MSM Photodiode Research Articles

Enhanced efficiency of high-speed Si and Si-based PbSe MSM photodiodes with integrated photon-trapping holes at 800–1550 nm wavelengths

Enhanced efficiency of high-speed Si and Si-based PbSe MSM photodiodes with integrated photon-trapping holes at 800–1550 nm wavelengths

Study of a solar cell with a silicon-based photodiode structure

This article presents the results of a study of the capacitance- voltage characteristics of MSM photodiode structures with silicon-based potential barriers. The results of studies aimed at creating Au-nCdS-nSi- pCdTe-Au photodiode structures for the spectral range of 1.0-1.4 microns with an area of 29 mm2, which were obtained by vacuum evaporation in a quasi-closed volume of sputtering layers of cadmium sulfide and cadmium telluride, are presented. onto a silicon substrate with resistivity ρ = 607.47 Ohm∙cm. A distinctive feature of the resulting photodiode Au - nCdS-nSi - pCdTe - Au structures are two-way sensitive and have a low capacitance value of C = 23.3 pF at room temperature.

Structural, Electrical, and Photodetection Characterization of a Pentacene Interdigitated MSM Photodiode

Structural, Electrical, and Photodetection Characterization of a Pentacene Interdigitated MSM Photodiode

P‐19: Performance Development of Oxide Semiconductor Photodiode with High Work Function Electrode Suitable for Mass Production

IGZO as the typical representative of oxide semiconductor used for TFT devices, has been widely used in display panel foundary, such as large size OLED, LTPO technology direction. To develop oxide based photodetector (sensor), not only can expand the application direction of oxide semiconductor material, moreover the oxide photodetector integrated with oxide TFT is more convenient. We developed several oxide based vertical MSM photodiode with schottky junction, the IGZO MSM can respond to ultra violet(UV), while new oxide material S1 and S2 can response to blue light. In order to form a schottky junction, metal electrodes materials should have high work function, thus we developed a high work function electrode suitable for mass production, and of witch work function is ~4.7eV. In addition, in order to gain the characteristics of diode, the ACT film need be deposited in high oxygen process to prevent form ohm contact. Assisted by TCAD simulation, we researched how to control the oxide schottky junction, including schottky junction, barrier tunneling, to instruct the material selection and electrical properties of control.

Enhanced absorption and EQE of Si MSM photodiodes with integrated periodic arrays of holes

In order to enhance the absorption of thin Si film, cylindrical-shaped holes arranged in square and hexagonal lattices with different designs of hole diameter, depth and period are integrated in the surface of Si films with a thickness of 1.5 μm and 2.5 μm on either bulk Si or SOI substrate. At the wavelengths between 800 ~ 950 nm, light bending and absorption enhancement of Si film with integrated hole array is analyzed by FDTD simulation. Hole array with a period similar to the wavelength and a diameter/period ratio around 0.7 enables a higher absorption of Si film. Si film with cylindrical-shaped holes in hexagonal lattice with a Si thickness of 1.5 μm and a hole depth of 250 nm provides an absorption of 43.16 % at 850 nm wavelength on a SiO2 substrate. Nanostructured Si MSM photodiodes are fabricated by integrating periodic arrays of holes in 1.5 μm thin absorption regions between metal fingers. The EQE is enhanced to 61 % at 850 nm, while the photodiodes without holes show only 23 %.

Theoretical study and design of n-ZnO/p-Si heterojunction MSM photodiode for optimized performance

The effects of using p-Si as a substrate on the performance of a thin-film ZnO-based metal–semiconductor–metal photodetector were examined theoretically via a two-dimensional numerical simulation. This study aimed at attaining a comprehensive understanding of carrier dynamics, leading to the optimization of the device structure for improved performance. The simulation indicated the presence of a hole accumulation at the heterojunction interface below the cathode contact. This layer plays a major role in the temporal-response characteristics of the device. The results indicate that a 1 μm finger spacing and a 1 μm ZnO active-layer thickness yielded excellent temporal-response characteristics and excellent noise-rejection ability.

Enhancing Performance of Porous Si-Doped GaN Based MSM Photodetector Using 50 Hz ACPEC

In this work, we report the formation of porous Si-doped GaN films under a novel alternating current (sine-wave a.c. (50 Hz)) photo-assisted electrochemical etching (ACPEC) conditions. The formation of porous Si-doped GaN by the novel ACPEC is performed in the same electrolyte concentration (4% KOH) used in common dc constant current electrochemical etching process. Ultra-violet (UV) illumination is used to assist in the generation of electron-hole pairs, where etching proceeds through the oxidation and consequently, dissolution of the semiconductor surface. The ac formed porous Si-doped GaN with excellent structural and optical properties. According to the FESEM micrographs, the GaN thin films exhibit a homogeneous nanoporous structures with spatial nano-flakes arrangement. The porous layer exhibited a substantial photoluminescence (PL) intensity enhancement with red-shifted band-edge PL peaks associated with the relaxation of compressive stress. The shift of E2 (high) to the lower frequency in Raman spectra of the porous GaN films further confirms such a stress relaxation. Electrical characterizations of the MSM photodiodes were carried out by using current-voltage (I-V) measurements indicated that the devices were highly sensitive to ambient light.

10 Gb/s OEIC optical receiver front-end and 3.125 Gb/s PHEMT limiting amplifier

A 10 Gb/s OEIC (optoelectronic integrated circuit) optical receiver front-end has been studied and fabricated based on the Φ-76 mm GaAs PHEMT process; this is the first time that a limiting amplifier (LA) has been designed and realized using depletion mode PHEMT. An OEIC optical receiver front-end mode composed of an MSM photodiode and a current mode transimpedance amplifier (TIA) has been established and optimized by simulation software ATLAS. The photodiode has a bandwidth of 10 GHz, a capacitance of 3 fF/μm and a photosensitive area of 50 × 50 μm2. The whole chip has an area of 1511 × 666 μm2. The LA bandwidth is expanded by spiral inductance which has been simulated by software HFSS. The chip area is 1950 × 1910 μm2 and the measured results demonstrate an input dynamic range of 34 dB (10–500 mVpp) with constant output swing of 500 mVpp.

InAlAs/InAs/InGaAs pseudomorphic high electron mobility transistors exhibiting ultra‐fast optical response

AbstractHigh electron mobility transistors with a pseudomorphically strained InAs channel (InAs‐PHEMTs) have superior electron‐transport properties and high electron density, which are due to a large conduction‐band discontinuity. In this work, we demonstrate that InAs‐PHEMTs have an additional property: they exhibit an ultra‐fast optical response with a time‐constant of 3.5 × 10–11 s. By irradiating the optical signal onto the InAs‐PHEMTs, hole‐electron pairs are created in the channel layer. Holes accumulated in the source region of the channel layer recombine immediately with 2DEG due to an Auger recombination mechanism. Holes generated in the region outside the gate also recombine immediately with the 2DEG due to the Auger recombination mechanism before they drift or diffuse toward the gate region. This is why the optical response time of an InAs‐PHEMT is extremely small and it is restricted by the time for holes to transit across the gate region. A circuit incorporating an InAs‐PHEMT as a transistor and an InAlAs/InAs/InGaAs MSM photodiode that has the same structure as an InAs‐PHEMT as an optical detector has the potential to be applied as an ultra‐fast receiver optoelectronic integrated circuit. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Monolithic integration of a ZnS MSM photodiode and an InGaP/GaAs HBT on a GaAs substrate

A monolithic integrated photoreceiver constructed of a ZnS MSM photodiode and an InGaP/GaAs HBT utilizing the pattern-oxide growth technique is demonstrated. The XRD and PL analyses of the as-grown ZnS epilayers exhibit good quality. The optical and electrical performance of the ZnS MSM photodiode, InGaP/GaAs HBT and integrated photoreceiver is estimated. Photocurrent induced from the ZnS MSM photodiode is amplified linearly by a common-emitter preamplifier based on an InGaP/GaAs HBT. The current amplification ratio and the voltage amplification sensitivity of the integrated photoreceiver are 18.2 and −8.7 mV µW−1, respectively. The ZnS-based integrated photoreceiver carried out successfully on a GaAs substrate indicates the potential of the pattern-oxide growth technique in the development for the II–VI WBG-based short wavelength integrated devices.

Monolithic Photoreceiver Constructed With a ZnSe MSM Photodiode and an InGaP/GaAs HBT

The monolithic integration of a ZnSe metal-semiconductor-metal photodiode and an InGaP/GaAs heterojunction bipolar transistor has been achieved successfully on a GaAs substrate. As a result of a current amplification ratio of 20.8, the present monolithic photoreceiver illuminated at an optical input-power intensity of 10 muW has shown high voltage amplification sensitivity of -29.6 mV/muW. The fabrication process and characterization for the integrated device will be useful for the development of wide-bandgap-based short-wavelength optoelectronic integrated circuits in the future.

Characteristics of III-nitride MSM photodiodes with SAQDs

A novel metal-semiconductor-metal photodiode with InGaN self-assembled quantum dots was fabricated and compared with a conventional InGaN metal-semiconductor-metal photodiode. It was found that the InGaN QD photodiode with lower dark current can operate in the normal incidence mode. We achieved a much larger photocurrent to dark current contrast ratio from the fabricated photodiodes with nanoscale InGaN self-assembled quantum dots. The scanning near-field optical microscopy results revealed that the devices made by InGaN nanostructures could have better absorption for the near-field light with the wavelength of 457–514 nm.

Novel Optical Distance Sensor Based on MSM Technology

This paper describes a novel distance-sensor concept based on photodiodes in metal-semiconductor-metal technology (MSM). MSM photodiodes can be operated as electrooptical mixers functioning similar to the so-called photonic mixing device (PMD). This paper employs the correlation techniques previously used with the PMD to the MSM. First, experimental results obtained with the MSM inserted into the authors' standard laboratory setup are provided. Additionally, different configurations well suited for mixer operation of the MSM are pointed out. Throughout this paper, similarities between the PMD and MSM are pointed out, as well as key differences.

The laser calibration system of the HARP TOF

The calibration and monitoring system constructed for the HARP experiment scintillator-based time of flight system is described. It is based on a Nd-Yag laser with passive Q-switch and active/passive mode-locking, with a custom made laser light injection system based on a bundle of IR monomode optical fibers. A novel ultrafast InGaAs MSM photodiode, with 30 ps risetime, has been used for the laser pulse timing . The first results from the 2001–2002 data taking are presented, showing that drifts in timing down to about 70 ps can be traced.

Laser-based calibration for the HARP time of flight system

A precise calibration and monitoring system has been developed for the HARP experiment scintillator-based time of flight system. An Nd-YAG laser with passive Q-switch and active/passive mode-locking and a custom-made laser light injection system based on a bundle of IR monomode optical fibers were used. The laser pulse timing was provided by a novel ultrafast InGaAs MSM photodiode, with 30 ps risetime. Experience over a several month data taking period in 2001 and 2002 shows that drifts in timing down to about 70 ps can be traced.

Complete monolithic integrated 2.5 Gbit/s optoelectronicreceiverwithlarge area MSM photodiode for 850 nm wavelength

A novel optoelectronic receiver chip for a data rate of 2.5 Gbit/s has been developed and tested. It integrates a metal-semiconductor-metal photodiode with a GaAs HEMT transimpedance amplifier, a high gain amplifier and a limiting output buffer which is able to drive a 50 Ω load. A special feature of the chip is that it comprises a very large photodiode of 300 µm diameter, eliminating the need for expensive fibre alignment. Measurements reveal that the receiver achieves the required sensitivity of –15.7 dBm at a bit error rate of 10-9.

Monolithically integrated optoelectronic receivers by AlGaAs/InGaAs doped-channel heterostructures

A monolithic optoelectronic receiver, consisting of an MSM photodiode and a transimpedance (TZ) amplifier, based on the AlGaAs/InGaAs doped-channel heterostructure, has been fabricated and investigated. The TZ amplifier demonstrated a transimpedance gain (ZT) of 2.1 kΩ and a 3 dB bandwidth of 7.6 GHz by a 1 μm gate-length technology, resulting in a transimpedance–bandwidth product (ZT⋅BW) of 17 GHz⋅kΩ. A 100×100 μmMSM photodetector (MSM–PD) with a 2 μm finger width and a 4 μm finger spacing demonstrated a responsivity of 0.25 A/W with a dark current of 10 nA at 5 V. The 3 dB bandwidth of this integrated optical receiver is 2.3 GHz. © 2000 John Wiley & Sons, Inc. Microwave Opt Technol Lett 27: 79–80, 2000.

Effects of Bias on the Responsivity of GaN Metal–Semiconductor–Metal Photodiodes

We report on the fabrication and characterization of AlGaN MSM photodetectors, which show a low dark current density and a sharp cutoff, with a visible rejection of four to five orders of magnitude, at 5 V bias. The devices behave linearly with optical power, for illumination over and below the bandgap. The study of the responsivity of AlGaN MSM photodiodes reveals a gain mechanism which is only active at bias over 2 V, and for excitation over the bandgap. This mechanism is responsible for the superlinear increase of the responsivity with bias, and also for the enhancement of the UV/visible contrast observed in these devices. A NEP* lower than 2 pW/Hz1/2 has been obtained in GaN MSM photodetectors, at 28 V bias.

High-speedmonolithicallyintegratedMSM-FETphotoreceiver based on GaAs/InGaAs strained layer superlattice

We report, for the first time, the realization of a long-wavelength monolithically integrated MSM-FET photoreceiver using a GaAs/InGaAs strained layer superlattice (SLS) as the photoabsorbing layer of the detector. The channel of the MESFET, made from an n-doped GaAs layer, is grown above the SLS after a thin intermediate, GaAs/AlGaAs superlattice, smoothing layer. The MSM photodiodes exhibited a very low dark current, 26 nA at 10 V bias, a very fast pulse response with FWHM of about 42 ps. The photoreceivers, consisting of an MSM detector and a single stage amplifier, exhibited a very fast impulse response with FWHM, rise time and fall time of 105, 44 and 130 ps, respectively. By assuming a gaussian pulse, these correspond to a bandwidth in excess of 4.5GHz.

Optoelectronic integrated receiver

The performance of a GaAs based optoelectronic receiver is described. The receiver has an MSM photodiode, a preamplifier, a postamplifier, a comparator, a decision circuit and an ECL driver, all integrated on the same chip. An error rate of < 10-9 has been demonstrated at 2.4 Gbit/s.