Microelectronic Engineering 67–68 (2003) 182–188 www.elsevier.com / locate / mee An efficient proximity-effect correction method for electron-beam patterning of photonic-crystal devices a, a b a,b b a * ¨ ¨ R. Wuest , P. Strasser , M. Jungo , F. Robin , D. Erni , H. Jackel a Electronics Laboratory, Swiss Federal Institute of Technology, Zurich, Switzerland b Laboratory for Electromagnetic Fields and Microwave Electronics, Swiss Federal Institute of Technology, Zurich, Switzerland Abstract A simple and accurate method was developed for proximity-effect correction (PEC) in electron-beam patterning of two-dimensional photonic-crystal devices. The method relies on the inherent periodicity of the underlying photonic-crystal structure, which is given as a corresponding matrix representation. This formulation sets up an ‘‘inverse exposure dose problem’’ which is then solved by matrix inversion. The proximity effect parameters are determined experimentally with the doughnut technique for a 30 kV acceleration voltage and 220 nm PMMA on InP substrates. A generic photonic-crystal bend structure, written into PMMA resist, shows an improvement of hole-size homogeneity by a factor of two, when comparing corrected with uncorrected structures.  2003 Elsevier Science B.V. All rights reserved. Keywords: Proximity effect correction; Electron beam lithography; Photonic crystal 1. Introduction In the last few years photonic crystals have been the object of growing interest due to their photonic band-structure properties including, e.g., a photonic bandgap and the superprism effect [1]. These novel properties promise an increased capability to control light in photonic integrated circuits and microcavities as well as novel functionalities for the optical communication technology (such as a vertical add / drop multiplexer [2]). One of the most promising waveguiding concepts—especially when aiming at active devices—consists in a semiconductor slab waveguide which provides vertical light confinement and a two-dimensional (2D) photonic crystal structure of deeply etched holes for lateral light control [3]. *Corresponding author. ¨ E-mail address: wueest@ife.ee.ethz.ch (R. Wuest). 0167-9317 / 03 / $ – see front matter  2003 Elsevier Science B.V. All rights reserved. doi:10.1016 / S0167-9317(03)00070-4