Reactive Sputtering Deposition of Epitaxial TiC Film on Si (100) Substrate

Epitaxial (100) TiC film deposition on Si (100) substrate by direct current magnetron reactive sputtering of a metallic Ti target with 3%–6% CH₄ in Ar gas was investigated. X-ray diffraction and cross-sectional scanning transmission electron microscopy (STEM) reveal that epitaxial cubic TiC can be grown on the Si substrate by domain matching epitaxy in 5/4 ratio with the epitaxial relationship of TiC (100)[0 $\overline{1}$ 1] // Si (100)[0 $\overline{1}$ 1]. For sputtering with 3% and 4% CH₄, the deposited films are found to consist of both TiC and metallic Ti phases. Increasing the CH₄ flow ratio to 5% results in a deposited film completely consisting of TiC without metallic Ti phase. The crystallinity of the deposited TiC is also improved with increasing the CH₄ ratio to 5%. X-ray photoelectron spectroscopy shows that the [C]/[Ti] atomic ratio in TiC is nearly close to 1 for growth with 5% CH₄ flow ratio and above. The measured electrical resistivities of the deposited films also increase from 41 to 153 μΩ·cm with increasing the CH₄ ratio from 3% to 6%. With film growth beyond 50 nm thickness, it is shown that some disoriented TiC grains are formed.