APPARATUS FOR LANGMUIR PROBE MONITORING OF PLASMA DURING DEPOSITION PROCESSES

A computer-controlled system for measurements of Langmuir probe characteristics is described. Fast data collection (one point in 200-mu-s, measurement of the total characteristic in less than 1 s) enables measurements to be made in a time which is short compared with changes of the probe surface condition. Various operation modes facilitate an effective check of the probe surface contamination. The test measurements using conducting (Cu) and dielectric (Al2O3) deposits illustrate the possibility of application of this probe assembly to PECVD Of organometallic compounds.