Improved SiC Schottky Barrier Diodes Using Refractory Metal Borides

Improved SiC Schottky Barrier Diodes Using Refractory Metal Borides PDF Author: Rani S. Kummari
Publisher:
ISBN:
Category : Diodes, Schottky-barrier
Languages : en
Pages : 134

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Book Description
This research demonstrates how the deposition temperature of Schottky contacts on 4H-SiC affects the electrical and thermal properties of a Schottky diode. Several refractory metal borides are investigated for the contacts which are deposited at room temperature (20 °C) and high temperature (600 °C). The electrical properties of the diodes are characterized by using current-voltage (I-V) and capacitance-voltage (C-V) measurements. Thermal properties are investigated by using rapid thermal processor (RTP). Schottky contacts which are deposited at 600 °C produced better Schottky diodes with smaller ideality factors from 1.05 to 1.10), barrier heights from 0.94 to 1.15 eV, smaller resistances, and smaller current density in reverse bias conditions when compared to the contacts deposited at room temperature. These values remained stable after annealing in RTP at 600 °C for 20 minutes. The improved electrical properties and thermal stability of the diodes with contacts deposited at 600 °C are related to the removal of O2 from the boride/SiC interface, as revealed by the Rutherford backscattering spectroscopy (RBS) analysis. These results indicate improved electrical and thermal properties of boride/SiC Schottky contacts, making them attractive for high temperature applications.

Improved SiC Schottky Barrier Diodes Using Refractory Metal Borides

Improved SiC Schottky Barrier Diodes Using Refractory Metal Borides PDF Author: Rani S. Kummari
Publisher:
ISBN:
Category : Diodes, Schottky-barrier
Languages : en
Pages : 134

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Book Description
This research demonstrates how the deposition temperature of Schottky contacts on 4H-SiC affects the electrical and thermal properties of a Schottky diode. Several refractory metal borides are investigated for the contacts which are deposited at room temperature (20 °C) and high temperature (600 °C). The electrical properties of the diodes are characterized by using current-voltage (I-V) and capacitance-voltage (C-V) measurements. Thermal properties are investigated by using rapid thermal processor (RTP). Schottky contacts which are deposited at 600 °C produced better Schottky diodes with smaller ideality factors from 1.05 to 1.10), barrier heights from 0.94 to 1.15 eV, smaller resistances, and smaller current density in reverse bias conditions when compared to the contacts deposited at room temperature. These values remained stable after annealing in RTP at 600 °C for 20 minutes. The improved electrical properties and thermal stability of the diodes with contacts deposited at 600 °C are related to the removal of O2 from the boride/SiC interface, as revealed by the Rutherford backscattering spectroscopy (RBS) analysis. These results indicate improved electrical and thermal properties of boride/SiC Schottky contacts, making them attractive for high temperature applications.

Silicon Carbide Microsystems for Harsh Environments

Silicon Carbide Microsystems for Harsh Environments PDF Author: Muthu Wijesundara
Publisher: Springer Science & Business Media
ISBN: 1441971211
Category : Technology & Engineering
Languages : en
Pages : 247

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Book Description
Silicon Carbide Microsystems for Harsh Environments reviews state-of-the-art Silicon Carbide (SiC) technologies that, when combined, create microsystems capable of surviving in harsh environments, technological readiness of the system components, key issues when integrating these components into systems, and other hurdles in harsh environment operation. The authors use the SiC technology platform suite the model platform for developing harsh environment microsystems and then detail the current status of the specific individual technologies (electronics, MEMS, packaging). Additionally, methods towards system level integration of components and key challenges are evaluated and discussed based on the current state of SiC materials processing and device technology. Issues such as temperature mismatch, process compatibility and temperature stability of individual components and how these issues manifest when building the system receive thorough investigation. The material covered not only reviews the state-of-the-art MEMS devices, provides a framework for the joining of electronics and MEMS along with packaging into usable harsh-environment-ready sensor modules.

Electrical Properties of Molybdenum Silicon Carbide Schottky Barrier Diodes

Electrical Properties of Molybdenum Silicon Carbide Schottky Barrier Diodes PDF Author: Sai Bhargav Naredla
Publisher:
ISBN:
Category : Diodes, Schottky-barrier
Languages : en
Pages : 126

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Book Description
Molybdenum (Mo) is one of the metals categorized as refractory metal due to its thermal properties. For that reason, it is very attractive for high-temperature applications. This thesis covers the investigation of silicon carbide (SiC) Schottky diodes fabricated using Mo as the Schottky contact. The Mo Schottky contacts were deposited using magnetron sputtering on the n-type 4H-SiC. The temperature of the SiC substrates was varied from 25 °C to 900 °C. The electrical properties of the diodes were determined by current-voltage, capacitance-voltage and current-voltage-temperature measurements. Structural properties of Schottky contacts deposited at different temperatures were also characterized using x-ray diffraction spectroscopy. The results obtained reveal that the as-deposited diodes had energy barrier heights that ranged from 1.02 to 1.67 eV and ideality factors varying from 1.04 to 1.23. Contacts deposited at 600 °C produced the optimum property consisting of a barrier height of 1.34 eV and ideality factor of 1.05. The diodes were further thermally processed by keeping them exposed to 500 °C for 24 hours diodes in vacuum. From these, the barrier height ranging from 1.00 eV to 1.70 eV was obtained. The variation in electrical properties is explained as due to changes in crystal quality. Current-voltage temperature measurements to further characterize the electrical properties of diodes at different temperatures were performed. Contacts deposited at 500°C produced the largest Richardson's constant (A**) of 3.74 A/K-cm2 and a barrier height of 1.32 eV. Changes in ideality factors and barrier heights are observed due to the formation of interfacial silicide layers. X-ray diffraction results show the formation of MoSi2 and Mo5Si2

The Properties of SiC Barrier Diodes Fabricated with Ti Schottky Contacts

The Properties of SiC Barrier Diodes Fabricated with Ti Schottky Contacts PDF Author: Krishna Chaitanya Kundeti
Publisher:
ISBN:
Category : Diodes, Schottky-barrier
Languages : en
Pages : 142

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Book Description
Titanium (Ti) is a popular metal contact used in fabricating Schottky barrier diodes on silicon carbide (SiC) semiconductor. In this research, Ti/4H-SiC Schottky barrier diodes have been fabricated to investigate the effect of deposition temperature and annealing on the electrical characteristics of the fabricated devices. The parameters such as barrier height, ideality factor and on-resistance were determined from the current-voltage (I-V) and the capacitance-voltage (C-V) measurements at room temperature. The temperature-dependent electrical characteristics are realized by performing current-voltage-temperature (I-V-T) measurements. Furthermore, the material characterizations were performed using Auger Electron Spectroscopy (AES) and x-ray diffraction (XRD) measurements. Thin films of Titanium (Ti) as Schottky contacts were deposited on n-type 4H-SiC substrate by magnetron sputtering at different temperatures form room temperature ~25 °C to 900 °C. In addition, thermal processing was performed by annealing at 500 °C in vacuum and argon environment up to 60 hours and characterized using I-V, C-V, and I-V-T measurements accordingly. The diodes with Ti deposited at 200 °C yield better devices with an average ideality factor of 1.04 and Schottky barrier height of 1.13 eV. The electrical properties shows that the deposition of Schottky contact should be at least below 700 °C and the Schottky contact should be annealed at 500 °C for 12-36 hours in order to obtain acceptable quality of Schottky diode. We believe that these variations in the electrical properties are due to the change in the quality of interfacial layer. The variations in physical/compositional properties of Ti/SiC interface has been investigated using Auger electron spectroscopy and x-ray diffraction, which reveled mainly two kinds of phases: Ti5Si3 and Ti3SiC2 formed at the interfacial layer.

Design and Fabrication of High Voltage 4H-SiC Schottky Barrier Diodes

Design and Fabrication of High Voltage 4H-SiC Schottky Barrier Diodes PDF Author: Luo, Xixi
Publisher:
ISBN:
Category :
Languages : en
Pages : 116

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Book Description
A novel design of mesa-etch termination and Superjunction JBS diode structure has been proposed and optimized. The new mesa-etch termination can achieve over 90% of ideal maximal breakdown voltage within a wide sidewall implant dose window (~9e16 cm−3). Besides the high tolerance on implant dose, the proposed design also exhibits high tolerance on the etch sidewall angle: minimal maximum breakdown voltage was observed with etch sidewall angle variations. The Superjunction JBS diode can obtain both 96.4% maximum super junction breakdown voltage and 76.6% JBS Schottky surface electric field reduction. The super junction maximal breakdown voltage is 1.5 times large as the conventional Schottky diode breakdown voltage and the leakage current is logarithmically related to the surface electric field. The superior breakdown voltage represents a large improvement on the power rectifier performance. Based on these structure improvements, vertical 4H-SiC Schottky Diodes have been fabricated and tested. Vertical 4H-SiC Schottky Diode without any edge termination has a breakdown voltage as large as 692 V and exhibits an on-state specific resistance as small as 7.9 mΩ*cm2. Such breakdown voltage is much higher than simulation results. In the meantime, on-state resistance is also much larger than the simulation results. The mechanism for these improved power rectifier performances will be furthered investigated in future studies

Silicon Carbide

Silicon Carbide PDF Author: Wolfgang J. Choyke
Publisher: Springer Science & Business Media
ISBN: 3642188702
Category : Technology & Engineering
Languages : en
Pages : 911

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Book Description
Since the 1997 publication of "Silicon Carbide - A Review of Fundamental Questions and Applications to Current Device Technology" edited by Choyke, et al., there has been impressive progress in both the fundamental and developmental aspects of the SiC field. So there is a growing need to update the scientific community on the important events in research and development since then. The editors have again gathered an outstanding team of the world's leading SiC researchers and design engineers to write on the most recent developments in SiC.

Chemical Abstracts

Chemical Abstracts PDF Author:
Publisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 2692

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Book Description


Electrical & Electronics Abstracts

Electrical & Electronics Abstracts PDF Author:
Publisher:
ISBN:
Category : Electrical engineering
Languages : en
Pages : 976

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Book Description


Properties and Applications of Silicon Carbide

Properties and Applications of Silicon Carbide PDF Author: Rosario Gerhardt
Publisher: BoD – Books on Demand
ISBN: 9533072016
Category : Science
Languages : en
Pages : 550

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Book Description
In this book, we explore an eclectic mix of articles that highlight some new potential applications of SiC and different ways to achieve specific properties. Some articles describe well-established processing methods, while others highlight phase equilibria or machining methods. A resurgence of interest in the structural arena is evident, while new ways to utilize the interesting electromagnetic properties of SiC continue to increase.

CRC Handbook of Metal Etchants

CRC Handbook of Metal Etchants PDF Author: Perrin Walker
Publisher: CRC Press
ISBN: 9781439822531
Category : Science
Languages : en
Pages : 1434

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Book Description
This publication presents cleaning and etching solutions, their applications, and results on inorganic materials. It is a comprehensive collection of etching and cleaning solutions in a single source. Chemical formulas are presented in one of three standard formats - general, electrolytic or ionized gas formats - to insure inclusion of all necessary operational data as shown in references that accompany each numbered formula. The book describes other applications of specific solutions, including their use on other metals or metallic compounds. Physical properties, association of natural and man-made minerals, and materials are shown in relationship to crystal structure, special processing techniques and solid state devices and assemblies fabricated. This publication also presents a number of organic materials which are widely used in handling and general processing...waxes, plastics, and lacquers for example. It is useful to individuals involved in study, development, and processing of metals and metallic compounds. It is invaluable for readers from the college level to industrial R & D and full-scale device fabrication, testing and sales. Scientific disciplines, work areas and individuals with great interest include: chemistry, physics, metallurgy, geology, solid state, ceramic and glass, research libraries, individuals dealing with chemical processing of inorganic materials, societies and schools.