The surface chemistry of the pulsed process was probed by using graphite substrates with trenches to study the influence of precursor pulsing on the coating step coverage (SC). The initial pulsed-CVD cycle was chosen as 3 s Si-pulse -1 s purge -3 s C-pulse -1 s purge, which was one of the combinations that did not result in co-deposition of elemental Si (Figure ). In contrast to a subconformal SiC coating deposited at 1200 ℃ by continuous CVD reported in our previous studies , a superconformal SiC growth with a SC of nearly 9 was achieved at 1200 °C in a trench with an aspect ratio (AR) of 4 via pulsed CVD. The thickness difference between the top and the bottom corner of a trench in the 3C-SiC coatings deposited by pulsed and continuous CVD can be seen in Figure .