Effects of residual oxygen on properties of cubic silicon carbide films

我们报告的0 D，1D和2D纳米SiC结构（晶粒，晶须，和薄片）的自组织生长的氢等离子体溅射技术，其中少量的氧气被添加到氢原料气。不同结构的选择性生长受衬底温度控制，晶须低于约800℃，晶粒在800-900℃范围内，而薄片在较高温度下。在第一种情况下，额外的氧原子与Si键合，在SiC薄膜中形成四方SiO_2微晶，静电形核晶须生长。当基片温度高于800℃时，无定形碳的沉积使显影膜破碎成小颗粒。随着温度的进一步升高，碳沉积物由于氧的存在而优先形成sp^2键而变得越来越石墨化，从而导致SiC薄片的生长。

We report the self-organized growth of 0D-, 1D- and 2D-nanoscale SiC structures (grains, whiskers, and flakes) by a hydrogen plasma sputtering technique in which a small amount of oxygen is added to the hydrogen feed gas. Selective growth of the different structure is controlled by the substrate temperature, whiskers below approximately 800℃, grains in the range 800-900℃, and flakes at higher temperature. In the case of the first, the additional O atoms bond to Si resulting in tetragonal SiO_2 microcrystals in the SiC films, which nucleate whisker growth electrostatically. When the substrate temperature is above 800℃ deposits of amorphous carbon break up the developing film into small grains. With further increase of temperature, the carbon deposits are increasingly graphitic due to preferential formation of sp^2 bonding due to the presence of oxygen, resulting in the growth of SiC flakes.