High Temperature Stable Titanium Carbide Ohmic and Schottky Contacts to SiC

1998 ◽  
Vol 512 ◽  
Author(s):  
C.-M. Zetterling ◽  
M. östling ◽  
L. Norin ◽  
U. Jansson

ABSTRACTEpitaxial titanium carbide is investigated as a low resistivity, high temperature stable Ohmic and Schottky contact to 4H and 6H SiC. The titanium carbide films were deposited at 500°C using co-evaporation of titanium (e-beam) and C60 (Knudsen cell) in a UHV system. Schottky diodes and TLM structures were fabricated on low and high doped SiC material respectively. The samples were annealed at 700 °C in a vacuum furnace, and electrical measurements were performed up to 300 °C.

2011 ◽  
Vol 679-680 ◽  
pp. 453-456
Author(s):  
Denis Perrone ◽  
Sergio Ferrero ◽  
Luciano Scaltrito ◽  
Marco Naretto ◽  
Edvige Celasco ◽  
...  

In this work we studied different Schottky contacts to 4H-SiC with the aim to obtain Schottky Barrier diodes (SBDs) and Junction Barrier Schottky diodes (JBS) able to operate at high temperatures, frequencies and power densities with low power losses. Schottky contacts were fabricated using Mo and Mo/Al layers annealed up to 600 °C using a Rapid Thermal Process (RTP). A comparison with previous results obtained with Ni, Ti and Ti/Al layers annealed up to 400 °C is also proposed. The Schottky contacts were characterized by means of standard Current-Voltage (I-V) and Capacitance-Voltage (C-V) techniques. X-ray Photoelectron Spectroscopy (XPS) analyses were performed in depth profile mode in order to study the structural evolution of the interface Mo/SiC and Al/Mo during annealing treatments. Mo/Al contacts show a lower barrier height and better overall performances in forward polarization when compared to the Ti- and Ni-based contacts, and they are very promising for Schottky contact fabrication on SBD and JBS.


Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 298
Author(s):  
Marilena Vivona ◽  
Filippo Giannazzo ◽  
Fabrizio Roccaforte

Silicon carbide (4H-SiC) Schottky diodes have reached a mature level of technology and are today essential elements in many applications of power electronics. In this context, the study of Schottky barriers on 4H-SiC is of primary importance, since a deeper understanding of the metal/4H-SiC interface is the prerequisite to improving the electrical properties of these devices. To this aim, over the last three decades, many efforts have been devoted to developing the technology for 4H-SiC-based Schottky diodes. In this review paper, after a brief introduction to the fundamental properties and electrical characterization of metal/4H-SiC Schottky barriers, an overview of the best-established materials and processing for the fabrication of Schottky contacts to 4H-SiC is given. Afterwards, besides the consolidated approaches, a variety of nonconventional methods proposed in literature to control the Schottky barrier properties for specific applications is presented. Besides the possibility of gaining insight into the physical characteristics of the Schottky contact, this subject is of particular interest for the device makers, in order to develop a new class of Schottky diodes with superior characteristics.


2009 ◽  
Vol 615-617 ◽  
pp. 959-962
Author(s):  
Ferdinando Iucolano ◽  
Fabrizio Roccaforte ◽  
Filippo Giannazzo ◽  
Salvatore di Franco ◽  
Giuseppe Moschetti ◽  
...  

The recent improvement of GaN material quality launched new perspective for its application in power devices. However, ion-implanted guard-ring edge terminations, necessary to improve the breakdown voltage, are not well developed as in SiC technology. Indeed, the effects of high-temperature annealing, required for the electrical activation of the implanted species in GaN, on the electrical behaviour of Schottky contact was not reported. In this work, the influence of high temperature annealing (1150-1200°C) on the surface morphology of GaN and on the electrical behaviour of Schottky contact was studied. Although the morphology of GaN surface did not substantially change after annealing, a worsening of the electrical behaviour of Schottky contact was observed. This latter was ascribed to the formation of a high density of interface states after annealing.


Author(s):  
Yih-Cheng Shih ◽  
E. L. Wilkie

Tungsten silicides (WSix) have been successfully used as the gate materials in self-aligned GaAs metal-semiconductor-field- effect transistors (MESFET). Thermal stability of the WSix/GaAs Schottky contact is of major concern since the n+ implanted source/drain regions must be annealed at high temperatures (∼ 800°C). WSi0.6 was considered the best composition to achieve good device performance due to its low stress and excellent thermal stability of the WSix/GaAs interface. The film adhesion and the uniformity in barrier heights and ideality factors of the WSi0.6 films have been improved by depositing a thin layer of pure W as the first layer on GaAs prior to WSi0.6 deposition. Recently WSi0.1 has been used successfully as the gate material in 1x10 μm GaAs FET's on the GaAs substrates which were sputter-cleaned prior to deposition. These GaAs FET's exhibited uniform threshold voltages across a 51 mm wafer with good film adhesion after annealing at 800°C for 10 min.


Author(s):  
I. Khidirov ◽  
V. V. Getmanskiy ◽  
A. S. Parpiev ◽  
Sh. A. Makhmudov

This work relates to the field of thermophysical parameters of refractory interstitial alloys. The isochoric heat capacity of cubic titanium carbide TiCx has been calculated within the Debye approximation in the carbon concentration  range x = 0.70–0.97 at room temperature (300 K) and at liquid nitrogen temperature (80 K) through the Debye temperature established on the basis of neutron diffraction analysis data. It has been found out that at room temperature with decrease of carbon concentration the heat capacity significantly increases from 29.40 J/mol·K to 34.20 J/mol·K, and at T = 80 K – from 3.08 J/mol·K to 8.20 J/mol·K. The work analyzes the literature data and gives the results of the evaluation of the high-temperature dependence of the heat capacity СV of the cubic titanium carbide TiC0.97 based on the data of neutron structural analysis. It has been proposed to amend in the Neumann–Kopp formula to describe the high-temperature dependence of the titanium carbide heat capacity. After the amendment, the Neumann–Kopp formula describes the results of well-known experiments on the high-temperature dependence of the heat capacity of the titanium carbide TiCx. The proposed formula takes into account the degree of thermal excitation (a quantized number) that increases in steps with increasing temperature.The results allow us to predict the thermodynamic characteristics of titanium carbide in the temperature range of 300–3000 K and can be useful for materials scientists.


Alloy Digest ◽  
1964 ◽  
Vol 13 (7) ◽  

Abstract Kentanium K138-A is a high temperature titanium carbide that greatly widens the scope of the engineering design where conditions of intermittent or continuous high temperatures in oxidizing atmospheres are combined with abrasion, and compressive or tensile loads. This datasheet provides information on composition, physical properties, hardness, elasticity, and compressive strength as well as fracture toughness, creep, and fatigue. It also includes information on machining and joining. Filing Code: Ti-40. Producer or source: Kennametal Inc..


1993 ◽  
Vol 320 ◽  
Author(s):  
S. P. Murarka

ABSTRACTSilicides have found application as high conductivity, high temperature, and corrosion resistance materials that form good electrical contacts to silicon and good low resistivity cladding on polysilicon films used as gate metal. Of various silicides investigated in past CoSi2 offers several advantages including lowest resistivity, self-aligned formation, low lattice mismatch with silicon, stability in presence of dopants and on SiO2, Si3N4, or Sioxynitrides, and reliability to process temperatures ≤900°C even when used in thicknesses as thin as 50-60 nm. Thus, CoSi2 has found an application in VLSI and ULSI. In this paper, the properties, formation and processing, reliability, and applicability of CoSi2 will be reviewed. It will be shown that CoSi2 is only silicide that offers properties and reliability for continued use in sub-0.25 pm VLSI and ULSI integrated circuits.


Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 942
Author(s):  
Razvan Pascu ◽  
Gheorghe Pristavu ◽  
Gheorghe Brezeanu ◽  
Florin Draghici ◽  
Philippe Godignon ◽  
...  

A SiC Schottky dual-diode temperature-sensing element, suitable for both complementary variation of VF with absolute temperature (CTAT) and differential proportional to absolute temperature (PTAT) sensors, is demonstrated over 60–700 K, currently the widest range reported. The structure’s layout places the two identical diodes in close, symmetrical proximity. A stable and high-barrier Schottky contact based on Ni, annealed at 750 °C, is used. XRD analysis evinced the even distribution of Ni2Si over the entire Schottky contact area. Forward measurements in the 60–700 K range indicate nearly identical characteristics for the dual-diodes, with only minor inhomogeneity. Our parallel diode (p-diode) model is used to parameterize experimental curves and evaluate sensing performances over this far-reaching domain. High sensitivity, upwards of 2.32 mV/K, is obtained, with satisfactory linearity (R2 reaching 99.80%) for the CTAT sensor, even down to 60 K. The PTAT differential version boasts increased linearity, up to 99.95%. The lower sensitivity is, in this case, compensated by using a high-performing, low-cost readout circuit, leading to a peak 14.91 mV/K, without influencing linearity.


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