PECVD

Plasma enhanced chemical vapor deposition is an established commercial technique for the deposition of insulating films such as silicon nitride and silicon oxide. The major advantage of PECVD is its lower temperature capability compared to that of thermally driven CVD. For example, deposition temperatures of 700 to 900°C are required to deposit silicon nitride films by thermal CVD, while only 250 to 350°C are sufficient to deposit similar films by PECVD. This lower temperature capability is made possible by the addition of electrical energy to the CVD environment and effective substitution of this electrical energy for thermal energy. The properties of the deposited films depend strongly on the used process parameters. Our PECVD system (Oxford Plasmalab 80 plus) is equipped wit the gases SiH4, NH3 and N2O in order to allow the deposition of SiNx, SiOx and SiOxNy. The films stick well to semiconductors or metals and are used for insulation layers, optical waveguides, etch masks and dielectric Bragg mirrors. The thickness of the deposited films (10nm ... 5 µm) is controlled by time.

Specifications:
Excitation frequency: 13.56 MHz
Sample size limited to 20 cm diameter
Heated Table: 200°C ... 400°C
Typical depostion rates are:
SiNx 12 nm/min
SiOx 40 nm/min