Silicon dioxide hydrogen impurity

These authors found that it was possible to deposit amorphous films whose Ta concentration ranged from 10 to 80 mol % by changing the reactive gas mix. Another feature of the films was that under certain conditions they contained substantial quantities of chlorine and hydrogen. Also, they did not adhere to either silicon or silicon dioxide after annealing (argon atmosphere for 1 hour at 900°C). When the substrates were dry etched in an HCI plasma for 2 minutes, they adhered to the substrate even after annealing. Since this etch removed about 50 A, it appears that the native oxide on the silicon and/or some other surface impurities on both the silicon and silicon dioxide were causing the lack of adhesion. 

Acetylene manufactured from carbide made in the United States and Canada normally contains less than 0.4 percent impurities other than water vapor. Apart from water, the chief impurity is air, in concentrations of approximately 0.2 percent and 0.4 percent. The remainder is mostly phosphine, ammonia, hydrogen sulfide, and in some instances, small amounts of carbon dioxide, hydrogen, methane, carbon monoxide, organic sulfur compounds, silicon hydrides, and arsine. Purified acetylene is substantially free from phosphine, ammonia, hydrogen sulfide, organic sulfur compounds, and arsine. The other impurities are nearly the same as in the original gas. 

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