Design of continuous full complex modulation proximity printing masks using a quadratic phase distribution L. G. Neto a , G. A. Cirino b , R. D. Mansano c , P. Verdonck c A.C. Seabra c a EESC - University of São Paulo, Av. Dr. Carlos Botelho, 1465, 13560-970 - São Carlos - SP - Brazil Phone:(55)(16)273-9350, FAX (55)(16)273-9372 lgneto@sel.eesc.usp.br b EletroPPAr Indústria Eletrônica Ltda Av. Dr. Labieno da Costa Machado, 3370 17400-000 – Garça – SP - Brazil giuseppe@ppa.com.br c LSI-PSI-EPUSP - University of São Paulo, Av. Prof. Luciano Gualberto, trav.3, 158 05508-900 - São Paulo - SP, Brazil Phone: (55)(11)3091-5666 Fax: (55)(11)3091-5664 patrick@lsi.usp.br ABSTRACT In this work we propose the use of a quadratic phase distribution to implement continuous, full complex amplitude modulation proximity printing masks. The mask is calculated based on the inverse light propagation, determining values of both continuous phase and amplitude modulation. The novelty in this proposition is the use of a quadratic phase distribution in the desired reconstruction pattern in order to achieve a smooth phase and amplitude modulation during the mask calculation. The use of a quadratic phase distribution on the desired reconstruction pattern allows to spread the light of this pattern over a wide region of the calculated proximity-printing mask, generating a magnification of the information to be modulated by the mask. As a consequence, the feature sizes on the mask are larger than in the image reconstruction plane. We believe that this approach will allow the generation of a continuous variation of light in the final required pattern, allowing the generation of arbitrary 3D structures. The smooth phase and amplitude modulation distributions can also minimize the errors caused by using the scalar diffraction to calculate and encode the phase and amplitude modulation of the final mask. Keywords: Proximity printing, mask making, quadratic phase distribution, full complex amplitude modulation, optical phase modulation, optical amplitude modulation. 1. INTRODUCTION Proximity printing is an effective photolithographic technique for microelectronic fabrication [1]. In a previous work [2] we have proposed a hybrid phase and amplitude modulation proximity printing mask fabricated using a diamond like carbon (DLC) thin layer on top of a fused silica (SiO 2 ) substrate. The resolution of the lithographic process could be dramatically improved by replacing the conventional mask with this one that employs the concept of Fresnel Holograms in order to decrease the diffraction effect of the edges of the mask features. The mask projects the required pattern at a Micromachining Technology for Micro-Optics and Nano-Optics II, edited by Eric G. Johnson, Gregory P. Nordin, Proceedings of SPIE Vol. 5347 (SPIE, Bellingham, WA, 2004) 0277-786X/04/$15 · doi: 10.1117/12.524564 71 DownloadedFrom:http://proceedings.spiedigitallibrary.org/on02/11/2015TermsofUse:http://spiedl.org/terms