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1.
James A. Fellows Y. K. Yeo Mee-Yi Ryu R. L. Hengehold 《Journal of Electronic Materials》2005,34(8):1157-1164
Comprehensive and systematic electrical and optical activation studies of Si-implanted GaN were made as a function of ion dose and anneal temperature. Silicon ions were implanted at 200 keV with doses ranging from 1×1013 cm?2 to 5×1015 cm?2 at room temperature. The samples were proximity-cap annealed from 1050°C to 1350°C with a 500-Å-thick AlN cap in a nitrogen environment. The optimum anneal temperature for high dose implanted samples is approximately 1350°C, exhibiting nearly 100% electrical activation efficiency. For low dose (≤5×1014 cm?2) samples, the electrical activation efficiencies continue to increase with an anneal temperature through 1350°C. Consistent with the electrical results, the photoluminescence (PL) measurements show excellent implantation damage recovery after annealing the samples at 1350°C for 20 sec, exhibiting a sharp neutral-donor-bound exciton peak along with a sharp donor-acceptor pair peak. The mobilities increase with anneal temperature, and the highest mobility obtained is 250 cm2/Vs. The results also indicate that the AlN cap protected the implanted GaN layer during high-temperature annealing without creating significant anneal-induced damage. 相似文献
2.
Atomic profiles of ion-implanted Be and S in GaAs have been measured as a function of implant fluence and annealing temperature.
Concentration versus depth profiles were ob-tained by means of secondary ion mass spectrometry (SIMS) techniques. Pyrolytically
deposited and sputter-coated Si02 and Si3N4 films were used as encapsulants for the 500 to 900° annealing study. Semi-insulating GaAs was implanted with 200 keV34S+ to fluences of 1 × 1014 and 52× 1014/cm2, and 100 keV9Be+ in the 1 × 1013 to 1 × 1015/cm2 fluence range. The S profiles did not change significantly after annealing at 800°C, although there was some skewing after
annealing above 600°C. In contrast, the Be profiles showed significant changes and a decrease in the peak concentration for
the ≥ 5 × 10T4/cm2 implants after a 700°C anneal. After a 800°C anneal the Be profile was essentially flat with a monotonic decrease from the
surface into the implanted re-gion and a 900°C anneal caused a further decrease in the Be concentration. Profiles of Be implants
of ≤ 1 × 1014/cm2 did not change significantly after annealing indicating that the higher fluence cases were related to solubility effects.
This work supported by the Naval Electronic Systems Command and the Office of Naval Research. 相似文献
3.
Close contact rapid thermal annealing of semi-insulating GaAs:Cr implanted with Si, Si + Al, and Si + P has been studied using
variable temperature Hall effect measurements and low temperature (4.2K) photoluminescence (PL) spectroscopy. Isochronal (10
sec) and isothermal (1000° C) anneals indicate that As is lost from the surface during close contact annealing at high anneal
temperatures and long anneal times. Samples which were implanted with Si alone show maximum activation at an annealing temperature
of 900° C, above which activation efficiency decreases. Low temperature Hall and PL measurements indicate that this reduced
activation is due to increasing auto-compensation of Si donors by Si acceptors at higher anneal temperatures. However, co-implantation
of column V elements can increase the activation of Si implants by reducing Si occupancy of As sites and increasing Si occupancy
of Ga sites, and therebyoffset the effects of As loss from the surface. For samples implanted with Si + P, activation increases continuously up to a maximum at an anneal temperature
of 1050° C, and both low temperature Hall and PL measurements indicate that autocompensation does not increase in this case
as the anneal temperature increases. In contrast, samples implanted with Si + Al show very low activation and very high compensation
at all anneal temperatures, as expected. The use of column V co-implants in conjunction with close contact RTA can produce
excellent donor activation of Si implanted GaAs. 相似文献
4.
A. A. Andreev V. B. Voronkov V. G. Golubev A. V. Medvedev A. B. Pevtsov 《Semiconductors》1999,33(1):93-96
Erbium-doped a-Si:H films are prepared by magnetron sputtering of a Si-Er target at a deposition temperature of 200 °C. The films are then
subjected to cumulative thermal annealing. A sharp increase (∼50-fold) in the photoluminescence intensity at a wavelength
of 1.54 μm is observed after a 15-min anneal at 300 °C in a nitrogen atmosphere. At an anneal temperature ⩾500 °C the photoluminescence
signal decreases essentially to zero. The influence of thermal annealing processes is discussed in the context of the model
of partial transformation of the structural network of amorphous a-Si(Er):H films.
Fiz. Tekh. Poluprovodn. 33, 106–109 (January 1999) 相似文献
5.
A. J. Steckl J. Devkajan W. J. Choyke R. P. Devaty M. Yoganathan S. W. Novak 《Journal of Electronic Materials》1996,25(5):869-873
The effect of post-implantation anneal on erbium-doped 6H-SiC has been investigated. 6H-SiC has been implanted with 330 keV
Er+ at a dose of 1 × 1013 /cm2. Er depth profiles were obtained by secondary ion mass spectrometry (SIMS). The as-implanted Er-profile
had a peak concentration of∼1.3 × 1018/cm3 at a depth of 770Å. The samples were annealed in Ar at temperatures from 1200 to 1900°C. The photoluminescence intensity
integrated over the 1.5 to 1.6 μm region is essentially independent of annealing temperature from 1400 to 1900°C. Reduced,
but still significant PL intensity, was measured from the sample annealed at 1200°C. The approximate diffusivity of Er in
6H SiC was calculated from the SIMS profiles, yielding values from 4.5 × 10−16 cm2/s at 1200°C to 5.5 × 10−15 cm2/s at 1900°C. 相似文献
6.
V. Yu. Davydov V. V. Lundin A. N. Smirnov N. A. Sobolev A. S. Usikov A. M. Emel’yanov M. I. Makoviichuk E. O. Parshin 《Semiconductors》1999,33(1):1-5
The influence of rapid-anneal conditions and subsequent coimplantation of oxygen ions on the photoluminescence of erbium ions
implanted with an energy of 1 MeV and dose of 5×1014 cm−2 in MOCVD-grown GaN films is investigated. The erbium photoluminescence intensity at a wavelength ∼ 1.54 μm increases as the
fixed-time (15 s) anneal temperature is raised from 700 °C to 1300 °C. The erbium photoluminescence intensity can be increased
by the coimplantation of oxygen ions at anneal temperatures in the indicated range below 900 °C. The transformation of the
crystal structure of the samples as a result of erbium-ion implantation and subsequent anneals is investigated by Raman spectroscopy.
Fiz. Tekh. Poluprovodn. 33, 3–8 (January 1999) 相似文献
7.
Mee-Yi Ryu Y. K. Yeo M. A. Marciniak T. W. Zens E. A. Moore R. L. Hengehold T. D. Steiner 《Journal of Electronic Materials》2006,35(4):647-653
Electrical and optical activation studies of lower dose Si-implanted AlxGa1?xN (x=0.14 and 0.24) have been made systematically as a function of ion dose and anneal temperature. Silicon ions were implanted at 200 keV with doses ranging from 1×1013 cm?2 to 1×1014 cm?2 at room temperature. The samples were proximity cap annealed from 1,100°C to 1,350°C with a 500-Å-thick AlN cap in a nitrogen environment. Nearly 100% electrical activation efficiency was obtained for Al0.24Ga0.76N implanted with a dose of 1 × 1014 cm?2 after annealing at an optimum temperature around 1,300°C, whereas for lower dose (≤5×1013 cm?2) implanted Al0.24Ga0.76N samples, the electrical activation efficiencies continue to increase with anneal temperature up through 1,350°C. Seventy-six percent electrical activation efficiency was obtained for Al0.14Ga0.86N implanted with a dose of 1 × 1014 cm?2 at an optimum anneal temperature of around 1,250°C. The highest mobilities obtained were 89 cm2/Vs and 76 cm2/Vs for the Al0.14Ga0.86N and Al0.24Ga0.76N, respectively. Consistent with the electrical results, the photoluminescence (PL) intensity of the donor-bound exciton peak increases as the anneal temperature increases from 1,100°C to 1,250°C, indicating an increased implantation damage recovery with anneal temperature. 相似文献
8.
SIDDARTH G. SUNDARESAN MULPURI V. RAO YONGLAI TIAN JOHN A. SCHREIFELS MARK C. WOOD KENNETH A. JONES ALBERT V. DAVYDOV 《Journal of Electronic Materials》2007,36(4):324-331
Rapid solid-state microwave annealing was performed for the first time on N+-, Al+-, and B+-implanted SiC, and the results were compared with the conventional furnace annealing. For microwave annealing, temperatures
up to 2,000 °C were attained with heating rates exceeding 600 °C/s. An 1,850 °C/35 s microwave anneal yielded a root-mean-square
(RMS) surface roughness of 2 nm, which is lower than the 6 nm obtained for 1,500 °C/15 min conventional furnace annealing.
For the Al implants, a minimum room-temperature sheet resistance (R
s
) of 7 kΩ/□ was measured upon microwave annealing. For the microwave annealing, Rutherford backscattering (RBS) measurements
indicated a better structural quality, and secondary-ion-mass-spectrometry (SIMS) boron implant depth profiles showed reduced
boron redistribution compared to the corresponding results of the furnace annealing. 相似文献
9.
The properties of TiN/TiSi2 bilayer formed by rapid thermal annealing (RTA) in an NH3 ambient after the titanium film is deposited on the silicon substrate is investigated. It is found that the formation of
TiN/TiSi2 bilayer depends on the RTA temperature and a competitive reaction for the TiN/TiSi2 bilayer occurs at 600°C. Both the TiN and TiSi2 layers represent titanium-rich films at 600°C anneal. The TiN layer has a stable structure at 700°C anneal while the TiSi2 layer has C49 and C54 phase. Both the TiN and TiSi2 layers have stable structures and stoichiometries at 800°C anneal. When the TiN/TiSi2 bilayer is formed, the redistribution of boron atoms within the TiSi2 layer gets active as the anneal temperature is increased. According to secondary ion mass spectroscopy analysis, boron atoms
pile up within the TiN layer and at the TiSi2−Si interface. The electrical properties for n+ and p+ contacts are investigated. The n+ contact resistance increases slightly with increasing annealing temperature but the p+ contact resistance decreases. The leakage current indicates degradation of the contact at high annealing temperature for
both n+ and p+ junctions. 相似文献
10.
S. P. Guo Y. Chang J. M. Zhang X. C. Shen J. H. Chu S. X. Yuan 《Journal of Electronic Materials》1996,25(5):761-764
HgCdTe epilayers were grown by molecular beam epitaxy. A series of As+-implanted CdTe and HgCdTe epilayers annealed under different temperatures were investigated by photoluminescence spectroscopy.
More As+ ions can occupy the Te sublattice after the samples were annealed at 450°C, and the acceptor level of As+ on the Te sublattice for HgCdTe material (x ≈ 0.39) is 31.5 meV. The Raman spectrum study indicates a recovery of the crystalline
perfection after the post-As+-implantation thermal treatment. 相似文献
11.
R. E. Kroon J. R. Botha J. H. Neethling T. J. Drummond 《Journal of Electronic Materials》1999,28(12):1466-1470
Degenerately doped n-type GaAs produces band-to-band luminescence with the peak energy dependent on the carrier concentration.
In this study the photoluminescence of Si-doped GaAs is examined after implantation with high energy Be ions and annealing.
The band-to-band peak energy in the unimplanted (reference) material is shown to be smaller than reported values in Te-doped
GaAs of the same carrier concentration. This is attributed to compensation in the Si doped material as a result of its amphoteric
nature. For the implanted samples, no luminescence was recorded for the unannealed samples or those annealed at 400°C and
500°C. Comparing the relative peak intensities from material annealed at 600°C for 15 min and 30 min indicates an increase
in the number of As vacancies with anneal time. For samples annealed at 700°C and 800°C, the dominant luminescence is associated
with GaAs antisite defects. It is suggested that formation of these defects occurs predominantly only at these higher temperatures.
Crystal recovery as measured by the luminescence intensity increased with both anneal temperature and time. For the implanted
sample annealed at 800°C for 15 min, the dominant peak height was 25% of that from the reference sample. 相似文献
12.
C. Miclaus G. Malouf S. M. Johnson M. S. Goorsky 《Journal of Electronic Materials》2005,34(6):859-863
As part of a series of wafer bonding experiments, the exfoliation/blistering of ion-implanted Cd0.96Zn0.04Te substrates was investigated as a function of postimplantation annealing conditions. (211) Cd0.96Zn0.04Te samples were implanted either with hydrogen (5×1016 cm−2; 40–200 keV) or co-implanted with boron (1×1015 cm−2; 147 keV) and hydrogen (1–5×1016 cm−2; 40 keV) at intended implant temperatures of 253 K or 77 K. Silicon reference samples were simultaneously co-implanted. The
change in the implant profile after annealing at low temperatures (<300°C) was monitored using high-resolution x-ray diffraction,
atomic force microscopy (AFM), and optical microscopy. The samples implanted at the higher temperature did not show any evidence
of blistering after annealing, although there was evidence of sample heating above 253 K during the implant. The samples implanted
at 77 K blistered at temperatures ranging from 150°C to 300°C, depending on the hydrogen implant dose and the presence of
the boron co-implant. The production of blisters under different implant and annealing conditions is consistent with nucleation
of subsurface defects at lower temperature, followed by blistering/exfoliation at higher temperature. The surface roughness
remained comparable to that of the as-implanted sample after the lower temperature anneal sequence, so this defect nucleation
step is consistent with a wafer bond annealing step prior to exfoliation. Higher temperature anneals lead to exfoliation of
all samples implanted at 77 K, although the blistering temperature (150–300°C) was a strong function of the implant conditions.
The exfoliated layer thickness was 330 nm, in good agreement with the projected range. The “optimum” conditions based on our
experimental data showed that implanting CdZnTe with H+ at 77 K and a dose of 5×1016/cm2 is compatible with developing high interfacial energy at the bonded interface during a low-temperature (150°C) anneal followed
by layer exfoliation at higher (300°C) temperature. 相似文献
13.
J. C. Zolper J. Han R. M. Biefeld S. B. van Deusen W. R. Wampler D. J. Reiger S. J. Pearton J. S. Williams H. H. Tan R. F. Karlicek Jr. R. A. Stall 《Journal of Electronic Materials》1998,27(4):179-184
Implant activation annealing of Si-implanted GaN is reported for temperatures from 1100 to 1400°C. Free electron concentrations
up to 3.5×1020 cm−3 are estimated at the peak of the implanted profile with Hall mobilities of ∼60 cm2/Vs for annealing at 1300°C for 30 s with an AIN encapsulant layer. This mobility is comparable to epitaxial GaN doped at
a similarly high level. For annealing at ≥1300°C, the sample must be encapsulated with AIN to prevent decomposition of the
GaN layer. Channeling Rutherford backscattering demonstrates the partial removal of the implant damage after a 1400°C anneal
with a minimum channeling yield of 12.6% compared to 38.6% for the as-implanted spectrum. Scanning electron microscope images
show evidence of decomposition of unencapsulated GaN after a 1300°C anneal and complete sublimation after 1400°C. The use
of AIN encapsulation and annealing at temperatures of ∼1300°C will allow the formation of selective areas of highly doped
GaN to reduce the contact and access resistance in GaN-based transistors and thyristors. 相似文献
14.
Thedata presented here show that Ge- implanted GaAs has a complex amphoteric behavior which is controlled by the implantation dose, implantation temperature, and anneal temperature.
Annealing was performed with rf plasma deposited Si3N4 as the encapsulant. Implantations at-100° C resulted in p-layers, while those performed at 100° C and above resulted in n-layers
regardless of the dose and anneal temperature. Room temperature implants resulted in p- or n-layers depending on the combination
of dose and anneal temperature. Electrical activation and carrier mobilities were low for anneal temperatures ≤ 850°C. Low
temperature (6 K) photoluminescence indicated that a significant amount of residual damage remained after annealing. Atomic
Ge distribution profiles, carrier con-centration profiles, and junction characteristics of Ge-implanted GaAs planar diodes
are also presented.
This work was supported by the Joint Services Electronics Program (U.S. Army, U.S. Navy, U.S. Air Force) under contract N00014-79-C-0424,
and by the Office of Naval Research under contract N00014-76-C-0806. 相似文献
15.
A. M. Emel’yanov N. A. Sobolev E. I. Shek V. V. Lundin A. S. Usikov E. O. Parshin 《Semiconductors》2005,39(9):1045-1047
Room-temperature photoluminescence (PL) has been studied in AlGaN/GaN superlattices and GaN epitaxial layers implanted with 1-MeV erbium at a dose of 3 × 1015 cm?2 and annealed in argon. The intensity of PL from Er3+ ions in the superlattices exceeds that for the epitaxial layers at annealing temperatures of 700–1000°C. The strongest difference (by a factor of ~2.8) in PL intensity between the epitaxial layers and the superlattices and the highest PL intensity for the superlattices are observed upon annealing at 900°C. On raising the annealing temperature to 1050°C, the intensity of the erbium emission from the superlattices decreases substantially. This circumstance may be due to their thermal destruction. 相似文献
16.
Cleber Biasotto Viktor Gonda Lis K. Nanver Tom L.M. Scholtes Johan van der Cingel Daniel Vidal Vladimir Jovanović 《Journal of Electronic Materials》2011,40(11):2187-2196
Good-quality ultrashallow n
+
p junctions are formed using 5-keV amorphizing As+ implantations followed by a single-shot excimer laser anneal for dopant activation. By using an implant that is self-aligned
to the contact windows etched in an oxide isolation layer, straightforward processing of the diodes is achieved with postimplantation
processing temperatures kept below 400°C. A possible source of junction leakage at the perimeter caused by dip-etch enlargement
of the contact window, also confirmed by transmission electron microscopy (TEM) analysis, is identified, and diode performance
is improved by increasing the junction/contact window overlap. The optimum performance in terms of low leakage, shallow junctions,
and low resistivity is achieved for 30° tilted implants and by applying a thin laser-reflective aluminum layer. This work
isolates the minimum requirements for achieving low-leakage diode characteristics. 相似文献
17.
Bonding and thermal stability of implanted hydrogen in silicon 总被引:1,自引:0,他引:1
H. J. Stein 《Journal of Electronic Materials》1975,4(1):159-174
The behavior of implanted hydrogen in Si has been investigated by differential infrared transmittance measurements using multiple-internal-reflection
(MIR) plates. Si-H bonding of implanted hydrogen is detected by seven absorption bands between 4.5 and 5.5 μm after implantation
with 1016 H+/cm2 at ion energies between 70 and 400 keV. The absorption bands are close in frequency to those for SiH stretching modes for
silane, and they are produced only by hydrogen implantation. Implantation with deuterium gave absorption bands shifted to
lower frequencies in accord with the square root of the reduced mass ratio for Si-H relative to Si-D.
The multiplicity of hydrogen-associated bands is apparently a consequence of defects in the implanted layer. A dependence
of the hydrogen-associated bands on the disorder is suggested by the annealing loss of five of the initial seven bands, and
a growth of the other two, for the same temperatures (100–300°C) as those for annealing out the broad divacancy band at 1.8
μm. A disorder dependence of the Si-H vibrational frequencies is further demonstrated by a regeneration of the bands annealing
below 300°C when a hydrogen-implanted MIR plate annealed at 300°C was subsequently bombarded with neon. In addition to the
seven resolved bands after H+ implantation, five other bands in the same range of frequencies grow in and anneal out between 100 and 700°C. Annealing at
700°C eliminates all SiH bands, and they cannot be regenerated by bombardment with other ions. It is suggested that implanted
hydrogen in Si is bonded at defect sites, and that a loss of an SiH band is caused by either a change in charge state of a
defect or by the loss of a defect.
This work was supported by the United States Atomic Energy Commission 相似文献
18.
Cobalt disilicide is grown epitaxially on (100) Si from a 15 nm Co/2 nm Ti bilayer by rapid thermal annealing (RTA) at 900°C.
Polycrystalline CoSi2 is grown on (100) Si using a 15 nm Co layer and the same annealing condition. Silicide/p+-Si/n-Si diodes are made using the silicide as dopant source:11B+ ions are implanted at 3.5–7.5 kV and activated by RTA at 600–900°C. Shallow junctions with total junction depth (silicide
plus p+ region) measured by high-resolution secondaryion mass spectroscopy of 100 nm are fabricated. Areal leakage current densities
of 13 nA/cm2 and 2 nA/cm2 at a reverse bias of -5V are obtained for the epitaxial silicide and polycrystalline silicide junctions, respectively, after
700°C post-implant annealing. 相似文献
19.
Rapid thermal annealing (RTA) technology offers potential advantages for GaAs MESFET device technology such as reducing dopant
diffusion and minimizing the redistribution of background impurities. LEC semi-insulating GaAs substrates were implanted with
Si at energies from 100 to 400 keV to doses from 1 × 1012 to 1 × 1014/cm2. The wafers were encapsulated with Si3N4 and then annealed at temperatures from 850-1000° C in a commercial RTA system. Wafers were also annealed using a conventional
furnace cycle at 850° C to provide a comparison with the RTA wafers. These implanted layers were evaluated using capacitance-voltage
and Hall effect measurements. In addition, FET’s were fabricated using selective implants that were annealed with either RTA
or furnace cycles. The effects of anneal temperature and anneal time were determined. For a dose of 4 × 1012/cm2 at 150 keV with anneal times of 5 seconds at 850, 900, 950 and 1000° C the activation steadily increased in the peak of the
implant with overlapping profiles in the tail of the profiles, showing that no significant diffusion occurs. In addition,
the same activation could be obtained by adjusting the anneal times. A plot of the equivalent anneal times versus 1/T gives
an activation energy of 2.3 eV. At a higher dose of 3 × 1013 an activation energy of 1.7 eV was obtained. For a dose of 4 × 1012 at 150 keV both the RTA and furnace annealing give similar activations with mobilities between 4700 and 5000 cm2/V-s. Mobilities decrease to 4000 at a dose of 1 × 1013 and to 2500 cm2/V-s at 1 × 1014/cm2. At doses above 1 × 1013 the RTA cycles gave better activation than furnace annealed wafers. The MESFET parameters for both RTA and furnace annealed
wafers were nearly identical. The average gain and noise figure at 8 GHz were 7.5 and 2.0, respectively, for packaged die
from either RTA or furnace annealed materials. 相似文献
20.
J. Y. Dai K. K. Ong D. Z. Chi M. H. Liang K. C. Leong L. Chan S. K. Lahiri 《Journal of Electronic Materials》2001,30(7):850-854
Effects of temperature and dosage on the evolution of extended defects during annealing of MeV ion-implanted Czochralski (CZ)
p-type (001) silicon have been studied using transmission electron microcopy. Excess interstitials generated in a 1 1015 cm−2/1.5 MeV B+ implanted Si have been found to transform into extended interstitial {311} defects upon rapid thermal annealing at 800°C
for 15 sec. During prolonged furnace annealing at 960°C for 1 h, some of the {311} defects grow longer at the expense of the
smaller ones, and the average width of the defects seems to decrease at the same time. Formation of stable dislocation loops
appears to occur only above a certain threshold annealing temperature (∼1000°C). The leakage current in diodes fabricated
on 1.5 MeV B+ implanted wafers was found to be higher for a dosage of 1 1014cm−2 and less, as compared to those fabricated with a dosage of 5 1014 cm−2 and more. The difference in the observed leakage current has been attributed to the presence of dislocations in the active
device region of the wafers that were implanted with the lower dosage. 相似文献