Oxygen etch gas

The effectiveness of chemical etching is largely dependent on the volatility of fragmented species. For instance, oxygen plasma is an effective etching gas for most... 

C for 30 minutes in a vacuum oven. Plasma development was carried out either in a barrel etcher or a planar etcher. For the barrel etcher, 02 (oxygen) was used as the etch gas. In Figure 4, the normalized film thickness remained after development vs exposure dose is plotted for two different bake temperatures. It appears from the figure that 60° bake has produced a more sensitive resist but 100° bake has produced a thicker resist at high dose. The exposed patterns were 10 micron by 500 micron rectangles. 

Khulbe KC, Matsuura T. Characterization of PPO membranes by oxygen plasma etching, gas separation and atomic force microscopy. J. Memb. Sci. 2000 171 273-284... 

Tungsten films can be etched easily in fluorine-containing plasma 73,80). If carbon or sulfur is present in the gas atmosphere, oxygen is typically added to prevent polymer and residue formation and to increase the concentration of fluorine atoms. 

Many of the mechanisms discussed in Sect. 2.2.6.1 with regard to ions may also apply to chemical reactions enhanced by electron bombardment. A discussion of that type will not be repeated in this section. However, a mechanism for the electron-enhanced etching of SiOj can be suggested on the basis of processes which are known to occur. It is known, for example, that electron bombardment of SiOj causes oxygen to be desorbed into the gas phase, i.e., electron stimulated desorption occurs . The silicon which remains upon the surface can now be attacked by the XeFjfgas) to produce SiF4(gas). In this manner both oxygen and silicon are removed from the SiOj lattice and the material is etched. The chemistry involved is likely to be more complex, but this simple model illustrates a possible mechanism. 

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