Implantation-Induced Voids for Thermally Stable Electrical Isolation in GaAs

1991 ◽  
Vol 240 ◽  
Author(s):  
K. Y. Ko ◽  
Samuel Chen ◽  
S. Tong ◽  
G. Braunstein
Keyword(s):  
High Temperatures ◽  
Point Defects ◽  
High Resistivity ◽  
Thermally Stable ◽  
Electrical Isolation ◽  
Isolation Techniques ◽  
Lattice Damage ◽  
High Processing

ABSTRACTMicroscopic voids, formed from the condensation of supersaturated vacancy point defects, were recently discovered in implanted and annealed GaAs. These defects have been shown to suppress carrier concentrations. Since voids are formed only at relatively high temperatures (> 650 °C), the possibility exists that voids can be used for thermally stable implant isolation. In this paper, we report on the formation of highly resistive layers in GaAs, created by Al+ implantation and annealing in the 700–900 °C range. In samples containing voids, their sheet resistivities increased by about six orders of magnitude from the as-grown value. Formation of these thermally stable, high resistivity regions is different from the conventional H or O implant isolation techniques, which use lattice damage to create the isolation characteristics. However, since lattice damage is annealed out between 400–700 °C, this type of isolation becomes ineffective at high processing temperatures. By contrast, voids are stable at high processing temperatures, and potential advantages of using such defects for device isolation in GaAs are pointed out.

Simultaneous Implant Activation and Isolation Formation in GaAs in a Single High-Temperature Anneal

1992 ◽  
Vol 262 ◽  
Author(s):  
Kei-Yu Ko ◽  
S. Chen ◽  
G. Braunstein ◽  
L.-R. Zheng ◽  
S.-T. Lee
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
High Temperatures ◽  
Active Regions ◽  
High Resistivity ◽  
Thermally Stable ◽  
Electrical Isolation ◽  
Device Processing ◽  
High Temperature Anneal ◽  
Thermal Stability Of

ABSTRACTUsing void-related compensation in Al-implanted GaAs, high-resistivity isolation regions that are thermally stable to high temperatures (> 700 °C) are demonstrated. The high-temperature thermal stability of the isolation regions allows the simplification of device processing in which a single high-temperature anneal (e.g., at 900 °C) can be used to activate the implant dopants in the device-active regions, and simultaneously to convert the Al-implanted regions highly resistive for electrical isolation. Other advantages of using void-related isolation will also be discussed.

Exceptionally Stable Sol-immobilization Derived Pd/SBA-15 Catalyst for Methane Combustion

2021 ◽  
Author(s):  
Ramana Murthy Palle ◽  
Jing-Cai Zhang ◽  
Wei-Zhen Li
Keyword(s):  
High Temperatures ◽  
Methane Combustion ◽  
Thermally Stable ◽  
Sintering Effect

Pd-based catalysts are efficient for methane combustion but impractical at high temperatures due to sintering effect. Here in, we report a thermally stable Pd/SBA-15 catalyst that was prepared by using...

scholarly journals The impact of point defects in n-type GaN layers on thermal decomposition of InGaN/GaN QWs

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mikolaj Grabowski ◽  
Ewa Grzanka ◽  
Szymon Grzanka ◽  
Artur Lachowski ◽  
Julita Smalc-Koziorowska ◽  
...  
Keyword(s):  
Quantum Wells ◽  
High Temperatures ◽  
Point Defects ◽  
X Ray Diffraction ◽  
Helium Ions ◽  
X Ray ◽  
Sapphire Substrates ◽  
Transmission Electron ◽  
The Impact ◽  
Ingan Quantum Wells

AbstractThe aim of this paper is to give an experimental evidence that point defects (most probably gallium vacancies) induce decomposition of InGaN quantum wells (QWs) at high temperatures. In the experiment performed, we implanted GaN:Si/sapphire substrates with helium ions in order to introduce a high density of point defects. Then, we grew InGaN QWs on such substrates at temperature of 730 °C, what caused elimination of most (but not all) of the implantation-induced point defects expanding the crystal lattice. The InGaN QWs were almost identical to those grown on unimplanted GaN substrates. In the next step of the experiment, we annealed samples grown on unimplanted and implanted GaN at temperatures of 900 °C, 920 °C and 940 °C for half an hour. The samples were examined using Photoluminescence, X-ray Diffraction and Transmission Electron Microscopy. We found out that the decomposition of InGaN QWs started at lower temperatures for the samples grown on the implanted GaN substrates what provides a strong experimental support that point defects play important role in InGaN decomposition at high temperatures.

scholarly journals Antibiofilm Activity of Polyamide 11 Modified with Thermally Stable Polymeric Biocide Polyhexamethylene Guanidine 2-Naphtalenesulfonate

2019 ◽  
Vol 20 (2) ◽  
pp. 348 ◽  
Author(s):  
Olena Moshynets ◽  
Jean-François Bardeau ◽  
Oksana Tarasyuk ◽  
Stanislav Makhno ◽  
Tetiana Cherniavska ◽  
...  
Keyword(s):  
Total Content ◽  
Melt Processing ◽  
Antibiofilm Activity ◽  
Thermally Stable ◽  
Polyamide 11 ◽  
Opportunistic Bacteria ◽  
Polyhexamethylene Guanidine ◽  
Decomposition Point ◽  
High Processing ◽  
Potential Use

The choice of efficient antimicrobial additives for polyamide resins is very difficult because of their high processing temperatures of up to 300 °C. In this study, a new, thermally stable polymeric biocide, polyhexamethylene guanidine 2-naphtalenesulfonate (PHMG-NS), was synthesised. According to thermogravimetric analysis, PHMG-NS has a thermal degradation point of 357 °C, confirming its potential use in joint melt processing with polyamide resins. Polyamide 11 (PA-11) films containing 5, 7 and 10 wt% of PHMG-NS were prepared by compression molding and subsequently characterised by FTIR spectroscopy. The surface properties were evaluated both by contact angle, and contactless induction. The incorporation of 10 wt% of PHMG-NS into PA-11 films was found to increase the positive surface charge density by almost two orders of magnitude. PA-11/PHMG-NS composites were found to have a thermal decomposition point at about 400 °C. Mechanical testing showed no change of the tensile strength of polyamide films containing PHMG-NS up to 7 wt%. Antibiofilm activity against the opportunistic bacteria Staphylococcus aureus and Escherichia coli was demonstrated for films containing 7 or 10 wt% of PHMG-NS, through a local biocide effect possibly based on an influence on the bacterial eDNA. The biocide hardly leached from the PA-11 matrix into water, at a rate of less than 1% from its total content for 21 days.

Point Defect Injection Kinetics by N2O Oxidation of Silicon

1997 ◽  
Vol 469 ◽  
Author(s):  
C. Tsamis ◽  
D. N. Kouvatsos ◽  
D. Tsoukalas
Keyword(s):  
Point Defect ◽  
High Temperatures ◽  
Point Defects ◽  
Silicon Substrate ◽  
Oxidation Process ◽  
Stacking Faults ◽  
Defect Injection ◽  
Dry Oxidation ◽  
Kinetics Of

ABSTRACTThe influence of N2O oxidation of silicon on the kinetics of point defects at high temperatures is investigated. Oxidation Stacking Faults (OSF) are used to monitor the interstitials that are generated during the oxidation process. We show that at high temperatures (1050°-1150°C) the supersaturation of self-interstitials in the silicon substrate is enhanced when oxidation is performed in an N2O ambient compared to 100% dry oxidation. This behavior is attributed to the presence of nitrogen at the oxidizing interface. However, at lower temperatures this phenomenon is reversed and oxidation in N2O ambient leads to reduced supersaturation ratios.

Effect of defect structure on gas sensitivity of LaCrO3

1996 ◽  
Vol 11 (12) ◽  
pp. 3077-3082 ◽  
Author(s):  
Rong-Fong Huang ◽  
Wei-Yean Howng
Keyword(s):  
Point Defects ◽  
Defect Structure ◽  
Isopropyl Alcohol ◽  
Sensitivity Enhancement ◽  
High Resistivity ◽  
Stoichiometric Ratio ◽  
Gas Sensitivity ◽  
Conduction Behavior ◽  
Positively Charged ◽  
Trapping Sites

The isopropyl alcohol gas sensitivity of LaCrO3 at 250 °C is found to depend on the amount of TiO2 content and cation stoichiometric ratio of the sample. The gas sensitivity enhancement is related to the defect structure and electrical conduction behavior of p-type, donor-doped semiconductive oxides. The high resistivity coupled with the increasing point defects by the donor dopants are responsible for the high gas sensitivity of TiO2 doped LaCrO3. It is believed that the positively charged ionic-type defects created by dopants act as trapping sites to adsorb oxygen.

Electrical And Structural Properties Of LT-GaAs: Influence Of As/Ga Flux Ratio And Growth Temperature

1996 ◽  
Vol 442 ◽  
Author(s):  
M. Luysberg ◽  
H. Sohn ◽  
A. Prasad ◽  
P. Specht ◽  
H. Fujioka ◽  
...  
Keyword(s):  
Structural Properties ◽  
Point Defects ◽  
Growth Temperature ◽  
Conduction Mechanism ◽  
Growth Parameters ◽  
Flux Ratio ◽  
Growth Conditions ◽  
High Resistivity ◽  
Antisite Defects ◽  
Band Conduction

AbstracThe deposition of GaAs by MBE at low temperatures results in a material of unique properties. However, up to now the control and understanding of the electrical and structural properties are unsatisfactory. To investigate the influence of growth parameters on the formation of point defects and electrical properties, the substrate temperature and the As/Ga flux ratio were systematically varied. In a well defined parameter range the lattice expansion was found to be dominated by the formation of As antisite defects. After annealing a high resistivity is obtained independent of the growth conditions. A strong influence of the growth temperature on the band conduction mechanism is observed, whereas a variation of the As/Ga flux ratio induces only slight changes of the temperature dependence of the conductivity.

Formation of thermally stable high‐resistivity AlGaAs by oxygen implantation

1988 ◽  
Vol 52 (5) ◽  
pp. 395-397 ◽  
Author(s):  
S. J. Pearton ◽  
M. P. Iannuzzi ◽  
C. L. Reynolds ◽  
L. Peticolas
Keyword(s):  
High Resistivity ◽  
Thermally Stable ◽  
Oxygen Implantation

Stratified Ion Damage and in Situ Regrowth in GaAs/AlAs Heterostructures

1990 ◽  
Vol 201 ◽  
Author(s):  
A G Cullis ◽  
D J Eaglesham ◽  
D C Jacobson ◽  
J M Poate ◽  
C R Whitehouse ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Point Defects ◽  
Multilayer Structures ◽  
Dependent Manner ◽  
Characteristic Boundary ◽  
Transmission Electron ◽  
Wide Range ◽  
Ion Damage ◽  
Lattice Damage

AbstractThe material-dependent manner in which ion damage occurs in AlAs/GaAs heteroepitaxial structures is demonstrated using conventional and high resolution transmission electron microscopy. Both 150keV and 2MeV Si+ ion implants are employed over a wide range of ion doses. Under conditions which yield rapid build-up of lattice damage in GaAs, the AlAs is found to be relatively resistant to structure breakdown. Indeed, the crystalline AlAs exerts a novel protective effect on immediately adjacent regions of the GaAs layers. For high implantation doses amorphous-crystal superlattices are formed in multilayer structures. For the highest ion doses the AlAs lattice begins to be disrupted by a characteristic, boundary-dependent, heterogeneous mechanism. These observations suggest that mobile point defects play a significant role in AlAs in situ restructuring processes.

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