共查询到20条相似文献,搜索用时 0 毫秒
1.
Jayadev Vellanki Ravi K. Nadella Mulpuri V. Rao Harry B. Dietrich David S. Simons Peter H. Chi 《Journal of Electronic Materials》1993,22(5):559-566
Room temperature and elevated temperature sulfur implants were performed into semi-insulating GaAs and InP at variable energies
and fluences. The implantations were performed in the energy range 1–16 MeV. Range statistics of sulfur in InP and GaAs were
calculated from the secondary ion mass spectrometry atomic concentration depth profiles and were compared with TRIM92 values.
Slight in-diffusion of sulfur was observed in both InP and GaAs at higher annealing temperatures for room temperature implants.
Little or no redistribution of sulfur was observed for elevated temperature implants. Elevated temperature implants showed
higher activations and higher mobilities compared to room temperature implants in both GaAs and InP after annealing. Higher
peak electron concentrations were observed in sulfur-implanted InP (n ≈ 1 × 1019 cm−3) compared to GaAs (n ≈ 2 × 1018 cm−3). The doping profile for a buried n+ layer (n ≈ 3.5 × 1018 cm−3) of a positive-intrinsic-negative diode in GaAs was produced by using Si/S coimplantation. 相似文献
2.
GaAs亚微米自对准工艺技术研究 总被引:2,自引:2,他引:0
总结了在50mmGaAs圆片上实现自对准介质膜隔离等平面工艺技术的研究,着重描述了离子注入、自对准亚微米难熔栅制备、钝化介质膜生长、干法刻蚀、电阻和电容制备等关键工艺的研究结果。这套工艺的均匀性、重复性好,在50mmGaAs圆片上获得了满意的成品率。采用这套工艺已成功地研制出多种性能良好的GaAsIC和GaAs功率MESFET,证明国家自然科学基金委员会这一重大课题的选择对发展我国GaAsIC确实具有重大意义。 相似文献
3.
G. Pensl F. Ciobanu D. Kirmse S. Reshanov M. Weidner H. Itoh 《Microelectronic Engineering》2006,83(1):146-149
Three examples are given, which show that ion implantation and electron irradiation can drastically modify the electrical properties of SiC and SiC-based MOS capacitors. (1) It is demonstrated that sulphur ions (S+) implanted into 6H-SiC act as double donors with ground states ranging from 310 to 635 meV below the conduction bandedge. (2) Co-implantation of nitrogen (N+) - and silicon (Si+) - ions into 4H-SiC leads to a strong deactivation of N donors. Additional experiments with electron (e−)-irradiated 4H-SiC samples (E(e−) = 200 keV) support the idea that this deactivation is due to the formation of an electrically neutral (Nx-VC, y)-complex. (3) Implantation of a surface-near Gaussian profile into n-type 4H-SiC followed by a standard oxidation process leads to a strong reduction of the density of interface traps Dit close to the conduction bandedge in n-type 4H-SiC/SiO2 MOS capacitors. 相似文献
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6.
经过对GaAs MESFET输出功率及其线性失真的综合分析,提出了无拖尾双峰n~+n载流子浓度分布的最佳设计。用Si离子注入和Be注入埋层方法,以及优化的快速退火技术,满意地制备出所希望的无拖尾双峰n~+n浓度分布。用于DX571功率GaAs MESFET器件时的研究表明,与常规注入分布的器件相比,无拖尾n浓度分布器件在4GHz下测得的1dB增益压缩功率输出增加了0.4W;在输入信号提高50mW情况下增益仍为9dB,漏极效率提高3%,加上n~+注入后饱和压降又下降0.3V,预计其线性输出功率能力将会有进一步改善。 相似文献
7.
N. D. Jäger A. K. Verma P. Dreszer N. Newman Z. Liliental-Weber M. van Schilfgaarde E. R. Weber 《Journal of Electronic Materials》1993,22(12):1499-1502
Nonstoichiometric arsenic-rich GaAs grown at low temperatures by molecular beam epitaxy (LT-GaAs) has been found to be semi-insulating
after high-temperature annealing. The origin of this technologically important conversion is not yet fully understood. In
order to study this effect, we performed photocurrent measurements on p-LT GaAs-n diodes in the spectral range between 0.75
and 1.5eV at 8K. The photocurrent spectra revealed the following features which are unique to the EL2 level: photoquenching,
characteristic photoionization transitions to conduction band minima and a presence of a broad band due to the effect of auto-ionization
from the excited state. Moreover, modeling of the optical excitation process using realistic band structure demonstrates that
these features cannot be explained by “internal photoemission” originating from As precipitates, as the “buried Schottky barrier
model” predicts. This is the first direct experimental evidence for the existence of EL2-like defect levels and their importance
for understanding the optical and electronic properties of annealed LT-GaAs. 相似文献
8.
H. Kanber M. Feng V. K. Eu R. C. Rush W. B. Henderson 《Journal of Electronic Materials》1982,11(6):1083-1114
We compare the chemical profiles of Cr, Mn, Si and Se with the electron concentration profiles in Si, Se and S implanted semi-insulating
Cr-O doped bulk GaAs substrates and undoped VPE buffer layers annealed with and without a SiO2 encapsulant in a H2-As4 atmosphere. A higher activation efficiency in the net electron concentration and the gateless saturated channel current is
measured for SiO2 encapsulated wafers annealed under arsine overpressure than for capless annealed ones using Cr-O doped bulk GaAs substrates.
On the other hand, the net donor concentration peak is higher for implanted buffer epi layers capless annealed under arsine
overpressure than for SiO2 encapsulated ones. Secondary ion mass spectrometry (SIMS) studies of the Cr decoration of the implant damage indicate that
the damage from the 100 keV Si implant anneals out at 840°C while a temperature of 900°C is required to anneal out the 260
keV Se implant damage. An explanation of these differences is provided using an impurity redistribution model and charge neutrality
considerations. Excellent Hall electron mobilities at liquid nitrogen temperature of 5400–9200 cm2/V-sec are measured for Si-implanted buffer epi substrates. 相似文献
9.
The residual electrically active defects in(4×10~(12)cm~(-2)(30KeV)+5×10~(12)cm~(-2)(130KeV))si-implanted LEC undoped si-GaAs activated by two-step rapid thermal annealing(RTA)LABELED AS 970℃(9S)+750℃(12S)have been investigated with deep level transient spec-troscopy(DLTS).Two electron traps ET_1(E_c-0.53eV,σ_n=2.3×10~(-16)cm~2)and ET_2(E_c-0.81eV,σ_n=9.7×10(-13)cm~2)are detected.Furthermore,the noticeable variations of trap's con-centration and energy level in the forbidden gap with the depth profile of defects induced by ion im-plantation and RTA process have also been observed.The[As_i·V_(As)·As_(Ga)]and[V_(As)·As_i·V_(Ga)·As_(Ga)]are proposed to be the possible atomic configurations of ET_1 and ET_2,respectively to explaintheir RTA behaviors. 相似文献
10.
Fereydoon Namavar N. M. Kalkhoran A. Claverie Z. Liliental-Weber E. R. Weber P. A. Sekula-Moisé S. Vernon V. Haven 《Journal of Electronic Materials》1993,22(12):1409-1412
We have demonstrated the formation of arsenic precipitates in GaAs using arsenic implantation and annealing. Electrical measurements
show that very high resistivity (surface or buried) GaAs layers can be produced by this method. The arsenic-implanted materials
are similar to GaAs:As buffer layers grown by low-temperature molecular beam epitaxy, which are used for eliminating backgating
problems in GaAs circuits. Arsenic implantation is a nonepitaxial process which is compatible with current GaAs technology.
Formation of insulating GaAs layers by this technique may improve the performance and packing density of GaAs integrated circuits,
leading to advanced novel III–V compound-based technologies for high-speed and radiation-hard circuits. 相似文献
11.
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
12.
J. Jasinski Z. Liliental-Weber J. Washburn H. H. Tan C. Jagadish A. Krotkus S. Marcinkevicius M. Kaminska 《Journal of Electronic Materials》1997,26(5):449-458
The structural properties of GaAs implanted with high doses of 2 MeV arsenic or gallium ions with subsequent annealing at
different temperatures were studied by transmission electron microscopy, Rutherford backscattering spectrometry-channeling,
double crystal x-ray diffraction. Optical absorption, electrical conductivity, Hall effect and time-resolved photoluminescence
were applied to monitor changes in electrical and optical characteristics of the material. An important conclusion from this
investigation is that there was hardly any difference between materials implanted with gallium or arsenic. For implantation
of either species, a large number of point defects was introduced and for a high enough dose a buried amorphous layer was
formed. Hopping conduction and high absorption below band-to-band transition were observed for both cases. After low temperature
annealing of the amorphous material, a high density of stacking faults and microtwins were found. Regrowth rates at the front
and back amorphous-crystalline interfaces showed a significant difference. This was attributed to differences in local nonstoichiometry
of the material at the upper and lower amorphous-crystalline interfaces. Structural studies showed the presence of some residual
damage (a band of polycrystalline material in the center of the regrown area) with some associated strain even after annealing
at high temperatures. Recovery to the conduction band transport in annealed samples was observed but mobilities, of the order
of 2000 cmWs, were still smaller than in unimplanted GaAs. These results show that, in as-implanted material and even after
annealing at lower temperatures, the point defects introduced by the implantation are responsible for the very short photocarrier
lifetime.
*On leave from Institute of Experimental Physics, Warsaw University, Poland. 相似文献
13.
J. S. Sewell S. C. Dudley M. G. Mier D. C. Look D. C. Walters 《Journal of Electronic Materials》1989,18(2):191-197
A technique for automated measurement of whole-wafer etch pit density (EPD) for GaAs wafers is presented. The technique relies
on an infrared transmission experiment similar to that used to measure EL2 concentration. A theoretical relationship between
transmission and EPD is established, including effects due to pit size. The new automated and old visual-count methods are
compared on a 3“, low-pressure, liquid-encapsulated Czochralski wafer; it is established that the automated method has much
better repeatability. An [EL2] map of this same wafer is also presented. 相似文献
14.
In this paper, a simple computational framework to propose a generic defect detection system based on orthogonal polynomials transcoded coefficients, with a statistical procedure is presented. Initially, the defective input image is partitioned into blocks and subjected to orthogonal polynomials transformation. The resulting coefficients are then applied with a modified lifting scheme, to produce transcoded coefficients with reduced block size. These coefficients are modeled as a probability distribution to propose a block classification scheme that classifies the block under investigation to have dominantly either texture or edge or smooth with total number of transcoded coefficients that are above the mean of the sample. With simple statistical procedure, we then introduce a new defect detection technique on each of these block classification result. The proposed defect detection technique employs homogeneity among variance of transcoded coefficients with Box’s M Test, and group distribution model to verify the presence of defect in texture and edge block respectively. By analyzing the magnitude of transcoded coefficients, defective blocks in a smooth region are identified. The proposed defect detection system, an application independent, is experimented with natural images and few measures are introduced with a simple Defect Measurement Matrix (DMM) to analyze the performance of the proposed system. The applicability of the proposed scheme is also extended to identify defects in fabrics. 相似文献
15.
本文给出了关于半绝缘GaAs中1.06μm ps光脉冲产生的自由电子的理论及计算结果,并讨论了从深能级跃迁与双光子跃迁的自由电子浓度的空间Fourier分量随激发光强度的变化。 相似文献
16.
J. C. Zolper M. E. Sherwin A. G. Baca R. P. Schneider 《Journal of Electronic Materials》1995,24(1):21-24
Nitrogen ion implantation is shown to form high resistivity regions (ps ≥ 1 × 1010 Ω/) in C-doped GaAs and Al0.35Ga0.65As that remains compensated after a 900°C anneal. This is in contrast to oxygen or fluorine implantation in C-doped GaAs which
both recover the initial conductivity after a sufficiently high temperature anneal (800°C for F and 900°C for O). In C-doped
Al0.35Ga0.65As N- and O-implant isolation is thermally stable but F-implanted samples regain the initial conductivity after a 700°C anneal.
A dose dependence is observed for the formation of thermally stable N-implant compensation for both the GaAs and AIGaAs samples.
A C-N complex is suggested as the source of the compensating defect level for the N-implanted samples. Sheet resistance data
vs anneal temperature and estimates of the depth of the defect levels are reported. This result will have application to heterojunction
bipolar transistors and complementary heterostructure field effect transistor technologies that employ C-doped AIGaAs or GaAs
layers along with high temperature post-implant isolation processing. 相似文献
17.
E. F. Schubert T. H. Chiu J. E. Cunningham B. Tell J. B. Stark 《Journal of Electronic Materials》1988,17(6):527-531
Spatial localization and diffusion of atomic Si is studied inσ-doped GaAs by employing capacitance-voltage (CV) measurements and rapid thermal annealing. It is found that diffusion and segregation are irrelevant inσ-doped GaAs grown at temperatures below 550° C. Combination of rapid thermal annealing and capacitance-voltage profiling is a novel method which is most sensitive to diffusion and it is shown that this method is able to detect diffusion on a length scale of 10Å. CV-profile widths broaden from?40Å to 137Å upon rapid thermal annealing at 1000° C for 5 sec. The diffusion coefficient and the activation energy of atomic Si-diffusion in GaAs are determined to beD o = 4 × 10?4 cm2/s andE a = 2.45 eV, respectively. The basic theory of CV-measurements on a quantum-mechanical electron system is developed. 相似文献
18.
N. Duhamel K. Daoud-Ketata B. Descouts P. Krauz M. Gauneau S. Godefroy 《Journal of Electronic Materials》1986,15(6):377-382
The aim of this work is to study the electrical properties of Mg24 and Zn64 implanted and annealed samples (semi-insulating GaAs substrates,n
+ doped GaAs epilayers, GaAs-GaAlAs heterostructures) with the final objective of realizing the contact region for the p-type
base layer of heterojunction bipolar transistor (HBT). We show that, for HBT applications, Mg+ is a more suitable candidate because its characteristics (depth, concentration) are easier to control: they are not very
sensitive to doping level and composition of different layers. Low specific contact resistivity (<10-5Ωcm2) have been obtained with Au-Mn alloy on Mg+ implanted GaAs. 相似文献
19.
J. M. Tartaglia S. M. Crochiere C. E. Kalnas D. L. Farrington J. A. Kronwasser P. J. Pearah 《Journal of Electronic Materials》1991,20(5):345-352
The relationship of structural defects to the electrical properties of semiconductor materials is discussed. Etch pit density
(EPD) measurements are normally used to evaluate dislocation density. A nondestructive, quantitative method for evaluation
of substrate defect populations is needed for quality assurance. In this study, double crystal x-ray diffraction rocking curves
are investigated for this purpose. Rocking curve widths are determined experimentally for a set of GaAs substrated with a
range of EPD. The experimentally determined values are also compared with those calculated from simulated rocking curves based
on x-ray diffraction theory. Limited correlation between rocking curve widths and EPD is observed.
Formerly of Spectrum Technology Inc., Holliston, MA 相似文献
20.
We present a study of electrically active defects induced by ion implantation, for two dopants: arsenic and phosphorous. Our
analysis technique is Deep Level Transient Spectroscopy (D.L.T.S.). We have studied the generation of defects by direct implantation,
and indirect implantation, that is through an SiO2 layer. We follow the defect spectrum evolution for different doses (108 to 1014 atoms/cm2) and for different annealing temperatures (from room temperature up to 800° C). The comparison of our results with other
published ones allows us to improve the knowledge about the role of a protecting oxide layer, the influence of moderate thermal
annealing, and the effect of oxygen on deep centers produced by ion bombardment. 相似文献