Low-voltage operation and low processing temperature of metal oxide transistors remain a challenge. Commonly metal oxide transistors are fabricated at very high processing temperatures (above 500°C) and their operating voltage is quite high (30-50 V). Here, thin-film transistors (TFT) are reported based upon solution processable indium oxide (In ₂ O ₃ ) and room temperature processed anodized high-κ aluminum oxide (Al ₂ O ₃ ) for gate dielectrics. The In ₂ O ₃ TFTs operate well below the drain bias (Vds) of 3.0 V, with on/off ratio 105, subthreshold swing (SS) 160 mV/dec, hysteresis 0.19 V, and low threshold voltage (V _th ) 0.6 V. The electron mobility (μ) is as high as 3.53 cm2/V.s in the saturation regime and normalized transconductance(gm) is 75 μS/mm. In addition, the detailed capacitance-voltage (C-V) analysis to determine interface trap states density was also investigated.The interface trap density (Dit) in the oxide/semiconductor interface was quite low, i.e., 0.99 × 10 ¹¹ -2.98 × 10 ¹¹ eV ^-1 ·cm ^-2 , signifying acceptable compatibility of In ₂ O ₃ with anodic Al ₂ O ₃ .

Anodizing

10.1109/led.2019.2918492

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Citations (15)

Substrate orientation effects on dopant incorporation in InP grown by metalorganic chemical vapor deposition

Journal of Applied Physics (1993)

Paul R. Berger S. N. G. Chu R. A. Logan Erin K. Byrne D. Coblentz

We have investigated the doping incorporation and activation of InP growth using metalorganic chemical vapor deposition on <100≳, <311≳B, and <110≳ InP substrates. Effects of orientation, growth temperature, and V/III fluxes were studied. The dopants used were Zn from dimethylzinc [(CH3)2Zn] and diethylzinc [(C2H5)2Zn], S from hydrogen sulfide [H2S], Si from silane [SiH4], and Sn from tetraethyltin [(C2H5)4Sn]. The incorporation and activation of the p-type dopant Zn are elevated on the <311≳B and <110≳ planes, while the incorporation is suppressed for the n-type dopants (S, Si, and Sn). The n-type dopant Sn has similar incorporation and activation on the various substrate orientations studied. Anomalous Zn doping on the higher order planes <311≳B and <110≳ lead to the Zn incorporation exceeding the solubility limit in InP. Incorporated Zn levels as high as 1.0×1019 cm−3 were measured, and the corresponding activated Zn level was as high as 5.4×1018 cm−3 on a <110≳ InP substrate. Interdiffusion of the p-type dopant Zn into the S-doped n-type InP substrate is inhibited by a high S-doping level and segregates at the substrate–epilayer interface. If the S-doping level is lower than the Zn concentration, then Zn diffuses deep into the substrate at a uniform level.

Dimethylzinc

10.1063/1.352839

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Citations (20)

Substantial improvement by substrate misorientation in dc performance of Al0.5Ga0.5As/GaAs/Al0.5Ga0.5As double-heterojunction NpN bipolar transistors grown by molecular beam epitaxy

Applied Physics Letters (1991)

Naresh Chand Paul R. Berger Niloy K. Dutta

Al0.5Ga0.5As/GaAs/Al0.5Ga0.5As NpN double-heterojunction bipolar transistors have been grown simultaneously by molecular beam epitaxy on (100) and 3° off (100) towards 〈111〉A GaAs substrates. On the tilted substrate, the current gain is significantly higher, comparable to the maximum expected value, with a marked reduction of its dependence on current and device geometry. For 10 μm×40 μm emitter devices, maximum common emitter current gains (β) of 1630 and 725 were measured at a current density of ∼6.3 kA/cm2 on the tilted and flat substrates, respectively. On the tilted substrate, both the emitter injection efficiency and base transport factor are increased. We have used compositionally graded emitter-base (e-b) and abrupt base-collector (b-c) junctions. We find that the abrupt b-c junction does not result in an offset voltage but certainly reduces the electron collection efficiency, and hence the gain, in the region where it is forward biased. The device characteristics and the current gain on both substrates were essentially independent of temperature between 25 and 100 °C, except for a slight decrease of gain with increasing temperature.

Input offset voltage

Misorientation

10.1063/1.105961

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Citations (11)

IEEE Transactions on Electron Devices publication information

IEEE Transactions on Electron Devices (2019)

F Guarin Samar K. Saha Junior Past M Meyappan Jacobus W. Swart

10.1109/ted.2019.2943759

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Citations (0)

IEEE Electron Device Letters

IEEE Electron Device Letters (2021)

R Todi F Guarin Junior Past M Radhakrishnan Secretary B Treasurer

10.1109/led.2021.3050943

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IEEE Electron Devices Society

IEEE Transactions on Electron Devices (2022)

R Todi Junior Past M Radhakrishnan B Zhao Samar K. Saha

10.1109/ted.2022.3140911

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Towards in vivo biosensors for low‐cost protein sensing

Electronics Letters (2013)

R. Anisha F. Ren Paul R. Berger Patricia Casal Andrew Theiss

In vivo biosensing requires stable transistor operation in high-salt concentration bodily fluids while exhibiting impermeability to mobile alkali ions that would otherwise render the metal-oxide-semiconductor (MOS) threshold voltage to drift. Metal oxide semiconductor capacitor structures using Al2O3 as the gate dielectric were soaked in a sterile physiological buffer solution (PBS) up to 24 hours and for thicknesses from 100 to 10 nm. The triangular voltage sweep technique characterised alkali ion penetration, and measured no detectable alkali ions for the Al2O3 capacitors. By contrast, the dose of alkali ions in silicon dioxide MOS capacitors steadily increased with increasing soak times in the PBS solution.

Silicon dioxide

10.1049/el.2012.4283

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Citations (6)

Radiation tolerance of Si/Si0.6Ge0.4 resonant interband tunneling diodes

Journal of Applied Physics (2004)

B. D. Weaver Philip E. Thompson Ni Jin Sung-Yong Chung Anthony T. Rice

The effect of 2 MeV proton irradiation on the current–voltage (IV) characteristics of Si/Si0.6Ge0.4 resonant interband tunneling diodes (RITDs) is reported. A fluence of 5×1014 H+/cm2 causes the peak current to increase by about 4% the valley current to nearly double and the peak-to-valley current ratio to be reduced by about half. At comparable fluences, most minority carrier diodes are inoperational. Radiation-induced changes are compared to changes in the IV curves of irradiated Si- and Ge Esaki diodes, GaSb-based RITDs and InP-based resonant tunneling diodes.

10.1063/1.1710719

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Citations (8)

IEEE Electron Device Letters

IEEE Electron Device Letters (2019)

F Guarin Samar K. Saha Junior Past M. Meyyappan Jacobus W. Swart

10.1109/led.2019.2905461

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Citations (5)