Ion enhanced etching

C2.18.3.2 EXPERIMENTAL STUDIES OF ION-ENHANCED ETCHING REACTION KINETICS AND DYNAMICS... 

Similar conclusions can be drawn from the data shown in Fig. 27 where the partial pressure of SiF4 is monitored mass spectrometrically as an Si sample is rotated into a jet of XeFj gas with and without ion bombardment. The ion-enhanced etching of silicon is indicated by the much larger evolution of SiF4 when the sample is exposed... 

Ion-enhanced etching mechanisms using MD were addressed by Barone and Graves (1995a,b, 1996) in several papers. In the first paper, the Stillinger-Weber potentials were used for Si-Si, Si-F, and F-F interactions. Si-Ar... 

Fig. 16. The four basic mechanisms of etching by a plasma, (a) sputtering, (b) chemical etching by the action of neutrals only, (c) ion-induced etching reaction occurs only on surfaces undergoing ion bombardment, and (d) ion-enhanced etching neutrals could etch even in the absence of ion bombardment the latter increase the etch rate. In order to avoid etching of the sidewalls by neutrals in case (d), the plasma chemistry is selected so as to coat the sidewalls by an extremely thin layer which inhibits sidewall etching. Ion bombardment clears the inhibitor film allowing etching to proceed anisotropically. After [12].

In general, the total etch rate can be expressed as the sum of three components physical sputtering, spontaneous (chemical) etching and ion-induced or ion-enhanced etching [64, 69-71]. 

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