Publications by Krishnaparvathy Puthankovilakam

Unified rule based correction for corners in proximity lithography mask using high resolution features

Hans Peter Herzig, Toralf Scharf, Krishnaparvathy Puthankovilakam

Printing industry and printing techniques are increasing its market value by new methodologies. The resolution and accuracy of the pattern transfer is always a challenge for the industry, especially for the proximity printing industries which use mask alig ...

Elsevier2017

Limitations of Proximity Lithography Printing : Simulations, Experiments, and Applications

Krishnaparvathy Puthankovilakam

Photolithography is one of the earliest technologies used to transfer patterns to a substrate. It is also known as optical lithography since it uses light to transfer the pattern. The main exposure techniques exist in the industry are projection printing, ...

EPFL2017

Light fields behind microstructures: study of the Babinet-principle in the Fresnel regime

Hans Peter Herzig, Myun Sik Kim, Toralf Scharf, Krishnaparvathy Puthankovilakam

The Babinet’s principle is a general theorem that holds for electromagnetic waves and is often applied to diffraction of light. Diffraction pattern of a body and that of the complement body are compared and the sum of both radiation patterns must be the sa ...

Spie-Int Soc Optical Engineering2017

Intensity and phase fields behind phase-shifting masks studied with high-resolution interference microscopy

Hans Peter Herzig, Myun Sik Kim, Toralf Scharf, Ali Naqavi, Krishnaparvathy Puthankovilakam

We try to find out the details of how light fields behind the structures of photomasks develop in order to determine the best conditions and designs for proximity printing. The parameters that we use approach real situations like structure printing at prox ...

SPIE-Intl Soc Optical Eng2016

Lightfields behind amplitude masks: Creating phase discontinuities

Hans Peter Herzig, Wilfried Noell, Myun Sik Kim, Toralf Scharf, Krishnaparvathy Puthankovilakam

Shaping of light fields behind amplitude and phase masks the basis the lithographic structure reproduction. The aerial image or better the intensity distribution defines the resolution of the structure to be printed. Contrast is the main parameter and to a ...

Ieee2016

Structured amplitude and phase fields behind microstructures: The quest for high contrast modulation at proximity

Hans Peter Herzig, Myun Sik Kim, Toralf Scharf, Johana Bernasconi, Krishnaparvathy Puthankovilakam

Microstructures can be used to realize repetitive and singular high contrast features at different distances behind a structure. For practical applications, the amplitude field needs to be considered. To realize defined amplitude features at long distances ...

Spie-Int Soc Optical Engineering2016

Shaping intensity behind amplitude masks for proximity correction lithography: Design, measurement and realization

Hans Peter Herzig, David Nguyen, Qing Tan, Toralf Scharf, Krishnaparvathy Puthankovilakam

Proximity exposure techniques in lithography are getting more and more popular because of the cost of ownership advantage of mask aligners compared to projection systems. In this paper a gap between simulation and the final result, the prints will be close ...

Spie-Int Soc Optical Engineering2014