Characterization of reverse-bias leakage currents and their effect on the holding time characteristics of MOS dynamic RAM circuits

AbstractWe describe the successful fabrication of device-quality a-Si:H thin-film transistors (TFTs) on stainless-steel foil substrates. These TFTs demonstrate that transistor circuits can be made on a flexible, non-breakable substrate. Such circuits could be used in reflective or emissive displays, and in other applications that require rugged macroelectronic circuits.Two inverted TFT structures have been made, using 200 gim thick stainless steel foils with polished surfaces. In the first structure we used the substrate as the gate and utilized a homemade mask set with very large feature sizes: L = 45 μm; W = 2.5 mm. The second, inverted staggered, structure used a 9500 Å a-SiNx:H passivating/insulating layer deposited on the steel to enable the use of isolated gates. For this structure we used a mask set which is composed of TFTs with much smaller feature sizes. Both TFT structures exhibit transistor action. Current-voltage characterization of the TFTs with the inverted staggered structure shows typical on/off current ratios of 107, leakage currents on the order of 10-12 A, good linear and saturation current behavior, and channel mobilities of 0.5 cm2/V·sec. These characteristics clearly identify the TFTs grown on stainless steel foil as being of device quality.

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Material Characterization Of Methyl Siloxane Sogs

MRS Proceedings ◽

10.1557/proc-381-255 ◽

1995 ◽

Vol 381 ◽

Cited By ~ 8

Author(s):

Ken Numata ◽

Thomas R. Seha ◽

Shin-Puu Jeng ◽

Tsuyoshi Tanaka

Keyword(s):

Material Characterization ◽

Interesting Property ◽

Moisture Resistance ◽

Filling Material ◽

Number Density ◽

Gap Filling ◽

Leakage Currents ◽

Ft Ir ◽

Low Permittivity

AbstractMethyl siloxane spin-on-glass (SOG) is a conventional gap-filling material. In accordance with the requirement of low permittivity, many of major SOG suppliers are developing new types of methyl siloxane SOGs.The most interesting property of these SOGs is their permittivity, which we measured by making stack structures of Al-0.5%Cu / TEOS CVD SiO2 / SOG / n+ Si. We also studied I-V characteristics, refractive indices, FT-IR spectra, stress, and moisture resistance.All of the SOGs showed small stress and fair moisture resistance. Leakage currents were less than 2.5E-10 A/cm2 for bias voltages up to 5V. Permittivities ranged from 2.9 to 3.6. We observed a correlation between permittivity and FT-IR spectral features associated with Si-O-Si bonds. Reducing the number density of Si-O-Si bonds may be an effective way to lower the permittivity of this class of SOGs

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Characterization of Er/O-doped Si-LEDs with Low Thermal Quenching

MRS Proceedings ◽

10.1557/proc-866-v4.2/ff4.2 ◽

2005 ◽

Vol 866 ◽

Cited By ~ 1

Author(s):

A. Karim ◽

W.-X. Ni ◽

A. Elfving ◽

P.O.Å. Persson ◽

G.V. Hansson

Keyword(s):

Temperature Dependence ◽

Reverse Bias ◽

Thermal Quenching ◽

Constant Current ◽

Cross Sectional ◽

Transmission Electron ◽

Low Energy Electrons ◽

Higher Temperature ◽

Electron Emitters

AbstractElectroluminescence studies of MBE-grown Er/O-doped Si-diodes at reverse bias have been done. For some devices there is much reduced thermal quenching of the emission at 1.54 νm. There are examples where the temperature dependence is abnormal in that the intensity for a constant current even increases with temperature up to e.g. 80 °C. These devices have been studied with cross-sectional transmission electron microscopy to see the microstructure of the Er/O-doped layers as well as the B-doped SiGe-layers that are used as electron emitters during reverse bias. Although there are defects in the layers there is no evidence for large thick precipitates of SiO2. While reduced thermal quenching often is attributed to having the Er-ions within SiO2 layers, this is not the case for our structures as evidenced by our TEM-studies. The origin of the abnormal temperature dependence is attributed to the two mechanisms of breakdown in the reverse-biased diodes. At low temperature the breakdown current is mainly due to avalanche resulting in low-energy electrons and holes that quenches the intensity by Auger deexcitation of the Er-ions. At higher temperature the breakdown current is mainly phonon-assisted tunneling which results in a more efficient pumping with less de-excitation of the Er-ions. Finally at the highest temperatures the thermal quenching sets in corresponding to an activation energy of 125 meV, which is slightly lower than 150 meV that has been reported in other studies.

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Investigation of the Causes and Variation of Leakage Currents in Amorphous Silicon P-I-N Diodes

MRS Proceedings ◽

10.1557/proc-762-a7.7 ◽

2003 ◽

Vol 762 ◽

Cited By ~ 3

Author(s):

Todd R. Johnson ◽

Gautam Ganguly ◽

George S. Wood ◽

David E. Carlson

Keyword(s):

Zinc Oxide ◽

Amorphous Silicon ◽

Point Defects ◽

Tin Oxide ◽

Reverse Bias ◽

Hydrogenated Amorphous Silicon ◽

Cell Area ◽

Leakage Currents ◽

Single Junction ◽

Hydrogenated Amorphous

AbstractExcess leakage currents under reverse bias (known as shunting) and spontaneous reductions of this excess leakage under increased reverse bias (known as curing) were investigated in hydrogenated amorphous silicon (a-Si:H) based single junction p-i-n type diodes. An increase in the frequency of shunting was observed when the front contacts were switched from tin oxide to zinc oxide, most likely due to defects in the previously deposited zinc oxide coated glass was observed. Storage in the dark and light soaking up to 100 hours were both observed to independently increase the leakage current in previously leaking diodes. Models for the distribution of shunt-causing defects within a given cell area were considered. Comparing the measured frequency of shunting using cells of varying area (1 to 16 mm2) to the models' predictions indicate a distribution of point defects separated by relatively large average distances that are slightly larger for tin oxide (5-6 mm) than for zinc oxide (4 mm).

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Fabrication of 2.5kV 4H-SiC PiN Diodes with High Energy Implantation (>12MeV) of Al+ and B+

Materials Science Forum ◽

10.4028/www.scientific.net/msf.924.573 ◽

2018 ◽

Vol 924 ◽

pp. 573-576 ◽

Cited By ~ 3

Author(s):

Reza Ghandi ◽

Peter Losee ◽

Alexander Bolotnikov ◽

David Lilienfeld

Keyword(s):

Reverse Bias ◽

High Energy ◽

Avalanche Breakdown ◽

Leakage Currents ◽

Pin Diodes ◽

Minimal Defect ◽

Low Leakage ◽

Pn Junction ◽

Defect Sites

In this work, >2kV PiN diodes with >10um deep implant of B+ and 6um deep implant of Al+ have been fabricated to evaluate the quality of resulting pn junction after high-energy implantation. Acceptable low leakage currents at reverse bias and stable avalanche breakdown were observed for high energy implanted diodes (HEI-diodes) when compared to No-HEI-diodes that suggests minimal defect sites present after activation anneal.

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Solar-Blind AlGaN-based Schottky Photodiodes With High Detectivity and Low Noise

MRS Proceedings ◽

10.1557/proc-743-l7.11 ◽

2002 ◽

Vol 743 ◽

Author(s):

Necmi Biyikli ◽

Orhan Aytur ◽

Ibrahim Kimukin ◽

Turgut Tut ◽

Ekmel Ozbay

Keyword(s):

Power Density ◽

Dark Current ◽

Reverse Bias ◽

Low Noise ◽

Noise Power ◽

Cutoff Wavelength ◽

Solar Blind ◽

Fabrication And Characterization ◽

Noise Power Density

AbstractWe report on the design, fabrication and characterization of solar-blind Schottky photodiodes with high detectivity and low noise. The devices were fabricated on n-/n+ AlGaN/GaN hetero-structures using a microwave compatible fabrication process. Using Al0.38Ga0.62N absorption layer, true solar-blind operation with a cutoff wavelength of ∼274 nm was achieved. The solar-blind detectors exhibited < 400 fA dark current in the 0–25 V reverse bias regime, and a maximum responsivity of 89 mA/W around 267 nm. The photovoltaic detectivity of the devices were in excess of 2.6×1012 cmHz1/2/W, and the detector noise was 1/f limited with a noise power density less than 3×10−29 A2/Hz at 10 KHz.

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Sem-Ebic Characterization of Semiconducting and Semi-Insulating LEC-GaAs

MRS Proceedings ◽

10.1557/proc-69-165 ◽

1986 ◽

Vol 69 ◽

Cited By ~ 1

Author(s):

Yozo Tokumaru ◽

Yasumasa Okada

Keyword(s):

Reverse Bias ◽

Current Method ◽

Experimental Result ◽

Reverse Bias Voltage ◽

Induced Current ◽

Cell Structures ◽

Lec Gaas ◽

Electron Beam Induced Current ◽

Insulating Liquid

AbstractWe have applied the SEM-EBIC technique (electron-beam-induced current method using a scanning electron microscope) to the characterization of both semiconducting and semi-insulating liquid encapsulated Czocralski (LEC) grown GaAs and have found this technique to be effective for semiinsulating materials as well as semiconducting ones. In semiconducting Si-, In- and undoped LEC-GaAs, growth striations were observed under usual measurement conditions. In semi-insulating undoped LEC-GaAs, clear EBIC images of individual dislocations and cell structures of dislocations were obtained by applying a high reverse bias voltage of about 10∼100 V to the specimens. We have also investigated nearly dislocation-free semiinsulating In-doped LEC-GaAs and found inhomogeneities which are different from those observed in undoped specimens. The spatial resolution of this technique is estimated to be 2–3 μm, which agrees with the experimental result

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A Comparative Study Of GaN Diodes Grown by MBE on Sapphire and HVPE-GaN /Sapphire Substrates

MRS Proceedings ◽

10.1557/proc-595-f99w11.1 ◽

1999 ◽

Vol 595 ◽

Author(s):

Anand V. Sampath ◽

Mira Misra ◽

Kshitij Seth ◽

Yuri. Fedyunin ◽

Hock M. Ng ◽

...

Keyword(s):

Comparative Study ◽

Reverse Bias ◽

Schottky Diodes ◽

Forward Bias ◽

Etch Pits ◽

Sapphire Substrates ◽

Fabrication And Characterization

AbstractIn this paper we report on the fabrication and characterization of GaN diodes (Schottky and p-n junctions) grown by plasma assisted MBE. We observed that Schottky diodes improve both in reverse as well as forward bias when deposited on 5 μm thick HVPE n+-GaN/sapphire instead of bare sapphire substrates. These improvements are attributed to the reduction of disloctions in the MBE homoepitaxially grown GaN. Similar benefits are observed in the reverse bias of the p-n junctions which according to EBIC measurements are attributed to the reduction of etch pits in the MBE grown p-GaN.

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Fabrication and Characterization of In Situ Synthesized SiC/Al Composites by Combustion Synthesis and Hot Press Consolidation Method

Scanning ◽

10.1155/2017/9314740 ◽

2017 ◽

Vol 2017 ◽

pp. 1-11 ◽

Cited By ~ 11

Author(s):

Hongyu Yang ◽

Erting Dong ◽

Bingqi Zhang ◽

Yanyan Yuan ◽

Shili Shu

Keyword(s):

Combustion Synthesis ◽

Maximum Size ◽

Holding Time ◽

Mass Ratio ◽

Hot Press ◽

Uniform Size ◽

Average Hardness ◽

Sic Particles

The in situ SiC/Al composites were fabricated in Al-Si-C systems with different Si/C mass ratios and holding time by the method of combustion synthesis and hot press consolidation. The influences of Si/C mass ratio and holding time on the phase constitution, microstructure, and hardness of the composites were investigated. The results indicate that the increase of Si/C mass ratio leads to more uniform size distribution of the SiC particles in the Al matrix. Moreover, by improving the Si/C mass ratio from 4 : 1 to 5 : 1, the maximum size of SiC particle was reduced from 4.1 μm to 2.0 μm. Meanwhile, the percentage of submicroparticles was increased from 22% to 63%, and the average hardness value of the composites was increased by 13%. In addition, when the holding time is set to be fifteen minutes, the Al4C3 phase did not exist in the composites because of its total reactions with Si atoms to form SiC particles, and the average hardness value was 73.8 HB.

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