Ohmic and Rectifying Contacts to n and p-type GaN Films

2002 ◽  
Vol 743 ◽  
Author(s):  
H. P. Hall ◽  
M. A. Awaah ◽  
A. Kumah ◽  
K. Das ◽  
F. Semendy
Keyword(s):  
Electron Beam ◽  
Ohmic Contacts ◽  
Deep Level ◽  
Electron Beam Evaporation ◽  
Electrical Contacts ◽  
Sputtered Films ◽  
Current Conduction ◽  
Deposition By Sputtering ◽  
P Type ◽  
Deposited Films

ABSTRACTElectrical contacts to both n and p-type GaN films have been investigated using electron-beam evaporated and sputtered films of metals such as Al, Au, Cr, Cu, Ni, Pt, and Ti. Films deposited by electron-beam evaporation for the n-type films with doping levels of 1 × 1018/cm3 and lower showed rectifying characteristics with all the metals studied with the exception of Al. Aluminum contact diodes were ohmic in the as-deposited state. The Pt rectifying contact was near-ideal with an ideality factor close to 1.0. Ideality factors for the other metals were much greater than 1. This deviation from thermionic behavior was interpreted as space charge limited current conduction in the presence of deep-level states. Sputtered films showed very similar characteristics to electron-beam deposited films, with the exception of Ti. The Ti contact was ohmic in the as-deposited state. Non-linear Cu contacts to n-type films became ohmic on annealing. However, for p-type films, Ar ion sputter-cleaning prior to metal deposition by sputtering created ohmic contacts with Cu and Pt. Low resistance ohmic contacts were achieved by ion implantation and anneal of Si in n-type and Mg in p-type films, prior to metallization. The implant parameters and anneal temperatures are currently being optimized.

Introduction of Electrical Defects in P-Type Silicon due to Electron-Beam and RF Sputtering Metallization Processes

1983 ◽  
Vol 25 ◽  
Author(s):  
O. Paz ◽  
F. D. Auret
Keyword(s):  
Electron Beam ◽  
Deep Level ◽  
Rf Sputtering ◽  
Electron Beam Evaporation ◽  
Defect States ◽  
Type Silicon ◽  
Carrier Recombination ◽  
Electron Beam Induced Current ◽  
Transient Spectroscopy ◽  
P Type

ABSTRACTDefects introduced in p-type silicon during RF sputter deposition of Ti-W and electron-beam evaporation of hafnium were investigated using I-V, deep level transient spectroscopy and electron-beam induced current techniques. DLTS measurements indicate the presence of several deposition and evaporation induced defect states. H(0.35) at EV + .35 eV and H(0.38) were the most prominent defects. Minority carrier diffusion length results taken after annealing showed that in the case of the Hf contacts the damage was annealed out while in the case of Ti-W it was not. These differences in carrier recombination are traced to the concentration of H(0.35). Sputtering or evaporation induced damage also increased the barrier height. This observed increase was modeled assuming the introduction of donor-like defects.

Fabrication of a Peltier Device Based on InSb and SbTe Thin Films

2011 ◽  
Vol 254 ◽  
pp. 50-53 ◽  
Author(s):  
Tatsuya Ishii ◽  
Hideyuki Homma ◽  
Shigeo Yamaguchi
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Electron Beam ◽  
Vapor Phase ◽  
Electron Beam Evaporation ◽  
Peltier Effect ◽  
Insb Thin Films ◽  
Peltier Device ◽  
P Type ◽  
Direct Current Sputtering

We fabricated a thin film Peltier device based on an InSb film and a SbTe film. N-type InSb thin films were grown on sapphire (0001) substrate with InAsSb buffer layer by metalorganic vapor phase epitaxy, and P-type SbTe thin films were deposited on the substrate by electron beam evaporation. N-type and P-type films were separated on the substrate, and between them, a Au thin film was deposited by direct-current sputtering. We observed partial Peltier effect in the device.

INFLUENCE OF OXYGEN IMPURITY ON SEEBECK COEFFICIENT OF NANOSCALE MnSi1.7 FILMS

2009 ◽  
Vol 23 (20n21) ◽  
pp. 2421-2427 ◽  
Author(s):  
Q. R. HOU ◽  
Y. B. CHEN ◽  
Y. J. HE
Keyword(s):  
Electron Beam ◽  
Transition Temperature ◽  
Seebeck Coefficient ◽  
Thermal Annealing ◽  
Oxygen Content ◽  
Layer Structure ◽  
Electron Beam Evaporation ◽  
Silicon Substrates ◽  
Oxygen Impurity ◽  
P Type

Nano-scale MnSi 1.7 films are prepared by thermal annealing of three-layer Si / MnSi x/ Si or bi-layer Si / MnSi x (x < 1.7) structures at 923 K for 20–65 minutes. These layers are deposited on thermally oxidized silicon substrates at about 393 K by electron beam evaporation. It is found that the oxygen content in the MnSi 1.7 film can be reduced from about 10 at.% to 6 at.% by using the bi-layer structure MnSi x/ Si with the MnSi x layer on top. With the reduction of oxygen content in the MnSi 1.7 film, the transition temperature from p-type to n-type decreases from 508 K to 463 K or less.

scholarly journals Effect of Annealing Temperature on CuInSe2/ZnS Thin-Film Solar Cells Fabricated by Using Electron Beam Evaporation

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
H. Abdullah ◽  
S. Habibi
Keyword(s):  
Electron Beam ◽  
Solar Cells ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Electron Beam Evaporation ◽  
Thin Film Solar Cells ◽  
X Ray ◽  
Annealing Temperatures ◽  
Pure Cu ◽  
Deposited Films

CuInSe2(CIS) thin films are successfully prepared by electron beam evaporation. Pure Cu, In, and Se powders were mixed and ground in a grinder and made into a pellet. The pallets were deposited via electron beam evaporation on FTO substrates and were varied by varying the annealing temperatures, at room temperature, 250°C, 300°C, and 350°C. Samples were analysed by X-ray diffractometry (XRD) for crystallinity and field-emission scanning electron microscopy (FESEM) for grain size and thickness. I-V measurements were used to measure the efficiency of the CuInSe2/ZnS solar cells. XRD results show that the crystallinity of the films improved as the temperature was increased. The temperature dependence of crystallinity indicates polycrystalline behaviour in the CuInSe2films with (1 1 1), (2 2 0)/(2 0 4), and (3 1 2)/(1 1 6) planes at 27°, 45°, and 53°, respectively. FESEM images show the homogeneity of the CuInSe2formed. I-V measurements indicated that higher annealing temperatures increase the efficiency of CuInSe2solar cells from approximately 0.99% for the as-deposited films to 1.12% for the annealed films. Hence, we can conclude that the overall cell performance is strongly dependent on the annealing temperature.

РЕЗУЛЬТАТЫ ПРИМЕНЕНИЯ ОТЕЧЕСТВЕННОГО ОБОРУДОВАНИЯ ДЛЯ РЕАЛИЗАЦИИ КЛЮЧЕВЫХ ТЕХНОЛОГИЧЕСКИХ ОПЕРАЦИЙ ПРИ ИЗГОТОВЛЕНИИ СВЧ ЭКБ НА ОСНОВЕ GAN И GAAS

2020 ◽  
Vol 96 (3s) ◽  
pp. 494-497
Author(s):  
А.Н. Алексеев ◽  
С.И. Петров
Keyword(s):  
Electron Beam ◽  
Plasma Etching ◽  
Ohmic Contacts ◽  
Electron Beam Evaporation ◽  
Production Cycle ◽  
Technological Equipment ◽  
Microwave Transistors ◽  
Mbe Growth ◽  
Power Microwave

Показаны результаты применения отечественного оборудования (ЗАО «НТО») для разработки и проведения ключевых технологических операций при изготовлении мощных полевых транзисторов и МИС СВЧ-диапазона на основе GaN и GaAs. Обсуждаются особенности и результаты оптимизации технологических установок для таких операций, как выращивание гетероструктур методом МЛЭ, нанесение контактной и затворной металлизации при помощи электронно-лучевого напыления, отжиг омических контактов, травление меза-изоляции и нанесение диэлектрика при помощи плазмохимических методов. Кроме того, представлены особенности установок и технологических процессов глубокого плазмохимического травления для формирования сквозных металлизированных отверстий в SiC и GaAs, а также прецизионного травления GaN и GaAs. Продемонстрированы технологические результаты использования оборудования ЗАО «НТО» в производственном цикле АО «Светлана-Рост». The paper highlights the results of using domestic equipment (SemiTEq JSC) for the development and implementation of key technological operations for producing GaN and GaAs based power microwave transistors. Features and results of optimization of the technological equipment have also been discussed for such operations as: MBE growth of heterosructures, deposition of the contacts and gate metallization using electron beam evaporation and ohmic contacts annealing, plasma etching of mesa isolation and PECVD of the dielectric. In addition, the features of systems for deep plasma etching of SiC and GaAs as well as GaN and GaAs precision etching have been presented. The technological results of using SemiTEq equipment in the production cycle of Svetlana-Rost JSC have been demonstrated.

scholarly journals Electrical Characterization of Defects Introduced in n-Type N-Doped 4H-SiC during Electron Beam Exposure

2015 ◽  
Vol 242 ◽  
pp. 427-433 ◽  
Author(s):  
Ezekiel Omotoso ◽  
Walter Ernst Meyer ◽  
Francois Danie Auret ◽  
Sergio Manuel Martins Coelho ◽  
Phuti Ngako Mahloka Ngoepe
Keyword(s):  
Electron Beam ◽  
Deep Level ◽  
Electrical Characterization ◽  
Beam Current ◽  
High Energy ◽  
Electron Beam Evaporation ◽  
High Energy Particle ◽  
Electron Beam Current ◽  
Intrinsic Nature ◽  
Carbon Vacancy

Deep level transient spectroscopy (DLTS) was used to characterize the defects introduced in n-type, N-doped, 4H-SiC while being exposed to electron beam evaporation conditions. This was done by heating a tungsten source using an electron beam current of 100 mA, which was not sufficient to evaporate tungsten. Two new defects were introduced during the exposure of 4H-SiC samples to electron beam deposition conditions (without metal deposition) after resistively evaporated nickel Schottky contacts. We established the identity of these defects by comparing their signatures to those of high energy particle irradiation induced defects of the same materials. The defect E0.42 had acceptor-like behaviour and could be attributed to be a silicon or carbon vacancy. The E0.71 had intrinsic nature and was linked to a carbon vacancy and/or carbon interstials.

Tunnel Type Magnetoresistance in Electron Beam Deposited Films of Compositions (Co0.5Fe0.5)x(Al2O3)(100-x) (7 ≤ x ≤ 52)

1999 ◽  
Vol 602 ◽  
Author(s):  
H.R. Khan ◽  
A. Ya Vovk ◽  
A.F. Kravets ◽  
O.V. Shipil ◽  
A.N. Pogoriliy
Keyword(s):  
Electron Beam ◽  
Room Temperature ◽  
Electron Beam Evaporation ◽  
Tunneling Magnetoresistance ◽  
Metal Insulator ◽  
Glass Substrates ◽  
Electron Beam Evaporation Technique ◽  
Crystallite Sizes ◽  
Evaporation Technique ◽  
Deposited Films

AbstractA series of 400 nm thick metal-insulator films of compositions (Co50Fe50)x(Al2O3(100-x) (7 ≤ x ≤ 52; x is in vol.%) are deposited on glass substrates using dual electron beam evaporation technique. The films are nanocrystalline with crystallite sizes of 1-3 nm. Resistivity of the films varies as a function of (I/T)0.5 showing a tunneling type behaviour. The films show isotropic and negative magnetoresistance (GMR). A film of composition (Co50Fe50)82.5(Al2O3)17.5 show maximum tunneling magnetoresistance (TMR) of 7.2% at room temperature and in a magnetic field of 8.2 kOe.

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