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1.
Limin Zhang Xiaodong Zhang Wei You Zhen Yang WenXiu Wang Qing Ge Zhengmin Liu 《Central European Journal of Physics》2008,6(2):283-288
The effects of Si, O, C and N ion implantation with different implantation doses on yellow luminescence (YL) of GaN have been
investigated. The as-grown GaN samples used in the work were of unintentional doped n-type, and the photoluminescence (PL)
spectra of samples had strong YL. The experimental results showed that YL of ion implanted samples exhibited marked reductions
compared to samples with no implantation, while the near band edge (NBE) emissions were reduced to a lesser extent. The deep-level
centers associated with YL may be produced in GaN films by O and C ion implantation, and identities of these deep-level centers
were analyzed. It was also found that the dose dependence of YL was analogous with the one of the intensity ratios of YL to
the near band edge (NBE) emission (I
YL
/I
NBE
) for ion implanted samples. The possible reason for this comparability has been proposed.
相似文献
2.
W. You 《Physica B: Condensed Matter》2008,403(17):2666-2670
The influence of C, N, O, Mg, Si and co-implants (Mg+Si) ions implantation with fluences in the wide range 1013-1017 cm−2 on the yellow luminescence (YL) properties of wurtzite GaN has been studied by photoluminescence (PL) spectroscopy. Two types of n-type GaN samples grown by metal-organic chemical vapor deposition method (MOCVD) and labeled as No-1 and No-2 were studied. In their as-grown states, No-1 samples had strong YL, while No-2 samples had weak YL. Results of the frontside and backside PL measurements in one of the as-grown GaN epifilms are also presented. Comparing the intensity of YL between frontside and backside PL spectra, the backside PL spectrum shows the more intense YL intensity. This implies that most of the intrinsic defects giving rise to YL exist mainly near the interface between the epilayer and buffer layer. Our experimental results show that the intensity ratio of YL to near-band-edge UV emission (IYL/IUV) decreases gradually by increasing the C implantation fluence from 1013 to 1016 cm−2 for No-1 samples after annealing at 900 °C. When the fluence is 1017 cm−2, a distinct change of the IYL/IUV is observed, which is strongly increased after annealing. For No-2 samples, after annealing the IYL/IUV decreases gradually with increase in the C implantation fluence from 1013 to 1015 cm−2. The IYL/IUV is gradually increased with increasing C fluence from 1016 to 1017 cm−2 after annealing, while IYL/IUV for other ions-implanted GaN samples decreases monotonically with increase in the ions implantation fluences from 1013 to 1017 cm−2 for both No-1 samples and No-2 samples. It is noted that for annealed C-implanted No-2 samples IYL/IUV is much higher than that of the as-grown one and other ion-implanted ones. In addition, IYL/IUV for the Mg, Si, and co-implants (Mg+Si) implanted No-2 samples with a fluence of 1013 cm−2 after being annealed at 900 °C is higher than that of the as-grown one. Based on our experimental data and literature results reported previously, the origins of the YL band have been discussed. 相似文献
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Structure and luminescence of a-plane GaN on r-plane sapphire substrate modified by Si implantation
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Lijie Huang 《中国物理 B》2021,30(5):56104-056104
We show the structural and optical properties of non-polar a-plane GaN epitaxial films modified by Si ion implantation. Upon gradually raising Si fluences from 5×1013 cm-2 to 5×1015 cm-2, the n-type dopant concentration gradually increases from 4.6×1018 cm-2 to 4.5×1020 cm-2, while the generated vacancy density accordingly raises from 3.7×1013 cm-2 to 3.8×1015 cm-2. Moreover, despite that the implantation enhances structural disorder, the epitaxial structure of the implanted region is still well preserved which is confirmed by Rutherford backscattering channeling spectrometry measurements. The monotonical uniaxial lattice expansion along the a direction (out-of-plane direction) is observed as a function of fluences till 1×1015 cm-2, which ceases at the overdose of 5×1015 cm-2 due to the partial amorphization in the surface region. Upon raising irradiation dose, a yellow emission in the as-grown sample is gradually quenched, probably due to the irradiation-induced generation of non-radiative recombination centers. 相似文献
5.
This paper reports that the yellow luminescence intensity of N-polar GaN Epi-layers is much lower than that of Ga-polar ones due to the inverse polarity,and reduces drastically in the N-polar unintentionally-doped GaN after etching in KOH solution.The ratio of yellow luminescence intensity to band-edge emission intensity decreases sharply with the etching time.The full width at half maximum of x-ray diffraction of(10-12) plane falls sharply after etching,and the surface morphology characterized by scanning electron microscope shows a rough surface that changes with the etching time.The mechanism for the generation of the yellow luminescence are explained in details. 相似文献
6.
Vikas Baranwal Richa Krishna Ambuj Tripathi Dinakar Kanjilal 《Applied Surface Science》2007,253(12):5317-5319
GaN phase is synthesized using systemic implantation of nitrogen ions of multiple energies (290, 130 and 50 keV) into Zn-doped GaAs (1 0 0) at room temperature and subsequent annealing at 850 °C for 30 min in Ar + H2 atmosphere. The implanted doses of nitrogen ions are 5 × 1016 and 1 × 1017 ions-cm−2. Glancing angle X-ray diffraction studies show that hexagonal phase of GaN were formed. The photoluminescence studies show the emission from the band edge as well as from point defects. 相似文献
7.
M. Herrera-Zaldívar P. Fernández J. Piqueras V.V. Sukhoveyev V.A. Ivantsov Y.G. Shreter 《Applied Physics A: Materials Science & Processing》2000,71(1):55-58
Cathodoluminescence (CL) in the scanning electron microscope has been applied to study the luminescence emission of GaN single crystals grown by LPE methods. CL spectra show the presence of near band edge and of yellow emissions. The latter has been found to be mainly related to rows of hillocks formed at the growth steps. The origin of the yellow luminescence is discussed 相似文献
8.
This paper reports that the 150-keV Mn ions are implanted into GaN thin film grown on Al2O3 by metal-organic chemical vapour deposition.The X-ray diffraction reciprocal spacing mapping is applied to study the lattice parameter variation upon implantation and post-annealing.After implantation,a significant expansion is observed in the perpendicular direction.The lattice strain in perpendicular direction strongly depends on ion fluence and implantation geometry and can be partially relaxed by post-annealing.While in the parallel direction,the lattice parameter approximately keeps the same as the unimplanted GaN,which is independent of ion fluence,implantation geometry and post-annealing temperature. 相似文献
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11.
D. Pacifici G. Franz F. Iacona F. Priolo 《Physica E: Low-dimensional Systems and Nanostructures》2003,16(3-4):404
In this paper the amorphization of Si nanocrystals (nc) by ion beam irradiation and the subsequent recrystallization are investigated in detail. The luminescence properties of Si nanocrystals embedded within a SiO2 matrix are used as a probe of the damaging effects generated by high-energy ion beam irradiation. Samples have been irradiated with 2 MeV Si+ ions at different doses, in the range between 1×109 and 1×1016 cm−2. By increasing the ion dose, the nc-related photoluminescence (PL) strongly decreases after a critical dose value. It is shown that the lifetime quenching alone cannot quantitatively explain the much stronger PL drop, but the total number of emitting centers has to diminish too. Moreover, we studied the recovery of the amorphized Si nc by performing thermal annealings. It is demonstrated that the recovery of the PL properties of completely amorphized Si nc is characterized by a single activation energy, whose value is 3.4 eV. Actually, this energy is associated to the transition between the amorphous and the crystalline phases of each Si grain. The recrystallization kinetics of Si nanostructures is demonstrated to be very different from that of a bulk system. 相似文献
12.
CHAI XuZhao ZHANG Yun LIU Bin XIE ZiLi HAN Ping YE JianDong HU LiQun XIU XiangQian ZHANG Rong ZHENG YouDou 《中国科学:物理学 力学 天文学(英文版)》2013,(9):1694-1698
Effect of the V/III ratio during buffer layer growth on the yellow and blue luminescence in undoped GaN epilayer has been studied by means of photoluminescence spectroscopy and high resolution X-ray diffraction.It is found that the densities of screw and edge threading dislocations increase with the V/III ratio of the buffer layer,and the intensities of the yellow luminescence(YL) and blue luminescence(BL) emissions also increase dramatically.However,the density ratio of the edge threading dislocation to the screw threading dislocation remains invariant,as well as the intensity ratio of YL emission to BL emission.It can be concluded from these phenomena that the edge threading dislocation and screw threading dislocation can enhance the YL and BL emissions,respectively. 相似文献
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To study ion beam induced modifications into MOCVD grown wurtzite AlInN layers, neon ions were implanted on the samples with four doses ranging from 1014 to 9×1015 ions/cm2. Structural characterization was carried out by X-ray diffraction and Rutherford backscattering spectroscopy (RBS) techniques. XRD analysis revealed that GaN related peak for all samples remains at its usual Bragg position of 2θ=34.56° whereas a shift in AlInN peak takes place from its position of 2θ=35.51° for as-grown sample. Rutherford back scattering (RBS) analysis indicated that peak related to Ga atoms in capping layer provided evidence of partial sputtering of GaN cap layers. Moreover, Al peak position is shifted towards lower channel side and width of the signal is increased after implantation, which pointed to the inwards migration of Al atoms away from the AlInN surface. The results suggested that partial sputtering of cap layer has taken place without uncovering the underneath AlInN layer. 相似文献
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N. A. Sobolev D. V. Denisov A. M. Emel’yanov E. I. Shek E. O. Parshin 《Physics of the Solid State》2005,47(1):117-120
Features appearing in the photo-and electroluminescence spectra of light-emitting structures based on MBE-grown Si: Er layers are studied. The luminescence properties of Si layers implanted by Er and O ions were used as a reference. The temperature quenching of the photoluminescence intensity of Er-containing centers in MBE-grown and implanted layers can be approximated adequately by the same functional relationships with equal activation energies but with preexponential factors differing by more than two orders of magnitude. It is shown that the electroluminescence of Er3+ ions can be increased by additional coimplantation of erbium and oxygen ions into MBE-grown light-emitting diode structures and subsequent annealing. After this treatment, the Er-containing centers continue to dominate the luminescence spectrum. 相似文献
17.
J. Teichert L. Bischoff S. Hausmann M. Voelskow H. Hobert 《Applied Physics A: Materials Science & Processing》2000,71(2):175-180
The lattice damage of silicon produced by ion implantation at extremely high current density of 0.8 A/cm2 (2.5᎒18 cm-2 s-1) was investigated. In a focused ion beam system, implantation was carried out with 70 keV Co ions, fluences of 1.2᎒16 cm-2 and 6.7᎒15 cm-2 into Si (111) at room temperature and elevated temperatures between 355 °C and 400 °C. Radiation damage measurements were performed by Rutherford backscattering/channeling spectroscopy and micro-Raman analysis. The radiation damage was studied as a function of pixel dwell-time and implantation temperature. The critical temperature for amorphization increases with current density. Although the fluence of the focused ion implantation was constant, crystalline layers were obtained for short and amorphous layers for long pixel dwell-times. The critical dwell-time of crystalline/amorphous transition increases with implantation temperature. From the results a typical time for defect annealing of 10-5 s at 400 °C and an activation energy of (2.5ǂ.6) eV were deduced. 相似文献
18.
用等离子体增强化学气相淀积(PECVD)生长了200nm的SiGe薄膜,然后将C离子注入SiGe层,经两步热退火处理制备了Si1-x-yGexCy三元合金半导体薄膜.应用卢瑟福背散射(RBS),傅里叶变换红外光谱(FTIR)和高分辨率x射线衍射(HRXRD)研究了薄膜的结构和外延特性.发现C原子基本处于替代位置,C原子的掺入缓解了SiGe层的压应变
关键词:
Si1-x-yGexCy薄膜
离子注入
固相外延 相似文献
19.
《Applied Surface Science》2005,239(3-4):335-341
We fabricated contact electrodes in Si for nanoelectronic device fabrication using 40 keV As ion implantation. Complete amorphization of the Si surface with contact electrodes using 400 eV Ar ion irradiation at room temperature followed by annealing at 700 °C produced Si surface with negligible SiC crystallites suitable for ultrahigh vacuum scanning tunneling microscope nanolithography. We could locate the implanted and unimplanted regions on Si and fabricate Si dangling bond wires between two contact electrodes, which is the first step for the fabrication of nanoelectronic devices in Si using UHV STM nanolithography. 相似文献
20.
Silicon-on-insulator(SOI) devices are sensitive to the total ionizing dose effect due to the existence of buried oxide.In this paper,an extra single-step Si ion implantation into buried oxide layer prior to the normal complementary metal–oxide–semiconductor transistor(CMOS) process is used to harden the SOI wafer.The top-Si quality of the hardened SOI wafer is confirmed to be good enough for device manufacturing through various characterization methods.The radiation experiments show that the total ionizing dose tolerance of the Si implanted SOI device is improved significantly.The metastable electron traps introduced by Si implantation is also investigated by electrical stress.The results show that these traps are very instable,and electrons will tunnel into or out of the metastable electron traps quickly after hot-electroninjection or hot-hole-injection. 相似文献