Title :
0.12 /spl mu/m hole pattern formation by KrF lithography for Giga bit DRAM
Author :
Nakao, S. ; Nakae, A. ; Yamaguchi, A. ; Kimura, H. ; Ohno, Y. ; Matsui, Y. ; Hirayama, M.
Author_Institution :
ULSI Lab., Mitsubishi Electr. Corp., Hyogo, Japan
Abstract :
Dense 0.10 /spl mu/m hole pattern formation has been achieved by optical lithography with KrF wavelength. Double exposure utilizing two alternative phase shift masks of lines and spaces patterns produces dense small hole images with enough focus and exposure latitude. Applying this method with a KrF stepper and chemically-amplified negative-tone resist, a 2-dimensional 0.13 /spl mu/m hole array with a pitch of 0.40 /spl mu/m has been resolved with 1.0 /spl mu/m DOF, and resolution limit size and pitch are less than 0.10 /spl mu/m and 0.28 /spl mu/m, respectively.
Keywords :
DRAM chips; ULSI; image resolution; krypton compounds; optical focusing; phase shifting masks; photolithography; 0.12 /spl mu/m hole pattern formation; 0.12 mum; 2D hole array; KrF; KrF lithography; KrF stepper; ULSI; chemically-amplified negative-tone resist; dense small hole images; double exposure; exposure latitude; focus latitude; giga bit DRAM; optical lithography; phase shift masks; pitch; resolution limit size; Fabrication; Focusing; Integrated optics; Lithography; Optical attenuators; Optical devices; Pattern formation; Random access memory; Resists; Ultra large scale integration;
Conference_Titel :
Electron Devices Meeting, 1996. IEDM '96., International
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-3393-4
DOI :
10.1109/IEDM.1996.553122
