Title :
Wavelet-based uniformity of plasma etching surface
Author :
Kim, Sungmo ; Sungmo Kim ; Lim, Myo Taeg
Author_Institution :
Dept. of Electron. Eng., Sejong Univ., Seoul, South Korea
Abstract :
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.
Keywords :
discrete wavelet transforms; plasma materials processing; scanning electron microscopy; sputter etching; tungsten; W; discrete wavelet transformation; efficient space-frequency localization; etch rate; etching profile surface; helicon plasma; plasma etching surface; plasma fluctuations; plasma-processed surfaces; process optimization; process quality; scanning electron microscopy; sensitivity analysis; tungsten etch; wavelet-based uniformity; Discrete wavelet transforms; Etching; Plasma applications; Plasma confinement; Plasma density; Plasma sources; Plasma temperature; Plasma waves; Scanning electron microscopy; Surface waves;
Journal_Title :
Plasma Science, IEEE Transactions on
DOI :
10.1109/TPS.2003.820967
