Study of an isopropyl alcohol plasma for deposition

Summary form only given, as follows. We have used an inductively coupled discharge to produce a plasma with the feed gas being a mixture of isopropyl alcohol and argon. The intended ion has atomic mass 45 (CH/sub 3/CH/sup +/OH), which is thought to have favorable properties for film deposition. This ion is generated from the alcohol via electron dissociation ionization. However in addition to this, an isopropyl ion (CH/sub 3/CH/sup +/CH/sub 3/) with atomic mass 43 is also produced, most likely by an ion molecule protonation/dehydrogenation reaction. This isopropyl ion has undesirable properties for film deposition if the goal is to deposit films with a C-O-C bond character. One goal of the experiment is to control the kinetic branching ratio between the different ion production channels, hence ultimately controlling the film deposition chemistry. Using Langmuir probe and in-situ spectrometry mass measurements, the production of the two main ions, as well as other plasma properties, is studied as a function of discharge parameters. Finally, we use X-ray photoelectron spectroscopy to interrogate the distribution of oxidation states of the carbon atoms deposited in the film, and we correlate these findings to the plasma ion impingement flux. We have also looked into the steady state theory of such a multicomponent plasma, with a variety of reaction chains. Despite the complexity, it turns out that typically in a low pressure plasma, all continuity equations are governed by a single boundary condition, that is, specifying a boundary condition for each continuity equation would over specify the problem. In addition, at least for relatively simple geometry, there are analytic solutions for the relative densities. We use this theory to compare with the experimental results.