Modelling Deposition Uniformity in Microwave Plasma CVD Diamond over 2“ Si wafers

A microwave plasma model is presented to understand the thickness variation of microwave plasma chemical vapour deposited (MPCVD) diamond across 2” Si wafers of various substrate thicknesses. The model is compared with experimentally grown CVD diamond of tens of microns in thickness on 2” Si wafers, characterised using surface profilometry and Raman spectroscopy. This work demonstrates that thicker Si substrates result in better uniformity over a 2” deposition area. This is likely due to the sample surface being pushed further into the plasma activation region, resulting in a more uniform temperature distribution and therefore a uniform diamond growth rate.