| 학회 | 한국재료학회 |
| 학술대회 | 2008년 가을 (11/07 ~ 11/07, 차세대융합기술연구원) |
| 권호 | 14권 2호 |
| 발표분야 | 전자재료 |
| 제목 | THE ROLE OF SURFACE FUNCTIONAL GROUPS OF SiOC:H LOW-K FILMS ON THE NUCLEATION OF ATOMIC-LAYER-DEPOSITED RUTHENIUM |
| 초록 | In most ALD systems, an initial transient cycle region exists before the growth process reaches the linear growth region with the increasing number of deposition cycles. If there are not enough nucleation sites on the surface, sparse nucleation may occur, which may cause a significant variation in the growth rate with the number of deposition cycles. This sparse nucleation may also lead to the generation of pinholes through which Cu can easily penetrate into the low-k dielectric layer, raising serious reliability concerns. Therefore, understanding the precursor adsorption phenomenon and minimizing the initial transient cycle of a Ru ALD on low-k dielectrics is essential to obtain a thinner and denser barrier. It was suggested that ultraviolet (UV)-assisted ozone (O3) treatment enhances the nucleation of Ru on surface-inhibited low-k dielectrics. To further clarify the nucleation of Ru on low-k films, the adsorption probability of the Ru precursor on low-k film is investigated. Ru was deposited using a shower-head type thermal ALD system using 2,4-(dimethylpentadienyl)(ethylcyclopentadienyl)Ru as the metal precursor and oxygen as a reducing agent at the a substrate temperature of 250 oC. Four SiOC:H low-k films with different chemical states were used as substrates to understand the adsorption behaviors of the precursor. The adsorption tendency of the precursor decreased with increasing concentration of methyl groups on the low-k film surface, resulting in the poor and sparse nucleation of Ru. On the other hand, the electron-deficient hydroxyl groups acted as preferential adsorption sites for the electron-rich ligands of the aromatic Ru precursor through the formation of pi-type chemical bonds. This led to the enhanced nucleation of Ru. The roles of the functional groups were corroborated by silylation experiments. No Ru was deposited on silylated low-k surface, indicating that increased CH3-functional groups again retard the adsorption of the Ru precursor. |
| 저자 | Jaeyeong Heo1, Seok-Jun Won2, Sanghyun Park1, Cheol Seong Hwang2, Hyeong Joon Kim1 |
| 소속 | 1Department of Materials Science and Engineering, 2Seoul National Univ. |
| 키워드 | ALD; Nucleation; Ruthenium |
