Download or read book High performance Germanium Photodetectors on Silicon Reflecting Substrates for Long haul Optical Communications written by Olufemi Isiade Dosunmu and published by . This book was released on 2005 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: In this work we have designed and fabricated resonant cavity enhanced (RCE) germanium-on-silicon (Ge-on-Si) photodetectors, operating around the 1550 nm wavelength for applications in long-haul communications. Without sacrificing bandwidth, the spectral response of the Ge photodetector is enhanced by fabricating the Ge detector within a Fabry-Perot cavity, where the Ge active region is grown atop one or two-period silicon-on-insulator (SOI) substrates designed for maximum reflectivity (>80%) in the 1300 nm-1600 nm wavelength range. The responsivity of these Ge/SOI RCE photodetectors around 1550 nm is further enhanced by the increased absorption coefficient due to the tensile strain-induced bandgap narrowing effect within the Ge film. Detector bandwidths approaching 13 GHz and quantum efficiencies of nearly 60% have been measured around 1550 nm, which demonstrates the compatibility of these Ge/SOI photodetectors with 10 Gb/s data communication systems. In addition, the measured full-width at half-maximum (FWHM) of the spectral resonant peak is approximately 50 nm, encompassing the entire C-band wavelength range (1528 nm-1565 nm) used in long-haul optical communications, making these high-speed Ge detectors ideal for integration with WDM-based telecommunication systems. To the author's knowledge, these detectors are the fastest, most efficient Ge photodetectors fabricated directly on Si and optimized for 1550 nm operation.
Download or read book Design Optimization of Ge on Si Photodetector written by Himadri Sekhar Dutta and published by LAP Lambert Academic Publishing. This book was released on 2014-03 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, extensive researches are going on high-speed low-noise photodetectors for optical communication. A photodetector plays a critical role in the overall performance of the system. III-V based photodetectors for high-performance communication system have already been reported.But, the technology is very expensive.Si is an obvious choice in such cases.Si technology has also the advantage of high reliability and high integrability. However, Si band-gap is not suitable for photodetection around the long-haul communication wavelength.Ge is a good candidate for designing such photodetectors(PD), given its smaller direct energy band-gap, and compatibility with Si. Si and Ge can also be combined to design PD at variable wavelengths.Here a physics based model is developed and then solved analytically or numerically by the appropriate initial and boundary conditions. The simulated results are then be verified with experimental data. The various performance of the PD are studied here. Finally the design optimization are carried out by choosing an appropriate objective function.This book is very much useful for Ph.D, M.Tech and B.Tech students of ECE branc
Download or read book Physics and Technology of Tensile strained Germanium for High performance Silicon compatible Optoelectronics written by Jinendra Raja Jain and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern high-bandwidth communications systems primarily use optical links to support data transmission across a range of length scales, from metro/long-haul for infrastructure backbones to shorter-range cables in data centers. As performance, cost, and energy-efficiency requirements become more demanding, optical links are expected to eventually supplant copper-based interconnects at the board-to-board, chip-to-chip, and on-chip levels as well. Most optoelectronic devices use III-V materials to achieve high performance. Though efficient, these materials are expensive, toxic, and incompatible with the standard high-volume silicon-based manufacturing used to build microprocessors. In order for the transition to optics to take place at the smaller length scales, a fully silicon-compatible photonics technology is needed to replace the III-Vs and allow us to leverage the practical advantages of silicon-based manufacturing. This dissertation presents a foundational set of new platform technologies that make major improvements to the current state of silicon-compatible optoelectronics research. In the first part, we present the development of a new method for manufacturing germanium--on--insulator substrates, an attractive materials platform for optical devices. In the second part of the dissertation, we introduce a new silicon-compatible platform technology that can be used to dramatically enhance the optical performance of germanium-based light emitters and detectors.
Download or read book Miniaturized Silicon Photodetectors written by Maurizio Casalino and published by MDPI. This book was released on 2021-01-15 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 from 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 has 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.
Download or read book Conference Proceedings written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Germanium Photodetectors on Amorphous Substrates for Electronic photonic Integration written by Brian Sung-Il Pearson and published by . This book was released on 2016 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon photonics has emerged as a leading technology to overcome the bandwidth and energy efficiency bottlenecks of standard metal interconnects. Integration of photonics in the back-end-of-line (BEOL) of a standard CMOS process enables the advantages of optical interconnects while benefiting from the low cost of monolithic integration. However, processing in the BEOL requires device fabrication on amorphous substrates, and constrains processing to 450C. In this thesis, a germanium photodetector is fabricated while adhering to these processing constraints in order to demonstrate a proof of concept for BEOL integration. In order to obtain high quality active material, crystalline Ge was grown on Si0 2 by implementing selective deposition in geometrically confined channels. The emerging Ge grains were coalesced to fill a lithographically defined trench, forming the active area of a photodetector. The Ge was measured to have a significant tensile strain of 0.5 %, which was caused by thermal expansion mismatch with the substrate, and concentrated by small voids from imperfect coalescence. The associated resolved shear stress was determined to be below the critical resolved shear stress, verifying that dislocation generation does not occur in this material. The strain was shown to increase the absorption of Ge at long wavelengths, allowing for implementation along the entire telecom window. A Schottky barrier to p-type Ge was developed by the addition of a 1 nm tunneling A120 3 layer between an Al/Ge metal contact. This successfully de-pinned the Fermi level, creating a barrier height of 0.46 eV. The Schottky contacts enabled the fabrication of metal-semiconductor-metal (MSM) photodetectors on standard epitaxial Ge with state-of-the-art dark current densities of 2.1 x 10-2 A cm-2. Gain was observed in these photodetectors, with internal quantum efficiencies (IQE) of 405 %. MSM detectors were also made using Ge on Si0 2, exhibiting an IQE of 370 %. This is the first demonstration of IQE 100% in a Ge MSM or pin photodetector and proves the feasibility of making high performance active photonic devices while adhering to BEOL processing constraints.
Download or read book Dissertation Abstracts International written by and published by . This book was released on 2005 with total page 860 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wafer scale High bandwidth Germanium on Silicon Photodetectors for Communications Applications written by Li He and published by . This book was released on 2012 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Silicon-on-Insulator (SOI) material system has emerged as a potentially attractive platform for integrated optics, due to the intrinsic low-cost of silicon manufacturing. An especially attractive application is that of telecommunications. One key component for telecommunications applications is high-performance photodetectors, which convert an optical signal to an electrical signal. The key performance metrics for waveguide-coupled photodetectors include low dark current, high responsivity and high bandwidth. In addition, the cross-wafer performance and defectivity is also of great importance, on which the yield of eventual systems will rely. Here I report the first cross-wafer data for waveguide-coupled Ge-on-Si photodetectors based on vertical p-i-n configuration. The performance across the whole wafer is relatively uniform and exhibits low defectivity. Detectors working at speeds up to 20 GHz with 4V reverse bias are achieved, with high responsivities of 0.5 A/W. I describe the testing and characterization methods used to measure the performance of these devices, and identify the source of the bandwidth limitations, and show how these photodetectors are optimal for use at telecom wavelengths, consisting of light with a free-space wavelength near 1550 nm. Finally, a path forward for optimizing the devices in this process is presented. Based on our measurements, using only modest changes in device geometry, it should be possible to improve bandwidths to 70 GHz or more, and responsivities to 1 A/W or more. I propose specific device geometries to implement this improvement. This level of performance is sufficient for SOI based Ge photodetectors to implement even the most high-bandwidth optical telecommunications systems, and should help to make SOI an important platform for integrated optics.
Download or read book Semiconductor Technologies written by Jan Grym and published by IntechOpen. This book was released on 2010-04-01 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: Semiconductor technologies continue to evolve and amaze us. New materials, new structures, new manufacturing tools, and new advancements in modelling and simulation form a breeding ground for novel high performance electronic and photonic devices. This book covers all aspects of semiconductor technology concerning materials, technological processes, and devices, including their modelling, design, integration, and manufacturing.
Download or read book High Performance Photodetectors for Multimode Optical Data Links written by Wojciech Piotr Giziewicz and published by . This book was released on 2006 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) Silicon detectors of various geometries were fabricated, with measured bandwidths at 5 V reverse bias up to 2 GHz for 200 ym diameter devices and 4 GHz for 50 and 100 ym diameter devices. The latter is the highest bandwidth reported for a silicon detector fabricated in a CMOS-compatible process and biased at a practically accessible voltage. Device performance was confirmed by simulation, and a novel structure is proposed featuring a buried junction on SOI determined by simulation to have twice as high a responsivity-bandwidth product as the best reported devices fabricated on high resistivity SOI. The silicon device structure was modified for epitaxial germanium wafers, and devices were fabricated. The germanium devices were simulated to determine the appropriate technology scaling direction and maximum device dimensions for desired performance specifications.
Download or read book Silicon germanium Photodetectors for Optical Telecommunications written by Dyan Ali and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Infrared Detectors written by Antonio Rogalski and published by CRC Press. This book was released on 2010-11-15 with total page 900 pages. Available in PDF, EPUB and Kindle. Book excerpt: Completely revised and reorganized while retaining the approachable style of the first edition, Infrared Detectors, Second Edition addresses the latest developments in the science and technology of infrared (IR) detection. Antoni Rogalski, an internationally recognized pioneer in the field, covers the comprehensive range of subjects necessary to un
Download or read book Strain engineered Complementary Metal Oxide Semiconductor compatible Ge Photodetectors written by Douglas Dale Cannon and published by . This book was released on 2003 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of CMOS-compatible photodetectors capable of operating throughout the entire telecommunications wavelength spectrum will aid in the integration of photodetectors with Si microelectronics, thus offering a low cost platform for high performance photoreceivers. This thesis demonstrates the first CMOS process compatible high-responsivity Ge p-i-n diodes for 1.55 [mu]m wavelengths. The thermal expansion mismatch between Ge epilayers and Si substrates was used to engineer tensile strain upon cooling from the growth temperature. This 0.2% tensile strain results in a lowering of the direct transition energy in Ge by 30 meV and extends the responsivity curve to near 1.6[mu]m. Design rules are given for high speed and high responsivity, and the advantages of waveguide integration for simultaneous achievement of high speed and high responsivity are illustrated. It is shown that waveguide integration has advantages to vertical illumination when optical saturation is considered. Optical saturation will become important as photodetector sizes shrink to the order of a few tens of microns in diameter. High Ge content SiGe could have applications for a SiGe electro-optic modulator utilizing the Franz-Keldysh effect. High Ge content SiGe films have been grown on Si substrates. The Franz-Keldysh effect has been observed in our pure Ge films as an increase in responsivity with increasing reverse bias for wavelengths longer than the bandgap energy.
Download or read book Si based Germanium Tin Photodetectors for Infrared Imaging and High speed Detection written by Huong Tran and published by . This book was released on 2021 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: Infrared (IR) radiation spans the wavelengths of the windows: (1) near-IR region ranging from 0.8 to 1.0 om, (2) shortwave IR (SWIR) ranging from 1.0 to 3.0 om, (3) mid-wave IR (MWIR) region covering from 3.0 to 5.0 om, (4) longwave IR (LWIR) spanning from 8.0 to 12.0 om, and (5) very longwave IR extending beyond 12.0 om. The MWIR and LWIR regions are important for night vision in the military, and since the atmosphere does not absorb at these wavelengths, they are also used for free-space communications and astronomy. Automotive and defect detection in the food industry and electronic circuits also use IR detection as non-contact inspection methods. IR detection is also applied in the medical field. The market of SWIR and MWIR detectors is primarily dominated by mature technology from III-V systems such as indium gallium arsenide (InGaAs and extended InGaAs), indium antimonide (InSb), from II-VI such as mercury cadmium telluride (MCT), lead sulfide (PbS), and from group IV such as silicon (Si) and germanium (Ge) for shorter wavelength. However, the mature IR photodetector technology is expensive, demands to operate at low temperatures, and has complicated fabrication processes. In order to lower cost by mass production, many approaches have been developed towards the hybrid integration of III-Vs or II-VIs on a Si substrate. At the same time, it is desirable to develop an alternative material to reduce the cost and improve the performance for high-temperature operations. The discovery of group IV (Si)GeSn alloys has opened a route for a new generation of IR detectors. The work in this dissertation set out to develop Si-based Ge1-xSnx photodetectors for low-cost infrared imaging and high-speed detection. A study of effective carrier lifetime and optical properties of Ge1-xSnx materials is presented. The carrier lifetime is then applied to model the Ge1-xSnx photodetectors. For optical properties of Ge1-xSnx materials, two empirical formulae with extracted constants and coefficients were developed: (1) Absorption coefficient. The absorption regarding Urbach tail, indirect and direct bandgap transitions were comprehensively considered; (2) refractive index. The developed formulae could simplify the optoelectronic device design process due to their parameter-based expressions. A comprehensive study of Si-based GeSn mid-infrared photodetectors is carried out. A set of photoconductors with Sn compositions ranging from 10.5% to 22.3% show the cutoff wavelength to be extended to 3.65 om. The devices' peak D* is comparable to that of commercial extended-InGaAs detectors. The GeSn photodiodes are also explored with an in-depth analysis of a dark current. The dark current is suppressed as the photodiode was passivated. Moreover, mid-infrared images were captured using GeSn photodetectors, showing the comparable image quality with that acquired by using commercial PbSe detectors. The performance of GeSn photodiodes with 6.44 % and 9.24 % Sn is evaluated under high-speed measurements and simulations. The cutoff wavelength is extended up to 2.2 om and 2.5 om for 6.44 % and 9.24 % Sn devices, respectively. The photodiodes' bandwidth is 1.78 GHz, and the simulation shows excellent agreement with measurement results.
Download or read book Advances in Optical Fiber Technology written by Moh Yasin and published by BoD – Books on Demand. This book was released on 2015-02-25 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a compilation of works presenting recent developments and practical applications in optical fiber technology. It contains 13 chapters from various institutions that represent global research in various topics such as scattering, dispersion, polarization interference, fuse phenomena and optical manipulation, optical fiber laser and sensor applications, passive optical network (PON) and plastic optical fiber (POF) technology. It provides the reader with a broad overview and sampling of the innovative research on optical fiber technologies.
Download or read book Silicon Based Photonics written by Erich Kasper and published by CRC Press. This book was released on 2020-07-24 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Silicon photonics has evolved rapidly as a research topic with enormous application potential. The high refractive index contrast of silicon-on-insulator (SOI) shows great promise for submicron waveguide structures suited for integration on the chip scale in the near-infrared region. Ge- and GeSn-Si heterostructures with different elastic strain levels already provide expansion of the spectral range, high-speed operation, efficient modulation and switching of optical signals, and enhanced light emission and lasing. This book focuses on the integration of heterostructure devices with silicon photonics. The authors have attempted to merge a concise treatment of classical silicon photonics with a description of principles, prospects, challenges, and technical solution paths of adding silicon-based heterostructures. The book discusses the basics of heterostructure-based silicon photonics, system layouts, and key device components, keeping in mind the application background. Special focus is placed on SOI-based waveguide configurations and Ge- and GeSn-Si heterostructure devices for light detection, modulation, and light emission and lasing. The book also provides an overview of the technological and materials science challenges connected with integration on silicon. The first half of the book is mainly for readers who are interested in the topic because of its increasing importance in different fields, while the latter half covers different device structures for light emission, detection, modulation, extension of the wavelength beyond 1.6 μm, and lasing, as well as future challenges.
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2002 pages. Available in PDF, EPUB and Kindle. Book excerpt:
