Etching anisotropy

It is our current opinion that all etching anisotropy or directionality is caused by energetic particle bombardment (primarily ions but in some cases, electrons). Other factors such as the degree of fluorine deficiency in the discharge can influence the... 

In a follow up full publication to the work above, Harrison et al. showed that using porous thin films as described above, pattern transfer could be accomplished in both Si and Ge substrates as well [23]. While an entire three-inch Si wafer was patterned using this technique, practical limitations, such as in etch anisotropy, were reported. In this paper, an effective technique for confirming porosity in these films was demonstrated. After ozonolysis of these thin films, an overlayer of PS remained at the surface of these porous samples. By using a low power CF4 RIE followed by periodic SEM analysis, this layer could be slowly etched to reveal thus revealing the cylindrical pores (now observed as trenches). Also, the authors showed that the low power CF4 etch did not result in significant surface roughness. 

The maximum anisotropy can be achieved when the ion flux is not too high (T ATiU K rio) and the surface is covered by chemisorbed complexes (0 1) (8-17). In this ion flux-limited regime, the etching anisotropy increases with an increase of ion energies and... 

Etching Anisotropy Analysis in the Framework of Surface Kinetics of Plasma Etching. Based on relation (8-22), analyze the substrate temperature effect on etching anisotropy. Which step of the ion energy-driven etching is most affected by substrate temperature Compare effects of translational gas temperature and electron temperature on the plasma etching process. 

High etching anisotropy for the desired etching profile... 

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