Low out-gassing organic spin-on hardmask

Beyond 45nm node processes, ArF hyper-NA immersion lithography systems are an inevitable choice for obtaining smaller patterns. A hyper-NA, dual BARC system is proposed to achieve low reflectivity. However, the ability for the resist to ask as a mask is severely challenged because of the increased film thickness associated with a dual BARC system. In order to obtain enough etch selectivity to the substrate, multi-layer resist processes can be applied. General multi-layer resist processes uses silicon containing an inorganic spin-on hard mask and an organic spin-on hard mask with a high carbon content. One of the problems of organic spin-on hard masks is high out-gassing, which can cause defect issues in mass production. We have developed a new organic hard mask with low out-gassing, good reflectivity control (< 0.2%) and good etch durability. Gap-filling performance also can be controlled by changing its fluidity and wettability on the substrate.