RATHOD, K. NAGARAJA, B. VENKATESUDU, and N. RAMESH, "Gauss Legendre quadrature over a triangle," J. Indian Inst. Sci, vol. 84, pp. 183-188, 2004.
[15] T. Tszeng, Y. Im, and S. Kobayashi, "Thermal analysis of solidification by the temperature recovery method," International Journal of Machine Tools and Manufacture, vol. 29, pp. 107-120, 1989.
[16] J. Stefan, "Über die Theorie der Eisbildung, insbesondere über die Eisbildung im Polarmeere," Annalen der Physik, vol. 278, pp. 269-286, 1891.
[17] Y. C. Liu and L. S. Chao, "Modified effective specific heat method of solidification problems," Materials Transactions, vol. 47, pp. 2737-2744, Nov 2006.
[18] K. A. Rathjen and L. M. Jiji, "Heat Conduction with Melting or Freezing in a Corner," Journal of Heat Transfer, vol. 93, pp. 101-&, 1971.
[19] R. D. Cook, Concepts and applications of finite element analysis: John Wiley & Sons, 2007.
[20] 李輝煌,田口方法品質設計的原理與實務,高立圖書有限公司, pp. 1-107, 2004。