Silicon etching isotropy

Figure 17. Degree of isotropy observed in silicon etching in CI2/CIF3 plasma as a function of CIF3 content of the feed. Conditions are 5 seem total flow, 0.02 Torr pressure, 100 W rf with 30 V cathode bias at a frequency of 13.6 MHz. (Reproduced with permission from Ref. 39J...

Fig. 12 SEM images of the composed etching profiles (a), (b) patterns realized by anisotropic silicon etching, deposition of passivation polymer layer, and isotropie...

The disadvantage, as far as silica is concerned, is the low degree of seledivity. For Si02 the etch rates are between 300 and 700nm/min. Silicon nitride and noble metals demonstrate better resistance to etching. Because of the isotropy, the asped... 

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