Effect of N2O on high-rate homoepitaxial growth of CVD single crystal diamonds

Abstract Various gases such as N 2 , O 2 , and CO 2 have been introduced in the typical reaction atmosphere of CH 4 /H 2 and proposed to improve the growth of chemical vapor deposited (CVD) single-crystal diamonds (SCDs). In this paper, we study the influence of a new adding gas nitrous oxide (N 2 O) on the growth rate, morphology, and optical properties of homoepitaxy (100) CVD SCDs. The reaction pressure (H 2 /CH 4 flow rates) was fixed at 300 Torr (750/90 in sccm) with the addition of a small amount of N 2 O gas varied at flow rates of 0, 2, 5, 8 and 10 sccm. With the appropriate addition of N 2 O, the growth rate was increased up to 135 μm/h and the surface roughness was decreased to around 2 nm. Furthermore, adding N 2 O is favorable for inhibiting the generation of large anti-pyramidal pits on the top surface of SCDs, which generally appeared in the products synthesized in CH 4 /H 2 ambient. The combined effect of the nitrogen- and oxygen-related radicals decomposed from N 2 O on the growth and properties of the CVD SCDs is discussed. As a result, the addition of N 2 O provides a new route to realize high-rate growth CVD SCDs instead of the traditional nitrogen.