Dr. Supratik Guha Profile

Dr. Supratik Guha

Director at IBM Thomas J Watson Research Ctr

SPIE Involvement:

Author

Proceedings Article | 14 April 1999 Paper

Gallium-nitride-based LEDs on silicon substrates

Nestor Bojarczuk, Supratik Guha

Proceedings Volume 3621, (1999) https://doi.org/10.1117/12.344486

KEYWORDS: Light emitting diodes, Silicon, Diodes, Gallium nitride, Luminescence, Ultraviolet radiation, Electroluminescence, Visible radiation, Metalorganic chemical vapor deposition, Semiconducting wafers

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Proceedings Article | 21 December 1994 Paper

Optical degradation of II-VI devices and heterostructures

Greg Haugen, Supratik Guha, Jim DePuydt, Michael Haase, Kwok Law, Thomas Miller, Bor-Jen Wu

Proceedings Volume 2346, (1994) https://doi.org/10.1117/12.197262

KEYWORDS: Luminescence, Quantum wells, Gallium arsenide, Heterojunctions, Semiconductor lasers, Chlorine, Optical imaging, Electroluminescence, Light emitting diodes, Doping

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Proceedings Article | 1 October 1990 Paper

Interfacet migration and defect formation in heteroepitaxy on patterned substrates: AlGaAs and InGaAs on GaAs (100) in MBE

Supratik Guha, Anupam Madhukar, Li-ping Chen, K. Rajkumar, Ravindra Kapre

Proceedings Volume 1285, (1990) https://doi.org/10.1117/12.20817

KEYWORDS: Gallium arsenide, Optical lithography, Semiconductors, Photomicroscopy, Thin films, Spatial light modulators, Indium gallium arsenide, Diodes, Arsenic, Mendelevium

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We present results for lattice matched (AlxGai..xAs, x=0.5 and x=0.0) and lattice mismatched (InxGai..xAs, x□0.25) growth on patterned GaAs (100) substrates. For the AlGai..xAs structures, the GaAs substrates were patterned in the form of elongated mesas parallel to [011 II with widths of approximately 3 tim. Interfacet migration effects observed on the nesas via cross-section transmission electron microscope studies are explained in terms of a ledge-ledge interaction on the vicinal surfaces formed due to growth on the mesas. InxGai..xAs (x□0.25) structures were grown on GaAs (100) substrates patterned in the form of elongated mesas parallel to [01 11 with widths of approximately 1 tim. This patterning direction was chosen since under cutting in the [0 1 1] direction eliminates inter-facet migration effects so that compositional change induced strain effects can be minimised. For x □0.15, we find a reduction in misfit dislocation densities in films upto five times the nominal critical thickness for growths on the patterned mesas as compared to the growths on the corresponding non patterned regions. For x=0.25 no such difference is observed and a large number ofthreading dislocations ( around iO cm2) are found in both the patterned and the non patterned regions. This is believed to be a consequence of the onset ofa 3-D island growth mode. Finally we present some results for the growth of InØ5Gaj•75As I AlAs resonant tunneling diode (RTD) structures and a 100 period InjØGaØ8As (80 A) IGaAs (160 A) Multiple Quantum Well (MQW) such as suited for spatial light modulator (SLM) structures on GaAs (100) substrates patterned in both <01 1> directions on a length scale of 12 to 20 tm. For the RTD structures we conclude that benefits from patterning are expected for x□0.25 provided the growth kinetics are appropriately adjusted to prevent 3D island growth mode. For the MQW -SLMstructure we demonstrate superior optical properties for the growth in the patterned region and a corresponding absence of threading dislocations in the central region of the mesas.

Conference Committee Involvement (11)

Low-Dimensional Materials and Devices 2018

22 August 2018 | San Diego, California, United States

Low-Dimensional Materials and Devices 2017

9 August 2017 | San Diego, California, United States

Low-Dimensional Materials and Devices 2016

30 August 2016 | San Diego, California, United States

Low-Dimensional Materials and Devices

12 August 2015 | San Diego, California, United States

Nanoepitaxy: Materials and Devices VI

19 August 2014 | San Diego, California, United States

Showing 5 of 11 Conference Committees

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