A New Breed of Wet-Developable BARC Materials

• Published in: Journal of Photopolymer Science and Technology 2009/06/30, Vol.22(1), pp.17-24
• Main Authors: Vyklicky, Libor, Huang, Wu-Song, Popova, Irene, Varanasi, Pushkara Rao, Cameron, James, Amara, Johan, Sung, Jin Wuk, Valeri, David, Prokopowicz, Greg, Ware, Adam, O'Connell, Kathleen, Desisto, Jason, Vohra, Vaishali, O'Shea, Kevin, Barclay, George, Yamamoto, Yoshihiro, Kurihara, Tomoki, Hidano, Manabu
• Format: Article
• Language: English
• Subjects: antireflective coating; D-BARC; Gain; Imaging; Implants; Optical density; Optical properties; Patterning; Photoresists; Reflectivity; wet-developable BARC
• ISSN: 0914-9244; 1349-6336; 1349-6336
• DOI: 10.2494/photopolymer.22.17

A new family of materials has been developed to serve as a wet-developable bottom antireflective coating (D-BARC) for patterning levels that have a strong need to avoid dry-etch processes for BARC-open steps. Such include some implant levels, where dry-etch introduces surface damage that consequently affects the final electrical performance of a device. Other levels that might benefit from all-wet patterning are those using special substrates such as high-k metal-gate (HKMG) levels. Our design of D-BARC materials combines the unique properties of traditional BARC as well as those of a photoresist to deliver a D-BARC solution that is photoimageable in nature. It was found that isotropically developable (i.e., non-imageable) D-BARCs do not provide viable solutions that satisfy the resolution requirements of the current 32 nm technology node and provide the extendibility to future nodes. The optical properties of the D-BARC material are critical for reflectivity control but high optical density can negatively impact the imaging performance of the material. Therefore a balance is needed where the D-BARC is co-optimized with the photoresist as a system, achieves good reflectivity control, residue-free imaging and process gains.