E-beam lithography at low voltages

Abstract

Electron beam lithography for the fabrication of 1X x-ray masks and optical lithography system such as Markle-Dyson system requires precision of edge placement of mask less than 100 nm. In this paper we report experimental results with low voltage exposures (2 keV). 100 nm features were delineated in 66 nm resist in both sparse and dense patterns on bare silicon and 300 nm Au/Si confirming the predicted dramatic reduction in proximity effects. In addition, both sparse and dense 100 nm patterns were resolved over doses from 16 to 28 (mu) C/cm2 on bare silicon and 14 to 27 (mu) C/cm2 on gold substrate illustrating the high dose tolerance enjoyed at low voltages. Electromagnetic interference and the lower electron beam brightness are not limiting factors for the low voltage exposure.