| 초록 |
Nanoporous ultralow dielectrics are definitely required for the next generation semiconductors (≤ 25 nm). The introduction of nano-sized pores into low dielectric materials is the most effective way to reduce the dielectric constant (k). However, introduction of a large number of pores causes dramatic decrease of mechanical properties such as elastic modulus and surface hardness. UV treatment has been used for mechanical enhancement because it induces chemical and structural changes of nanoporous dielectrics by breakage and rearrangement of Si- bonds. Matrix is copolymer of methyl trimethoxysilane and 1,2-bis(triethoxysilyl) ethane (k= 2.9, E= 12.46 GPa). Reactive porogen was synthesized by using xylitol to make more uniform. UV treatment resulted in the increased mechanical properties (E= 10.77 GPa at the porosity of 25.92), which was well above the requirements for CMP processing (E＞ 6 GPa), but decreased dielectric constant (k= 2.16). |
