| AVS 57th International Symposium & Exhibition | |
| Plasma Science and Technology | Wednesday Sessions |
| Session PS2-WeA |
| Session: | Neutral Beam Processing |
| Presenter: | T. Sasaki, Tohoku University, Japan |
| Authors: | T. Sasaki, Tohoku University, Japan S. Yasuhara, Tohoku University, Japan T. Shimayama, Semiconductor Technology Academic Research Center (STARC), Japan K. Tajima, Semiconductor Technology Academic Research Center (STARC), Japan H. Yano, Semiconductor Technology Academic Research Center (STARC), Japan S. Kadomura, Semiconductor Technology Academic Research Center (STARC), Japan M. Yoshimaru, Semiconductor Technology Academic Research Center (STARC), Japan N. Matsunaga, Semiconductor Technology Academic Research Center (STARC), Japan S. Samukawa, Tohoku University, Japan |
| Correspondent: | Click to Email |
To precisely control the dielectric constant and the structure of a low-k SiOC film, we have developed a neutral-beam-enhanced chemical vapour deposition (NBECVD) method. Using Ar NBECVD with precursors of methyl trimethoxy silane (MTMOS), dimethyl-dimethoxy-silane (DMDMOS), and dimethoxy-tetramethyl-disiloxine (DMOTMDS), we can precisely control the dielectric constant and the film modulus of low-k SiOC deposited on Si substrates because this method avoids precursor dissociation that results from electron collisions and UV photons in plasma. Optimizing the ratio between Si–O and Si–(CH3)x as well as the proportions of linear (two-dimensional SiOC), network and cage (three-dimensional SiOC) structures by changing the precursor and neutral beam energy, we obtained a k value of less than 1.9 and a reasonable modulus of more than 4GPa with an extremely water resistant and very thermally stable .
Additionally, we investigated the resistance of the NBECVD low-k SiOCH to plasma-irradiation damage in comparison with conventional plasma CVD (PECVD) techniques. We found that the durability of a low-k SiOCH film structure to plasma irradiation strongly depended on the kind of Si–O structure the film had. In particular, a linear Si–O structure was less affected by plasma exposure than were network/cage Si–O structures. In addition, this linear Si–O structure helped to reduce the number of methyl groups removed from the film by plasma irradiation, which preserved the dielectric constant. Since the NBECVD technique can generate a low-k SiOCH film with more linear Si–O structures than conventional plasma CVD, the NBECVD film has very strong plasma durability.