Uniformity of plasma etching has been conventionally examined only in terms of etch rate. A uniformity of etching profile surface is increasingly demanded to improve process quality. This is accomplished by applying a discrete wavelet transformation (DWT) to profile images obtained with a scanning electron microscopy. Applicability of DWT-based profile uniformity was evaluated with a tungsten etch experiment, conducted in an SF6 helicon plasma. Its suitability was investigated as a function of process parameters and scale levels. Compared to a conventional metric, the wavelet-based one characterized more effectively the uniformity of profile variations. The proposed metric can be applied to any other plasma-processed surfaces.
Bibliographical noteFunding Information:
Manuscript received February 10, 2003; revised October 7, 2003. This work was supported by the Korea Research Foundation (KRF-2002-041-D00117). B. Kim and S. Kim are with the Department of Electronic Engineering, Se-jong University, Seoul 143-747, Korea (e-mail: firstname.lastname@example.org). M. T. Lim is with the Department of Electrical Engineering, Korea University, Seoul 136-701, Korea. Digital Object Identifier 10.1109/TPS.2003.820967
- Plasma etching surface
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Condensed Matter Physics