共查询到20条相似文献,搜索用时 46 毫秒
1.
B. A. Andreev N. A. Sobolev Yu. A. Nikolaev D. I. Kuritsin M. I. Makovijchuk E. O. Parshin 《Semiconductors》1999,33(4):407-409
In this paper the photoluminescence (PL) of holmium-doped silicon is discussed. The silicon was first implanted with holmium
ions at energies of 1–2 MeV and doses of 1×1013–3×1014 cm−2, and then annealed at temperatures of 620–900 °C for 0.5–1 h. In order to increase the concentration of electrically and
optically active centers, the silicon was implanted a second time with oxygen ions at energies of 0.14–0.29 MeV and doses
of 1×1014–3×1015 cm−2. Several photoluminescence lines, which are attributable to the transitions of electrons from the first excited state of
the Ho3+ ion (5
I
7) to the ground state (5
I
8), were observed. The amplitudes of the most intense lines, which correspond to transitions at frequencies 5119 and 5103 cm−1, decreased by more than an order of magnitude in the temperature range 4.2−78 K. The PL intensity of the holmium ions increased
with increasing concentrations of the implanted rare-earth ions and oxygen.
Fiz. Tekh. Poluprovodn. 33, 420–422 (April 1999) 相似文献
2.
F. G. Kellert S. R. Sloan M. J. Ludowise J. E. Turner 《Journal of Electronic Materials》1992,21(10):983-987
We report on the control of zinc in organometallic vapor phase epitaxial (OMVPE) grown InP:Zn/InGaAs/InPp- i- n double heterojunctions with InGaAs:Zn contacting layers. As a function of diethylzinc (DEZn) flow, we measure net acceptor
concentrations for the InP:Zn p-layer in the range 2 × 1017≤N
a−N
d≤ 9 × 1017 cm−3. A 435°C post-growth anneal for 300 sec increases the net acceptor concentrations by a factor of 3.6 − to 6 × 1017≤N
a−N
d≤ 3 × 1018 cm−3. When the annealed value ofN
a − Ndin the InP:Zn layer is 6 × 1017 cm−3 , secondary ion mass spectrometry (SIMS) measurements show abrupt Zn-doping transitions at the heterojunction interfaces.
In contrast, when the annealed value ofN
a − Ndin the InP:Zn layer is near the saturation value of 3 × 1018 cm−3, SIMS measurements show significant movement of Zn into the nominally undoped InGaAs instrinsic layer. Increasedp-i-n diode capacitance is associated with the Zn movement. 相似文献
3.
Electrical activation studies of Al
x
Ga1−x
N (x = 0.45 and 0.51) implanted with Si for n-type conductivity have been made as a function of ion dose and anneal temperature. Silicon ions were implanted at 200 keV
with doses ranging from 1 × 1014 cm−2 to 1 × 1015 cm−2 at room temperature. The samples were subsequently annealed from 1150°C to 1350°C for 20 min in a nitrogen environment. Nearly
100% electrical activation efficiency was successfully obtained for the Si-implanted Al0.45Ga0.55N samples after annealing at 1350°C for doses of 1 × 1014 cm−2 and 5 × 1014 cm−2 and at 1200°C for a dose of 1 × 1015 cm−2, and for the Al0.51Ga0.49N implanted with silicon doses of 1 × 1014 cm−2 and 5 × 1014 cm−2 after annealing at 1300°C. The highest room-temperature mobility obtained was 61 cm2/V s and 55 cm2/V s for the low-dose implanted Al0.45Ga0.55N and Al0.51Ga0.49N, respectively, after annealing at 1350°C for 20 min. These results show unprecedented activation efficiencies for Al
x
Ga1−x
N with high Al mole fractions and provide suitable annealing conditions for Al
x
Ga1−x
N-based device applications. 相似文献
4.
E.A. Moore Y.K. Yeo G.J. Gruen Mee-Yi Ryu R.L. Hengehold 《Journal of Electronic Materials》2010,39(1):21-28
Electrical activation studies were carried out on Si-implanted Al0.33Ga0.67N as a function of ion dose, annealing temperature, and annealing time. The samples were implanted at room temperature with
Si ions at 200 keV in doses ranging from 1 × 1014 cm−2 to 1 × 1015 cm−2, and subsequently proximity-cap annealed from 1150°C to 1350°C for 20 min to 60 min in a nitrogen environment. One hundred
percent electrical activation efficiency was obtained for Al0.33Ga0.67N samples implanted with a dose of 1 × 1015 cm−2 after annealing at either 1200°C for 40 min or at 1300°C for 20 min. The samples implanted with doses of 1 × 1014 cm−2 and 5 × 1014 cm−2 exhibited significant activations of 74% and 90% after annealing for 20 min at 1300°C and 1350°C, respectively. The mobility
increased as the annealing temperature increased from 1150°C to 1350°C, showing peak mobilities of 80 cm2/V s, 64 cm2/V s, and 61 cm2/V s for doses of 1 × 1014 cm−2, 5 × 1014 cm−2, and 1 × 1015 cm−2, respectively. Temperature-dependent Hall-effect measurements showed that most of the implanted layers were degenerately
doped. Cathodoluminescence measurements for all samples exhibited a sharp neutral donor-bound exciton peak at 4.08 eV, indicating
excellent recovery of damage caused by ion implantation. 相似文献
5.
InP doping superlattices (DSLs) were grown by atmospheric pressure metalorganic vapor phase epitaxy (MOVPE) and their stability
was examined by annealing at high temperatures. Diethylzinc (DEZ) and H2S were used asp- andn-type doping sources, respectively. Photoluminescence (PL) measurements performed on as grown layers show a shift of the main
emission peak with increasing excitation power in very good agreement with theoretical models. A comparison of the PL results
between these structures and the annealed samples show that even at very high temperatures (up to 850° C) the tunability of
the effective bandgap of the annealed superlattices is possible, although less pronounced than for the as grown layers. This
is due to diffusion of the dopants, into adjacent layers and partial compensation of each other. Secondary ion mass spectrometry
(SIMS) done on the as grown and annealed samples shows that only the Zn atoms diffuse. Diffusion coefficients obtained from
the SIMS profiles give values in the range 1 × 10−14 <D < 9 × 10−14 cm2/s, still smaller than other published values estimated on layers, which did not suffer any treatment. This shows the high
quality and stability of our layers even at high temperatures. 相似文献
6.
Electrical activation studies of Si-implanted Al
x
Ga1−x
N with an Al mole fraction of 11% to 51% have been carried out as a function of ion dose and annealing temperature. The Al
x
Ga1−x
N samples were implanted at room temperature with Si ions at 200 keV in doses ranging from 1 × 1014 cm−2 to 1 × 1015 cm−2, and subsequently annealed from 1100°C to 1350°C for 20 min in a nitrogen environment. The maximum electrical activation
efficiencies for the Al
x
Ga1−x
N samples with an Al mole fraction less than 40% were obtained for samples implanted with the highest Si dose of 1 × 1015 cm−2. On the other hand, for the Al
x
Ga1−x
N samples with an Al mole fraction more than 40%, nearly perfect activation efficiencies of 99% and 100% were obtained for
the samples implanted with the lowest Si dose of 1 × 1014 cm−2. The mobility of the Si-implanted Al
x
Ga1−x
N samples increased with increasing annealing temperature in spite of the increased number of ionized donors and thus increased
impurity scattering, indicating that a greater amount of lattice damage is being repaired with each successive increase in
annealing temperature. These results provide suitable annealing conditions for Si-implanted Al
x
Ga1−x
N-based devices with an Al mole fraction from 11% to 51%. 相似文献
7.
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
8.
R. Nipoti A. Nath S.B. Qadri Y-L. Tian C. Albonetti A. Carnera Mulpuri V. Rao 《Journal of Electronic Materials》2012,41(3):457-465
Semi-insulating 4H-SiC ⟨0001⟩ wafers have been phosphorus ion implanted at 500°C to obtain phosphorus box depth profiles with
dopant concentration from 5 × 1019 cm−3 to 8 × 1020 cm−3. These samples have been annealed by microwave and conventional inductively heated systems in the temperature range 1700°C
to 2050°C. Resistivity, Hall electron density, and Hall mobility of the phosphorus-implanted and annealed 4H-SiC layers have
been measured in the temperature range from room temperature to 450°C. The high-resolution x-ray diffraction and rocking curve
of both virgin and processed 4H-SiC samples have been analyzed to obtain the sample crystal quality up to about 3 μm depth from the wafer surface. For both increasing implanted phosphorus concentration and increasing post-implantation annealing
temperature the implanted material resistivity decreases to an asymptotic value of about 1.5 × 10−3 Ω cm. Increasing the implanted phosphorus concentration and post-implantation annealing temperature beyond 4 × 1020 cm−3 and 2000°C, respectively, does not bring any apparent benefit with respect to the minimum obtainable resistivity. Sheet resistance
and sheet electron density increase with increasing measurement temperature. Electron density saturates at 1.5 × 1020 cm−3 for implanted phosphorus plateau values ≥4 × 1020 cm−3, irrespective of the post-implantation annealing method. Implantation produces an increase of the lattice parameter in the
bulk 4H-SiC underneath the phosphorus-implanted layer. Microwave and conventional annealing produce a further increase of
the lattice parameter in such a depth region and an equivalent recovered lattice in the phosphorus-implanted layers. 相似文献
9.
R. D. Dupuis C. J. Eiting P. A. Grudowski H. Hsia Z. Tang D. Becher H. Kuo G. E. Stillman M. Feng 《Journal of Electronic Materials》1999,28(3):319-324
Ion implantation into III–V nitride materials is animportant technology for high-power and high-temperature digital and monolithic
microwave integrated circuits. We report the results of the electrical, optical, and surface morphology of Si ion-implanted
GaN films using furnace annealing. We demonstrate high sheet-carrier densities for relatively low-dose (natoms=5×1014 cm−2) Si implants into AlN/GaN/sapphire heteroepitaxial films. The samples that were annealed at 1150°C in N2 for 5 min exhibited a smooth surface morphology and a sheet electron concentration ns ∼9.0×1013 cm−2, corresponding to an estimated 19% electrical activation and a 38% Si donor activation in GaN films grown on sapphire substrates.
Variable-temperature Hall-effect measurem entsindicate a Si donor ionization energy ∼15 meV. 相似文献
10.
M. K. Sharov 《Semiconductors》2012,46(5):595-597
The thermopower coefficient α0 and the electrical conductivity σ of Pb1 − x
Ag
x
Te solid solutions, where x = (0–0.007), are measured at T = 300 K. The hole concentration p is calculated. All samples are of the p type. With increasing silver content, α0 decreases, while p and σ increase. For undoped crystals, α0 = 251.0 μV/K, p = 1.1 × 1018 cm−3, and σ = 165 Ω−1 cm−1. At the silver-solubility limit for x = 0.007, α0 = 193.8 μV/K, p = 2.3 × 1018 cm−3, and σ = 216 Ω−1 cm−1. The hole concentration in all samples is much lower than the concentration of introduced silver atoms. The hole gas in Pb1 − x
Ag
x
Te solid solutions is weakly degenerate in the entire silver-concentration range. 相似文献
11.
N. Inoue A. Itoh T. Kimoto H. Matsunami T. Nakata M. Inoue 《Journal of Electronic Materials》1997,26(3):165-171
N+ implantation into p-type a-SiC (6H-SiC, 4H-SiC) epilayers at elevated temperatures was investigated and compared with implantation
at room temperature (RT). When the implant dose exceeded 4 × 1015 cm−2, a complete amorphous layer was formed in RT implantation and severe damage remained even after post implantation annealing
at 1500°C. By employing hot implantation at 500~800°C, the formation of a complete amorphous layer was suppressed and the
residual damage after annealing was significantly reduced. For implant doses higher than 1015 cm−2, the sheet resistance of implanted layers was much reduced by hot implantation. The lowest sheet resistance of 542Ω/ was
obtained by implantation at 500 ~ 800°C with a 4 × 1015 cm−2 dose. Characterization of n+-p junctions fabricated by N+ implantation into p-type epilayers was carried out in detail. The net doping concentration in the region close to the junction
showed a linearly graded profile. The forward current was clearly divided into two components of diffusion and recombination.
A high breakdown voltage of 615 ∼ 810V, that is almost an ideal value, was obtained, even if the implant dose exceeded 1015 cm−2. By employing hot implantation at 800°C, the reverse leakage current was significantly reduced. 相似文献
12.
G. Katulka K. J. Roe J. Kolodzey C. P. Swann G. Desalvo R. C. Clarke G. Eldridge R. Messham 《Journal of Electronic Materials》2002,31(5):346-350
The effects of implanted Ge on the resistance of nickel-metal contacts to n-type and p-type 4H-SiC are reported. The Ge was
implanted with an energy of 346 keV and a dose of 1.7×1016 cm−2, and the wafer was annealed up to 1700°C for 30 min. Contact resistance measurements using the transfer length method (TLM)
were performed on etched mesas of n-type and p-type 4H-SiC, with and without the Ge. For the annealed-Ni metal contacts, the
Ge lowered the specific contact resistivity from 5.3×10−4 Ωcm2 to 6.0×10−5 Ωcm2 for n-type SiC and from 1.2×10−3 Ωcm2 to 8.3×10−5 Ωcm2 for p-type SiC. For the as-deposited (unannealed) Ni, the Ge produced ohmic contacts, whereas the contacts without Ge were rectifying. These results suggest that the addition
of Ge can be an important process step to reduce the contact resistance for SiC-device applications. 相似文献
13.
V. V. Slyn’ko E. I. Slyn’ko A. G. Khandozhko Yu. K. Vygranenko 《Semiconductors》1997,31(10):1021-1024
A study is reported of the nuclear magnetic resonance spectra of 119Sn and 125Te in SnTe with hole concentrations p
77=1.42×1020−2.3×1021 cm−3 and in SnTe:Mn (N
Mn=0.5 and 5 at. %, p
77=8×1020 cm−3) at T=4.2–300 K. Considerable broadening of NMR lines due to hyperfine magnetic interactions between nuclear and electron spins
was observed in SnTe with p
77>2×20 cm−3. Asymmetric broadening of the resonance lines was observed in the rhombohedral phase of SnTe and SnTe:Mn. The temperature
dependence of the NMR line width of 125Te in SnTe:Mn is in agreement with the magnetic phase diagram for N
Mn=5 at. %. The superparamagnetic phase of SnTe:Mn is formed at T=20±2 K and the ferromagnetic phase is formed at T=4.2 K.
Fiz. Tekh. Poluprovodn. 31, 1187–1191 (October 1997) 相似文献
14.
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
15.
Surface roughening in ion implanted 4H-silicon carbide 总被引:1,自引:0,他引:1
M. A. Capano S. Ryu J. A. Cooper Jr. M. R. Melloch K. Rottner S. Karlsson N. Nordell A. Powell D. E. Walker Jr. 《Journal of Electronic Materials》1999,28(3):214-218
Silicon carbide (SiC) devices have the potential to yield new components with functional capabilities that far exceed components
based on silicon devices. Selective doping of SiC by ion implantation is an important fabrication technology that must be
completely understood if SiC devices are to achieve their potential. One major problem with ion implantation into SiC is the
surface roughening that results from annealing SiC at the high temperatures which are needed to activate implanted acceptor
ions, boron or aluminum. This paper examines the causes and possible solutions to surface roughening of implanted and annealed
4H-SiC. Samples consisting of n-type epilayers (5 × 1015 cm−3, 4 μm thick) on 4H-SiC substrates were implanted with B or Al to a total dose of 4 × 1014 cm−2 or 2 × 1015 cm−2, respectively. Roughness measurements were made using atomic force microscopy. From the variation of root mean square (rms)
roughness with annealing temperature, apparent activation energies for roughening following implantation with Al and B were
1.1 and 2.2 eV, respectively, when annealed in argon. Time-dependent activation and surface morphology analyses show a sublinear
dependence of implant activation on time; activation percentages after a 5 min anneal following boron implantation are about
a factor of two less than after a 40 min anneal. The rms surface roughness remained relatively constant with time for anneals
in argon at 1750°C. Roughness values at this temperature were approximately 8.0 nm. Annealing experiments performed in different
ambients demonstrated the benefits of using silane to maintain good surface morphology. Roughnesses were 1.0 nm (rms) when
boron or aluminum implants were annealed in silane at 1700°C, but were about 8 and 11 nm for B and Al, respectively, when
annealed in argon at the same temperature. 相似文献
16.
I. Chary A. Chandolu B. Borisov V. Kuryatkov S. Nikishin M. Holtz 《Journal of Electronic Materials》2009,38(4):545-550
We have studied the influence of surface treatment and annealing temperature on the specific contact resistance of Au/Ni ohmic
contacts to p-GaN with hole concentrations in the range of 1016 cm−3 to 1018 cm−3. The sample with a hole concentration of 1 × 1018 cm−3, treated with the surface treatment HCl:H2O = 3:1 solution and annealed at 500°C in a 90% N2 and 10% O2 atmosphere, yielded the lowest specific contact resistance of ~4 × 10−5 Ω cm2 and ~2 × 10−7 Ω cm2 at room temperature and at 150°C, respectively. To investigate the roles of interdiffusion between layer interfaces and the
formation of NiO and nickel gallides, we examined the metallization stacks before and after annealing using high-resolution
x-ray diffraction. We conclude that the nickel-gallide formation and the deterioration of the NiO layer are together responsible
for the large deviation in contact resistances observed for samples annealed at various temperatures. 相似文献
17.
M. V. Lebedev V. V. Sherstnev E. V. Kunitsyna I. A. Andreev Yu. P. Yakovlev 《Semiconductors》2011,45(4):526-529
The effect of passivation with the solution of sodium sulfide (Na2S) in isopropyl alcohol on the room-temperature performance of the GaInAsSb/GaAlAsSb and InAs/InAsSbP photodiodes is investigated.
After such a treatment the dark current density of the GaInAsSb/GaAlAsSb photodiodes at a reverse bias of 0.1 V is reduced
from 5.5 × 10−2 to 2.1 × 10−3 A/cm2 and a zero-bias resistance-area product (R
0
A) is improved from 1.0 to 25.6 Ω cm2. For the InAs/InAsSbP photodiodes, the dark current density at U = −0.1 V is decreased from 1.34 to 8.1 × 10−1 A/cm2, while the R
0
A value increases from 4.4 × 10−2 to 7.3 × 10−2 Ω cm2. The method offers long-term stability of the photodiode performance. 相似文献
18.
J. Antoszewski C. A. Musca J. M. Dell L. Faraone 《Journal of Electronic Materials》2000,29(6):837-840
This paper presents transport measurements on both vacancy doped and gold doped Hg0.7Cd0.3Te p-type epilayers grown by liquid phase epitaxy (LPE), with NA=2×1016 cm−3, in which a thin 2 μm surface layer has been converted to n-type by a short reactive ion etching (RIE) process. Hall and
resistivity measurements were performed on the n-on-p structures in van der Pauw configuration for the temperature range from
30 K to 400 K and magnetic field range up to 12 T. The experimental Hall coefficient and resistivity data has been analyzed
using the quantitative mobility spectrum analysis procedure to extract the transport properties of each individual carrier
contributing to the total conduction process. In both samples three distinct carrier species have been identified. For 77
K, the individual carrier species exhibited the following properties for the vacancy and Au-doped samples, respectively, holes
associated with the unconverted p-type epilayer with p ≈ 2 × 1016 cm−3, μ ≈ 350 cm2V−1s−1, and p ≈ 6 × 1015 cm−3, μ ≈ 400 cm2V−1s−1; bulk electrons associated with the RIE converted region with n ≈ 3 × 1015cm−3, μ ≈ 4 × 104 cm2V−1s−1, and n ≈ 1.5 × 1015 cm−3, μ ≈ 6 × 104 cm2V−1s−1; and surface electrons (2D concentration) n ≈ 9 × 1012 cm−2 and n ≈ 1 × 1013 cm−2, with mobility in the range 1.5 × 103 cm2V−1s−1 to 1.5 × 104 cm2V−1s−1 in both samples. The high mobility of bulk electrons in the RIE converted n-layer indicates that a diffusion process rather
than damage induced conversion is responsible for the p-to-n conversion deep in the bulk. On the other hand, these results
indicate that the surface electron mobility is affected by RIE induced damage in a very thin layer at the HgCdTe surface. 相似文献
19.
By the indirect Archimedean method, the density and the density-temperature relationship of the Sn-40Pb eutectic alloy and
two Pb-free solders, Sn-57Bi and Sn-9Zn eutectic alloys, were measured from room temperature to about 250°C. The results showed
that the density-temperature dependence for each alloy in both solid and melting states can be fitted linearly as ρS(Sn-40Pb)=8.51−8.94×10−4(T−25°C), ρL(Sn-40Pb)=8.15−13.8×10−4(T−Tm); ρS(Sn-57Bi)=8.54−5.86 × 10−4(T−25°C), ρL(Sn-57Bi)=8.51−10.9×10−4(T−Tm); and ρs(Sn-9Zn)=7.22−7.78×10−4(T−25°C), ρL(Sn-9Zn)=6.89−5.88×10 −4(T−Tm), where the density unit was g/cm3. At the melting point, density of the melt of these solders is 8.15 g/cm3, 8.51 g/cm3, and 6.89 g/cm3, respectively. The density decreased 2.6% for Sn-40Pb eutectic alloy during melting, and 2.7% for Sn-9Zn eutectic alloy,
but increased 0.5% for Sn-57Bi eutectic alloy. The excess molar volume for these alloys after mixing at their melting point
is 0.03 cm3/mol for Sn-40Pb, 0.09 cm3/mol for Sn-57Bi, and 0.21 cm3/mol for Sn-9Zn. 相似文献
20.
N. Nordell A. Schöner K. Rottner P. O. Å. Persson Q. Wahab L. Hultman M. K. Linnarsson E. Olsson 《Journal of Electronic Materials》1998,27(7):833-837
Implantation of B has been performed into an epitaxially grown layer of 6H SiC, at two different B concentrations, 2×1016 cm−3 and 2×1018 cm−3. Subsequently, an epitaxial layer was regrown on the B implanted layer. The samples were investigated by transmission electron
microscopy (TEM) and secondary ion mass spectrometry (SIMS). In the highly B-doped layers plate-like defects were found, associated
with large strain fields, and an increased B concentration. These defects were stable at the originally implanted region during
regrowth and at anneal temperatures up to 1700°C. In the samples implanted with the lower B concentration, no crystal defects
could be detected by TEM. No threading dislocations or other defects were observed in the regrown epitaxial layer, which shows
the possibility to grow a layer with high crystalline quality on B implanted 6H SiC. By SIMS, it was found that B piles up
at the interface to the regrown layer, which could be explained by enhanced diffusion from an increased concentration of point
defects created by implantation damage in the region. B is also spread out into the original crystal and in the regrown layer
at a concentration of below 2×1016 cm−3, with a diffusion constant estimated to 1.3×10−12 cm2s−1. This diffusion is most probably not driven by implantation damage, but by intrinsic defects in the grown crystal. Our investigation
shows that the combination of implantation and subsequent regrowth techniques could be used in SiC for building advanced device
structures, with the crystal quality in the regrown layer not being deteriorated by crystal defects in the implanted region.
A device process using B implantation and subsequent regrowth could on the other hand be limited by the diffusion of B. 相似文献