The role of AlGaN/GaN heterostructure properties in barrier height variation of Au-free ohmic contacts

2021 ◽  
Vol 129 ◽  
pp. 105806
Author(s):  
Aurore Constant ◽  
Elke Claeys ◽  
Joris Baele ◽  
Peter Coppens ◽  
Freddy De Pestel
Keyword(s):  
Barrier Height ◽  
Ohmic Contacts ◽  
Height Variation ◽  
Gan Heterostructure

The role of Ru in improving Schottky and ohmic contacts to InP

Vacuum ◽  
1995 ◽  
Vol 46 (8-10) ◽  
pp. 893-897 ◽  
Author(s):  
WO Barnard ◽  
G Myburg ◽  
FD Auret ◽  
JH Potgieter ◽  
P Ressel ◽  
...  
Keyword(s):  
Ohmic Contacts

scholarly journals Исследование формирования омических контактов Au/Mo/Ti с пониженным сопротивлением к эпитаксиальным слоям алмаза p-типа

2019 ◽  
Vol 89 (12) ◽  
pp. 1923
Author(s):  
М.Н. Дроздов ◽  
Е.В. Демидов ◽  
Ю.Н. Дроздов ◽  
С.А. Краев ◽  
В.И. Шашкин ◽  
...  
Keyword(s):  
Titanium Carbide ◽  
Contact Resistance ◽  
Ohmic Contacts ◽  
Contact Region ◽  
Effective Diffusion ◽  
Protective Properties ◽  
High Adhesion ◽  
Heavy Doping ◽  
P Type

The formation of ohmic Au/Mo/Ti contacts to epitaxial p-type diamond films is studied. The effect of annealing on the electrical and structural properties of contacts has been investigated. It was shown that during rapid thermal annealing, the outer layer of gold protects the contact system from oxidation up to a temperature of 850°C, unlike the simplified Au/Ti system, which is more common in modern works. In Au/Ti structures without a Mo layer after high-temperature annealing, effective diffusion of titanium into the gold layer occurs, which reduces its protective properties and accelerates the diffusion of oxygen to the boundary with the diamond. Oxidation of the Ti/C contact region blocks the formation of a conductive layer of titanium carbide with high adhesion at the border with diamond. The role of various factors in reducing the contact resistance is compared: annealing for the formation of titanium carbide, heavy doping of diamond with boron atoms, and crystalline perfection of epitaxial diamond substrates. For doped epitaxial films grown on single-sector quality substrates, non-annealed ohmic contacts with a record contact resistance of 4•10<-7> Ω•cm<2> were obtained.

Current Transport Mechanisms in Au-Free Metallizations for CMOS Compatible GaN HEMT Technology

2020 ◽  
Vol 1004 ◽  
pp. 725-730
Author(s):  
Fabrizio Roccaforte ◽  
Monia Spera ◽  
Salvatore Di Franco ◽  
Raffaella Lo Nigro ◽  
Patrick Fiorenza ◽  
...  
Keyword(s):  
Barrier Height ◽  
Ohmic Contacts ◽  
Specific Contact Resistance ◽  
Current Transport ◽  
Large Area ◽  
Si Substrates ◽  
Ohmic Behavior ◽  
Specific Contact ◽  
Thermionic Field Emission

Gallium nitride (GaN) and its AlGaN/GaN heterostructures grown on large area Si substrates are promising systems to fabricate power devices inside the existing Si CMOS lines. For this purpose, however, Au-free metallizations are required to avoid cross contaminations. In this paper, the mechanisms of current transport in Au-free metallization on AlGaN/GaN heterostructures are studied, with a focus on non-recessed Ti/Al/Ti Ohmic contacts. In particular, an Ohmic behavior of Ti/Al/Ti stacks was observed after an annealing at moderate temperature (600°C). The values of the specific contact resistance ρc decreased from 1.6×104 Ω.cm2 to 7×105 Ω.cm2 with increasing the annealing time from 60 to 180s. The temperature dependence of ρc indicated that the current flow is ruled by a thermionic field emission (TFE) mechanism, with barrier height values of 0.58 eV and 0.52 eV, respectively. Finally, preliminary results on the forward and reverse bias characterization of Au-free tungsten carbide (WC) Schottky contacts are presented. This contact exhibited a barrier height value of 0.82 eV.

Inhomogeneous ohmic contacts: Barrier height and contact area determination

2012 ◽  
Vol 101 (5) ◽  
pp. 051604 ◽  
Author(s):  
Yang Li ◽  
Wei Long ◽  
Raymond T. Tung
Keyword(s):  
Barrier Height ◽  
Contact Area ◽  
Ohmic Contacts ◽  
Area Determination

Metal - Gan Contact Technology

1998 ◽  
Vol 514 ◽  
Author(s):  
S. S. Lau
Keyword(s):  
Barrier Height ◽  
Carrier Transport ◽  
Ohmic Contacts ◽  
Accurate Determination ◽  
Surface Cleaning ◽  
Metal Contacts ◽  
Metal Thin Films ◽  
Ohmic Behavior ◽  
Metal Silicides

ABSTRACTIn this talk, we summarize the experimental results obtained on metal-GaN interactions in our laboratory. These interactions include the epitaxial growth of metal thin films on chemically cleaned GaN surfaces, metal silicides for Schottky contacts and metallization schemes for ohmic contacts. We found that many fcc and hcp metals can grow epitaxially on (0001) GaN surfaces at room temperature without in-situ surface cleaning. Metal silicide contacts (such as PtSi) may be more suitable for high temperature applications than elemental contacts, due to the thermal stability of silicides. The intrinsic mechanisms for ohmic behavior for various metal contacts are not well understood at present. More consistent barrier height values measured experimentally can shed light on this issue. Due to the defective nature of the GaN layers, carrier transport across the metal/GaN interface can be due to a number of transport mechanisms, thus making accurate determination of the barrier height difficult. In spite of these difficulties, it seems possible to draw certain general conclusions on the electrical behavior of metal contacts on n-GaN.

The Role of Ni in the Formation of Low Resistance Ni–Ge–Au Ohmic Contacts to n+ GaAs Heterostructures

1999 ◽  
Vol 14 (4) ◽  
pp. 1261-1271 ◽  
Author(s):  
Nancy E. Lumpkin ◽  
Gregory R. Lumpkin ◽  
Mark G. Blackford
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Wetting Agent ◽  
Dopant Distribution ◽  
Low Resistance ◽  
Ni Content ◽  
Alloy Microstructure

Nickel is a commonly used wetting agent in alloyed Au–Ge ohmic contacts to n-GaAs, resulting in uniformity improvements to the morphology and contact resistance. In order to study the role of Ni in Ni–Ge–Au alloys, we have fabricated samples with varying Ni content and characterized them using electron microbeam techniques. Our data indicate the amount of Ni in the alloy affects the microstructure and composition, the morphology of the metal/GaAs interface, and the amount of GaAs consumed during the alloy reaction. Also, the dopant distribution into the GaAs is heterogeneous depending on the alloy microstructure.

Sign in / Sign up

Export Citation Format

Share Document