Sivarama K Kuchibhotla

7106415, Sep 12, 2006

Dec 9, 2003

10/731187

Sivarama K. Kuchibhotla - Croton on Hudson NY, US
Kanti Jain - Hawthorne NY, US
Marc A. Klosner - White Plains NY, US

Anvik Corporation - Hawthorne NY

G03B 27/68
G03B 27/58
G03B 27/42

355 52, 355 47, 355 53

A zero power identical pair of oppositely-oriented meniscus lens elements mounted in the projection light path, serves as curved mask support while compensating for optical anomalies such as beam shift and beam deviations produced by other transparent supports for the curved mask. The zero-power meniscus lens pair, without affecting the transmission beam characteristics, lets the beam diffract as efficiently as does a regular planar mask, thus preserving the partial coherence effects and resolution concepts of projection lithography. This simple but novel optics device is not only expected to clear several barriers for curved mask projection lithography but also find place in other applications where collimated or converging light beams have to travel extra paths without significant aberration.

7158305, Jan 2, 2007

Jun 29, 2004

10/879887

Shyam Raghunandan - Briarcliff Manor NY, US
Kanti Jain - Hawthorne NY, US
Marc I. Zemel - West Harrison NY, US
Marc A. Klosner - White Plains NY, US
Sivarama K. Kuchibhotla - Croton on Hudson NY, US

Anvik Corporation - Hawthorne NY

G02B 5/02
G02B 6/26
G02B 6/10
F21V 7/04

359599, 385 43, 385129, 385146, 362551

An optimized illumination system that efficiently produces uniform illumination for exposure, photoablation, and laser crystallization systems. The illumination system includes a homogenizer that uniformizes and shapes a light beam, which is directed onto a mask by condenser optics. The illumination system recycles radiation by directing light reflected by the mask back into the illumination system, where an apertured mirror situated at the input end re-directs it back toward the mask. The relative areas of the mirror and aperture affect recycling efficiency and system throughput, so the system features a larger-diameter recycling segment enabling greater mirror-to-aperture area ratios. An added segment at the output end of the homogenizer matches the homogenizer diameter to the projection imaging system object field size. This standardizes the homogenizer and condenser lens integration, reducing the need for customized parts and thus reducing manufacturing time and expense.

7670727, Mar 2, 2010

Aug 30, 2006

11/512954

Sivarama K. Kuchibhotla - Croton on Hudson NY, US
Kanti Jain - Hawthorne NY, US
Marc A. Klosner - White Plains NY, US

Anvik Corporation - Hawthorne NY

G03F 1/00
G03B 27/54

430 5, 355 67

A zero power identical pair of oppositely-oriented meniscus lens elements mounted in the projection light path, serves as curved mask support while compensating for optical anomalies such as beam shift and beam deviations produced by other transparent supports for the curved mask. The zero-power meniscus lens pair, without affecting the transmission beam characteristics, lets the beam diffract as efficiently as does a regular planar mask, thus preserving the partial coherence effects and resolution concepts of projection lithography. This simple but novel optics device is not only expected to clear several barriers for curved mask projection lithography but also find place in other applications where collimated or converging light beams have to travel extra paths without significant aberration.

8596823, Dec 3, 2013

Dec 14, 2010

12/967330

Sivarama Krishna Kuchibhotla - San Jose CA, US

Coherent, Inc. - Santa Clara CA

G02B 27/20

362259, 362553, 362268, 362335

In optical apparatus for illuminating a mask-plane with a line of light, a light source includes four fast-axis stacks of laser diode bars. One optical arrangement collects light beams from all of the diode-laser bar stacks, homogenizes and expands the beams in the fast-axis direction of the diode-laser bar stacks and partially overlaps the homogenized and expanded beams in the fast-axis direction. Another optical arrangement homogenizes the sum of the partially overlapped beams and images the sum of the beams as a line of light having a length in the fast-axis-direction and a width in the slow-axis direction.

20040027550, Feb 12, 2004

Aug 12, 2002

10/217356

Sivarama Kuchibhotla - Lake Mohegan NY, US

G03B027/54

355/067000, 355/053000, 355/071000, 355/068000

Single-stage projection systems typically have a twice-folded optical path, with mask leg, crossover, 1:1 projection lens system, and substrate leg. They offer seamless patterning of large microlithographic substrates by overlapping complementary small-field scanning. A reverser maintains mask/substrate pattern congruence despite optical reversal, but presents the requirement of large working distance to permit access to the scanning stage. The required working distance demands large-diameter lens elements which are expensive in materials, grinding and assembly. A high-resolution 1:1 projection lens, for high-fluence laser light, adds extreme expense. Dividing the projection lens into two distributed-part-lenses, in mask and substrate legs, maintains satisfactory working distance, minimizes lens diameter requirements, and thus cuts cost. The aperture stop is positioned at the midpoint of the optical path, preferably at the time of manufacture, by an auxiliary stage. The aperture stop is physically asymmetrical because of the optical path length inherent in the reverser.

20070139791, Jun 21, 2007

Dec 18, 2006

11/640590

Shyam Raghunandan - Briarcliff Manor NY, US
Kanti Jain - Hawthorne NY, US
Marc Zemel - West Harrison NY, US
Marc Klosner - White Plains NY, US
Sivarama Kuchibhotla - Croton on Hudson NY, US

Anvik Corporation - Hawthorne NY

G02B 9/00

359738000

An optimized illumination system that efficiently produces uniform illumination for exposure, photoablation, and laser crystallization systems. The illumination system includes a homogenizer that uniformizes and shapes a light beam, which is directed onto a mask by condenser optics. The illumination system recycles radiation by directing light reflected by the mask back into the illumination system, where an apertured mirror situated at the input end re-directs it back toward the mask. The relative mirror and aperture sizes affect recycling efficiency and system throughput, so the system features a wide recycling segment enabling greater mirror-to-aperture area ratios. An added segment at the output end of the homogenizer matches the homogenizer diameter to the projection imaging system object field size. This standardizes the homogenizer and condenser lens construction system, reducing the need for customized parts and thus reducing manufacturing time and expense.

20090107966, Apr 30, 2009

Oct 26, 2007

11/977879

Leszek Wojcik - , US
Diwakar Wojcik - , US
Kanli Jain - Hawthorne NY, US
Sivarama K. Kuchibhotla - Thiells NY, US
Arun Panneerselvam - White Plains NY, US

B23K 26/16
B23K 26/36

21912172, 21912167

A turbulence-controlled vacuum debris removal subsystem safely exhausts particles ejected during photoablation. Nested interconnected chambers provide diminishing sweeping gas partial pressure and diminishing turbulence, ejecting particles from the ablation beam path between pulses, without compromising continuing particle conductance. Removal rate (debris generation rate) depends on conductance and particle sizes. The chambers interconnect through metering holes which enable optimization of partial pressure differentials. Controlled flow accomplishes debris removal, reducing turbulence of the mixture of debris and sweeping gases. A preferred embodiment uses a nest of concentric chambers, providing a clear light path. Another preferred embodiment uses orifices on chamber faces for removal and forming an envelope of gas around the processing region for dynamically containing the ejected particulate matter from the ablation site to the exhaust.