Prof. Srinivas A. Tadigadapa Profile

Prof. Srinivas A. Tadigadapa

Associate Professor at Northeastern Univ

SPIE Involvement:

Author

Proceedings Article | 20 February 2008 Paper

Thermopower measurement of freestanding nanowires using a MEMS workbench

Nicolas Duarte, Srinivas Tadigadapa

Proceedings Volume 6885, 68850G (2008) https://doi.org/10.1117/12.775801

KEYWORDS: Thermoelectric materials, Bridges, Nickel, Temperature metrology, Microelectromechanical systems, Gold, Molecular bridges, Photoresist materials, Silica, Nanowires

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Proceedings Article | 12 February 2007 Paper

Electrical properties of back-gated n-layer graphene films

P. Joshi, A. Gupta, P. Eklund, S. Tadigadapa

Proceedings Volume 6464, 646409 (2007) https://doi.org/10.1117/12.707654

KEYWORDS: Graphene, Raman spectroscopy, Atomic force microscopy, Resistance, Raman scattering, Oxides, Microscopes, Transmission electron microscopy, Silicon, Physics

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Proceedings Article | 12 February 2007 Paper

Self assembled monolayer and protein adsorption studies on micromachined quartz crystal balances

Ping Kao, Abhijat Goyal, Jay Mathews, David Allara, Srinivas Tadigadapa

Proceedings Volume 6464, 646405 (2007) https://doi.org/10.1117/12.714796

KEYWORDS: Adsorption, Quartz, Proteins, Crystals, Electrodes, Resonators, Self-assembled monolayers, Bioalcohols, Molecules, Molecular self-assembly

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Proceedings Article | 12 February 2007 Paper

Coated Tips for Scanning Thermal Microscopy

Nicolás Duarte, Peter Eklund, Srinivas Tadigadapa

Proceedings Volume 6464, 646408 (2007) https://doi.org/10.1117/12.702157

KEYWORDS: Temperature metrology, Resistance, Bridges, Silicon, Coating, Gold, Microelectromechanical systems, Microscopy, Wheatstone bridges, Thermal modeling

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Proceedings Article | 23 January 2006 Paper

High aspect ratio plasma etching of bulk lead zirconate titanate

Srimath Subasinghe, Abhijat Goyal, Srinivas Tadigadapa

Proceedings Volume 6109, 61090D (2006) https://doi.org/10.1117/12.657751

KEYWORDS: Etching, Ferroelectric materials, Argon, Ions, Plasma, Reactive ion etching, Nickel, Plasma etching, Microsystems, Sputter deposition

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Proceedings Article | 6 January 2006 Paper

High-speed anisotropic etching of quartz using SF₆/C₄F₈/Ar/O₂ based chemistry in inductively coupled plasma reactive ion etching system

Abhijat Goyal, Vincent Hood, Srinivas Tadigadapa

Proceedings Volume 6111, 61110P (2006) https://doi.org/10.1117/12.657730

KEYWORDS: Etching, Surface roughness, Argon, Plasma, Gases, Reactive ion etching, Diffractive optical elements, Oxygen, Chemistry, Anisotropic etching

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Etching of quartz and glass for microsystems applications requires optimization of the etch process for high etch rates, high aspect ratios and low rms surface roughness of the etched features. Typically, minimum surface roughness of the etched feature accompanied with maximum etch rate and anisotropy are desired. In this article, we investigate the effect of different gas chemistries on the etch rate and rms surface roughness of the Pyrex(R) 7740 in an inductively coupled plasma reactive ion etching (ICP-RIE) system. The gases considered were SF6 and c-C4F8, with additives gases comprising of O2, Ar, and CH4. A standard factorial design of experiment (DOE) methodology was used for finding the effect of variation of process parameters on the etch rate and rms surface roughness. By use of 2000 W of ICP power, 475 W of substrate power, SF6 flow rate of 5 sccm, Ar flow rate of 50 sccm, substrate holder temperature of 20°C, and distance of substrate holder from ICP source to be 120 mm, we were able to obtain an etch rate of 0.536 μm/min and a rms surface roughness of ~1.97 nm. For an etch process optimized for high etch rate and minimum surface roughness using C4F8/SF6/O2/Ar gases, an etch rate of 0.55 μm/min and a rms surface roughness of ~25 nm was obtained for SF6 flow rate of 5 sccm, C4F8 flow rate of 5 sccm, O2 flow rate of 50 sccm, Ar flow rate of 50 sccm. Keeping all other process parameters the same, increasing the SF6 flow rate to 50 sccm resulted in an etch rate of 0.7 μm/min at an rms surface roughness of ~800 nm whereas increasing the C4F8 flow rate to 50 sccm resulted in an etch rate of 0.67 μm/min at an rms surface roughness of ~450 nm . Addition of CH4 did not contribute significantly to the etch rate while at the same time causing significant increase in the rms surface roughness. Regression or least square fit was used define an arbitrary etch rate number (Wetch) and rms surface roughness number (Wrms). These numbers were calculated by least square fit to the data comprising of ten correlated etch variables and enable quantization of etch parameters in terms of process parameters. The etch numbers defined in this work as function of process parameters present a very useful tool for the optimization, quantification and characterization of the dielectric etch processes developed in this work for MEMS fabrication and packaging applications.

Proceedings Article | 6 January 2006 Paper

Improvement of the elastic modulus of micromachined structures using carbon nanotubes

Prasoon Joshi, Abhijat Goyal, Awnish Gupta, Srinivas Tadigadapa, Peter Eklund

Proceedings Volume 6111, 611107 (2006) https://doi.org/10.1117/12.657674

KEYWORDS: Single walled carbon nanotubes, Resonators, Bridges, Silicon, Carbon nanotubes, Semiconducting wafers, Molecular bridges, Raman spectroscopy, Boron, Chemical elements

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Proceedings Article | 8 December 2004 Paper

Electroactive-polymer-based microfluidic pump

Feng Xia, Srinivas Tadigadapa, Qiming Zhang

Proceedings Volume 5591, (2004) https://doi.org/10.1117/12.572023

KEYWORDS: Microfluidics, Polymers, Electroactive polymers, Diffusers, Microactuators, Actuators, Finite element methods, Protactinium, Polymer thin films, Numerical analysis

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Proceedings Article | 24 January 2004 Paper

Piezoelectric microflextensional actuator

Jongpil Cheong, Srinivas Tadigadapa, Christopher Rahn

Proceedings Volume 5344, (2004) https://doi.org/10.1117/12.524817

KEYWORDS: Ferroelectric materials, Actuators, Beam shaping, Silicon, Etching, Solids, Boron, Oxides, Bridges, Performance modeling

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Proceedings Article | 23 December 2003 Paper

Reliable bonding using indium-based solders

Jongpil Cheong, Abhijat Goyal, Srinivas Tadigadapa, Christopher Rahn

Proceedings Volume 5343, (2003) https://doi.org/10.1117/12.524823

KEYWORDS: Indium, Tin, Oxides, Microelectromechanical systems, Electroplating, Packaging, Interfaces, Ferroelectric materials, Glasses, Acoustics

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Proceedings Article | 16 January 2003 Paper

Solder bonding for microelectromechanical systems (MEMS) applications

Abhijat Goyal, Srinivas Tadigadapa, Rafiqul Islam

Proceedings Volume 4980, (2003) https://doi.org/10.1117/12.478202

KEYWORDS: Tin, Microelectromechanical systems, Acoustics, Semiconducting wafers, Metals, Wafer bonding, Packaging, Electroplating, Interfaces, Polishing

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Proceedings Article | 2 October 2001 Paper

Reliability of micro-electro-mechanical systems (MEMS)

Srinivas Tadigadapa, Nader Najafi

Proceedings Volume 4558, (2001) https://doi.org/10.1117/12.443002

KEYWORDS: Reliability, Sensors, Microelectromechanical systems, Packaging, Silicon, Biomedical optics, Temperature metrology, Interfaces, Sensing systems, Microsystems

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Proceedings Article | 2 October 2001 Paper

Reliable integration of piezoelectric lead zirconate titanate with MEMS fabrication processes

Steven Gross, Qingqi Zhang, Srinivas Tadigadapa, Susan Trolier-McKinstry, Thomas Jackson, Frank Djuth

Proceedings Volume 4558, (2001) https://doi.org/10.1117/12.442988

KEYWORDS: Etching, Ferroelectric materials, Silicon, Microelectromechanical systems, Platinum, Zirconium dioxide, Ion beams, Dielectric polarization, Wet etching, Ions

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Proceedings Article | 1 October 2001 Paper

Fabrication and performance of d33-mode lead-zirconate-titanate (PZT) MEMS accelerometers

Han Yu, Richard Wolf, Kan Deng, Lichun Zou, Srinivas Tadigadapa, Susan Troilier-McKinstry

Proceedings Volume 4559, (2001) https://doi.org/10.1117/12.443027

KEYWORDS: Ferroelectric materials, Electrodes, Capacitors, Microelectromechanical systems, Deep reactive ion etching, Etching, Semiconducting wafers, Thin films, Silicon, Sensors

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Proceedings Article | 26 May 1995 Paper

Multipurpose sensor based on free-standing microthermopiles

Tadigadapa Srinivas, Haroon Ahmed

Proceedings Volume 2448, (1995) https://doi.org/10.1117/12.210472

KEYWORDS: Sensors, Infrared sensors, Microsystems, Infrared detectors, Silicon, Infrared radiation, Gases, Convection, Electronic circuits, Calibration

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