The effects of varying plasma parameters on silicon thin film growth by ECR plasma CVD

The technique of electron cyclotron resonance (ECR) plasma enhanced chemica l vapour deposition (PECVD) is increasingly being used in electronic and ph otonic device applications. ECR offers a number of advantages including imp roved control of the deposition process, less damage to the growing film an d the possibility of high deposition rates. ECR occurs in a plasma under ap propriate magnetic and electric field conditions. In most cases, as in our system, this is achieved with a combination of 2.45 GHz microwave radiation and a 0.0875 T magnetic field, due to the use of standardized microwave su pplies. We have studied the effects on silicon film growth of changing the magnetic field configuration to produce one or more planes of ECR within th e system, and of changing the positions of the plane(s) relative to the dep osition substrate. The films were grown in silane-hydrogen discharges. The magnetic field in our system was provided by two electromagnets. It was mea sured experimentally for a number of operating current values and then a de tailed profile achieved by modelling using a proprietary software package. A process condition discharge under identical magnetic field configurations to growth was analysed by the use of a Langmuir probe and the results corr elated with film properties determined by Raman spectroscopy and Dektak pro filometry.