Synthesis and characterisation of NCD films on 10 × 10 mm~2 and deposition on 2 inch wafer using rotating substrate-holder set-up

摘要

In this study, we compare NCD films on 10 × 10 mm~2 silicon substrates synthesised with high methane concentration and NCD films synthesised with prolongated bias during the growth step. Further, we performed in-situ sequential XPS analysis (carbon binding state) using an UHV surface analysis system connected to the MPCVD reactor. AFM and HRSEM were used to characterize films morphology. Using the same substrate holder, NCD films have been deposited on silicon 2 in wafers. To improve the homogeneity, a rotating substrate-holder set-up enabling biasing and heating of the stage has rnbeen developed and coupled with computer control of the process for a better reproducibility. UV-interferometry was performed to map the film thickness an 2 inches.and quantify its thickness uniformity. Considering the symmetry of the system, AFM measurements were performed along the radius of the wafer to evaluate the surface homogeneity and its smoothness. The thickness uniformity of a NCD film of 1.6 μm deposited on 2 inch wafer is under 10% and the RMS roughness comprised between 13 and 14 nm.