scholarly journals Nonalloyed ohmic contacts in AlGaN/GaN HEMTs by ion implantation with reduced activation annealing temperature

2006 ◽  
Vol 27 (4) ◽  
pp. 205-207 ◽  
Author(s):  
F. Recht ◽  
L. McCarthy ◽  
S. Rajan ◽  
A. Chakraborty ◽  
C. Poblenz ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Ohmic Contacts ◽  
Annealing Temperature ◽  
Gan Hemts ◽  
Activation Annealing

A Comparative Optimization of Electrical Properties and Surface Morphology of Ti/Al/Ta/Au Ohmic Contacts in AlGaN/GaN HEMTs on Si(111), Sapphire, 4H-SiC Substrates

2012 ◽  
Vol 538-541 ◽  
pp. 2207-2210
Author(s):  
Sung Jin Cho ◽  
Cong Wang ◽  
Nam Young Kim
Keyword(s):  
Surface Morphology ◽  
Sapphire Substrate ◽  
Ohmic Contact ◽  
Annealing Time ◽  
Ohmic Contacts ◽  
Annealing Temperature ◽  
Contact Process ◽  
Annealing Temperatures ◽  
Ohmic Resistance ◽  
Gan Hemts

In the process of characterizing AlGaN/GaN HEMTs on Si (111), Sapphire, 4H-SiC substrates, various Rapid Thermal Annealing (RTA) conditions for the Ti/Al/Ta/Au ohmic contact process and the resulting surface analysis have been investigated. In order to achieve a low ohmic contact resistance (RC) and a high quality surface morphology, we tested seven steps (800 °C to 920 °C) annealing temperatures and two steps (15, 30 sec) annealing times. According to these annealing temperatures and times, the optimal ohmic resistance of 3.62 × 10-6 Ohm • cm2 on Si(111) substrate, 9.44 × 10-6 Ohm • cm2 on Sapphire substrate and 1.24 × 10-6 Ohm • cm2 on 4H-SiC substrate are obtained at an annealing temperature of 850 °C and an annealing time of 30 sec, 800 °C and an annealing time of 30 sec and 900 °C and an annealing time of 30 sec, respectively. The surface morphologies of the ohmic contact metallization at different annealing temperatures are measured using an Atomic Force Microscope (AFM). AFM morphology Root Mean Square (RMS) level determines the relationship of the annealing temperature and the annealing time for all of the samples. According to these annealing temperatures and times, the optimal ohmic surface RMS roughness of 13.4 nm on Si(111) substrate, 3.8 nm on Sapphire substrate and 2.9 nm on 4H-SiC substrate are obtained at an annealing temperature of 850 °C and an annealing time of 30 sec, 800 °C and an annealing time of 30 sec and 900 °C and an annealing time of 30 sec, respectively.

Crystalline Recovery after Activation Annealing of Al Implanted 4H-SiC

2008 ◽  
Vol 600-603 ◽  
pp. 585-590
Author(s):  
Ryo Hattori ◽  
Tomokatsu Watanabe ◽  
T. Mitani ◽  
Hiroaki Sumitani ◽  
Tatsuo Oomori
Keyword(s):  
Ion Implantation ◽  
Time Dependence ◽  
Annealing Time ◽  
Annealing Temperature ◽  
Annealing Process ◽  
Recovery Mechanism ◽  
Poly Type ◽  
Scattering Centers ◽  
Activation Annealing ◽  
Type Recovery

Crystalline recovery mechanism in the activation annealing process of Al implanted 4H-SiC crystals were experimentally investigated. Annealing temperature and annealing time dependence of acceptor activation and activated hole’s behavior were examined. Poly-type recovery from the implantation induced lattice disordering during the annealing was investigated. The existence of meta-stable crystalline states for acceptor activation, and related scattering centers due to annealing is reported To achieve 100% acceptor activation and to reduce strain after ion implantation, annealing at 2000°C for 10 min. was required.

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.

Optical Waveguide Formation by Ion Implantation of Ti or Ag

1988 ◽  
Vol 100 ◽  
Author(s):  
D. B. Poker ◽  
D. K. Thomas
Keyword(s):  
Ion Implantation ◽  
Concentration Profile ◽  
Optical Waveguides ◽  
Annealing Temperature ◽  
Solid Phase ◽  
Effective Means ◽  
Complete Removal ◽  
Solid Phase Epitaxy ◽  
Annealing Temperatures ◽  
Residual Damage

ABSTRACTIon implantation of Ti into LINbO3 has been shown to be an effective means of producing optical waveguides, while maintaining better control over the resulting concentration profile of the dopant than can be achieved by in-diffusion. While undoped, amorphous LiNbO3 can be regrown by solid-phase epitaxy at 400°C with a regrowth velocity of 250 Å/min, the higher concentrations of Ti required to form a waveguide (∼10%) slow the regrowth considerably, so that temperatures approaching 800°C are used. Complete removal of residual damage requires annealing temperatures of 1000°C, not significantly lower than those used with in-diffusion. Solid phase epitaxy of Agimplanted LiNbO3, however, occurs at much lower temperatures. The regrowth is completed at 400°C, and annealing of all residual damage occurs at or below 800°C. Furthermore, the regrowth rate is independent of Ag concentration up to the highest dose implanted to date, 1 × 1017 Ag/cm2. The usefulness of Ag implantation for the formation of optical waveguides is limited, however, by the higher mobility of Ag at the annealing temperature, compared to Ti.

Raman Spectra of Ion Implanted Graphite

1981 ◽  
Vol 7 ◽  
Author(s):  
B.S. Elman ◽  
H. Mazurek ◽  
M.S. Dresselhaus ◽  
G. Dresselhaus
Keyword(s):  
Raman Spectroscopy ◽  
Ion Implantation ◽  
Raman Spectra ◽  
Annealing Temperature ◽  
Annealing Process ◽  
Lattice Order ◽  
Annealing Temperatures ◽  
High Fluences ◽  
Lattice Damage ◽  
The Way

ABSTRACTRaman spectroscopy is used in a variety of ways to monitor different aspects of the lattice damage caused by ion implantation into graphite. Particular attention is given to the use of Raman spectroscopy to monitor the restoration of lattice order by the annealing process, which depends critically on the annealing temperature and on the extent of the original lattice damage. At low fluences the highly disordered region is localized in the implanted region and relatively low annealing temperatures are required, compared with the implantation at high fluences where the highly disordered region extends all the way to the surface. At high fluences, annealing temperatures comparable to those required for the graphitization of carbons are necessary to fully restore lattice order.

On a two-layer Si3N4/SiO2 dielectric mask for low-resistance ohmic contacts to AlGaN/GaN HEMTs

2016 ◽  
Vol 50 (8) ◽  
pp. 1117-1121 ◽  
Author(s):  
S. S. Arutyunyan ◽  
A. Yu. Pavlov ◽  
B. Yu. Pavlov ◽  
K. N. Tomosh ◽  
Yu. V. Fedorov
Keyword(s):  
Ohmic Contacts ◽  
Low Resistance ◽  
Gan Hemts

Characterization of Ion Implantation Damage in Capless Annealed GaAs

1983 ◽  
Vol 27 ◽  
Author(s):  
H. Kanber ◽  
M. Feng ◽  
J. M. Whelan
Keyword(s):  
Ion Implantation ◽  
Annealing Temperature ◽  
Rutherford Backscattering ◽  
Buffer Layers ◽  
Electrical Activation ◽  
Controlled Atmosphere ◽  
Damage Characteristics ◽  
Implantation Damage ◽  
Implantation Process

ABSTRACTArsenic and argon implantation damage is characterized by Rutherford backscattering in GaAs undoped VPE buffer layers grown on Cr-O doped semi-insulating substrates and capless annealed in a H2 −As4 atmosphere provided by AsH3. The damage detected in the RBS channeled spectra varies as a function of the ion mass, the implant depth and the annealing temperature of the stress-free controlled atmosphere technique. This damage is discussed in terms of the stoichiometric disturbances introduced by the implantation process. The as-implanted and annealed damage characteristics of the Ar and As implants are correlated to the electrical activation characteristics of Si and Se implants in GaAs, respectively.

Micro-structural evaluation of Ti/Al/Ni/Au ohmic contacts with different Ti/Al thicknesses in AlGaN/GaN HEMTs

2014 ◽  
Vol 183 ◽  
pp. 47-53 ◽  
Author(s):  
Somna S. Mahajan ◽  
Anuradha Dhaul ◽  
Robert Laishram ◽  
Sonalee Kapoor ◽  
Seema Vinayak ◽  
...  
Keyword(s):  
Ohmic Contacts ◽  
Structural Evaluation ◽  
Gan Hemts

Ultralow-Contact-Resistance Au-Free Ohmic Contacts With Low Annealing Temperature on AlGaN/GaN Heterostructures

2018 ◽  
Vol 39 (6) ◽  
pp. 847-850 ◽  
Author(s):  
Jinhan Zhang ◽  
Xuanwu Kang ◽  
Xinhua Wang ◽  
Sen Huang ◽  
Chen Chen ◽  
...  
Keyword(s):  
Contact Resistance ◽  
Ohmic Contacts ◽  
Annealing Temperature
Sign in / Sign up

Export Citation Format

Share Document