Real-time dose control for electron-beam lithography

Abstract

Shot-to-shot, or pixel-to-pixel, dose variation during electron-beam lithography is a significant practical and fundamental problem. Dose variations associated with charging, electron source instability, optical system drift, and ultimately shot noise in the e-beam itself conspire to critical dimension variability, line width/edge roughness, and limited throughput. It would be an important improvement to e-beam based patterning technology if real-time feedback control of electron-dose were provided so that pattern quality and throughput would be improved beyond the shot noise limit. In this paper, we demonstrate control of e-beam dose based on the measurement of electron arrival at the sample where patterns are written, rather than from the source or another point in the electron optical column. Our results serve as the first steps towards real-time dose control and eventually overcoming the shot noise.

Detectors Array for In Situ Electron Beam Imaging by 16-nm FinFET CMOS Technology

“…According to the simulation results in Fig. 3 , the e-beam is expected to penetrate and travel through a distance of a few microns, and the electron velocity before injection can reach to 6 cm/ns at energy of 10 keV [ 25 ], the response time is estimated to be within μsec level [ 26 ], enabling responses to fast scanning e-beams.…”