High-etch-rate low-bias bow outgassing BARC via-filling materials for 193-nm ArF lithographic process

Abstract

As critical dimensions in integrated circuit (IC) device fabrication continue to shrink to less than 90 nm, designing multi-functional organic bottom anti-reflective coating (BARC) materials has become a challenge. In this paper, we report novel high performance BARC materials that are simultaneously capable of controlling reflectivity, planarizing on substrate surface, low bias filling without forming voids, low outgassing, high etch selectivity with resists and broad compatibility with resists. The new materials comprise of a chromophore that absorbs at 193 nm to give anti-reflective properties. By intriguing design of the crosslinking system to minimize the amount of low molecular weight additives and the by-product formation in the curing process, low-bias and low sublimation filling without formation of voids are achieved. The filling properties, etch selectivity, lithographic and outgassing data of the new BARC materials will be presented.The novel via-filling BARC materials may find applications in next generation via-first dual damascene (DD) process, which combines palanarizing surface topography and antireflectivity into one step process using single layer BARC material. In another application, the reported low k ultra high etch rate BARC materials have demonstrated good resist compatibility in ArF immersion lithographic process.