Site Occupation of Implanted Te in Gaas As a Function of Implantation Dose

1987 ◽  
Vol 104 ◽  
Author(s):  
G. Langouche ◽  
D. Schroyen ◽  
H. Bemelmans ◽  
M. Van Rossum ◽  
W. Deraedt ◽  
...  

ABSTRACTTe atoms were implanted in GaAs with doses ranging from 1013 to 1016 atoms/cm2, and annealed with the rapid thermal annealing technique. The samples were studied by Mössbauer Spectroscopy, Rutherford Backscattering Spectroscopy – Channeling, and the Van der Pauw-method. While at the lowest implantation dose an unperturbed substitutional site is observed at all annealing temperatures, at the highest implantation dose a strong deviation from a central position in an unperturbed configuration is observed at all temperatures. At the intermediate doses a high degree of substitutionality is observed between annealing temperatures of 200°C and 500°C only.

1991 ◽  
Vol 240 ◽  
Author(s):  
T. E. Kazior ◽  
S. K. Brierley

ABSTRACTMBE grown GaAs/Al0.25Ga0.75As/In0.85Ga0.85 As structures were subjected to SiNx capped rapid thermal annealing and their electrical and material properties were characterized by Hall measurements and photoluminescence (PL). Low temperature (5°K) PL spectra from undoped structures annealed up to 900°C indicated negligible intermixing at the AIGaAs/lnGaAs interface. For planar doped structures (Nd≈5×1012/cm2) the Hall mobility began to decrease at anneal temperatures as low as 800°C with significant degradation observed for annealing temperatures at 850°C. This data is supported by PL spectra which indicate no significant change for samples annealed at 800°C. For the samples annealed at ≥ 850°C a large increase in the full width at half maximum of the transitions from the electron sub-bands of the InGaAs quantum well were observed, suggesting that the change in electrical characteristics is primarily due to diffusion of the Si doping pulse. In contrast. Hall measurement of uniformly doped structures reveal only small decreases in mobility and no significant change in sheet concentration for anneal temperatures up to 900°C and doping levels up to 2.5×1018/cm3. PL spectra reveal no structural changes.


1994 ◽  
Vol 299 ◽  
Author(s):  
M. Fernandez ◽  
T. Rodriguez ◽  
A. Almendra ◽  
J. Jimenez-Leube ◽  
H. Wolters

AbstractIridium silicide formation by rapid thermal annealing (RTA) in an Ar atmosphere or under vacuum has been investigated. The evolution of the silicide front and the identification of the phases were monitored by Auger Electron Spectroscopy (AES) and Rutherford Backscattering Spectrometry (RBS). Oxygen was incorporated during the RTA process in an Ar atmosphere. The oxygen effect is to slow down the silicide formation and eventually to stop it. In all the cases, the oxygen piled-up at the iridium-iridium silicide interface. No distinguishable phase was formed by RTA in an Ar atmosphere. No oxygen contarsi'nation was detected when the RTA was performed under a vacuum lower than 2×10−5 Torr. In this case Ir1Si1 and Ir1Si1.75 phases were formed.


1992 ◽  
Vol 268 ◽  
Author(s):  
Ikasko C. Dehm ◽  
H. Ryssel

ABSTRACTIn this study, the critical dose for ion-beam mixing of Co and Si with Ge-ions which results in homogenous CoSi2 formation after rapid thermal annealing was found. For this purpose, Co was deposited by sputtering on chemically cleaned, <100>-oriented Si and subsequently mixed with Ge ions at doses in the range of 2. 1014 to 1. 1015 cm−2. Silicidation was performed in a rapid thermal annealing (RTA) system at temperatures between 700° and 100°C. Rutherford backscattering measurements showed that annealing at 700°C results in an incomplete reaction when ion-beam mixing at a dose of 2.1014 cm−2 or no ion-beam mixing was performed. After annealing at 1000°C, TEM samples revealed an inhomogeneous CoSi2 film consisting of large grains embedded in the Si. Mixing at doses at or above 5.1014 cm−2 and subsequent RTA at 700°C resulted in uniform CoSi2 layers. Higher annealing temperatures cause larger grains and resistivity values as low as 18 μΩcm. Therefore, we demonstrated that the critical dose leading to complete formation of smooth CoSi2 films with abrupt interface is 5.1014 cm−2 which is nearly the same value as the amorphization dose of Ge in Si.


1988 ◽  
Vol 144 ◽  
Author(s):  
B.J. Skromme ◽  
N.G. Stoffel ◽  
A.S. Gozdz ◽  
M.C. Tamargo ◽  
S.M. Shibli

ABSTRACTWe describe the effects of rapid thermal annealing on the photoluminescence (PL) and electrical properties of heteroepitaxial ZnSe grown by molecular beam epitaxy on GaAs, using either no cap or plasma-deposited SiO2, Si3N4, or diamond-like C caps, and annealing temperatures from 500 to 800°C. Capless anneals (in contact with GaAs) produce badly degraded PL properties, while capped anneals can prevent this degradation. We show that Si3N4 is significantly more effective in preventing Zn out-diffusion through t e cap than previously employed SiO2 films, as evidenced by less pronounced PL features related to the creation of Zn vacancies during the anneal. Implant damage tends to enhance the Zn vacancy formation. Rapid thermal annealing with Si3N4 caps is shown to optically activate shallow N acceptor implants.


1992 ◽  
Vol 279 ◽  
Author(s):  
X. W. Lin ◽  
M. Behar ◽  
J. Desimoni ◽  
H. Bemas ◽  
W. Swider ◽  
...  

ABSTRACTSi (001) wafers were implanted at room temperature with 50-keV Fe ions to different doses and subsequently crystallized either by rapid thermal annealing (RTA) (900°C, 120 s) or by Si+ irradiation (500 keV, 320 °C). Transmission electron microscopy, as well as Rutherford backscattering and channeling, were used to study the phase formation of FeSi2 in Si. Depending on the implantation dose and the crystallization process, three phases of FeSi2 were produced. While RTA results in the formation of β-FeSi2, ion irradiation promotes the growth of either cubic FeSi2 phase for low implantation doses (< = 4 at.% Fe) or a-FeSi2 for high implantation doses (≈18 at.% Fe). All these phases of FeSi2 were found to grow epitaxially in the Si matrix and their orientation relationships relative to Si have been determined. The interfacial energy between FeSi2 and Si appears to be an important factor in determining the final structure of FeSi2.


2005 ◽  
Vol 865 ◽  
Author(s):  
Xuege Wang ◽  
Sheng. S. Li ◽  
V. Craciun ◽  
S. Yoon ◽  
J. M. Howard ◽  
...  

AbstractRapid thermal annealing (RTA), with fast ramp up and down rates, was performed on several Cu(In,Ga)Se2 (CIGS) films and solar cells under various peak annealing temperatures and holding times. The XRD, SEM, Hall- effect, photo J-V, and quantum efficiency (Q-E) measurements were made on CIGS films and cells before and after RTA treatments to study the effects of RTA on the CIGS film properties and cell performance. The results show that RTA treatments under optimal annealing condition can provide significant improvements in the electrical properties (resistivity, carrier concentration, and mobility) of CIGS films and cell performance while preserving the film composition and microstructure morphology.


1993 ◽  
Vol 301 ◽  
Author(s):  
D. W. Elsaesser ◽  
J. E. Colon ◽  
Y. K. Yeo ◽  
R. L. Hengehold ◽  
G. S. Pomrenke

ABSTRACTElectrical and optical measurements were performed on p-type GaAs implanted with 1013 Er ions/cm2 at an energy of 1 MeV. The samples were annealed at 650, 750, 850, or 900 °C for 15 seconds using the rapid thermal annealing technique. Although annealing at 650 °C was insufficient to recover measureable electrical conductivity in the implanted region, Er3+ 4f-4f emissions were still observed. Annealing at 750 TC produced a large concentration of hole traps at EV + 360 meV, and the most intense Er-related emissions at 1.54 μm. The two higher annealing temperatures returned the implanted region to the conductivity of the substrate but resulted in weak Er-related emissions. Two distinct Er-related centers were found, and they are believed to be the cause of the intense and weak emissions, an Er-interstitial and Er substituting for Ga, respectively.


1985 ◽  
Vol 46 ◽  
Author(s):  
R. A. Street ◽  
N. M. Johnson ◽  
R. D. Burnham

AbstractElectronic deep levels in GaAs have been investigated by correlated luminescence and DLTS measurements on material in which the defects were systematically perturbed by rapid thermal annealing. The samples were grown by MOCVD and encapsulated with silicon nitride. Annealing was performed at temperatures from 800°C to 950°C for 5 seconds. The luminescence spectra were measured from 0.7 to 1.6 eV at temperatures from 4-80 K and have features at 0.97, 1.17, 1.35, 1.40 and 1.5 eV. The band-to-acceptor luminescence shows the formation of Si acceptors, starting at an anneal temperature of about 850°C. The luminescence peak at 1,35 eV, attributed to As vacancy - acceptor complexes, is observed to increase in intensity with higher annealing temperatures. In contrast, the Ga vacancy-donor complex peak at 1,17 eV decreases in intensity. DLTS data show an increase in the density of deep levels and new levels not present in the unannealed material. Capacitance-voltage data find a reduction in carrier concentration, although type conversion is not observed even after annealing to 950°C.


2012 ◽  
Vol 1394 ◽  
Author(s):  
L. Vines ◽  
P.T. Neuvonen ◽  
A. Yu. Kuznetsov ◽  
J. Wong-Leung ◽  
C. Jagadish ◽  
...  

ABSTRACTPotassium (K) ions have been implanted in hydrothermally grown ZnO to a dose of 1 × 1015 cm-2, followed by isochronal annealing in a tube furnace (30min) and by rapid thermal annealing (30s) on two separate samples. For annealing temperatures below 700°C, only a minor redistribution of Li is observed behind the projected range of the K+ ions. At temperatures between 700 and 750°C, however, both annealing treatments show a wide region behind the implantation peak which is depleted of Li, and this depletion is used as a tracer to monitor diffusion of intrinsic defects like the Zn interstitial. The results are interpreted as Zn interstitials being released from the implanted region in a burst at temperatures above ∼700°C, followed by rapid migration, replacement of Li on Zn site through the kick-out mechanism, and migration of Li away from the active region.


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