Sub quarter-micron bilayer electron beam resist with enhanced sensitivity

Because of the need for 100 nm structures in the very near future, Electron Beam Lithography (E-beam) as a means for high resolution lithography is di scussed not only to be used for ASICs or mask fabrication, but also for the application in a standard lithographic production. Besides the improvement of new E-beam writing concepts with the necessary enhanced hardware, the d evelopment of new resist systems and processes is a main objective for a hi gh throughput production. This paper reports about a new bilayer E-beam res ist system based on the CARL process (Chemical Amplification of Resist Line s). It comprises chemical amplification in a thin top-resist layer, wet sil ylation after the standard wet development and dry development in an oxygen plasma to transfer the structures into the thick bottom layer. The achieva ble resolution could be shown to be better than 0,15 mu m lines and spaces. The development of new photoactive compounds in combination with a fluoren e carboxylic acid senzitizer yields sensitivities of only 1 mu C/cm(2) at a n electron energy of 30 keV. (C) 1999 Elsevier Science BN. All rights reser ved.