Quantitative determination of element distributions in silicon based thin film solar cells using SNMS

The determination of elemental distributions in thin film solar cells based on amorphous silicon using electron beam SNMS is possible by quantifying the measured ion intensities. The relative sensitivity factors (RSFs) for all elements measured have to be known. The RSFs have been determined experimentally using implantation and bulk standards with known concentrations of the interesting elements. The measured RSFs have been compared with calculated RSFs. The model used for the calculation of the RSFs takes into account the probability for electron impact ionization and the dwell time of the neutrals inside the postionization region. The comparison between measured and calculated RSF shows, that this model is capable to explain the RSFs for most elements. Differences between calculated and measured values can be explained by the formation of hydride and fluoride molecules (in case of H and F) and influences of the angular distribution of the sputtered neutrals in case of Al. The experimentally determined RSFs have been used for a quantification of depth profiles of the i-, buffer-, p- and front contact layers of a-Si solar cells.     

Quantitative determination of element distributions in silicon based thin film solar cells using SNMS

The determination of elemental distributions in thin film solar cells based on amorphous silicon using electron beam SNMS is possible by quantifying the measured ion intensities. The relative sensitivity factors (RSFs) for all elements measured have to be known. The RSFs have been determined experimentally using implantation and bulk standards with known concentrations of the interesting elements. The measured RSFs have been compared with calculated RSFs. The model used for the calculation of the RSFs takes into account the probability for electron impact ionization and the dwell time of the neutrals inside the postionization region. The comparison between measured and calculated RSF shows, that this model is capable to explain the RSFs for most elements. Differences between calculated and measured values can be explained by the formation of hydride and fluoride molecules (in case of H and F) and influences of the angular distribution of the sputtered neutrals in case of Al. The experimentally determined RSFs have been used for a quantification of depth profiles of the i-, buffer-, p- and front contact layers of a-Si solar cells.     

Comparative studies of MCs+-SIMS and e–-beam SNMS for quantitative analysis of bulk materials and layered structures

For the quantification of heterostructure depth profiles the knowledge of relative sensitivity factors (RSF) and the influence of matrix effects on the measured profiles is necessary. Matrix dependencies of the measured ion intensities have been investigated for sputtered neutral mass spectrometry (SNMS) and MCs(+)-SIMS. The use of Cs as primary ions for SNMS is advantageous compared to Ar because the depth resolution is improved without changing RSFs determined under Ar bombardment. No significant amount of molecules has been found in the SNMS spectra under Cs bombardment. Using MCs(+)-SIMS the RSFs are matrix dependent. An improvement of depth resolution can be achieved by biasing the sample against the primary ion beam for SNMS due to a reduction of the net energy of the primary ions and a resulting more gracing impact angle.     

Comparative studies of MCs+-SIMS and e?-beam SNMS for quantitative analysis of bulk materials and layered structures

For the quantification of heterostructure depth profiles the knowledge of relative sensitivity factors (RSF) and the influence of matrix effects on the measured profiles is necessary. Matrix dependencies of the measured ion intensities have been investigated for sputtered neutral mass spectrometry (SNMS) and MCs⁺-SIMS. The use of Cs as primary ions for SNMS is advantageous compared to Ar because the depth resolution is improved without changing RSFs determined under Ar bombardment. No significant amount of molecules has been found in the SNMS spectra under Cs bombardment. Using MCs⁺-SIMS the RSFs are matrix dependent. An improvement of depth resolution can be achieved by biasing the sample against the primary ion beam for SNMS due to a reduction of the net energy of the primary ions and a resulting more gracing impact angle.     

直流辉光放电质谱法测定多晶硅中关键杂质元素的相对灵敏度因子

采用直流辉光放电质谱(dc-GD-MS)测定多晶硅中关键杂质元素的相对灵敏度因子(RSF).标样制作过程中主要是在连续通入氩气条件下将固定量的非标准多晶硅样品熔化,向硅熔体中均匀掺入浓度范围为1～30 μg/g的关键杂质元素(如B和P),采用快速固化法制成标样;再将制成的标准样品加工成一系列适合GD-MS扁平池(Flat Cell)的片状样品(20 mm×20 mm×2mm).采用二次离子质谱法(SI-MS)对标准样品中关键掺杂元素进行多次定量测定,取平均值作为关键杂质元素的精确含量.优化一系列质谱条件后,运用GD-MS对标样中关键掺杂元素的离子强度进行多次测定,计算平均结果,得到未校正的表观浓度,利用标准曲线法计算出关键杂质元素的相对灵敏度因子.     

Application of the glow discharge mass spectrometry (GDMS) for the multi-element trace and ultratrace analysis of sputtering targets

Glow discharge mass spectrometry using a VG9000 high resolution mass spectrometer has been applied to both the multi-element trace and ultra trace analyses of sputtering target materials, i.e. aluminium-based alloys, cobalt-based alloys, titanium and platinum. Element dependent relative sensitivity factors (RSF) have been determined using reference materials in order to provide the possibility for quantitative analyses. Aluminium-based and cobalt-based alloys have been extensively analysed to demonstrate precision of GDMS analyses. Detection limits in the ng/g and sub-ng/g ranges, i.e. 0.2 ng/g for U and Th have been determined in aluminium-based alloys. Comparative analyses for alloy components in cobalt-based alloys as well as trace concentrations in titanium have been performed. GDMS has been also applied to multi-element depth profile analyses in contaminated and noncontaminated platinum targets.     

Relative sensitivity factors for hard X-ray photoelectron spectroscopy with photon energies of 3.0, 5.9, 7.9, and 9.9 keV

Empirical relative sensitivity factors (RSFs) for the 1s, 2p_3/2, and 3d_5/2 levels relative to O1s were derived from the hard X-ray photoelectron spectroscopy measurements with photon energies of 3.00, 5.95, 7.94, and 9.92 keV. The data for 5.95, 7.94, and 9.92 keV were obtained at BL46XU in SPring-8, and those for 3.00 keV were obtained at BL6N1 in AichiSR (note that the measurement conditions, i.e., electron spectrometer and measurement geometry, at the two beamlines were different; for details, see Section >3). It was found that the empirical RSFs showed the linear behaviors as a function of the binding energy on a log–log plot. Also, from the comparison of the empirical RSFs and the theoretical RSFs calculated from Hartree–Slater cross sections reported by Scofield combined with the energy dependence on the spectrometer function and the inelastic mean free path, it is observed that there is an agreement between the empirical and the theoretical RSF values with several exceptions.     

激光剥蚀电感耦合等离子体质谱分析硅酸盐矿物基体效应的研究

标样与样品之间基体效应的差异是影响LA-ICP-MS分析结果准确度的重要因素,而元素的相对灵敏度因子(RSF)是基体效应的重要表征.本研究考察了17个玻璃标样中49种常见元素及10个电子探针天然硅酸盐矿物标样中10种主、微量元素RSF的差异,比较了以Ca,Al,Si为内标对基体效应的补偿作用及元素分馏效应的影响.结果表...     

Quantitative SIMS analysis of SiC

We performed a systematic study of ion‐implanted 6H‐SiC standards to find the optimal regimes for SIMS analysis. Relative sensitivity factors (RSFs) were acquired for operating conditions typical of practical SIMS applications. The experimental SiC RSFs were compared with those found for silicon: 1 the matrix effect was insignificant in most cases. It was found that the SiO^? cluster ion cannot represent correctly the real oxygen distribution in SiC. The physics of the effect is discussed. Copyright © 2003 John Wiley & Sons, Ltd.     

Studies on the Element Characteristics of Nephrite Minerals from Different Deposits by GD‐MS

Element characteristics of nephrite minerals were determined by glow discharge mass spectrometry (GD‐MS) through surface adherence method. To solve the conductivity problem of non‐conductive nephrite samples, high purity indium pin (>99.9999%) was used as discharge host. During the preparation procedure, a small piece of nephrite sample was ground into powder (about 200 meshes), and then the sample powder was coated on the surface of indium pin to form a rod sample. Typical elements of nephrite minerals were analyzed by GD‐MS, and the relative standard deviations showed that the stability and reproducibility of this method were good. Meanwhile, four nephrite samples from two different deposits were further studied by this method. The GD‐MS results of major elements and trace elements revealed that typical elements of the nephrite minerals from same deposit were similar, and those from different deposits exhibited significant difference. In addition, results of external‐beam proton induced X‐ray emission (PIXE) were consistent with the result of GD‐MS determination. The present approach had been proven to be simple, efficient to perform the rapid screening and multi‐element semi‐quantitative analysis of nephrite samples.     

Multielemental characterisation of cobalt by glow discharge quadrupole mass spectrometry

Multielemental determination and the assessment of purity of cobalt metal used in the preparation of Ni-based super-alloys have been carried out by glow discharge quadrupole mass spectrometry (GD-QMS). Relative sensitivity factors (RSF) generated from certified iron matrix reference samples (NIST 663 and 664 low alloy steel pin standards) could be used for the determination of different trace element constituents of the sample. Different wet chemical procedures were also carried out for the determination of the trace constituents in the sample. The GD-QMS results are in reasonably good agreement with those obtained from wet chemical procedures, validating the use of the RSF values generated on low alloy steel standards for the computation of trace element concentrations in cobalt metal. A variety of molecular ions formed through the reaction of cobalt (matrix) with the discharge gas (argon) were also detected.     

Quantification of hard X-ray photoelectron spectroscopy: Calculating relative sensitivity factors for 1.5- to 10-keV photons in any instrument geometry

A method for the rapid determination of theoretical relative sensitivity factors (RSFs) for hard X-ray photoelectron spectroscopy (HAXPES) instruments of any type and photon energy has been developed. We develop empirical functions to describe discrete theoretically calculated values for photoemission cross sections and asymmetry parameters across the photon energy range from 1.5 to 10 keV for all elements from lithium to californium. The formulae describing these parameters, in conjunction with similar practical estimates for inelastic mean free paths, allow the calculation of a full set of theoretical sensitivity factors for a given X-ray photon energy, X-ray polarisation and instrument geometry. We show that the anticipated errors on these RSFs are less than the typical errors generated by extracting X-ray photoelectron spectroscopy (XPS) intensities from the spectra and thus enable adequate quantification for any XPS/HAXPES experiment up to 10 keV. A spreadsheet implementation of this method is provided in the supporting information, along with example RSFs for existing commercial instruments.     

New Approach to the Calculation of Relative Sensitivity Factors in Inductively Coupled Plasma Mass Spectrometry

The relative sensitivity factors (RSFs) of 68 elements in inductively coupled plasma mass spectrometry were determined. The ionization process in an inductively coupled plasma was found to be only approximately described by the Saha–Eggert equation. A relationship between the RSFs and the absolute electronegativities of atoms was found. This factor has the strongest effect on the accuracy of the calculations of RSFs for chemically active elements. The average relative systematic error of the calculations of RSFs taking into account absolute electronegativity was reduced to 0.30.     

Investigation of glow-discharge-induced morphology modifications on silicon wafers and chromium conversion coatings by AFM and rugosimetry

The effect of radiofrequency glow-discharge sputtering on the sample surface in terms of modifications in the surface morphology were investigated in this work by using atomic force microscopy (AFM) and rugosimetry measurements. The influence of GD operating parameters (e.g. rf power, discharge pressure and sputtering time) on surface roughening was investigated using two different types of samples: mirror-polished and homogeneous silicon wafers and chromate conversion coatings (CCCs). Surface morphology changes produced by GD sputtering into the sample surface were carefully investigated by AFM and rugosimetry, both at the original sample surface and at the bottom of GD craters using different GD experimental conditions, such as the sputtering time (from 1 s to 20 min), rf forward power (20–60 W for the Si wafer and 10–60 W for the CCC), and discharge pressure (400–1,000 Pa for the Si wafer and 500–1000 Pa for the CCC). In the present study, GD-induced morphology modifications were observed after rf-GD-OES analysis, both for the silicon wafers and the CCC. Additionally, the changes observed in surface roughness after GD sputtering were found to be sample-dependent, changing the proportion, shape and roughness of the micro-sized patterns and holes with the sample matrix and the GD conditions.     

Comparison between the use of direct current glow discharge mass spectrometry and inductively coupled plasma quadrupole mass spectrometry for the analysis of trace elements in nuclear samples

The quantitative determination of trace elements in nuclear samples by GDMS and ICP-MS is presented and compared. Spectral interferences, matrix effects, detection limits, precision and accuracy are discussed. Results for selected samples demonstrated that both techniques are complementary. The use of a multi-standard solution provides the most accurate results in ICP-MS, whereas in GDMS this is achieved by relative sensitivity factors (RSF) matrix matched. Nevertheless, the use of standard RSF allows a fast screening.     

Comparison between the use of direct current glow discharge mass spectrometry and inductively coupled plasma quadrupole mass spectrometry for the analysis of trace elements in nuclear samples

The quantitative determination of trace elements in nuclear samples by GDMS and ICP-MS is presented and compared. Spectral interferences, matrix effects, detection limits, precision and accuracy are discussed. Results for selected samples demonstrated that both techniques are complementary. The use of a multi-standard solution provides the most accurate results in ICP-MS, whereas in GDMS this is achieved by relative sensitivity factors (RSF) matrix matched. Nevertheless, the use of standard RSF allows a fast screening.     

Relative sensitivity factors in direct current glow discharge mass spectrometry using Kr and Xe gas — Estimation of the role of Penning ionization

Relative sensitivity factors (RSF) (Fe=1) were determined for steel, aluminium and copper standard samples by direct current glow discharge mass spectrometry using Kr and Xe as discharge gas. In general, the RSF values in Kr and Xe were higher than in Ar; however for S and P in Kr gas and P, As and Se in Xe gas they were considerably lower. This decrease is related to the relative importance of the Penning ionization process in overall ionization of the sputtered species. The results showed the percentage of Penning ionization to account for 75.6–82.0% for Se, As and P and 64.2% for S.     

激光剥蚀-电感耦合等离子体质谱(ICP-MS)法测定纯钌中19种杂质元素

建立了激光剥蚀-电感耦合等离子体质谱(LA-ICP-MS)法测定纯钌中Mg、Al、Fe、Ni、Cu、Zn、Rb、Rh、Pd、Mo、Ag、Cd、Sn、Ba、Ir、Pt、Au、Pb和Si等19种杂质元素的分析方法。优化了仪器参数,给出了激光能量为60%,剥蚀孔径为110μm,扫描速率为50μm/s,脉冲频率为10 Hz,载气流量为0.74 L/min条件下,信号强度和稳定性最佳。由于钌标准样品难以获得,因此选择用纯钌粉样品,高温高压溶解后,采用ICP-MS法定值所测元素(除硅外)。根据钌粉样品的ICP-MS法定值结果确定了测定元素的相对灵敏度因子(RSF),采用相对灵敏度因子(RSF)对所测结果进行校正,方法准确、快速,检出限为0.007~12.8μg/g,相对标准偏差(RSD)为10%~30%。测定纯钌中杂质元素,结果与ICP-MS法测定的结果吻合。     

辉光放电质谱法在高纯材料分析中的应用

高纯材料是现代高新技术发展的基础,在电子、光学和光电子等尖端科学领域发挥着重要作用。采用固体样品直接分析的辉光放电质谱法(GDMS),在高纯金属、高纯半导体材料的痕量和超痕量杂质分析中有着非常广泛的应用。综述了GDMS法对高纯金属、高纯半导体材料进行的元素分析,并对分析过程中工作参数、溅射时间、干扰峰等因素的影响进行了阐述。同时,也详述了应用GDMS法对高纯金属钛、镉,高纯半导体硅,分别进行的痕量杂质元素分析,结果显示放电稳定性良好,典型元素含量的相对标准偏差均在较为理想范围内。GDMS应用前景广泛,未来,GDMS将在除固体样品之外的其他样品类型的分析领域中发挥重要作用。