REBL: A novel approach to high speed maskless electron beam direct write lithography

Abstract

The system concepts used in a novel approach for a high throughput maskless lithography system called reflective electron beam lithography (REBL) are described. The system is specifically targeting five to seven wafer levels per hour throughput on average at the 45nm node, with extendibility to the 32nm node and beyond. REBL incorporates a number of novel technologies to generate and expose lithographic patterns at estimated throughputs considerably higher than electron beam lithography has been able to achieve as yet. A patented reflective electron optic concept enables the unique approach utilized for the digital pattern generator (DPG). The DPG is a complementary metal oxide semiconductor application specific integrated circuit chip with an array of small, independently controllable metallic cells or pixels, which act as an array of electron mirrors. In this way, the system is capable of generating the pattern to be written using massively parallel exposure by ∼1×106 beams at extremely high data rates (∼1Tbit∕s compressed data). A rotary stage concept using a rotating platen carrying multiple wafers optimizes the writing strategy of the DPG.