Patent ID: 8247332

Claim:
A method of forming a hardmask film on a semiconductor substrate, the method comprising: receiving the semiconductor substrate in a plasma-enhanced chemical vapor deposition (PECVD) process chamber; and forming a hardmask film having a hardness of greater than about 12 GPa, and a stress of between about −600 MPa and 600 MPa by PECVD on the semiconductor substrate, wherein the PECVD hardmask deposition process comprises: depositing doped or undoped multi-layer silicon carbide film using multiple densifying plasma treatments, the process comprising; (a) introducing a process gas comprising tetramethylsilane and an inert gas into the process chamber and forming a dual frequency plasma to deposit a first sublayer of the silicon carbide hardmask film, wherein the power level for high frequency plasma is between about 0.04-0.2 W/cm 2 and the power level for low-frequency plasma is between about 0.17-0.6 W/cm 2 ; (b) removing the tetramethylsilane from the process chamber, wherein said removing comprises purging the process chamber with a gas selected from the group consisting of Ar, He, H 2 , and mixtures thereof; (c) introducing a plasma treatment gas into the process chamber and treating the substrate with plasma to densify the deposited sublayer, wherein densifying the deposited sublayer comprises flowing a process gas selected from the group consisting of Ar, He, H 2 , and mixtures thereof and forming a dual frequency plasma, wherein LF/HF power ratio is at least about 1.5; and (d) repeating (a)-(c) to form and densify additional sublayers of silicon carbide.