New generation spin on carbon for device scaling

Progress on advance of semiconductor scaling technology, the etching technology using Chemical Vapor Deposited Carbon (CVD Carbon) has become mainstream in recent process. However, while CVD carbon showed good etching resistance properties based on high film modulus and hardness, there are some issues such as gap-filling performance, flatness, and wiggling margin during fine line processing by film stress. On the other hand, Spin on Carbon (SOC), conventional technology, has excellent gap-filling and flatness, but from the viewpoint of film characteristics, the etching resistance is insufficient for fine processing technology and high aspect ratio patterning. Therefore, we needed to invent new technologies to improve etching properties of SOC. Herein, we described the novel SOC by novel reforming process with plasma treatment. Reformed SOC by this treatment had about three times improvement in film hardness and 40% improvement in etching resistance compared to no-treated SOC. Also, by Raman analysis, sp2/sp3 carbon ratio of the SOC was like CVD carbon. These results were contributed to induce combined recombination in inter- or intramolecular in the film by performing this post treatment under certain conditions on the SOC. In addition, the aspect ratio is improved during fine L/S patterning, and we have succeeded in developed the novel post treatment SOC with ACL characteristics. In this report, we described the estimation of the assumed mechanism during post processing, and the results of processability improvement.