Contact Resistance Study of Pt, Ni and Au on La0.7Sr0.3MnO3 (LSMO)/Si for Heterojunction Device Applications

2013 ◽  
Vol 1507 ◽  
Author(s):  
Rajashree Nori ◽  
Pankaj Kumbhare ◽  
Prashanth Paramahans ◽  
S. N. Kale ◽  
R. Pinto ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Mechanical Stability ◽  
Electrical Performance ◽  
Transfer Length ◽  
Si Substrates ◽  
Semiconductor Interfaces ◽  
Specific Contact ◽  
Device Applications ◽  
Heterojunction Device

ABSTRACTAchieving low resistance ohmic contacts for heavily doped devices is critical towards ensuring that contact resistance does not dominate the device performance. Here, we report contact resistance studies done on Pt/LSMO, Ni/LSMO and Au/LSMO metal-semiconductor interfaces. Phase-pure LSMO thin films deposited on n+ Si substrates were lithographically patterned and metallized to produce circular transfer length method (CTLM) based specific contact resistivity (ρc) and transfer length (LT) evaluation structures. Based on the electrical performance, interfacial reactivity and mechanical stability of the three metal junctions, the lowest ρc and LT metal for LSMO films on Si is identified for device applications.

Al/Ni And Al/Ti Ohmic Contact To P-type SiC Diffused Layer

2000 ◽  
Vol 640 ◽  
Author(s):  
Xaiobin Wang ◽  
Stanislav Soloviev ◽  
Ying Gao ◽  
G. Straty ◽  
Tangali Sudarshan ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Metal Contacts ◽  
Transfer Length ◽  
Type Layer ◽  
Transmission Line Method ◽  
Specific Contact ◽  
Background Doping ◽  
P Type

ABSTRACTOhmic contacts to p-type SiC were fabricated by depositing Al/Ni and Al/Ti followed by high temperature annealing. A p-type layer was fabricated by Al or B diffusion from vapor phase into both p-type and n-type substrates. The thickness of the diffused layer was about 0.1–0.2 μm with surface carrier concentration of about 1.0×1019cm−3. Metal contacts to a p-type substrate with a background doping concentration of 1.2×1018cm−3, without a diffusion layer, were also formed. The values of specific contact resistance obtained by Circular Transmission Line Method (CTLM) and Transfer Length Method (TLM) for the n-type substrate, and by Cox & Strack method for p-type substrate, respectively, varied from 1.3×10−4Ωcm2 to 8.8×10−3 Ωcm2. The results indicate that the specific contact resistance could be significantly reduced by creating a highly doped diffused surface layer.

Low Specific Contact Resistance to 3C-SiC Grown on (100) Si Substrates

2007 ◽  
Vol 556-557 ◽  
pp. 721-724 ◽  
Author(s):  
Anne Elisabeth Bazin ◽  
Thierry Chassagne ◽  
Jean François Michaud ◽  
André Leycuras ◽  
Marc Portail ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Transmission Line ◽  
Doping Level ◽  
Nitrogen Doping ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Silicon Doping ◽  
Transmission Line Model ◽  
Si Substrates ◽  
Specific Contact

In this work, ohmic contacts, formed by 100nm Ni layer RTA annealed or not, were investigated on 3C-SiC epilayers exhibiting different nitrogen doping levels. The epilayers were grown on (100) silicon. Doping level (N) and eventual dopant contamination (Al) were analyzed by C-V and/or SIMS. The specific contact resistance was determined by using Transmission Line Model (TLM) patterns for each condition (doping and annealing). Our results clearly evidence that very low specific contact resistance (~10-51.cm²) is obtained on highly doped 3C-SiC epilayers, enlightening the interest of both material and Ni contacts for future devices fabrication.

Ti/Al/Si Ohmic Contacts for both n-Type and p-Type 4H-SiC

2014 ◽  
Vol 778-780 ◽  
pp. 669-672 ◽  
Author(s):  
Hideto Tamaso ◽  
Shunsuke Yamada ◽  
Hiroyuki Kitabayashi ◽  
Taku Horii
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Contact Process ◽  
Oxide Semiconductor ◽  
Specific Contact Resistance ◽  
Transfer Length ◽  
Specific Contact ◽  
Effect Transistor ◽  
P Type ◽  
20 Nm

An ohmic contact process by using tri-layer materials for a source contact of a silicon carbide (SiC) metal oxide semiconductor field effect transistor (MOSFET) is proposed. The authors validate its extremely low contact resistance for both n-type and p-type SiC by a simple process. The characteristics of Ti/Al/Si ohmic contacts were measured by using the transfer length method (TLM). We examined the dependence of the contact resistance on the thickness of each layer of Ti/Al/Si. Then, it is found that Ti/Al/Si contacts with an appropriate thickness show excellent ohmic properties for both n-type and p-type SiC. N-type specific contact resistance (ρn) of 3.7 × 10-6 Ω cm2 and p-type specific contact resistance (ρp) of 1.7 × 10-4 Ω cm2 are obtained with Ti (20 nm) /Al (30 nm) /Si (30 nm).

Calculations of the Specific Resistance of Contacts to III-V Nitride Compounds

1995 ◽  
Vol 395 ◽  
Author(s):  
P.A. Barnes ◽  
X-J Zhang ◽  
M.L. Lovejoy ◽  
T.J. Drummond ◽  
H.P. Hjalmarson ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Barrier Height ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Semiconductor Interface ◽  
Barrier Heights ◽  
Effective Masses ◽  
Specific Contact ◽  
Correct Determination ◽  
Device Applications

ABSTRACTWe present calculations of the specific contact resistance for metals to GaN. Our calculations include a correct determination of the Fermi level taking into account the effect of the degenerate doping levels, required in creating tunneling ohmic contacts. Using a recently reported improved WKB approximation suitable in representing the depletion width at the metal-semiconductor interface, and a two band k-p model for the effective masses, specific contact resistance was determined as a function of doping concentration. The specific contact resistance was calculated using the best data available for barrier heights, effective masses and dielectric coefficients for GaN. Because the barrier height at the metal-semiconductor interface has a very large effect on the contact resistance and the available data is sketchy or uncertain, the effect of varying the barrier height on the calculated specific contact resistance was investigated. Further, since the III-V nitrides are being considered for high temperature device applications, the specific contact resistance was also determined as a function of temperature.

Pt/Ti Low Resistance Non-Alloyed Ohmic Contacts to InP-Based Photonic Devices

1989 ◽  
Vol 146 ◽  
Author(s):  
A. Katz ◽  
S. N. G. Chu ◽  
P. M. Thomas ◽  
W. C. Dautremont-Smith
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Metal Layer ◽  
Photonic Devices ◽  
Electrical Performance ◽  
Specific Contact Resistance ◽  
Low Resistance ◽  
Specific Contact ◽  
20 Nm ◽  
Resistance Value

ABSTRACTPt/ri low resistance non-alloyed ohmic contacts to p-InP-based contact layers in photonic devices, which were formed by rapid thermal processing (RTP), were studied. E-gun evaporated Pt/Ti metallization deposited onto 1.5· 1019 cm−3 Zn doped In0.53Ga0.47 As yielded the best electrical performance. These contacts were ohmic as deposited with a specific contact resistance value of 3.0 · 10−4 Ωcm2. RTP at higher temperatures led to decrease of the specific contact resistance to 3.4 · 10−8 Ωcm2 (0.08Ωmm) as a result of heating at 450°C for 30 sec. This heat treatment caused only a limited interfacial reaction (about 20 nm thick) between the Ti and the InGaAs, resulted in a thermally stable contact and induced tensile stress of 5.6 · 109 dyne · cm−2 at the metal layer but without degrading the adhesion. Heating at temperatures higher than 500°C resulted in an extensive interaction and degradation of the contact.

Improvement of the Specific Contact Resistance on P-Type 4H-SiC by Using a Highly P-Typed Doped 4H-SiC Layer Selectively Grown by VLS Transport

2014 ◽  
Vol 806 ◽  
pp. 57-60
Author(s):  
Nicolas Thierry-Jebali ◽  
Arthur Vo-Ha ◽  
Davy Carole ◽  
Mihai Lazar ◽  
Gabriel Ferro ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Schottky Barrier Height ◽  
Annealing Temperature ◽  
Process Condition ◽  
Specific Contact Resistance ◽  
High Doping Level ◽  
Annealing Temperatures ◽  
Specific Contact ◽  
P Type

This work reports on the improvement of ohmic contacts made on heavily p-type doped 4H-SiC epitaxial layer selectively grown by Vapor-Liquid-Solid (VLS) transport. Even before any annealing process, the contact is ohmic. This behavior can be explained by the high doping level of the VLS layer (Al concentration > 1020 cm-3) as characterized by SIMS profiling. Upon variation of annealing temperatures, a minimum value of the Specific Contact Resistance (SCR) down to 1.3x10-6 Ω.cm2 has been obtained for both 500 °C and 800 °C annealing temperature. However, a large variation of the SCR was observed for a same process condition. This variation is mainly attributed to a variation of the Schottky Barrier Height.

Current Transport in Ti/Al/Ni/Au Ohmic Contacts to GaN and AlGaN

2007 ◽  
Vol 556-557 ◽  
pp. 1027-1030 ◽  
Author(s):  
Ferdinando Iucolano ◽  
Fabrizio Roccaforte ◽  
Filippo Giannazzo ◽  
A. Alberti ◽  
Vito Raineri
Keyword(s):  
Contact Resistance ◽  
Field Emission ◽  
Ohmic Contacts ◽  
Theoretical Models ◽  
Specific Contact Resistance ◽  
Strong Increase ◽  
Current Transport ◽  
Electrical Characteristics ◽  
Structural And Electrical Properties ◽  
Specific Contact

In this work, the structural and electrical properties of Ti/Al/Ni/Au contacts on n-type Gallium Nitride were studied. An ohmic behaviour was observed after annealing above 700°C. The structural analysis showed the formation of an interfacial TiN layer and different phases in the reacted layer (AlNi, AlAu4, Al2Au) upon annealing. The temperature dependence of the specific contact resistance demonstrated that the current transport occurs through thermoionic field emission in the contacts annealed at 600°C, and field emission after annealing at higher temperatures. By fitting the data with theoretical models, a reduction of the Schottky barrier from 1.21eV after annealing at 600°C to 0.81eV at 800°C was demonstrated, together with a strong increase of the carrier concentration at the interface. The reduction of the contact resistance upon annealing was discussed by correlating the structural and electrical characteristics of the contacts.

Modelling Geometrical Effects of Parasitic and Contact Resistance of FET Devices

1996 ◽  
Vol 427 ◽  
Author(s):  
Geoffrey K. Reeves ◽  
H. Barry Harrison ◽  
Patrick W. Leech
Keyword(s):  
Contact Resistance ◽  
Material Properties ◽  
Ohmic Contacts ◽  
Difficult Problem ◽  
Specific Contact Resistance ◽  
Metal Silicide ◽  
Transmission Line Model ◽  
Specific Contact ◽  
Geometrical Effects ◽  
Contact Parameters

AbstractThe continual trend in decreasing the dimensions of semiconductor devices results in a number of technological problems. One of the more significant of these is the increase in contact resistance, Rc. In order to understand and counteract this increase, Rc needs to be quantitatively modelled as a function of the geometrical and material properties of the contact. However the use of multiple semiconductor layers for ohmic contacts makes the modelling and calculation of Rc a more difficult problem. In this paper, a Tri-Layer Transmission Line Model (TLTLM) is used to analyse a MOSFET ohmic contact and gatedrain region. A quantitative assessment of the influence on Rc of important contact parameters such as the metal-silicide specific contact resistance, the silicide-silicon specific contact resistance and the gate-drain length can thus be made. The paper further describes some of the problems that may be encountered in defining Rc when the dimensions of certain types of contact found in planar devices decrease.

Ohmic Contacts to p-Type InGaAs/InP with a Graded Bandgap Heterobarrier

1993 ◽  
Vol 318 ◽  
Author(s):  
Patrick W. Leech ◽  
Geoffrey K. Reeves
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Rutherford Backscattering Spectrometry ◽  
Specific Contact Resistance ◽  
Superlattice Structure ◽  
Specific Contact ◽  
P Type ◽  
Metal Layers ◽  
Anneal Temperature ◽  
Graded Bandgap

ABSTRACTOhmic contacts to p-type InP with an In0.47Ga0.53As buffer layer and an interposed superlattice of 50 Å In0.47Ga0.53As/ 50 Å InP have been investigated. Initial studies of contacts to In0.47Ga0.53As/ InP without the superlattice structure have shown that Pd/Zn/Pd/Au metallization produced a lower specific contact resistance (pc = 1.1 × 10−4 Ω cm2) than Pd/Ge/Au, and over a wider range of anneal temperature than Au/Zn/Au. The incorporation of the superlattice in the p-In0.47Ga0.53As/ InP structure resulted in Pd/Zn/Pd/Au contacts with pc of 3.2 × 10−5 Ω cm2 as-deposited and 7.5 × 10−6 Ω.cm2 after a 500 °C anneal. The presence of Pd/Zn in the metallization was shown as important in reducing pc. Significant intermixing of the metal layers and In0.47Ga0.53As occured at ≥ 350 °C, as revealed by Rutherford backscattering spectrometry.

Ni-Al-Ti Ohmic Contacts with Preserved Form Factor and Few 10- 4 Ωcm2 Specific Resistance on 0.1-1 Ωcm p-Type 4H-SiC

2018 ◽  
Vol 924 ◽  
pp. 385-388 ◽  
Author(s):  
Roberta Nipoti ◽  
Maurizio Puzzanghera ◽  
Maria Concetta Canino ◽  
Giovanna Sozzi ◽  
Paolo Fedeli
Keyword(s):  
Form Factor ◽  
Contact Resistance ◽  
Contact Area ◽  
Room Temperature ◽  
Ohmic Contacts ◽  
Specific Resistance ◽  
Thickness Ratio ◽  
Specific Contact Resistance ◽  
Specific Contact ◽  
P Type

This study shows that a thin Ni film on Al/Ti/4H-SiC metal pads allows to preserve the pad form factor during a 1000 °C/2 min treatment, provided that the Al and Ti film thicknesses are sufficiently thin. Moreover, by reducing the Al to Ti thickness ratio, droplet formation in the contact area is avoided and a mirror-like appearance is obtained. This optimal contact morphology corresponds to a specific contact resistance of few 10-4Ωcm2at room temperature on p-type 4H-SiC with resistivity in the range 0.1 – 1 Ωcm.

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