Activation of Beryllium-Implanted GaN by Two-Step Annealing

1999 ◽  
Vol 595 ◽  
Author(s):  
Yuejun Sun ◽  
Leng Seow Tan ◽  
Soo Jin Chua ◽  
Savarimuthu Prakash
Keyword(s):  
Gallium Nitride ◽  
Ionization Energy ◽  
Variable Temperature ◽  
Annealing Process ◽  
Pure Nitrogen ◽  
Hall Measurements ◽  
Enhanced Diffusion ◽  
Activation Efficiency ◽  
First Time

AbstractFor the first time, p-type doping through beryllium implantation in gallium nitride was achieved by using a new annealing process, in which the sample was first annealed in forming gas (12% H2 and 88% N2), followed by annealing in pure nitrogen. Variable temperature Hall measurements showed that sheet hole concentrations of the annealed samples were about 1×1013 cm−2 with low hole mobilities. An ionization energy of 127 meV was estimated with a corresponding activation efficiency of ∼ 100%. SIMS results revealed a relationship between the enhanced diffusion of Be and activation of the acceptors.

scholarly journals Activation of Beryllium-Implanted GaN by Two-Step Annealing

2000 ◽  
Vol 5 (S1) ◽  
pp. 315-321 ◽  
Author(s):  
Yuejun Sun ◽  
Leng Seow Tan ◽  
Soo Jin Chua ◽  
Savarimuthu Prakash
Keyword(s):  
Gallium Nitride ◽  
Ionization Energy ◽  
Variable Temperature ◽  
Annealing Process ◽  
Pure Nitrogen ◽  
Hall Measurements ◽  
Enhanced Diffusion ◽  
Activation Efficiency ◽  
P Type ◽  
First Time

AbstractFor the first time, p-type doping through beryllium implantation in gallium nitride was achieved by using a new annealing process, in which the sample was first annealed in forming gas (12% H2 and 88% N2), followed by annealing in pure nitrogen. Variable temperature Hall measurements showed that sheet hole concentrations of the annealed samples were about 1×1013 cm−2 with low hole mobilities. An ionization energy of 127 meV was estimated with a corresponding activation efficiency of ∼ 100%. SIMS results revealed a relationship between the enhanced diffusion of Be and activation of the acceptors.

scholarly journals Effects of Thermal Annealing on Optical Properties of Be-Implanted GaN Thin Films by Spectroscopic Ellipsometry

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 439
Author(s):  
Wenwang Wei ◽  
Jiabin Wang ◽  
Yao Liu ◽  
Yi Peng ◽  
Mudassar Maraj ◽  
...  
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Gallium Nitride ◽  
Thermal Annealing ◽  
Spectroscopic Ellipsometry ◽  
Communication Systems ◽  
Variable Temperature ◽  
Crystal Quality ◽  
Surface Decomposition

Wide bandgap III-V compounds are the key materials for the fabrication of short-wavelength optical devices and have important applications in optical displays, optical storage devices and optical communication systems. Herein, the variable-angle spectroscopic ellipsometry (SE) measurements are performed to investigate the thickness and optical properties of beryllium-implanted gallium nitride thin films that have been deposited on (0001) sapphire substrates by using low-pressure metalorganic chemical vapor deposition (LPMOCVD). The film layer details are described by using Parametric Semiconductor oscillators and Gaussian oscillators in the wavelength range of 200–1600 nm. The thickness, refractive indices and extinction coefficients of the Be-implanted films are determined at room temperature. Analysis of the absorption coefficient shows that the optical absorption edge of Be-implanted films changes from 3.328 eV to 3.083 eV in the temperature range of 300–850 K. With the variable temperature, Eg is demonstrated to follow the formula of Varshni. A dual-beam ultraviolet–visible spectrophotometer (UV–VIS) is used to study the crystal quality of samples, indicating that the quality of rapid thermal annealing (RTA) sample is better than that unannealed sample. By transport of ions in matter (TRIM) simulation and SE fitting the depths of Be implanted gallium nitride (GaN) films are estimated and in good agreement. The surface and cross-section morphologies are characterized by atomic force microscopy (AFM) and scanning electron microscope (SEM), respectively. The surface morphologies and thickness measurements of the samples show that RTA can improve crystal quality, while increasing the thickness of the surface roughness layer due to partial surface decomposition in the process of thermal annealing.

Field Emission from Nitrogen-Doped Diamond Film

1997 ◽  
Vol 498 ◽  
Author(s):  
M. Park ◽  
L. Bergman ◽  
W. B. Choi ◽  
A. T. Sowers ◽  
R. J. Nemanich ◽  
...  
Keyword(s):  
Field Emission ◽  
Diamond Films ◽  
Ring Structure ◽  
Minor Effect ◽  
Nitrogen Gas ◽  
Pure Nitrogen ◽  
Nitrogen Doped ◽  
Field Emission Properties ◽  
A Minor ◽  
First Time

ABSTRACTNitrogen-doped diamond films were prepared for the first time using melamine (C3H6N6) as the nitrogen source. To explore the differences in the films produced with different precursors, nitrogen-doped films were also produced using pure nitrogen gas as the source. Since melamine has a ring structure with pre-existing C-N bonds, the incorporation of nitrogen on substitutional sites of diamond lattice are expected. Relatively large amounts of substitutional nitrogen were successfully doped into diamond without degrading its quality. However, when pure nitrogen gas was used as a doping source, the quality of the diamond was not as high as the sample doped with nitrogen by melamine. Raman spectroscopy, photoluminescence spectroscopy (PL), and field emission measurements were carried out to characterize the samples. Nitrogen-doped diamond samples did not exhibit any significant reduction in turn-on fields. It is suggested that nitrogen doping has only a minor effect on the field emission properties of the diamond films.

New Results on the Bound Exciton Luminescence in Germanium

2011 ◽  
Vol 178-179 ◽  
pp. 289-294 ◽  
Author(s):  
Matthias Allardt ◽  
Vladimir Kolkovsky ◽  
Sabine Kolodinski ◽  
Nikolay V. Abrosimov ◽  
K. Irmscher ◽  
...  
Keyword(s):  
Dissociation Energy ◽  
Ionization Energy ◽  
Exciton Luminescence ◽  
Shallow Donors ◽  
First Time

Photoluminescence from excitons bound to shallow donors or acceptors was studied in Al-, As-, B-, Ga- and P-doped Ge. Excitons bound to Al and B acceptors were identified for the first time. The dissociation energy of the excitons satisfies Haynes rule and changes with a factor of 0.1 linearly with the ionization energy of the dopants.

What Elements Belong in Group 3 of the Periodic Table?

2018 ◽  
Author(s):  
Eric R. Scerri ◽  
William Parsons
Keyword(s):  
Ionization Energy ◽  
Periodic Table ◽  
Considerable Importance ◽  
Clear Cut ◽  
Interesting Article ◽  
Mistaken Belief ◽  
Science News ◽  
Group 3 ◽  
First Time ◽  
The Way

The question of precisely which elements should be placed in group 3 of the periodic table has been debated from time to time with apparently no resolution. This question has also received a recent impetus from several science news articles following an article in Nature Magazine in which the measurement of the ionization energy of the element lawrencium was reported for the first time. We believe that this question is of considerable importance for chemists and physicists as well as students of these subjects. It is our experience that students are typically puzzled by the fact that published periodic tables show variation in the way that group 3 is displayed. Instructors typically cannot answer questions that students may have on this matter. The aim of this chapter is to make a clear-cut recommendation regarding the membership of group 3, which we believe should consist of the elements scandium, yttrium, lutetium, and lawrencium. Although the arguments in favor of replacing lanthanum and actinium by lutetium and lawrencium are rather persuasive there is a popular and mistaken belief that IUPAC supports the traditional periodic table with lanthanum and actinium in group 3. This view has been disputed by Jeffrey Leigh in an interesting article in which he made it clear that IUPAC has not traditionally taken a view as to the correctness of any version of the periodic table and that there is no such thing as an officially approved IUPAC periodic table. We will briefly review the previous arguments that have been provided in favor of moving lutetium and lawrencium into group 3 of the periodic table in place of lanthanum and actinium. We will then reiterate what we take to be a categorical argument in favor of this placement and will discuss any remaining issues. When added to other arguments made over more than 50 years it becomes clear that the time may have arrived for IUPAC to make a ruling on this question.

scholarly journals GO-modified flexible polymer nanocomposites fabricated via 3D stereolithography

2019 ◽  
Vol 13 (4) ◽  
pp. 736-743 ◽  
Author(s):  
Chi Him Alpha Tsang ◽  
Adilet Zhakeyev ◽  
Dennis Y. C. Leung ◽  
Jin Xuan
Keyword(s):  
Thermal Properties ◽  
Annealing Process ◽  
Mechanical And Thermal Properties ◽  
Flexible Polymers ◽  
Scanning Calorimetry ◽  
Flexible Polymer ◽  
3D Printed ◽  
Resin Formulation ◽  
User Friendly ◽  
First Time

Abstract Graphene oxide (GO) induced enhancement of elastomer properties showed a great deal of potential in recent years, but it is still limited by the barrier of the complicated synthesis processes. Stereolithography (SLA), used in fabrication of thermosets and very recently in “flexible” polymers with elastomeric properties, presents itself as simple and user-friendly method for integration of GO into elastomers. In this work, it was first time demonstrated that GO loadings can be incorporated into commercial flexible photopolymer resins to successfully fabricate GO/elastomer nanocomposites via readily accessible, consumer-oriented SLA printer. The material properties of the resulting polymer was characterized and tested. The mechanical strength, stiffness, and the elongation of the resulting polymer decreased with the addition of GO. The thermal properties were also adversely affected upon the increase in the GO content based on differential scanning calorimetry and thermogravimetric analysis results. It was proposed that the GO agglomerates within the 3D printed composites, can result in significant change in both mechanical and thermal properties of the resulting nanocomposites. This study demonstrated the possibility for the development of the GO/elastomer nanocomposites after the optimization of the GO/“flexible” photoreactive resin formulation for SLA with suitable annealing process of the composite in future.

Electrospun hollow cage-like α-Fe2O3 microspheres: synthesis, formation mechanism, and morphology-preserved conversion to Fe nanostructures

CrystEngComm ◽  
2014 ◽  
Vol 16 (46) ◽  
pp. 10618-10623 ◽  
Author(s):  
Liqun Wang ◽  
Xuegang Lu ◽  
Chang Han ◽  
Ruie Lu ◽  
Sen Yang ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Annealing Process ◽  
First Time

Novel 3D hollow cage-like α-Fe2O3 and Fe microspheres were fabricated by electrospinning followed by an annealing process for the first time.

4H-SiC MOS Capacitors and MOSFET Fabrication with Gate Oxidation at 1400°C

2014 ◽  
Vol 778-780 ◽  
pp. 607-610 ◽  
Author(s):  
Harsh Naik ◽  
T. Paul Chow
Keyword(s):  
High Temperature ◽  
Oxidation Process ◽  
Annealing Process ◽  
Mos Capacitors ◽  
Hall Measurements ◽  
Dry Oxidation

This paper compares the performance of 4H-SiC MOS capacitors and MOSFETs made using the conventional NO annealing process and a high-temperature (1400°C) dry oxidation process. Through extensive C-V, G-ω, I-V and Hall measurements, the limitations of both the processes are discussed.

A Novel Technique For Rtp Annealing Of Compound Semiconductors

1997 ◽  
Vol 483 ◽  
Author(s):  
M. Fu ◽  
V. Sarvepalli ◽  
R. K. Singh ◽  
C. R. Abernathy ◽  
X. Cao ◽  
...  
Keyword(s):  
Thermal Processing ◽  
Compound Semiconductors ◽  
Halogen Lamp ◽  
University Of Florida ◽  
High Annealing ◽  
Activation Efficiency ◽  
Activation Annealing ◽  
The University ◽  
First Time ◽  
High Processing

AbstractWe introduce for the first time a novel rapid thermal processing (RTP) unit called ZapperTM, which has recently been developed by MHI Inc. and the University of Florida for high temperature thermal processing of semiconductors. This ZapperTM unit is capable of reaching much higher temperatures (>1500 °C) than conventional tungsten-halogen lamp RTP equipment and achieving high ramp-up and ramp-down rates. We have conducted implant activation annealing studies of Si+-implanted GaN thin films (with and without an AIN encapsulation layer) using the ZapperTM unit at temperatures up to 1500 °C. The electrical property measurements of such annealed samples have led to the conclusion that high annealing temperatures and AIN encapsulation are needed for the optimum activation efficiency of Si+ implants in GaN. It has clearly been demonstrated that the ZapperTM unit has tremendous potential for RTP annealing of semiconductor materials, especially for wide bandgap compound semiconductors that require very high processing temperatures.

Co-Implantation of Si And Be in GaAs by Rapid Thermal Annealing

1987 ◽  
Vol 92 ◽  
Author(s):  
Tan-Hua Yu ◽  
Sujane Wang
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Annealing Process ◽  
Superior Performance ◽  
Rapid Thermal Annealing Process ◽  
Gaas Mesfet ◽  
Activation Efficiency ◽  
Annealing Cycle ◽  
Thermal Annealing Process ◽  
Dopant Redistribution

ABSTRACTA buried p-layer in GaAs MESFET channel is successfully formed by (Si,Be) co-implantation and rapid thermal annealing process. The annealing cycle is optimized to activate Si and Be simultaneously and to minimize the dopant redistribution for precise dopant control. As a result, more than 80% activation efficiency for both Si and Be, as well as the greatly improved doping abruptness from 85 nm/decade to 65 nm/decade are achieved. Devices are fabricated and superior performance including sharper pinchoff, an increase of RF gain by 2–3dB and a 40% decrease in backgating effect is observed.

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