Lecture_8_2_Dry_Etching - Lecture 8.2 Dry Etching IH2655...

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Dry Etching Lecture 8.2
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IH2655 Spring 2009 Mikael Östling KTH ETCHING Introduction : • Etching of thin films and sometimes the silicon substrate are very common process steps. • Usually selectivity, and directionality are the first order issues.
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IH2655 Spring 2009 Mikael Östling KTH Drawbacks of Wet Etching In the manufacture of large-scale ICs, wet etching is being replaced by dry etching. (1) Wet etching is isotropic while dry etching can be anisotropic. (2) Dry etching can achieve high resolution. Wet etching has poor resolution. (3) Wet etching depends on a lot of corrosive chemicals, which are harmful to human bodies and environments. (4) Wet etching needs a large number of chemical reagents to wash away the residues. Non-economical!!
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