Diffusion Direct-current plasma source

A direct-current reactive plasma sputtering technique was used to obtain a B diffusion source in the form of a borosilicate glass. The sheet resistance of Si was measured by using a 4-point probe technique, and the depth of the diffusion... 

With the so-called current-free or transferred plasma, the observation zone is situated outside the current-carrying zone. A source such as this can e.g. be realized by the use of a supplementary gas flow directed perpendicular to the direction of the arc current and by the observation zone being in the tail-flame. In this observation zone no current is flowing. This type of plasma reacts significantly on cooling as no power can be delivered to compensate for temperature drops. Therefore, it is fairly insensitive to the addition of easily ionized elements. They do not cause a temperature drop but only shift the ionization equilibrium and give rise to ambipolar diffusion, as discussed previously. 

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