Papers by Temel Buyuklimanli
Journal of Crystal Growth, Nov 1, 2023
Surface and Interface Analysis, Feb 1, 1994
Fracture and commercial float glass surfaces have been analyzed in a Cameca IMS-3f spectrometer u... more Fracture and commercial float glass surfaces have been analyzed in a Cameca IMS-3f spectrometer using bombardment. Sample charging was controlled through the use of different combinations of a gold grid and thin gold coating. Depth profiles have been quantified with relative sensitivity factors (RSFs) that were determined from fracture surfaces of float glasses of known composition. The sodium and potassium RSFs have been found to be more sensitive to the method of charge compensation than the RSFs of the other elements in the glass. The integrity of the sodium signal is not guaranteed by the presence of a grid on the sample surface. Depth profiles of fracture surfaces show unexpected gradients that can extend to 100 nm, complicating the interpretation of profiles obtained from manufactured surfaces. The calculation of the atomic fraction of all the elements in the glass is difficult within-300 nm of the surface owing to effects from the measured oxygen signal. Fortunately, the composition of the glass as expressed in mole percent of the oxides is more reliable, but still not free of artifacts. The results of these studies and those performed on similar glasses and materials in other laboratories suggest that, regardless of the primary beam, fracture surface analysis should precede the analyses of treated surfaces, especially if quantitative information is required within 100 nm of the surface.
Journal of Non-crystalline Solids, Apr 1, 1990
... Journal of Non-Crystalline Solids 120 (1989) 262-266 North-Holland Section 6. Characteristics... more ... Journal of Non-Crystalline Solids 120 (1989) 262-266 North-Holland Section 6. Characteristics of amorphous surfaces and thin films XPS STUDIES OF POLYHEDRAL LINKAGES IN BINARY FLUORIDE FILMS Temel H. BOYUKLIMANLI ... 2] Carol Phifer, PhD dissertation, Purdue ...
Bulk-doped silicon wafers were measured at four EAG (Evans Analytical Group) site laboratories in... more Bulk-doped silicon wafers were measured at four EAG (Evans Analytical Group) site laboratories in a roundrobin study of the calibration of SIMS measurements of dopant concentrations in silicon. Mean B, P, and As concentrations were determined for several bulk-doped silicon reference wafers. Absolute concentration calibration scales are determined by NIST Standard Reference Materials (B, As) or accepted Consensus Reference Materials (P). At any single EAG measurement site, the average repeatibility of an individual dopant concentration measurement was about 0.7% for B, 2.1% for P, and 2.3% for As. Across the four sites, the best reproducibility for concentration measurements was found when bulk-doped standards were used for calibration. Average reproducibility of dopant concentration measurements across the EAG was 0.9% for B, 2.5% for P, and 2.6% for As.
Applied Physics Letters, Jul 3, 2000
Boron, a P-type dopant, experiences Transient Enhanced Diffusion (TED) via interstitials. The Bor... more Boron, a P-type dopant, experiences Transient Enhanced Diffusion (TED) via interstitials. The Boron TED and {311} dissolution rates are explored as a function of implant energy dependence. Silicon implants of 10 14 /cm 2 at 20, 40, 80, and 160 keV were used to damage the surface of a wafer with an epitaxially grown boron marker layer. Samples were annealed at 750°C for 15 to 135 minutes and 800˚C for 10 to 30 minutes to observe the diffusion exhibited by the marker layer and to correlate this with the dissolution of {311} type defects. The diffusion enhancement depends strongly on implant energy but the {311} dissolution rate is weakly dependent.
Journal of vacuum science & technology, 2006
Plasma based implant systems produce multiple ion species as compared to a beamline implant using... more Plasma based implant systems produce multiple ion species as compared to a beamline implant using a single mass selected ion, such as BF2+. Similarly, plasma implant produces a distribution of ion energies relative to the nearly monoenergetic ions of a beamline implant. To evaluate the significance of these differences, the ultra shallow junction (USJ) dopant depth profiles of these two implant techniques are compared with an advanced secondary ion mass spectrometry (SIMS) profiling technique and a novel diagnostic to measure the “as-implanted” ion mass and energy distributions during the pulse of a plasma implant. The plasma and beamline implants match depth and dose extremely well, consistent with the measured plasma ion characteristics. Additionally, the depth profile effects of plasma pulse timing, relative to the application of the bias voltage pulse, a collisional sheath, and USJ dose loss during device mask removal are explored.
... 3. This study suggests contamination control is important in achieving high conversion effici... more ... 3. This study suggests contamination control is important in achieving high conversion efficiency in CIGS solar cells. REFERENCES [1] AM Gabor, JR Tuttle, DS Albin, MA Contreras, and R Noufi, Appl. Phys. Lett. 65, 198 1994. ...
Journal of Physics D: Applied Physics
In this study, Cu(In,Ga)(Te,S)2 (CIGTS) thin films with [Ga]/([In] ± [Ga]) atomic ratios in the r... more In this study, Cu(In,Ga)(Te,S)2 (CIGTS) thin films with [Ga]/([In] ± [Ga]) atomic ratios in the ranges of 0.22–0.28 and 0.50–0.67 were fabricated using a two-stage technique. During the first stage of the technique, in one set of samples, Cu, In and Ga layers were deposited by electrodeposition on a Mo coated stainless steel (SS) foil substrate forming a SS/Mo/Cu/In/Ga precursor structure. For another set of samples, a Te layer was also deposited by e-beam evaporation on the SS/Mo/Cu/In/Ga structure forming a SS/Mo/Cu/In/Ga/Te precursor structure. During the second stage, SS/Mo/Cu/In/Ga and SS/Mo/Cu/In/Ga/Te stacks were reacted using rapid thermal annealing (RTA) for 5 min at 600 °C with or without presence of S vapors to produce CIGTS series thin films. SS/Mo/Cu/In/Ga stack under S atmosphere yielded CuInGaS2 with a Ga-In gradient across the thickness by RTA process. SS/Mo/Cu/In/Ga/Te stack reacted without S in the reaction atmosphere yielded the CuInGaTe2 compound. When S was pres...
Journal of vacuum science and technology, Apr 20, 2023
Well, do you remember when a factor of 2 was good enough? Probably, not unless you have been arou... more Well, do you remember when a factor of 2 was good enough? Probably, not unless you have been around secondary ion mass spectrometry (SIMS) since the early 1960s, like one of us has been. This paper will give many references back to the early days of quantification when a local thermal equilibrium model was used to obtain the first results that were accurate to within a factor of 2, but only 60% of the time. It only worked for bulk silicate matrixes. People were not even using SIMS on semiconductors in those days. Several early references showing profiles of ion implants in Si will be referenced, but it was not until 1980 that the first paper was published that explicitly showed how to use ion implants as SIMS standards. People were using ion implants as standards before 1980, but only in limited cases, and with no formal published equations specifying how to use them. But, the samples for which ion implants were used as standards were for dilute concentrations in a single matrix, which had a uniform matrix composition with depth. The rest of the paper will show how we at Eurofins EAG Laboratories tackled the problem of quantification of both major and minor elements in nonuniform, multi-element matrices with continuously graded composition changes using point-by-point CORrected-SIMS. These include SiGe heterostructure bipolar transistors, AlGaAs vertical cavity surface emitting lasers, and B plasma-implanted poly-silicon gates.
Journal of vacuum science & technology, Jun 26, 2023
Journal of Optoelectronics and Advanced Materials, 2010
We report growth optimizations of the thin AlN film on (0001) 4H-SiC substrates by metalorganic c... more We report growth optimizations of the thin AlN film on (0001) 4H-SiC substrates by metalorganic chemical vapor deposition. The influence of growth conditions, such as growth temperature and the V/III molar ratio, on the material quality of AlN film is studied. The surface morphology and crystalline quality of the epitaxial layers are investigated by atomic force microscope, X-ray diffraction, and transmission electronic microscope. A new approach is demonstrated to improve the crystalline quality of a 100 nm-thick AlN film by the use of a 5 nm-thick low temperature AlN nucleation layer. Compared to a conventional AlN layer directly grown on SiC substrate at high temperature, the surface morphology of two-step AlN film is remarkably improved along with a decreasing of defect density, leading to the improvement of crystalline quality for the subsequently grown GaN layer. The mechanisms of crystalline quality improvement by use of a low temperature AlN nucleation layer are also investigated and discussed.
IEEE Transactions on Electron Devices, Aug 1, 2007
In this paper, we showed that the maximum active P concentration of approximately 2 × 10 20 cm −3... more In this paper, we showed that the maximum active P concentration of approximately 2 × 10 20 cm −3 exists during solid-phase epitaxial recrystallization (SPER). This maximum active concentration is close to the reported values for other active impurity concentrations during SPER. We introduced the concept of an isolated impurity that has no neighbor impurities with a certain lattice range. Assuming that impurities interact with three or four neighbor impurities, we can explain the activation phenomenon during SPER. According to our model, the isolated P concentration N iso has a maximum value of approximately 2 × 10 20 cm −3 at a total impurity concentration of approximately 10 21 cm −3 , and it decreases with a further increase in total impurity concentration. Deactivation occurs after the completion of SPER with increasing annealing time, and the active impurity concentration decreases with time but is always higher than the maximum diffusion concentration N Diff max. We also observed that N Diff max is independent of the annealing time despite nonthermal activation in the high-concentration region. We evaluated the dependence of N Diff max on annealing temperatures. We think that this N Diff max can be regarded as the electrical solid solubility N Esol that the active impurity concentration reaches in thermal equilibrium. We observed the transient enhanced diffusion (TED) after the completion of SPER, and that, the deactivation process continues during and after TED, and the corresponding diffusion coefficient is still much higher than that in thermal equilibrium even after TED has finished, which suggests that the deactivation process releases point defects.
Applied Surface Science, Oct 1, 2014
Nitridation of the SiO 2-4H-SiC interface using post-oxidation annealing in nitric oxide (NO) is ... more Nitridation of the SiO 2-4H-SiC interface using post-oxidation annealing in nitric oxide (NO) is the most established process for obtaining high quality 4H-SiC MOS interfaces. In this paper, a detailed study of the interfacial nitrogen uptake kinetics is reported for the (0 0 0 1) Si-terminated and (0 0 0-1) C-terminated crystal faces of 4H-SiC. The results indicate a significantly faster kinetics for the C-face compared to the Si-face. For the first time, the correlation between N-uptake and the interface trap density reduction was observed on the C-face. First-order kinetics models are used to fit the nitrogen uptake. Empirical equations predicting N coverage at the SiO 2-4H-SiC interface via NO annealing have been established. The result also shows that the N-uptake rate is associated with the oxidation rate.
Journal of Applied Physics, Feb 1, 1999
We report that a room temperature hydrogen plasma exposure in a parallel plate diode type reactiv... more We report that a room temperature hydrogen plasma exposure in a parallel plate diode type reactive ion etcher can reduce the time required for the subsequent thermal crystallization of amorphous silicon time by a factor of five. Exposure to hydrogen plasma reduces the incubation time, while the rate of crystallization itself is not greatly affected. This plasma enhanced crystallization can be spatially controlled by masking with patterned oxide, so that both amorphous and polycrystalline areas can be realized simultaneously at desired locations on a single substrate. The enhancement of crystallization rate is probably due to the creation of seed nuclei at the surface. The films have been characterized by UV reflectance, x-ray diffraction, plan view transmission electron microscopy, Fourier transform infrared absorption, secondary ion mass spectroscopy, and four-point probe measurement of electrical conductivity.
We evaluated the redistribution profiles of ionimplanted impurities during solid-phase epitaxy us... more We evaluated the redistribution profiles of ionimplanted impurities during solid-phase epitaxy using Rutherford backscattering spectrometry (RBS). RBS data revealed that the As concentration changes only near the moving amorphous/crystal interface. We derived an analytical model for the redistribution profiles using a segregation coefficient m between amorphous and crystalline Si, introduced a parameter of reaction length l that is the distance where impurities were exchanged, and obtained good agreement with experimental data with an m value of 3 and an l value of 1 nm for As. Furthermore, we applied our model to P and B redistribution profiles and obtained good agreement with corresponding m value of 4 and l value of 1 nm for P and m value of 0.3 and l value of 1 nm for B.
IEEE Transactions on Electron Devices, Feb 1, 2007
We evaluated the redistribution profiles of ionimplanted impurities during solid-phase epitaxy us... more We evaluated the redistribution profiles of ionimplanted impurities during solid-phase epitaxy using Rutherford backscattering spectrometry (RBS). RBS data revealed that the As concentration changes only near the moving amorphous/crystal interface. We derived an analytical model for the redistribution profiles using a segregation coefficient m between amorphous and crystalline Si, introduced a parameter of reaction length l that is the distance where impurities were exchanged, and obtained good agreement with experimental data with an m value of 3 and an l value of 1 nm for As. Furthermore, we applied our model to P and B redistribution profiles and obtained good agreement with corresponding m value of 4 and l value of 1 nm for P and m value of 0.3 and l value of 1 nm for B.
ECS transactions, Jul 20, 2018
Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms, Aug 1, 2007
Numerous experimental studies for near-surface analyses of B in Si have shown that the B distribu... more Numerous experimental studies for near-surface analyses of B in Si have shown that the B distribution within the top few nanometers is distorted by secondary ion mass spectrometry (SIMS) depth profiling with O 2-flooding or normal incidence O 2 bombardment. Furthermore, the presence of surface oxide affects the X j determination as well as B profile shape when SIMS analyses are conducted while fully oxidizing the analytical area. Nuclear techniques such as elastic recoil detection (ERD), nuclear reaction analysis (NRA), and highresolution Rutherford backscattering spectrometry (HR-RBS), are known to provide a profile shape near the surface that is free of artifacts. Comparisons with SIMS analyses have shown that SIMS analyses without fully oxidizing the analytical area agree well with these techniques at sufficiently high concentrations (where the nuclear techniques are applicable). The ability to measure both the B profile and an oxide marker with this non-oxidizing SIMS technique also allows accurate positioning of the B profile with respect to the SiO 2 /Si interface. This SIMS analysis protocol has been used to study the differences in near-surface dopant distribution for plasma-based implants. This study specifically focuses on measuring near-surface profile shapes as well as total implant doses for ultra-shallow B implants in Si especially those made with high peak B concentrations.
MRS Advances, Feb 23, 2023
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Papers by Temel Buyuklimanli