Resolution limits and process latitude of comformable contact nano-lithography

Conformable Contact Lithography enables researchers to attain high-resolution lithographic patterning at manageable cost. This thesis characterizes the minimum resolvable feature size and process latitude of Conformable Contact Lithography. Beginning with a review of current lithographic patterning techniques, choice of Conformable Contract Lithography as an exposure technique is discussed. A design for a trilayer stack that optimizes optical properties is established using experimental and simulated reflectance data to choose appropriate stack film thicknesses. The simulated process latitude is constructed using electromagnetic simulations of grating patterns. Image analysis of experimentally-exposed diffraction grating patterns is described and used to characterize the effect of exposure dose on printed linewidth. The resulting simulated and experimental process latitudes for printed gratings are presented for masks utilizing protruding chrome lines and embedded chrome lines. Experimental and simulated reflectance for single-layer and bilayer film stacks are compared to yield an optimized trilayer stack design of 225nm of anti-reflection-coating chemically separated from the resist by 70nm of evaporated silicon oxide. This design results in less than 1.5% back-reflection from the oxide into the resist for 10% film thickness variation. Finite-difference time-domain simulations are optimized by comparing higher variable-resolution, more realistic simulations to more efficient, lower variable-resolution simulations. Building on the trilayer stack and optimal simulation specification, simulated exposures of diffraction gratings are analyzed assuming a clipping model of development. Exposures of dense grating patterns with two geometries are performed on trilayer-stack-coated silicon wafers for a range of doses.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2007

Author dc:creator

• Fucetola, Corey Patrick

Advisor dc:contributor.advisor

• David J. Carter and Henry I. Smith.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/41640

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/41640