Lattice location and annealing studies of Hf implanted CaF2

Hafnium ions were implanted into calcium fluoride single crystals. The lattice damage introduced by the implantation was investigated with the Rutherford backscattering (RBS) channelling technique. The lattice location of the implanted ions was determined by performing channelling measurements for the 〈1 1 0〉 crystal direction. A comparison of the angular scan with Monte Carlo simulations leads to the conclusion that >90% of the Hf ions are on Ca sites directly after implantation. Subsequent annealing of the samples was performed in a rapid thermal annealing apparatus. Perturbed angular correlation (PAC) measurements with ¹⁸¹Hf(¹⁸¹Ta) show quadrupole interactions with ν_Q1 = 300(3) MHz (η = 0.00), ν_Q2 = 1285(13) MHz (η = 0.43) and ν_Q3 = 1035(10) MHz (η = 0.00) after annealing up to 1200 K.     

Optical and structural behaviour of Mn implanted sapphire

Sapphire single crystals were implanted at room temperature with 180 keV manganese ions to fluences up to 1.8 × 10¹⁷ cm⁻². The samples were annealed at 1000 °C in oxidizing or reducing atmosphere. Surface damage was observed after implantation of low fluences, the amorphous phase being observed after implantation of 5 × 10¹⁶ cm⁻², as seen by Rutherford backscattering spectroscopy under channelling conditions. Thermal treatments in air annealed most of the implantation related defects and promoted the redistribution of the manganese ions, in a mixed oxide phase. X-ray diffraction studies revealed the presence of MnAl₂O₄. On the contrary, similar heat treatments in vacuum led to enhanced out diffusion of Mn while the matrix remained highly damaged. The analysis of laser induced luminescence performed after implantation showed the presence of an intense red emission.     

Behaviors of optical and chemical state of Nb+ implanted sapphire after annealing

The behavior of the radiation damage of sapphire crystal ,produced by implantation with 380 keV Nb^ ion followed by annealing in a series of steps from 500to 11000℃ at reducing atmosphere,was investigated in optical absorption and XPS measurements.It is found that the implanted niobium in sapphire is in different local environments with different chemical states after the annealing,The changes in optical denstiy (OD) from the bands,based on the well known E-type centers,show that the annealing behavior of the radiation damage may be divided into different stages due to different mechansisms.     

Effects of environment on annealing behavior of In+ implanted c-axis sapphire

Single crystal samples of 〈0001〉α-Al₂O₃ were implanted with 360 keV indium ions of doses of 1 × 10¹⁶ and 3 × 10¹⁶ ions/cm², at room temperature (RT). The implanted samples were annealed isothermally in air or in flowing high purity argon ambient at 900°C for 2 or 12 h. The damage and thermal annealing were evaluated using Rutherford Backscattering Spectrometry and Channeling (RBS-C) and X-ray Diffraction (XRD). Amorphization of sapphire was not observed, despite damage energy densities up to 105 dpa (displacements per atom obtained from TRIM code calculation) for the Al sublattice, which indicated that self-annealing was severe during In ion implantation of sapphire at RT. RBS-C measurement revealed differences in the annealing characteristics of the implanted indium ions that depended on the annealing environment. The XRD spectrum indicated the presence of the In₂O₃ phase in the subsurface region of the sample after annealing in air.     

Lattice location calculation of elements implanted in Si by miedema parameters

Fitting parameters for site energy difference expression of Miedema coordinates has been determined for Si.     

Lattice location and electrical conductivity in ion implanted TiO2 single crystals

Single crystals of TiO₂ (rutile) were implanted at room temperature with Ar, Sn and W ions applying fluences of 10¹⁵/cm² to 10¹⁶/cm² at 300 keV. The lattice location, together with ion range and damage distribution was measured with Rutherford Backscattering and Channeling (RBS-C). The conductivity, σ, was measured as a function of temperature. The implanted Sn and W atoms were entirely substitutional on Ti sites in the applied fluence region, where the radiation damage did not yet reach the random level. A large σ increase was observed for all implants at displacement per atom values (dpa) below 1. Above dpa = 1, σ reveals a saturation value of 0.3 Ω⁻¹ cm⁻¹ for Ar implants, while for W and Sn implants a further increase of σ up to 30 Ω⁻¹ cm⁻¹ was measured. Between 70 K and 293 K ln σ was proportional to T^−1/2, (Ar,W) and T^−1/4 (Sn), indicating that the transport mechanism is due to variable range hopping.     

Low temperature epitaxial regrowth of mercury implanted sapphire

Hg ions were implanted into sapphire at room temperature and 80 keV energy to a fluence of 1 × 10¹⁵ Hg⁺ / cm². This fluence was enough to produce an amorphous surface layer. The annealing behaviour was studied combining RBS/channeling and hyperfine interaction techniques. Surprisingly, the RBS/channeling results show there is an epitaxial regrowth of the damaged layer after annealing at 800°C for 20 min. Although some of the implanted Hg segregates to the surface during the epitaxial regrowth, a significant fraction is incorporated into regular sites along the c-axis. The hyperfine interactions results, obtained after implantation of a dose of 5 × 10¹² Hg⁺ / cm², show that a small fraction of Hg is probably bound to oxygen. This result is in agreement with the RBS/channeling measurements which also show that the system formed after annealing is stable even at high temperatures.     

In~+离子注入蓝宝石(α-A1_2O_3单晶)的表面改性研究

研究了＜０００１＜和＜１２１０＞晶向蓝宝石（α－Ａｌ２Ｏ３单晶）在注入３６０ｋｅＶ．１×１０￣１６ｃｍ￣－２或１００ｋｅＶ、６×１０￣１６ｃｍ￣－２的Ｉｎ￣＋后产生的损伤、注入层的性能变化和退火行为。实验结果表明，退火过程中损伤的恢复和Ｉｎ的分布与退火气氛有关：在１００ｋｅＶ、６×１０￣１６ｃｍ￣－２的Ｉｎ￣＋注入时，注入层电阻率降低了１０个量级，大小为６．８×１０￣３·ｃｍ，表面损伤层的显微硬度提高了９２％；在３６０ｋｅＶ，１×１０￣１６ｃｍ￣－２的Ｉｎ＋注入时，其表面损伤层的显微硬度提高了４５％，在空气中不同温度下退火后，其显微硬度的变化和损伤的变化具有相同的规律。     

Thermal stress resistance of ion implanted sapphire crystals

Monocrystals of sapphire have been subjected to ion implantation with 86 keV Si⁻ and 80 keV Cr⁻ ions to doses in the range of 5 × 10¹⁴–5 × 10¹⁶ cm⁻² prior to thermal stress testing in a pulsed plasma. Above a certain critical dose ion implantation is shown to modify the near-surface structure of samples by introducing damage, which makes crack nucleation easier under the applied stress. The effect of ion dose on the stress resistance is investigated and the critical doses which produce a noticeable change in the stress resistance are determined. The critical dose for Si ions is shown to be much lower than that for Cr⁻ ions. However, for doses exceeding 2 × 10¹⁶ cm⁻² the stress resistance parameter decreases to approximately the same value for both implants. The size of the implantation-induced crack nucleating centers and the density of the implantation-induced defects are considered to be the major factors determining the stress resistance of sapphire crystals irradiated with Si⁻ and Cr⁻ ions.     

Transient annealing of Sn implanted GaAs

High temperature ( 900°C) transient annealing of Sn⁺ implants into GaAs have been studied by secondary ion mass spectroscopy, electrical measurements and transmission electron microscopy. A two-layer encapsulant (Si₃N₄ + AlN) has been used prior to annealing using an incoherent light furnace. Secondary ion mass spectroscopy measurements show that outdiffusion of tin has occurred which depends both on the dose and annealing conditions. The as implanted atomic profiles are wider than the theoretical profiles and up to 17% further broadening occurs during annealing. Electron concentrations approaching 10¹⁹ cm⁻³ have been measured reproducibly. Transmission electron microscopy results show both faulted and unfaulted dislocation loops and dislocation lines, all defects being decorated with precipitates which contain metallic tin. A large concentration of stacking fault tetrahedra is also produced.     

硫对注入YSZ单晶的金属铂在退火过程中结晶的影响

秀卢瑟福背散射－沟道技术（ＲＢＳ－Ｃ）和Ｘ射线衍射技术（ＸＲＤ）研究了Ｐｔ和注入ＹＳＺ（Ｙ２Ｏ３稳定的ＺｒＯ２）后产生的损伤和退火过程中损伤的恢复及注入Ｐｔ的晶化，ＲＢＳ－Ｃ分析表明ＹＳＺ室温下的存在较强自退火效应，ＸＲＤ分析结果示出硫以铂的晶化产生很大影响。     

High temperature annealing of Europium implanted AlN

AlN was implanted with 300 keV Eu ions within a wide fluence range from 4 × 10¹⁴ to 1.4 × 10¹⁷ at/cm². The damage build-up was investigated by Rutherford Backscattering/Channelling. Sigmoidal shaped damage build-up curves indicate efficient dynamic annealing. A regime with low damage increase for fluences below 10¹⁵ at/cm² is followed by a strong increase for intermediate fluences. For the highest fluences the damage curve rises slowly until a buried amorphous layer is formed. High temperature annealing was performed in nitrogen atmospheres at low pressure (1300 °C, 10⁵ Pa) or at ultra-high pressure (1450 °C, 10⁹ Pa). Implantation damage was found to be extremely stable and annealing only resulted in slight structural recovery. For high fluences out-diffusion of Eu is observed during annealing. Nevertheless, photoluminescence (PL) measurements show intense Eu-related red light emission for all samples with higher PL intensity for the high temperature high pressure annealing.     

Radiation damage annealing of Hg implanted InP

The formation of shallow p-type layers in InP has been previously achieved by Hg implantation. In this work, for the first time, microscopic information of the near surrounding of the Hg dopant and the recovery of the damaged layer is derived combining RBS and hyperfine interactions studies. It is shown that most of the radiation damage created by the implantation can be recovered with a two step furnace annealing at 400°C and 800°C using a proximity cap.     

X射线衍射法研究刚玉注入层的结构

用Ｘ射线衍射法和ＰＯＷＤ１２理论计算程序探讨了多晶刚玉Ｆｅ离子注入层的结构变化。     

Temperature behavior of damage in sapphire implanted with light ions

In this study, we compare and discuss the defect behavior of sapphire single crystals implanted with different fluences (1 × 10¹⁶–1 × 10¹⁷ cm^?2) of carbon and nitrogen with 150 keV. The implantation temperatures were RT, 500 °C and 1000 °C to study the influence of temperature on the defect structures. For all the ions the Rutherford backscattering-channeling (RBS-C) results indicate a surface region with low residual disorder in the Al-sublattice. Near the end of range the channeled spectrum almost reaches the random indicating a high damage level for fluences of 1 × 10¹⁷ cm^?2. The transmission electron microscopy (TEM) photographs show a layered contrast feature for the C implanted sample where a buried amorphous region is present. For the N implanted sample the Electron Energy Loss Spectroscopy (EELS) elemental mapping give evidence for the presence of a buried damage layer decorated with bubbles. Samples implanted at high temperatures (500 °C and 1000 °C) show a strong contrast fluctuation indicating a defective crystalline structure of sapphire.     

高剂量铂和钇离子注入Al2O3单晶的表面改性

研究了〈０００１〉和〈１２↑－１０〉晶向α－Ａｌ２Ｏ３单晶在高剂量的Ｙ、Ｐｔ离子注入后产生的损伤,注入层的性能变化和退火行为。实验结果表明,在室温,１７１ｋｅＶ、１×１０＾１７／ｃｍ＾２Ｙ离子注入的〈１２↑－１０〉α－Ａｌ２Ｏ３单晶的表面层约有１３９ｎｍ厚被无定形化。而１５８ｋｅＶ、９×１０＾１７／ｃｍ＾２Ｐｔ离子注入的〈０００１〉α－Ａｌ２Ｏ３单晶的表面层不产生无定形,且实际离子注入进衬底的剂量     

Analysis of sapphire implanted with different elements using artificial neural networks

Five elements (Ti, Fe, Co, Er and Au) were implanted in sapphire to fluences between 8×10¹³ and 5×10¹⁷ at/cm², and energies between 200 and 800 keV. We used Rutherford backscattering to determine the dose and depth of the implanted elements. The data analysis is performed using an artificial neural network (ANN). Here we report a generalisation of previous works where ANNs were successfully applied for specific implantations such as Er in sapphire and Ge in Si. We have now developed a code that it is able to analyse data from implantations of any element with Z between 18 and 83 into sapphire. Although this problem is considerably more complex than single-system ANNs, the ANN developed produced excellent results when applied to experimental data. We discuss the reliability of the ANN and its applicability to the analysis of large batches of implanted samples.     

Optical absorption of metallic Zn nanoparticles in Zn ion implanted sapphire

Zn⁺ ion implantation (48 keV) was performed at room temperature up to a fluence of 5 × 10¹⁷ cm⁻² in -Al₂O₃ single crystals. X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and optical absorption spectroscopy were utilized to characterize the optical properties, chemical charge states and the microstructure of embedded metallic Zn nanoparticles, respectively. XPS analysis indicated that implanted Zn ions are in the charge state of metallic Zn⁰. TEM analysis revealed the metallic Zn nanoparticles of 3–10 nm in the as-implanted sample at a fluence of 1 × 10¹⁷ cm⁻². A selected area electron diffraction (SAD) pattern indicates the random orientation of the Zn nanoparticles. A clear absorption peak appeared gradually in the optical absorption spectra of the as-implanted crystals, due to surface plasma resonance (SPR) of Zn nanoparticles. The wavelength of the absorption peak shifted from 260 nm to 285 nm with the increasing ion fluence, ascribed to the growth of Zn nanoparticles.     

离子注入半导体的快速热退火与SOI技术

自1977年以来,为了摸索离子注入半导体的新退火方法,各国学者进行了大量的研究工作。这种努力是从激光退火的研究开始的。激光与半导体材料相互作用的研究,已派生出若干很有生命力的应用项目,其中,快速热退火、SOI(Semiconductor on Insulator)技术等已显示了重要的应用前景,并正在走向实用化。