Ohmic Contacts to n-Type 6H-SiC Without Post-Annealing

1996 ◽  
Vol 423 ◽  
Author(s):  
Tokuyuki Teraji ◽  
Shiro Hara ◽  
Hideyo Okushi ◽  
Koji Kajimura
Keyword(s):  
Fermi Level ◽  
Schottky Barrier ◽  
Epitaxial Layer ◽  
Ohmic Contacts ◽  
Thermionic Emission ◽  
Contact Resistivity ◽  
Current Transport ◽  
Flat Surfaces ◽  
Barrier Heights ◽  
Post Annealing

AbstractWe formed titanium Ohmic contacts to n-type 6H-SiC epitaxial layer byreducing the Schottky barrier heights. The barrier heights were reduced enough toform the Ohmic contacts by releasing the Fermi level from pinning through makingatomically-flat surfaces. The current transport by thermionic emission wasdominant at the Ti/SiC interface. Since the Ti contacts were formed without postannealing,surfaces of the Ti electrodes were flat and homogeneous maintaining asdepositedstructures. Contact resistivity was (6±1)×10−3 Ω-cm2, which is comparableto that of the annealed Ni contact formed on the SiC epitaxial layer with the samecarrier concentration.

Current Transport in Low-Resistance Metal-InP Contacts

1993 ◽  
Vol 300 ◽  
Author(s):  
Thomas Clausen ◽  
Otto Leistiko
Keyword(s):  
Schottky Barrier ◽  
Ohmic Contact ◽  
Ohmic Contacts ◽  
Current Flow ◽  
Thermionic Emission ◽  
Transport Processes ◽  
Potential Difference ◽  
Current Transport ◽  
Diffusion Limited ◽  
P Type

ABSTRACTThe limiting transport processes for current flow across metal-semiconductor (MS) ohmic contacts to n- and p-type InP have been investigated for Au-based metallizations containing the doping elements Germanium and Zinc. It has been found that the Schottky barrier is lowered and in some cases vanishes during annealing. The current flow for an optimal ohmic contact is diffusion limited by a Fermi potential difference between the alloyed metallization and the bulk InP. For non-optimal ohmic contacts the current flow is also limited by thermionic emission across a low effective Schottky barrier.

Fermi-level pinning and Schottky barrier heights on epitaxially grown fully strained and partially relaxed n-type Si1−xGex layers

1999 ◽  
Vol 86 (12) ◽  
pp. 6890-6894 ◽  
Author(s):  
M. Mamor ◽  
O. Nur ◽  
M. Karlsteen ◽  
M. Willander ◽  
F. D. Auret
Keyword(s):  
Fermi Level ◽  
Schottky Barrier ◽  
Fermi Level Pinning ◽  
Barrier Heights

TEMPERATURE DEPENDENCE OF ELECTRICAL CHARACTERISTICS OF Cr/p–Si(100) SCHOTTKY BARRIER DIODES

2008 ◽  
Vol 22 (14) ◽  
pp. 2309-2319 ◽  
Author(s):  
K. ERTURK ◽  
M. C. HACIISMAILOGLU ◽  
Y. BEKTORE ◽  
M. AHMETOGLU
Keyword(s):  
Temperature Dependence ◽  
Schottky Barrier ◽  
Barrier Height ◽  
Thermionic Emission ◽  
Electrical Characteristics ◽  
Schottky Barrier Diodes ◽  
Semiconductor Interface ◽  
Linear Portion ◽  
Barrier Heights ◽  
P Type

The electrical characteristics of Cr / p – Si (100) Schottky barrier diodes have been measured in the temperature range of 100–300 K. The I-V analysis based on thermionic emission (TE) theory has revealed an abnormal decrease of apparent barrier height and increase of ideality factor at low temperature. The conventional Richardson plot exhibits non-linearity below 200 K with the linear portion corresponding to activation energy 0.304 eV and Richardson constant (A*) value of 5.41×10-3 Acm-2 K -2 is determined from the intercept at the ordinate of this experimental plot, which is much lower than the known value of 32 Acm-2 K -2 for p-type Si . It is demonstrated that these anomalies result due to the barrier height inhomogeneities prevailing at the metal-semiconductor interface. Hence, it has been concluded that the temperature dependence of the I-V characteristics of the Cr/p – Si Schottky barrier diode can be successfully explained on the basis of TE mechanism with a Gaussian distribution of the barrier heights. Furthermore, the value of the Richardson constant found is much closer than that obtained without considering the inhomogeneous barrier heights.

Analysis of temperature-dependent Schottky barrier parameters of Cu–Au Schottky contacts to n-InP

2012 ◽  
Vol 90 (1) ◽  
pp. 73-81 ◽  
Author(s):  
V. Lakshmi Devi ◽  
I. Jyothi ◽  
V. Rajagopal Reddy
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Gaussian Distribution ◽  
Ideality Factor ◽  
Thermionic Emission ◽  
Schottky Contacts ◽  
Temperature Dependent ◽  
Semiconductor Interface ◽  
Zero Bias ◽  
Barrier Heights

In this work, we have investigated the electrical characteristics of Au–Cu–n-InP Schottky contacts by current–voltage (I–V) and capacitance–voltage (C–V) measurements in the temperature range 260–420 K in steps of 20 K. The diode parameters, such as the ideality factor, n, and zero-bias barrier height, Φb0, have been found to be strongly temperature dependent. It has been found that the zero-bias barrier height, Φb0(I–V), increases and the ideality factor, n, decreases with an increase in temperature. The forward I–V characteristics are analyzed on the basis of standard thermionic emission (TE) theory and the assumption of gaussian distribution of barrier heights, due to barrier inhomogeneities that prevail at the metal–semiconductor interface. The zero-bias barrier height Φb0 versus 1/2kT plot has been drawn to obtain the evidence of a gaussian distribution of the barrier heights. The corresponding values are Φb0 = 1.16 eV and σ0 = 159 meV for the mean barrier height and standard deviation, respectively. The modified Richardson plot has given mean barrier height, Φb0, and Richardson constant, A**, as 1.15 eV and 7.34 Acm−2K−2, respectively, which is close to the theoretical value of 9.4 Acm−2K−2. Barrier heights obtained from C–V measurements are higher than those obtained from I–V measurements. This inconsistency between Schottky barrier heights (SBHs) obtained from I–V and C–V measurements was also interpreted. The temperature dependence of the I–V characteristics of the Au–Cu–n-InP Schottky diode has been explained on the basis of TE mechanism with gaussian distribution of the SBHs.

Performance of Pt-based Low Schottky Barrier Silicide Contacts on Weakly Doped Silicon

2003 ◽  
Vol 765 ◽  
Author(s):  
Guilhem Larrieu ◽  
Emmanuel Dubois ◽  
Xavier Wallart
Keyword(s):  
Schottky Barrier ◽  
Cross Sections ◽  
Ohmic Contacts ◽  
Thermionic Emission ◽  
Current Drive ◽  
Silicon On Insulator ◽  
Grand Challenge ◽  
Electrical Measurements ◽  
Temperature Dependent ◽  
Current Voltage

AbstractOne of the grand challenge imposed by CMOS down-scaling is the optimisation of the source/drain (S/D) architecture, e.g., dopant activation above solid solubility, steep dopant profiling, low silicide specific contact resistivity. Recently, the concept of very low Schottky barrier S/D MOSFET has emerged as a possible alternative to conventional architecture using highly doped S/D and midgap silicide ohmic contacts. For p-MOSFETs integration, platinum silicide is an excellent candidate because of its very low barrier to holes. This enables the use of a weakly doped substrate that inherently solves the aforementioned challenges due to highly doped S/D. This paper proposes a detailed study of the platinum silicidation reaction obtained by rapid thermal annealing. The analysis is based on X-ray photoemission spectroscopy (XPS), transmission electron miscrocopy (TEM) and low temperature-dependent current-voltage measurements. Using XPS analysis, it is shown that: i) an initial silicide layer is formed at room temperature, ii) three stable phases Pt, Pt2Si, PtSi can not coexist providing that iii) the annealing ambience is strictly controlled to avoid the formation of a SiO2 barrier due to oxygen penetration into the platinum overlayer. Starting from an initial 15 nm thick Pt layer subsequently annealing at 300°C, TEM cross-sections reveal that homogeneous 32 nm PtSi layers with a uniform grain size distribution are formed. Finally, current-voltage characteristics have been measured on a special test structure that accounts for the lateral disposition of S/D regions in a typical MOSFET architecture. It consists in two back-to-back Schottky contacts separated by a narrow silicon gap both on bulk silicon and Silicon-On-Insulator (SOI) substrates. Based on temperature-dependent electrical measurements (Arrhenius plot), it is shown that field emission is involved in the current transport mechanism, in addition to thermionic emission. An excellent current drive performance of 220 μA per micron width has been obtained for a 45 nm silicon gap on a 10 nm thick SOI substrate.

Electrical Properties of Epitaxial Silicide-Silicon Interfaces

1985 ◽  
Vol 54 ◽  
Author(s):  
R. T. Tung ◽  
A. F. J. Levi ◽  
J. M. Gibson ◽  
K. K. Ng ◽  
A. Chantre
Keyword(s):  
Fermi Level ◽  
Single Crystal ◽  
Schottky Barrier ◽  
Surface Region ◽  
Ideal Behavior ◽  
Near Surface ◽  
Barrier Heights ◽  
Transmission Electron ◽  
Current Voltage ◽  
P Type

ABSTRACTThe Schottky barrier heights of single crystal NiSi2 layers on Si(111) have been studied by current-voltage, capacitance-voltage and activation energy techniques. Near ideal behavior is found for Schottky barriers grown on substrates cleaned at ∼820°C in ultrahigh vacuum. The Fermi level positions at the interfaces of single crystal type A and type B NiSi2 are shown to differ by ∼0.14 eV. Transmission electron microscopy demonstrated the epitaxial perfection of these suicide layers. At a cleaning temperature of 1050° C, the near surface region of lightly doped n-type Si was converted to p-type. The presence of a p-n junction was directly revealed by spreading resistance measurements and resulted in a high apparent Schottky barrier height (≥0.75 eV) which no longer bears immediate relationship to the interface Fermi level position.

Gaussian distribution of Schottky barrier heights on SnO2 nanowires

2011 ◽  
Vol 1406 ◽  
Author(s):  
Cleber A. Amorim ◽  
Olivia M. Berengue ◽  
Luana Araújo ◽  
Edson R. Leite ◽  
Adenilson J. Chiquito
Keyword(s):  
Schottky Barrier ◽  
Barrier Height ◽  
Ideality Factor ◽  
Schottky Barrier Height ◽  
Series Resistance ◽  
Small Deviation ◽  
Thermionic Emission ◽  
Barrier Heights ◽  
Sno2 Nanowires ◽  
Different Temperatures

ABSTRACTIn this work, we studied metal/SnO2 junctions using transport properties. Parameters such as barrier height, ideality factor and series resistance were estimated at different temperatures. Schottky barrier height showed a small deviation of the theoretical value mainly because the barrier was considered fixed as described by ideal thermionic emission-diffusion model. These deviations have been explained by assuming the presence of barrier height inhomogeneities. Such assumption can also explain the high ideality factor as well as the Schottky barrier height and ideality factor dependence on temperature.

Fermi Level Pinning in Au Schottky Barriers on InGaP and InGaAlP

1994 ◽  
Vol 340 ◽  
Author(s):  
V.A. Gorbyley ◽  
A.A. Chelniy ◽  
A.A. Chekalin ◽  
A.Y. Polyakov ◽  
S.J. Pearon ◽  
...  
Keyword(s):  
Quantum Well ◽  
Fermi Level ◽  
Plasma Treatment ◽  
Schottky Barrier ◽  
Hydrogen Plasma ◽  
Schottky Diodes ◽  
Schottky Barriers ◽  
Quantum Well Structures ◽  
Fermi Level Pinning ◽  
Barrier Heights

ABSTRACTIt is shown that in Au/InGaP and Au/InGaAlP Schottky diodes the Fermi level is pinned by metal-deposition-induced midgap states. Hydrogen plasma treatment of such diodes greatly improves the reverse currents. The measured Schottky barrier heights seem to correlate with the valence band offsets measured by DLTS on quantum well structures.

scholarly journals Rectifying Characteristics of Thermally Treated Mo/SiC Schottky Contact

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 388
Author(s):  
Jeongsoo Hong ◽  
Ki Hyun Kim ◽  
Kyung Hwan Kim
Keyword(s):  
Schottky Barrier ◽  
Transport Mechanism ◽  
Characteristic Curve ◽  
Schottky Contact ◽  
Current Transport ◽  
Carrier Injection ◽  
Voltage Measurement ◽  
Barrier Heights ◽  
Current Transport Mechanism ◽  
Current Voltage

The rectifying characteristics of a Mo/SiC Schottky contact fabricated by facing targets sputtering system were investigated through current–voltage measurement. The Schottky diode parameters were extracted from the forward current–voltage characteristic curve by the Cheung and Cheung method and the Norde method. The as-deposited Mo/SiC Schottky contacts possessed Schottky barrier heights of 1.17 and 1.22 eV, respectively. The Schottky barrier heights of the diodes were decreased to 1.01 and 0.91 eV after annealing at 400 °C for 30 min. The ideality factor was increased from 1.14 and 1.08 to 1.51 and 1.41, respectively. This implies the presence of non-ideal behaviors due to a current transport mechanism other than ideal thermionic emission, and the non-ideal behaviors increased as a result of excessive thermal annealing. In contrast, only a negligible change was observed in the crystallographic characteristics. This result suggests that the reason for the deviation from the ideal rectifying characteristics of the Mo/SiC Schottky contact through the annealing process was the variation in the current transport mechanism, including recombination, tunneling, and/or minority carrier injection.

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