scholarly journals Ohmic contacts to p-GaN Using Au/Ni-Mg-O Metallization

2010 ◽  
Vol 61 (6) ◽  
pp. 378-381 ◽  
Author(s):  
Jozef Liday ◽  
Peter Vogrinčič ◽  
Ivan Hotový ◽  
Alberta Bonanni ◽  
Helmut Sitter ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Contact Resistance ◽  
Carrier Concentration ◽  
Ohmic Contacts ◽  
Surface Region ◽  
Charge Carrier Concentration ◽  
Contact Structures ◽  
Low Concentration ◽  
P Type ◽  
Elemental Depth

Ohmic contacts to p-GaN Using Au/Ni-Mg-O Metallization Electrical characteristics and elemental depth profiles of ohmic contacts to p-GaN using Au/Ni-Mg-Ox metallization have been investigated. The objective was to examine the possibilities of increasing the charge carrier concentration in the surface region of GaN by adding Mg, thus of a p-type dopant into the Au/NiOx metallization structure. For this purpose, a Ni-Mg-Ox layer with a low concentration of Mg was deposited on p-GaN by dc reactive magnetron sputtering. The top Au layer was deposited in a similar way. The fabricated contact structures were annealed in N2. When the Ni-Mg layer in the Au/Ni-Mg-Ox/p-GaN structure was deposited in an atmosphere with a low concentration of oxygen (0.2 at%), the structure exhibited a low resistance ohmic nature. The contact resistance was lower than in the case of a Au/Ni-Ox/p-GaN structure without the Mg dopant in the metallic layer. An increase in the concentration of oxygen in the working atmosphere resulted in higher values of the contact resistance of the Au/Ni-Mg-Ox/p-GaN structure. In our opinion the ohmic nature of the contact structure is related to the existence of a metal/p-NiO/p-GaN scheme. The measured values of the contact resistance in the Au/Ni-Mg-Ox/p-GaN structure in comparison with the Au/Ni-Ox/p-GaN structure are caused by an increased charge carrier concentration in the surface region of p-GaN, which is a consequence of Mg diffusion from the Ni-Mg-Ox layer.

Enhanced Charge Carrier Concentration of SiC/CNT With N- and P-Type Doping Agents

2014 ◽  
Author(s):  
Kyle Edwards ◽  
Mujibur Khan ◽  
Rafael Quirino ◽  
Brenda Beckler ◽  
Saheem Absar
Keyword(s):  
Charge Carrier ◽  
Carrier Concentration ◽  
Raman Spectra ◽  
Structural Changes ◽  
Charge Carrier Concentration ◽  
X Ray ◽  
Seebeck Coefficients ◽  
P Type ◽  
Conductive Properties ◽  
Walled Carbon Nanotubes

Single-walled Carbon nanotubes (SWCNTs) have been shown to have excellent conductive properties. SWCNTs were dispersed in a SiC nanoparticle matrix to form a homogeneous mixture that is both mechanically durable and conductive. The SWCNT amount has been varied. SiC/SWCNT mixtures were then doped with various N- and P-type agents, and the resulting samples were analyzed by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD). Raman spectra of the samples were also measured for evidence of structural changes. Seebeck coefficients were measured for the doped samples demonstrating the change in thermoelectric properties. Shifts in the G peak (1580.6 cm-1) of the Raman spectra of the samples provides evidence of an increase in charge carrier concentration in the doped samples, correlating well with the Seebeck coefficient results.

scholarly journals Charge carrier concentration optimization of thermoelectric p-type half-Heusler compounds

APL Materials ◽  
2015 ◽  
Vol 3 (4) ◽  
pp. 041516 ◽  
Author(s):  
Elisabeth Rausch ◽  
Benjamin Balke ◽  
Torben Deschauer ◽  
Siham Ouardi ◽  
Claudia Felser
Keyword(s):  
Charge Carrier ◽  
Carrier Concentration ◽  
Charge Carrier Concentration ◽  
Heusler Compounds ◽  
P Type

Uniform Axial Charge Carrier Concentration in PVT-Grown p-Type 6H SiC by Non-Uniform Distribution of Boron in the Powder Source

2004 ◽  
Vol 457-460 ◽  
pp. 719-722
Author(s):  
Z.G. Herro ◽  
Matthias Bickermann ◽  
Boris M. Epelbaum ◽  
Roland Weingärtner ◽  
Ulrike Künecke ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Uniform Distribution ◽  
Carrier Concentration ◽  
Charge Carrier Concentration ◽  
Axial Charge ◽  
P Type

scholarly journals Электрофизические свойства нелегированных и легированных мышьяком эпитаксиальных слоев Hg-=SUB=-1-x-=/SUB=-Cd-=SUB=-x-=/SUB=-Te p-типа проводимости с x~0.4, выращенных методом MOCVD

2018 ◽  
Vol 52 (6) ◽  
pp. 554
Author(s):  
В.С. Евстигнеев ◽  
В.С. Варавин ◽  
А.В. Чилясов ◽  
В.Г. Ремесник ◽  
А.Н. Моисеев ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Carrier Concentration ◽  
Chemical Vapor ◽  
Charge Carrier Concentration ◽  
Recombination Mechanism ◽  
Temperature Dependences ◽  
Temperature Equilibrium ◽  
Activation Annealing ◽  
P Type ◽  
Fundamental Limitation

AbstractThe temperature dependences of the charge-carrier concentration and lifetime of minority carriers in undoped and arsenic-doped p -type Hg_1 – x Cd_ x Te epitaxial layers with x ≈ 0.4 grown by the MOCVD-IMP (metalorganic chemical vapor deposition–interdiffusion multilayer process) method are studied. It is shown that the temperature dependences of the charge-carrier concentration can be described by a model assuming the presence of one acceptor and one donor level. The ionization energies of acceptors in the undoped and arsenic-doped materials are 14 and 3.6 meV, respectively. It is established that the dominant recombination mechanism in the undoped layers is Shockley–Read–Hall recombination, and after low-temperature equilibrium annealing in mercury vapors (230°C, 24 h), the dominant mechanism is radiative recombination. The fundamental limitation of the lifetime in the arsenic-doped material is caused by the Auger-7 process. Activation annealing (360°C, 2 h) of the doped layers makes it possible to attain the 100% activation of arsenic.

Photoluminescence-Topography of the p-Type Doped SiC Wafers for Determination of Doping Inhomogeneity

2009 ◽  
Vol 615-617 ◽  
pp. 259-262
Author(s):  
Felix Oehlschläger ◽  
Sandrine Juillaguet ◽  
Hervé Peyre ◽  
Jean Camassel ◽  
Peter J. Wellmann
Keyword(s):  
Low Temperature ◽  
Charge Carrier ◽  
Carrier Concentration ◽  
Charge Carrier Concentration ◽  
Powerful Method ◽  
Carrier Distribution ◽  
Pl Intensity ◽  
P Type ◽  
Non Destructive

Photoluminescence(PL)-topography is a powerful method to determine the charge carrier concentration of SiC-wafers. The following work describes the development of a PL-topography method for the determination of charge carrier distribution in p-type SiC and shows the correlation of PL-Intensity and charge carrier concentration. With this setup it is possible to characterize wafers up to a size of 2” at room- and low temperature in a non-destructive way.

scholarly journals Au‐Free ohmic contacts and their impact on sub contact charge carrier concentration in AlGaN/GaN heterostructures

2021 ◽  
Author(s):  
Valentin Garbe ◽  
Alexander Schmid ◽  
Sarah Seidel ◽  
Barbara Abendroth ◽  
Hartmut Stöcker ◽  
...  
Keyword(s):  
Charge Carrier ◽  
Carrier Concentration ◽  
Ohmic Contacts ◽  
Charge Carrier Concentration

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.

The influence of composition on polymorphism, structure and charge carrier concentration in TL-2201.

1994 ◽  
Vol 235-240 ◽  
pp. 539-540
Author(s):  
C. Ström ◽  
S.-G. Eriksson ◽  
J. Albertsson ◽  
N. Winzek
Keyword(s):  
Charge Carrier ◽  
Carrier Concentration ◽  
Charge Carrier Concentration

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.

Sign in / Sign up

Export Citation Format

Share Document