Diamond coating on silicon nitride by intermittent discharge DC plasma chemical vapor deposition

A new diamond coating method on a silicon nitride throw away chip (SNTAC) by intermittent discharge DC plasma chemical vapor deposition (CVD), where the wave-form of the discharge is half-wave-rectified (HWR), has been developed. The coating was performed by exposing SNTAC in the plasma The discharge to form the plasma is performed by applying the voltage of HWR between the cathode and a piece of molybdenum sheet (sub-anode) placed on the anode. The crystalline quality of the film was superior at midway between the electrodes in comparison with the parts near the electrodes A uniform coating of the high quality diamond film on the edge part of the chip was realized by using this phenomenon and appropriate designing of the sub-anode.