• Title/Summary/Keyword: depth profiles

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Conversion from SIMS depth profiling to compositional depth profiling of multi-layer films

  • Jang, Jong-Shik;Hwang, Hye-Hyen;Kang, Hee-Jae;Kim, Kyung-Joong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2011.02a
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    • pp.347-347
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    • 2011
  • Secondary ion mass spectrometry (SIMS) was fascinated by a quantitative analysis and a depth profiling and it was convinced of a in-depth analysis of multi-layer films. Precision determination of the interfaces of multi-layer films is important for conversion from the original SIMS depth profiling to the compositional depth profiling and the investigation of structure of multi-layer films. However, the determining of the interface between two kinds of species of the SIMS depth profile is distorted from original structure by the several effects due to sputtering with energetic ions. In this study, the feasibility of 50 atomic % definition for the determination of interface between two kinds of species in SIMS depth profiling of multilayer films was investigated by Si/Ge and Ti/Si multi-layer films. The original SIMS depth profiles were converted into compositional depth profiles by the relative sensitivity factors from Si-Ge and Si-Ti alloy reference films. The atomic compositions of Si-Ge and Si-Ti alloy films determined by Rutherford backscattering spectroscopy (RBS).

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Performance Evaluation of Stealth Chamber as a Novel Reference Chamber for Measuring Percentage Depth Dose and Profile of VitalBeam Linear Accelerator (VitalBeam 선형가속기의 심부선량백분율과 측방선량분포 측정을 위한 새로운 기준 전리함으로서 스텔스 전리함의 성능 평가)

  • Kim, Yon-Lae;Chung, Jin-Beom;Kang, Seong-Hee;Kang, Sang-Won;Kim, Kyeong-Hyeon;Jung, Jae-Yong;Shin, Young-Joo;Suh, Tae-Suk;Lee, Jeong-Woo
    • Journal of radiological science and technology
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    • v.41 no.3
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    • pp.201-207
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    • 2018
  • The purpose of this study is to evaluate the performance of a "stealth chamber" as a novel reference chamber for measuring percentage depth dose (PDD) and profile of 6, 8 and 10 MV photon energies. The PDD curves and dose profiles with fields ranging from $3{\times}3$ to $25{\times}25cm^2$ were acquired from measurements by using the stealth chamber and CC 13 chamber as reference chamber. All measurements were performed with Varian VitalBeam linear accelerator. In order to assess the performance of stealth chamber, PDD curves and profiles measured with stealth chamber were compared with measurement data using CC13 chamber. For PPDs measured with both chambers, the dosimetric parameters such as $d_{max}$ (depth of maximum dose), $D_{50}$ (PDD at 50 mm depth), and $D_{100}$ (PDD at 100 mm depth) were analyzed. Moreover, root mean square error (RMSE) values for profiles at $d_{max}$ and 100 mm depth were evaluated. The measured PDDs and profiles between the stealth chamber and CC13 chamber as reference detector had almost comparable. For PDDs, the evaluated dosimetric parameters were observed small difference (<1%) for all energies and field sizes, except for $d_{max}$ less than 2 mm. In addition, the difference of RMSEs for profiles at $d_{max}$ and 100 mm depth was similar for both chambers. This study confirmed that the use of stealth chamber for measuring commission beam data is a feasible as reference chamber for fields ranging from $3{\times}3$ to $20{\times}20cm^2$. Furthermore, it has an advantage with respect to measurement of the small fields (less than $3{\times}3cm^2$ field) although not performed in this study.

Determination of Mean Shear Wave Velocity to the Depth of 30m Based on Shallow Shear Wave Velocity Profile (얕은 심도 전단파속도 분포를 이용한 30m 심도 평균 전단파속도의 결정)

  • Sun, Chang-Guk;Chung, Choong-Ki;Kim, Dong-Soo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.11 no.1 s.53
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    • pp.45-57
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    • 2007
  • The mean shear wave velocity to the depth of 30 m (Vs30) derived from the western Vs is the current site classification criterion for determining the design seismic ground motion taking into account the site amplification potential. In order to evaluate the Vs30 at a site, a shear wave velocity (Vs) Profile extending to at least 30 m in depth must be acquired from in-situ seismic test. In many cases, however, the resultant depth of the Vs profile may not extend to 30 m, owing to the unfavorable field condition and the limitation of adopted testing techniques. In this study, the Vs30 and the mean shear wave velocity to a depth shallower, than 30 m (VsDs) were computed from the Vs profiles more than 30 m in depth obtained by performing various seismic tests at total 72 sites in Korea, and a correlation between Vs30 and VsDs was drawn based on the computed mean Vs data. In addition, a method for extrapolating the Vs profile from shallow depth to 30 m was developed by building a shape curve based on the average data of all Vs profiles. For evaluating the Vs30 from the shallow Vs profiles, both the methods using VsDs and shape curve result in less bias than the simplest method of extending the lowermost Vs equally to 30 m in depth, and are usefully applicable particularly in the cases of the Vs profiles extending to at least 10 m in depth.

THE STUDY FOR THE PROFILES OF MIXED DENTITION (한국인 아동의 측모에 관한 연구)

  • Park T. W.
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.8 no.1
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    • pp.17-21
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    • 1978
  • The study was to analyze on the hard and soft tissue profiles in mixed dentition. The subject consisted of 100 males and 100 females from 9 to 12 years of age and with a normal occlusion and acceptable profiles. On the basis of SnH line and SnV line, the author traced all the cephalograms and calculated the mean value and standard deviation in each measuring category and evaluated the sexual difference, the proper limit of development. The obtained results were as follows; 1. Individual variations of the lower facial part were larger the upper facial part in depth and height. 2. Sexual difference of lower facial part was significant in depth and height. 3. All the measured values to the SnH and SnV line were larger in male than in female but revealed resemblance in the profilogram. 4. The measured values of the region of nose, upper lip and point A showed stable tendency.

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Decision of Interface and Depth Scale Calibration of Multilayer Films by SIMS Depth Profiling

  • Hwang, Hye-Hyun;Jang, Jong-Shik;Kang, Hee-Jae;Kim, Kyung-Joong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.02a
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    • pp.274-274
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    • 2012
  • In-depth analysis by secondary ion mass spectrometry (SIMS) is very important for the development of electronic devices using multilayered structures, because the quantity and depth distribution of some elements are critical for the electronic properties. Correct determination of the interface locations is critical for the calibration of the depth scale in SIMS depth profiling analysis of multilayer films. However, the interface locations are distorted from real ones by the several effects due to sputtering with energetic ions. In this study, the determination of interface locations in SIMS depth profiling of multilayer films was investigated by Si/Ge and Ti/Si multilayer systems. The original SIMS depth profiles were converted into compositional depth profiles by the relative sensitivity factors (RSF) derived from the atomic compositions of Si-Ge and Si-Ti alloy reference films determined by Rutherford backscattering spectroscopy. The thicknesses of the Si/Ge and Ti/Si multilayer films measured by SIMS depth profiling with various impact energy ion beam were compared with those measured by TEM. There are two methods to determine the interface locations. The one is the feasibility of 50 atomic % definition in SIMS composition depth profiling. And another one is using a distribution of SiGe and SiTi dimer ions. This study showed that the layer thicknesses measured with low energy oxygen and Cs ion beam and, by extension, with method of 50 atomic % definition were well correlated with the real thicknesses determined by TEM.

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Seasonal Variability of Sonic Layer Depth in the Central Arabian Sea

  • Bhaskar, TVS Udaya;Swain, Debadatta;Ravichandran, M
    • Ocean Science Journal
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    • v.43 no.3
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    • pp.147-152
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    • 2008
  • The seasonal variability of sonic layer depth (SLD) in the central Arabian Sea (CAS) (0 to $25^{\circ}N$ and $62-66^{\circ}E$) was studied using the temperature and salinity (T/S) profiles from Argo floats for the years 2002-2006. The atmospheric forcing responsible for the observed changes was explored using the meteorological data from NCEP/NCAR and Quickscat winds. SLD was obtained from sound velocity profiles computed from T/S data. Net heat flux and wind forcing regulated SLD in the CAS. Up-welling and down-welling (Ekman dynamics) associated with the Findlater Jet controlled SLD during the summer monsoon. While in winter monsoon, cooling and convective mixing regulated SLD in the study region. Weak winds, high insolation and positive net heat flux lead to the formation of thin, warm and stratified sonic layer during pre and post summer monsoon periods, respectively.

A morphologic evaluation of defects created by a piezoelectric ultrasonic scaler on casting gold alloy (압전방식초음파치석제거기의작업조건에따른치과주조용합금의삭제결손부 양상에 관한 고찰)

  • Kim, Young-Sung;Kim, Soo-Hwan;Kim, Won-Kyung;Lee, Young-Kyoo
    • Journal of Periodontal and Implant Science
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    • v.39 no.4
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    • pp.385-390
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    • 2009
  • Purpose: In this study we evaluated the morphologic aspects of defects created by a piezoelectric ultrasonic scaler with scaler tip on casting gold alloy using scanning electron microscope (SEM) images and defect surface profiles. Methods: 54 blocks of type III casting gold alloy (Firmilay, Jellenko Inc, CA, USA) were scaled by a piezoelectric ultrasonic scaler (P-MAX, Satelec, France) with scaler tip (No. 1 tip) on a sledge device. 2-dimensional profiles of defects on all samples were investigated by a surface profilometer (a-Step 500, KLA-Tencor, CA, USA). The selected working parameters were lateral force (0.5 N, 1.0 N, 2.0 N), mode (P mode, S mode), and power setting (2, 4, 8). SEM images were obtained. Defect surface profiles were made on Microsoft Excel program using data obtained by a surface profilometer. Results: Among P mode samples, there were similarities on defect surface profiles and SEM images regardless of lateral force. The defects created in P mode were narrow and shallow although the depth and the width increased as power setting changed low (2) to high (8). In P mode samples, the defect depth was the greatest when lateral force of 0.5 N was applied. However all the depths were smaller than 1 m. SEM images of Lateral force of 0.5 N, S mode, power setting 2 and 4 were similar to that of P mode, but the other SEM images of S mode showed discernible changes. Defect depth of S mode samples was the greatest when lateral force of 1.0 N was applied. Conclusions: Within the limitations of this study, it can be concoluded that removing capability of piezoelectric scaler with scaler tip becomes maximized as power level becomes higher but the capability is restricted when excessive lateral force is applied on scaler tip.

A study of profiles and annaealing behavior of As and Sb by MeV implantation in silicon (실리콘에 MeV로 이온주입된 AS 와 Sb의 profile과 열처리에 의한 이온의 거동에 관한 연구)

  • 정원채
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.35D no.3
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    • pp.46-55
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    • 1998
  • This stud demonstrates the profiles of heavy ions (As, Sb) in silicon by high energy (1~10 MeV) implantation. Implanted profiles were measured by SIMS (Cameca 4f) and compared with simulation results (TRIM) program and analytical description method using Pearson function). The experimental results have a little bit deviation with simulation data in the case of As high energy implatation. But in the case of Sb, the experimental results are in good agreement with TRIM data. SIMS profiles are perfectly fitted with a analytical description method only using one pearson function in Sb implantation. but in the case of As, fitted profilesshow with a little bit deviations by channeling effects of SIMS profiles. Thermal annealing for electrical activation of implanted ions was carried out by furnace annealing and RTA(Rapid Thermal Annealing). Concentration-depth profile after heat treatement were measured by SR(Spreading Resistance) method.

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Observed characteristics of tropical cyclone vertical wind profiles

  • Giammanco, Ian M.;Schroeder, John L.;Powell, Mark D.
    • Wind and Structures
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    • v.15 no.1
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    • pp.65-86
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    • 2012
  • Over the last decade substantial improvements have been made in our ability to observe the tropical cyclone boundary layer. Low-level wind speed maxima have been frequently observed in Global Positioning System dropwindsonde (GPS sonde) profiles. Data from GPS sondes and coastal Doppler radars were employed to evaluate the characteristics of tropical cyclone vertical wind profiles in open ocean conditions and at landfall. Changes to the mean vertical wind profile were observed azimuthally and with decreasing radial distance toward the cyclone center. Wind profiles within the hurricane boundary layer exhibited a logarithmic increase with height up to the depth of the wind maximum.