DRY ETCHING OF CONTACT WINDOWS IN SILICON DIOXIDE USING CHF

Due to decreasing in LSI, VLSI,(ULSI), dry etching steps (Plasma etch, RIE, RIBM...) replace most wet etchings. Initially, most of the attention was paid to patterning of silicon nitride and polysilicon (etching steep walls with no undercut.) Only during the last 2 years, dry etching of silicon dioxide became a hot topic. This paper gives a description of an integrated process for etching contact windows in silicon dioxide. Also basic mechanisms of the silicon dioxide etching are explainer.