| 摘要 |
An apparatus and method for chemical vapor deposition in which the reactants directed toward a substrate to be provided with one or more films are first subjected to an electric field. The electric field is applied between two electrodes and the reactants become polarized in the field, thus stretching their polarized chemical bonds close to the breaking point. The apparatus also applies voltage pulses between one of the electrodes and the substrate. By adjusting the pulse height, pulse width and pulse repetition rates, the chemical bonds of polarized reactants break to produce free radicals and some ions of the desired elements or compounds. The substrate is kept at a given temperature. The free radicals react to deposit the desired film of high purity on the substrate. The deposition characteristics of the deposited films in terms of isotropic, anisotropic and selective deposition are controlled by the pulse height, width, repetition rates and by other process parameters. Such parameters also control the grain size and orientation of the deposited films. By choosing appropriate reactants other than those for CVD, e.g., for reactive ion etching (RIE), in-situ cleaning prior to CVD, RIE and post CVD etching and treatment of the films can be accomplished. The latter technique is useful for achieving in-situ planarization. To aid the dissociation process for producing the free radicals in ions from the reactants, an axial magnetic field axial to the direction of the applied electric field may also be used.
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