Special Issue "Miniaturized Silicon Photodetectors: New Perspectives and Applications"

A special issue of Micromachines (ISSN 2072-666X). This special issue belongs to the section "A:Physics".

Deadline for manuscript submissions: closed (1 August 2020) | Viewed by 11279

Printed Edition Available!
A printed edition of this Special Issue is available here.

Special Issue Editor

Dr. Maurizio Casalino
E-Mail Website
Guest Editor
Institute of Applied Sciences and Intelligent Systems, 80131 Napoli, Italy
Interests: photodetectors; silicon; graphene; infrared; Schottky junction
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Silicon (Si) technologies provide an excellent platform for the design of microsystems where photonic and microelectronic functionalities are monolithically integrated on the same substrate. In recent years, a variety of passive and active Si photonic devices have been developed, and among them, photodetectors have attracted particular interest of the scientific community.

Si photodiodes are typically designed to operate at visible wavelengths, but, unfortunately, their employment in the infrared (IR) range is limited due to the neglectable Si absorption over 1100 nm, even though the use of germanium (Ge) grown on Si has historically allowed operations to be extended up to 1550 nm.

In recent years, significant progress have been achieved both by improving the performance of Si-based photodetectors in the visible range and by extending their operation to infrared wavelengths. Near-infrared (NIR) SiGe photodetectors have been demonstrated to have a “zero change” CMOS process flow, while the investigation of new effects and structures has shown that an all-Si approach could be a viable option to construct devices comparable with Ge technology. In addition, the capability to integrate new emerging 2D and 3D materials with Si, together with the capability of manufacturing devices at the nanometric scale, has led to the development of new device families with unexpected performance. Accordingly, this Special Issue of Micromachines seeks to showcase research papers, short communications, and review articles that show the most recent advances in the field of silicon photodetectors and their respective applications.

Dr. Maurizio Casalino
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Micromachines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2000 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • photodetector
  • silicon
  • infrared
  • plasmonics
  • germanium
  • 2D materials
  • CMOS
  • imaging
  • spectroscopy

Related Special Issue

Published Papers (9 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Editorial

Jump to: Research, Review

Editorial
Editorial for the Special Issue on Miniaturized Silicon Photodetectors: New Perspectives and Applications
Micromachines 2020, 11(11), 1010; https://doi.org/10.3390/mi11111010 - 17 Nov 2020
Viewed by 624
Abstract
Silicon (Si) technologies provide an excellent platform for monolithically integrating both photonic [...] Full article

Research

Jump to: Editorial, Review

Article
Avalanche Transients of Thick 0.35 µm CMOS Single-Photon Avalanche Diodes
Micromachines 2020, 11(9), 869; https://doi.org/10.3390/mi11090869 - 19 Sep 2020
Cited by 3 | Viewed by 1025
Abstract
Two types of single-photon avalanche diodes (SPADs) with different diameters are investigated regarding their avalanche behavior. SPAD type A was designed in standard 0.35-µm complementary metal-oxide-semiconductor (CMOS) including a 12-µm thick p- epi-layer with diameters of 50, 100, 200, and 400 µm; [...] Read more.
Two types of single-photon avalanche diodes (SPADs) with different diameters are investigated regarding their avalanche behavior. SPAD type A was designed in standard 0.35-µm complementary metal-oxide-semiconductor (CMOS) including a 12-µm thick p- epi-layer with diameters of 50, 100, 200, and 400 µm; and type B was implemented in the high-voltage (HV) line of this process with diameters of 48.2 and 98.2 µm. Each SPAD is wire-bonded to a 0.35-µm CMOS clocked gating chip, which controls charge up to a maximum 6.6-V excess bias, active, and quench phase as well as readout during one clock period. Measurements of the cathode voltage after photon hits at SPAD type A resulted in fall times (80 to 20%) of 10.2 ns for the 50-µm diameter SPAD for an excess bias of 4.2 V and 3.45 ns for the 200-µm diameter device for an excess bias of 4.26 V. For type B, fall times of 8 ns for 48.2-µm diameter and 5.4-V excess bias as well as 2 ns for 98.2-µm diameter and 5.9-V excess bias were determined. In measuring the whole capacitance at the cathode of the SPAD with gating chip connected, the avalanche currents through the detector were calculated. This resulted in peak avalanche currents of, e.g., 1.19 mA for the 100-µm SPAD type A and 1.64 mA for the 98.2-µm SPAD type B for an excess bias of 5 and 4.9 V, respectively. Full article
Show Figures

Figure 1

Article
Metal-Semiconductor-Metal GeSn Photodetectors on Silicon for Short-Wave Infrared Applications
Micromachines 2020, 11(9), 795; https://doi.org/10.3390/mi11090795 - 21 Aug 2020
Cited by 13 | Viewed by 1842
Abstract
Metal-semiconductor-metal photodetectors (MSM PDs) are effective for monolithic integration with other optical components of the photonic circuits because of the planar fabrication technique. In this article, we present the design, growth, and characterization of GeSn MSM PDs that are suitable for photonic integrated [...] Read more.
Metal-semiconductor-metal photodetectors (MSM PDs) are effective for monolithic integration with other optical components of the photonic circuits because of the planar fabrication technique. In this article, we present the design, growth, and characterization of GeSn MSM PDs that are suitable for photonic integrated circuits. The introduction of 4% Sn in the GeSn active region also reduces the direct bandgap and shows a redshift in the optical responsivity spectra, which can extend up to 1800 nm wavelength, which means it can cover the entire telecommunication bands. The spectral responsivity increases with an increase in bias voltage caused by the high electric field, which enhances the carrier generation rate and the carrier collection efficiency. Therefore, the GeSn MSM PDs can be a suitable device for a wide range of short-wave infrared (SWIR) applications. Full article
Show Figures

Figure 1

Article
Characterization of Impact Ionization Coefficient of ZnO Based on a p-Si/i-ZnO/n-AZO Avalanche Photodiode
Micromachines 2020, 11(8), 740; https://doi.org/10.3390/mi11080740 - 30 Jul 2020
Cited by 1 | Viewed by 874
Abstract
The avalanche photodiode is a highly sensitive photon detector with wide applications in optical communication and single photon detection. ZnO is a promising wide band gap material to realize a UV avalanche photodiode (APD). However, the lack of p-type doping, the strong self-compensation [...] Read more.
The avalanche photodiode is a highly sensitive photon detector with wide applications in optical communication and single photon detection. ZnO is a promising wide band gap material to realize a UV avalanche photodiode (APD). However, the lack of p-type doping, the strong self-compensation effect, and the scarcity of data on the ionization coefficients restrain the development and application of ZnO APD. Furthermore, ZnO APD has been seldom reported before. In this work, we employed a p-Si/i-ZnO/n-AZO structure to successfully realize electron avalanche multiplication. Based on this structure, we investigated the band structure, field profile, Current–Voltage (I-V) characteristics, and avalanche gain. To examine the influence of the width of the i-ZnO layer on the performance, we changed the i-ZnO layer thickness to 250, 500, and 750 nm. The measured breakdown voltages agree well with the corresponding threshold electric field strengths that we calculated. The agreement between the experimental data and calculated results supports our analysis. Finally, we provide data on the impact ionization coefficients of electrons for ZnO along the (001) direction, which is of great significance in designing high-performance low excess noise ZnO APD. Our work lays a foundation to realize a high-performance ZnO-based avalanche device. Full article
Show Figures

Figure 1

Article
Theoretical Investigation of Near-Infrared Fabry–Pérot Microcavity Graphene/Silicon Schottky Photodetectors Based on Double Silicon on Insulator Substrates
Micromachines 2020, 11(8), 708; https://doi.org/10.3390/mi11080708 - 22 Jul 2020
Cited by 3 | Viewed by 952
Abstract
In this work a new concept of silicon resonant cavity enhanced photodetector working at 1550 nm has been theoretically investigated. The absorption mechanism is based on the internal photoemission effect through a graphene/silicon Schottky junction incorporated into a silicon-based Fabry–Pérot optical microcavity whose [...] Read more.
In this work a new concept of silicon resonant cavity enhanced photodetector working at 1550 nm has been theoretically investigated. The absorption mechanism is based on the internal photoemission effect through a graphene/silicon Schottky junction incorporated into a silicon-based Fabry–Pérot optical microcavity whose input mirror is constituted by a double silicon-on-insulator substrate. As output mirror we have investigated two options: a distributed Bragg reflector constituted by some periods of silicon nitride/hydrogenated amorphous silicon and a metallic gold reflector. In addition, we have investigated and compared two configurations: one where the current is collected in the transverse direction with respect to the direction of the incident light, the other where it is collected in the longitudinal direction. We show that while the former configuration is characterized by a better responsivity, spectral selectivity and noise equivalent power, the latter configuration is superior in terms of bandwidth and responsivity × bandwidth product. Our results show responsivity of 0.24 A/W, bandwidth in GHz regime, noise equivalent power of 0.6 nW/cm√Hz and full with at half maximum of 8.5 nm. The whole structure has been designed to be compatible with silicon technology. Full article
Show Figures

Figure 1

Article
Effect of Various Defects on 4H-SiC Schottky Diode Performance and Its Relation to Epitaxial Growth Conditions
Micromachines 2020, 11(6), 609; https://doi.org/10.3390/mi11060609 - 24 Jun 2020
Cited by 6 | Viewed by 1206
Abstract
In this paper, the chemical vapor deposition (CVD) processing for 4H-SiC epilayer is investigated with particular emphasis on the defects and the noise properties. It is experimentally found that the process parameters of C/Si ratio strongly affect the surface roughness of epilayers and [...] Read more.
In this paper, the chemical vapor deposition (CVD) processing for 4H-SiC epilayer is investigated with particular emphasis on the defects and the noise properties. It is experimentally found that the process parameters of C/Si ratio strongly affect the surface roughness of epilayers and the density of triangular defects (TDs), while no direct correlation between the C/Si ratio and the deep level defect Z1/2 could be confirmed. By adjusting the C/Si ratio, a decrease of several orders of magnitudes in the noise level for the 4H-SiC Schottky barrier diodes (SBDs) could be achieved attributing to the improved epilayer quality with low TD density and low surface roughness. The work should provide a helpful clue for further improving the device performance of both the 4H-SiC SBDs and the Schottky barrier ultraviolet photodetectors fabricated on commercial 4H-SiC wafers. Full article
Show Figures

Figure 1

Article
A Graphene/Polycrystalline Silicon Photodiode and Its Integration in a Photodiode–Oxide–Semiconductor Field Effect Transistor
Micromachines 2020, 11(6), 596; https://doi.org/10.3390/mi11060596 - 17 Jun 2020
Cited by 2 | Viewed by 1222
Abstract
In recent years, the characteristics of the graphene/crystalline silicon junction have been frequently discussed in the literature, but study of the graphene/polycrystalline silicon junction and its potential applications is hardly found. The present work reports the observation of the electrical and optoelectronic characteristics [...] Read more.
In recent years, the characteristics of the graphene/crystalline silicon junction have been frequently discussed in the literature, but study of the graphene/polycrystalline silicon junction and its potential applications is hardly found. The present work reports the observation of the electrical and optoelectronic characteristics of a graphene/polycrystalline silicon junction and explores one possible usage of the junction. The current–voltage curve of the junction was measured to show the typical exponential behavior that can be seen in a forward biased diode, and the photovoltage of the junction showed a logarithmic dependence on light intensity. A new phototransistor named the “photodiode–oxide–semiconductor field effect transistor (PDOSFET)” was further proposed and verified in this work. In the PDOSFET, a graphene/polycrystalline silicon photodiode was directly merged on top of the gate oxide of a conventional metal–oxide–semiconductor field effect transistor (MOSFET). The magnitude of the channel current of this phototransistor showed a logarithmic dependence on the illumination level. It is shown in this work that the PDOSFET facilitates a better pixel design in a complementary metal–oxide–semiconductor (CMOS) image sensor, especially beneficial for high dynamic range (HDR) image detection. Full article
Show Figures

Figure 1

Review

Jump to: Editorial, Research

Review
Integrated Photodetectors Based on Group IV and Colloidal Semiconductors: Current State of Affairs
Micromachines 2020, 11(9), 842; https://doi.org/10.3390/mi11090842 - 08 Sep 2020
Cited by 8 | Viewed by 919
Abstract
With the aim to take advantage from the existing technologies in microelectronics, photodetectors should be realized with materials compatible with them ensuring, at the same time, good performance. Although great efforts are made to search for new materials that can enhance performance, photodetector [...] Read more.
With the aim to take advantage from the existing technologies in microelectronics, photodetectors should be realized with materials compatible with them ensuring, at the same time, good performance. Although great efforts are made to search for new materials that can enhance performance, photodetector (PD) based on them results often expensive and difficult to integrate with standard technologies for microelectronics. For this reason, the group IV semiconductors, which are currently the main materials for electronic and optoelectronic devices fabrication, are here reviewed for their applications in light sensing. Moreover, as new materials compatible with existing manufacturing technologies, PD based on colloidal semiconductor are revised. This work is particularly focused on developments in this area over the past 5–10 years, thus drawing a line for future research. Full article
Show Figures

Figure 1

Review
Low-Cost Microbolometer Type Infrared Detectors
Micromachines 2020, 11(9), 800; https://doi.org/10.3390/mi11090800 - 24 Aug 2020
Cited by 14 | Viewed by 2161
Abstract
The complementary metal oxide semiconductor (CMOS) microbolometer technology provides a low-cost approach for the long-wave infrared (LWIR) imaging applications. The fabrication of the CMOS-compatible microbolometer infrared focal plane arrays (IRFPAs) is based on the combination of the standard CMOS process and simple post-CMOS [...] Read more.
The complementary metal oxide semiconductor (CMOS) microbolometer technology provides a low-cost approach for the long-wave infrared (LWIR) imaging applications. The fabrication of the CMOS-compatible microbolometer infrared focal plane arrays (IRFPAs) is based on the combination of the standard CMOS process and simple post-CMOS micro-electro-mechanical system (MEMS) process. With the technological development, the performance of the commercialized CMOS-compatible microbolometers shows only a small gap with that of the mainstream ones. This paper reviews the basics and recent advances of the CMOS-compatible microbolometer IRFPAs in the aspects of the pixel structure, the read-out integrated circuit (ROIC), the focal plane array, and the vacuum packaging. Full article
Show Figures

Figure 1

Back to TopTop