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论文类型：期刊论文

发表时间：2014-01-01

发表刊物：VACUUM

收录刊物：SCIE、EI、Scopus

卷号：99

页面范围：180-188

ISSN号：0042-207X

关键字：Plasma etching; Sheath; Profile evolution; Neutral coverage; Charging

摘要：A sheath is generated over the rf biased substrate in etching processes, its properties play an important role in determining the transport of reactant species including ions and neutrals toward the substrate, as well as the surface reactions, and as a consequence the evolution of the etching profile. In this work, a multi scale model including the global, sheath and trench model is applied to simulate dry etching processes in nano-patterned samples. First, the global model gives the discharge parameters in chamber. Sheath properties in terms of external discharge parameters are decided using the sheath model, the reactant transports in sheath to trench surface are then obtained. At last, based on the surface reaction model and cellular removal algorithm, the evolution of trench profile is simulated. Influences of different discharge parameters like pressure and bias voltage on microscopic non-uniformity generation during etching are studied for better understanding of etching mechanism. Results show that the profiles have different evolution processes under various discharge conditions. Specially, the directionality, charging induced distortion and reflection for ions determine the profile of micro-trenching. Besides, neutral coverage associated with pressure and pattern geometry can influence the local etch rate, further decide the formation of RIE lag, undercut and bowing. (c) 2013 Elsevier Ltd. All rights reserved.