157nm photodissociation of polyamides

• Published in: Microelectronic engineering 2000-06, Vol.53 (1), p.465-468
• Main Authors: Cefalas, A.C., Sarantopoulou, E.
• Format: Article
• Language: English
• Subjects: Applied sciences; Design. Technologies. Operation analysis. Testing; Electronics; Exact sciences and technology; Integrated circuits; Lithography, masks and pattern transfer; Microelectronic fabrication (materials and surfaces technology); Microelectronics: LSI, VLSI, ULSI; integrated circuit fabrication technology; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/S0167-9317(00)00357-9

Research for new photoresists for 157nm photolithography requires the investigation of the basic photochemical studies at this wavelength. The parent molecule disintegrates to small fragments, which are flying apart with supersonic speed. Therefore the photodissociation process, could impose serious problems on the optics of the focusing system by contaminating it. In order to investigate the basic photochemical mechanisms of the photodissociation dynamics of various polymeric materials at 157nm, we have used nylon 6.6 as test material. This is mainly because the nylon 6.6 monomer has the potential to dissociate into small photofragments in which most of the photoresists used for 193 and 157nm photolithography are likely to be dissociated. Hence we report on the mass spectroscopy of nylon 6.6 at 157nm, using an F 2 pulsed discharge molecular laser. At this wavelength there is complete photochemical bond braking in the energy range from 1 to 8mJ/cm 2 per pulse. The monomer dissociates into fragments with the predominant mass at 28amu. Therefore the amide group is mainly involved in the photodissociation process of nylon 6.6 at 157nm.