Electronic Grade Research Articles

Synthesis of UiO-66-NH2@PSF Hollow Fiber Membrane with Enhanced Simultaneous Adsorption of Pb2+ and Phosphate for Hydrogen Peroxide Purification.

Electronic grade hydrogen peroxide plays a crucial role in the fabrication of large-scale integrated circuits. However, hydrogen peroxide prepared by the anthraquinone method contains impurities such as lead ions (Pb2+) and phosphate, which can seriously affect the yield of the circuit. Traditional adsorbent materials have difficulty in solving the problem of simultaneous adsorption of trace anions and cations in hydrogen peroxide due to the single adsorption site and poor adsorption kinetics. In this study, UiO-66-NH2 was prepared by introducing a -NH2 group on the terephthalic acid ligand, and a series of hybrid matrix hollow fiber membranes with different UiO-66-NH2 contents were prepared by loading it on polysulfone (PSF). This initiative not only improved the pore size and water flux of hollow fiber membranes but also enhanced the removal efficiency of ions from hydrogen peroxide solution, thereby facilitating practical application. Among them, UiO-66-NH2@PSF-1.5 showed the best adsorption of phosphate and lead ions with adsorption capacities of 3.099 and 2.160 mg g-1 and reached the removal efficiency of 67.1 and 60.1%, which fully confirms the practicability in the purification of electronic chemicals. This work innovatively proposes that UiO-66-NH2@PSF hybrid matrix hollow fiber membranes have great potential as simultaneous adsorbents for cations and anions in the efficient purification of electronic grade solvents.

The Trade-Off between Dechlorination and Polymerization for Facile Fabrication of Electronic Grade Epoxidized Cardol.

The dechlorination of epoxidized Cardol (E-Cardol), which is a high-performance and sustainable adhesive and packaging material for electronics, remains challenging. The previous work proposed a new alcohol-sodium refining method to efficiently remove the chlorine of E-Cardol. However, this method is strongly limited by the trade-off between the dechlorination efficiency and its polymerization side effect, which leads to the viscosity as well as the epoxy equivalent increase of E-Cardol. Based on the detailed analysis of the refining process using fourier transform infrared spectroscopy (FTIR), simultaneous thermal analysis (STA), and nuclear magnetic resonance spectrometer (NMR) epoxidized Cardol (E-Cardol), this trade-off is studied. It is found that the dechlorination efficiency increases with the increase of the usage of the alcohol sodium. Meanwhile, when the residual alcohol-sodium content after refining exceeds 3000ppm, the viscosity of the E-Cardol increases significantly due to the increased polymerization of E-Cardol by epoxy ring-opening reaction. It is demonstrated that the alcohol-sodium refining method can efficiently reduce the chlorine content of E-Cardol with the initial hydrolyzable chlorine content not higher than 3000ppm to below 300ppm without influencing their epoxy equivalent and viscosity. This paper thoroughly explores the mechanism and application range of the proposed alcohol-sodium refining method, which is crucial for the facile preparation of electronic-grade E-Cardol materials.

(Invited) Agricultural Waste Derived Anodes for Lithium and Sodium Ion Batteries

Hard or turbostratic carbon anodes are most often derived from thermolysis of biomass in oxygen free environments and considerable data has been accrued to suggest that low specific surface area HC offers the most stable materials for lithiation and sodiation. As part of our efforts to valorize rice hull ash (RHA, 90 wt % SiO2/8 wt % C), produced in 150k ton/yr in the U.S. alone; we learned to first distillatively remove excess SiO2 to produce silica depleted RHA or SDRHA40-70 (40-70 wt.% SiO2).1 The resulting materials are nanocomposites of carbon and SiO2 intermixed at nm length scales.2 The SDRHA carbon can be used as a reductant, and because of the very small diffusion distances, SDRHAxxcan be carbothermally reduced to electronics grade silicon (SiPV, 5’9’s purity)3 or SiC (Ar) or Si2N2O (90N2/10H2) or Si3N4 (N2) at much lower temperatures (1250°-1500 °C)4 than those used to produce the same materials commercially and at higher purities. At certain ratios, HC is a coproduct also intimately mixed with the major silicon containing material.We have previously found that SiC/HC mixtures can serve as anode materials (coin cells) offering capacities of ≈ 950 mAh/g after long term cycling. This usually is with HC contents of just 10-15 wt. %. In this talk we explore increasing the ratio of HC:SiC via carbothermal reduction of lower wt. % SiO2:C ratios in SDRHA40 to assess the effects on LIB capacity and rates of change and as time permits, sodium ion battery (NIB) properties. References (1) Laine, R. M.; Furgal, J. C.; Doan, P.; Pan, D.; Popova, V.; Zhang, X. Avoiding Carbothermal Reduction: Distillation of Alkoxysilanes from Biogenic, Green, and Sustainable Sources. Angew. Chem. Int. Ed. 2016, 55 1065–1069. https://doi.org/10.1002/anie.201506838.(2) Mengjie Yu; Eleni Temeche; Richard M. Laine. M. Yu, E. Temeche, R. M. Laine, Methods of Adjusting Carbon and Silica Content in Rice Hull Ash (RHA) Byproducts to Control Carbothermal Reduction Forming Nanostructured Silicon Car-Bide, Silicon Nitride, Silicon Oxynitride Nanocomposites,” Provisional Patent Application Filed Sept. 5, 2020.(3) Marchal, J. C.; Krug III, D. J.; McDonnell, P.; Sun, K.; Laine, R. M. A Low Cost, Low Energy Route to Solar Grade Silicon from Rice Hull Ash (RHA), a Sustainable Source. Green Chem. 2015, 17 (7), 3931–3940. https://doi.org/10.1039/C5GC00622H.(4) Temeche, Eleni; Yu, Mengjie; Laine, R. M. Silica Depleted Rice Hull Ash (SDRHA), an Agricultural Waste, as a High-Performance Hybrid Lithium-Ion Capacitor. Green Chemistry 2020, 22, 4656–4668.

200 cm2/Vs electron mobility and controlled low 1015 cm−3 Si doping in (010) β -Ga2O3 epitaxial drift layers

We report on metalorganic chemical vapor deposition (MOCVD) growth of controllably Si-doped 4.5 μm thick β-Ga2O3 films with electron concentrations in the 1015 cm−3 range and record-high room temperature Hall electron mobilities of up to 200 cm2/Vs, reaching the predicted theoretical maximum room temperature phonon scattering-limited mobility value for β-Ga2O3. Growth of the homoepitaxial films was performed on Fe-doped (010) β-Ga2O3 substrates at a growth rate of 1.9 μm/h using TEGa as the Gallium precursor. To probe the background electron concentration, an unintentionally doped film was grown with a Hall concentration of 3.43 × 1015 cm−3 and Hall mobility of 196 cm2/Vs. Growth of intentionally Si-doped films was accomplished by fixing all growth conditions and varying only the silane flow, with controllable Hall electron concentrations ranging from 4.38 × 1015 to 8.30 × 1015 cm−3 and exceptional Hall mobilities ranging from 194 to 200 cm2/Vs demonstrated. C-V measurements showed a flat charge profile with the ND+–NA− values correlating well with the Hall-measured electron concentration in the films. SIMS measurements showed the silicon atomic concentration matched the Hall electron concentration with carbon and hydrogen below detection limit in the films. The Hall, C-V, and SIMS data indicate the growth of high-quality 4.5 μm thick β-Ga2O3 films and controllable doping into the mid 1015 cm−3 range. These results demonstrate MOCVD growth of electronics grade record-high mobility, low carrier density, and thick β-Ga2O3 drift layers for next-generation vertical β-Ga2O3 power devices.

A microporous framework with aromatic pores for one-step purification of C2F6 from CF3CH2F/CF3CHF2/C2F6 mixture

Separating C2F6 from CF3CH2F/CF3CHF2/C2F6 is of great importance since electronic grade C2F6 is an important plasma etching gas that can be used for surface cleaning of electronic devices, as well as microelectronics, fiber optic cables and solar cells. Herein, a four-fold intermingled MOF material Ni(pba)2 was constructed, which has a high selectivity of CF3CH2F/C2F6 (38.8) and CF3CHF2/C2F6 (19.8). Breakthrough experiments show that high-purity C2F6 can not only be obtained from the binary CF3CHF2/C2F6 (5/95, v/v) and CF3CH2F/C2F6 (5/95, v/v) mixtures but also can be directly collected from ternary CF3CH2F/CF3CHF2/C2F6 (5/5/90, v/v/v) mixture with a high productivity of 7.1 mol/kg. Additionally, it is found that Ni(pba)2 can maintain good separation performance under different conditions. Finally, the theoretical calculation results show that the interactions between C2F6 and the aromatic pores are significantly lower than those of CF3CHF2 and CF3CH2F, which leads to good C2F6 separation performance.

Competitive adsorption mechanism of SiHCl3 with BCl3 under a hydrogen atmosphere: Boron impurities introduction into polysilicon

The primary method for electronic-grade (EG) polysilicon production is the modified Siemens process. Unfortunately, the EG polysilicon produced through this method contains excessive levels of boron impurities (> 0.2 ppb), thereby diminishing the product quality. This issue impedes the large-scale production of EG polysilicon. This study establishes the structure of the Si (100) surface within a hydrogen-rich environment under the BCl3-SiHCl3-H2 system and investigates the adsorption mechanisms of BCl3 and SiHCl3, as well as the competitive adsorption mechanism of BCl3-SiHCl3, on the Si (100) surface. The results indicate that the adsorption energy barriers for BCl3 and SiHCl3 on the Si (100) surface are 7.8383 kJ·mol−1 and 229.6970 kJ·mol−1, respectively, so that the preferential adsorption of BCl3 onto the Si (100) surface over SiHCl3. The B atom and the Si atom are competing for adsorption on the Si (100) surface and creating an ab-B-Si-ab structure, and the optimal adsorption path is as follows: ab-BCl3→ab-BCl2→ab-BCl2-SiHCl3→ab-BCl-SiHCl3→ab-B-SiHCl3→ab-B-SiHCl2→ab-B-SiHCl→ab-B-SiH-ab→ab-B-Si-ab.

Modified Clavien-Dindo-Sink Classification System for operative complications in adult spine surgery.

Currently there is no standardized mechanism to describe or compare complications in adult spine surgery. Thus, the purpose of the present study was to modify and validate the Clavien-Dindo-Sink complication classification system for applications in spine surgery. The Clavien-Dindo-Sink complication classification system was evaluated and modified for spine surgery by four fellowship-trained spine surgeons using a consensus process. A distinct group of three fellowship-trained spine surgeons completed a randomized electronic survey grading 71 real-life clinical case scenarios. The survey was repeated 2 weeks after its initial completion. Fleiss' and Cohen's kappa (κ) statistics were used to evaluate interrater and intrarater reliabilities, respectively. Overall, interobserver reliability during the first and second rounds of grading was excellent with a κ of 0.847 (95% CI 0.785-0.908) and 0.852 (95% CI 0.791-0.913), respectively. In the first round, interrater reliability ranged from good to excellent with a κ of 0.778 for grade I (95% CI 0.644-0.912), 0.698 for grade II (95% CI 0.564-0.832), 0.861 for grade III (95% CI 0.727-0.996), 0.845 for grade IV-A (95% CI 0.711-0.979), 0.962 for grade IV-B (95% CI 0.828-1.097), and 0.960 for grade V (95% CI 0.826-1.094). Intraobserver reliability testing for all three independent observers was excellent with a κ of 0.971 (95% CI 0.944-0.999) for rater 1, 0.963 (95% CI 0.926-1.001) for rater 2, and 0.926 (95% CI 0.869-0.982) for rater 3. The Modified Clavien-Dindo-Sink Classification System demonstrates excellent interrater and intrarater reliability in adult spine surgery cases. This system provides a useful framework to better communicate the severity of spine-related complications.

Diamond ∆E-E telescope with an ultra-thin ∆E-diamond detector

The limits of mechanical polishing and RIE/ICP etching process were investigated to reduce the thickness of detector-grade ultra-thin below 10 μm, preserving the high quality of starting single crystal diamond (SCD) material. Free standing electronic grade SCD films with sizes up 4.5 × 4.5 mm2 and thickness down to 5 μm with overall thickness uniformity of ±0.35 μm were fabricated. The ultra-thin films were flat demonstrating the low internal stress.Diamond ∆E − E telescope was made from 5 μm thick ΔE-detector and 500 μm thick E-detector. The telescope was installed at the MARS spectrometer (Cyclotron Institute, TAMU) and tested with 241Am and 228Th alpha sources and 20Ne ion-beam, demonstrating the good spectral resolution around 100 keV. Simulations with the LISE++ program indicate that the telescope will be suitable to measure low energy heavy ion beams at energies as low as 2–3 MeV/nu for Au and U heavy ions, and even lower energies for lighter ions. The diamond telescope will be superior to common Si radiation telescopes having a low life-time in intense heavy ion-beams.

Trace Cu (II) removal from N-methylpyrrolidone with hydrogel rich in O, N and S active sites

The presence of a considerable quantity of metal ions in N-methylpyrrolidone (NMP) applied for the cleaning of electronic devices, especially chips, results in a breakdown effect, thus affecting their overall durability and performance. Here, hydrogel that rich in O, N, and S active sites was prepared, which can effectively remove trace amounts of Cu (II) from N-methylpyrrolidone. The material was synthesized through a one-pot crosslinking and ion exchange method and is named SLH. The physicochemical properties and adsorption experiments were conducted. It was found that SLH-2 exhibited outstanding Langmuir maximum adsorption capacity of 136.99 mg/g at an initial Cu (II) concentration of 200 mg/L. By utilizing SLH-2 in electronic grade adsorption experiments, concentration of trace Cu (II) decreased from 12.3 μg/L to 5.39 μg/L. Additionally, concentration of Zn, Fe, Mg, and Ni significantly reduced to less than 1 μg/L, with –NH2 and –COOH playing crucial roles in the adsorption process. The research results indicate that predominant adsorption mechanisms are surface coordination and ion exchange. The adsorption energy between active functional groups and Cu (II) was calculated using density functional theory (DFT), revealing an affinity order of –COOH > –SO3H > –NH2 > –OH. This work not only developed an adsorbent for capturing trace Cu (II), but also provided new strategies for the removal of metal ions in wet chemicals.

Controlled synthesis and characterization of porous silicon nanoparticles for dynamic nuclear polarization.

Si nanoparticles (NPs) have been actively developed as a hyperpolarized magnetic resonance imaging (MRI) contrast agent with an imaging window close to one hour. However, the progress in the development of NPs has been hampered by the incomplete understanding of their structural properties that correspond to efficient hyperpolarization buildup and long polarization decays. In this work we study dynamic nuclear polarization (DNP) of single crystal porous Si (PSi) NPs with defined doping densities ranging from nominally undoped to highly doped with boron or phosphorus. To develop such PSi NPs we perform low-load metal-assisted catalytic etching for electronic grade Si powder followed by thermal oxidation to form the dangling bonds in the Si/SiO2 interface, the Pb centers. Pb centers are the endogenous source of the unpaired electron spins necessary for DNP. The controlled fabrication and oxidation procedures allow us to thoroughly investigate the impact of the magnetic field, temperature and doping on the DNP process. We argue that the buildup and decay rate constants are independent of size of Si crystals between approximately 10 and 60 nm. Instead, the rates are limited by the polarization transfer across the nuclear spin diffusion barrier determined by the large hyperfine shift of the central 29Si nuclei of the Pb centers. The size-independent rates are then weakly affected by the doping degree for low and moderately doped Si although slight doping is required to achieve the highest polarization. Thus, we find the room temperature relaxation of low boron doped PSi NPs reaching 75 ± 3 minutes and nuclear polarization levels exceeding ∼6% when polarized at 6.7 T and 1.4 K. Our study thus establishes solid grounds for further development of Si NPs as hyperpolarized contrast agents.

Flower-like tin oxide membranes with robust three-dimensional channels for efficient removal of iron ions from hydrogen peroxide

Membrane technology has become the mainstream process for the production of electronic grade hydrogen peroxide (H2O2). But due to the oxidation degradation of the organic membranes (e.g. polyamide) by the strong oxidative radicals (e.g. OH) generated via the activation of H2O2 by iron ions (Fe3+), the short effective lifetime of membranes remains a challenge. Inorganic nano tin oxide (SnO2) has great potential for the removal of Fe3+ in strongly oxidative H2O2 because of its ability to stabilize H2O2 and preferentially adsorb Fe3+. Herein, we have designed for the first time a flower-like robust SnO2 membrane on the ceramic support by in situ template-free one-step hydrothermal method. The three-dimensional loose pore structure in the membrane built by interlacing SnO2 nanosheets endows the SnO2 membrane with a high specific surface area and abundant adsorption sites (OH). Based on the coordination complexation and electrostatic attraction between the SnO2 surface and Fe3+, the membrane shows a high Fe3+ removal efficiency (83%) and permeability (24 L·m−2·h−1·MPa−1) in H2O2. This study provides an innovative and simple approach to designing robust SnO2 membranes for highly efficient removal of Fe3+ in harsh environments, such as strong oxidation conditions.

Characterization on the occurrence state of nitrogen getter Ti in HPHT grown synthetic diamond crystals

Type IIa diamonds are the most promising gem grade, optical and electronic grade materials with high quality and low defects, however natural type IIa diamonds are rare and therefore the synthetic methods to obtain the high quality type IIa diamonds have been a hot issue. Nitrogen getters play a crucial role in the synthesis of type IIa high temperature high pressure (HPHT) diamonds crystals by reacting with the nitrogen in the system and effectively removing it from the growth process. However, the occurrence state of nitrogen getter introduced after diamond crystal growth remains to be investigated. In this study, a group of HPHT synthetic diamond crystals with different mass fractions of Ti as a nitrogen getter were examined by scanning electron microscopy coupled with energy dispersive spectrometer (SEM-EDS) and X-ray fluorescent spectroscopy (micro-XRF) to observe the occurrence state of the nitrogen getter Ti within the synthetic diamond crystal, it was found that at the end of crystal growth, There are two forms of Ti present in the process: (i) Ti reacts with C to form TiC, which was deposited on the surface of the diamond crystal in the dendritic pattern, and (ii) Ti enters the diamond crystal to form metallic inclusions. This study provides reliable data to support a comprehensive analysis of the effect of Ti as a nitrogen getter in the growth procession of HPHT synthetic diamond crystal, and it will have a positive effect on the development of synthetic diamond technology.

Inherent flexibility design strategy of extractive distillation for binary azeotropic separation: Novel integration of optimization approach with penalty values

In our previous work (Sep. Purif. Technol. 312 (2023) 123344), we incorporated flexibility index (FI) into steady-state extractive distillation (ED) design for binary azeotropic separation. We pointed out the significant trade-off between the cost and FI, whereby good operational flexibility (i.e., FI) is always accompanied by a higher cost. One shortcoming, however, was that we did not determine an optimum configuration that provides a compromise trade-off between the cost and flexibility. In this work, we address this by introducing a novel approach, i.e., integrated total annual cost and FI objective function (TACFI), which combines cost and FI as a single objective function, to obtain the most economic configuration with the largest operational flexibility. Additional penalty terms based on values of 10, 100, and 1000, were also introduced to compensate for the unexpected offset when the system operates beyond its limit point. Using the same isopropyl alcohol (IPA) dehydration process with the same uncertainties of ±20% feed flowrate and ±20% IPA feed composition as before, the TACFI with penalty terms enables a lower cost relative to the previous work by 39–41%. We also observe significant enhancement in operational flexibility, with a penalty value of 10, resulting in a 520-fold enhancement. However, there is no improvement for penalty values of 100 and 1000 due to the physical and thermodynamic constraints for producing electronic grade IPA. This approach allows us to locate a new optimum point with lower cost under the same FI value, and the IPA dehydration using ethylene glycol (EG) with a penalty value of 10 provides the most significant improvement in both FI and cost by about 520 times and 5%, respectively.

Impact of Electronic Class Records on Faculty Productivity at the School of Engineering and Information Communication Technology

This study aimed to determine whether the School of Engineering and Information Communication Technology (SEICT) faculty at Universidad de Zamboanga is more effective when using the Electronic Grading System. Additionally, this was done to ascertain the drawbacks and benefits of using the Electronic Grading System (EGS) for students. This study used a survey questionnaire with self-assessment questions about efficiency (time, accuracy, and effort), user difficulties, and benefits of the tool. Sixteen professors took part in the investigation. The results of using frequency and % were as follows: Efficiency in terms of time, accuracy, and effort was demonstrated. Regarding time management, around 75.00% of people gave themselves extremely efficient ratings, 12.50% gave themselves efficient ratings, and 12.50% gave themselves ordinary ratings. Regarding accuracy, 18.75% of respondents gave themselves highly accurate ratings (no errors), 75% gave themselves accurate ratings (few errors), and 6.25% gave themselves an average grade (few more errors). 25% judged their effort levels as very efficient (no effort/at ease). The typical person reported being efficient (requiring less effort) at 6.25%. (with effort). Users using the Electronic Class Record (ECR) identified two issues: power outages (31.25%) and difficulty retrieving unsaved data (6.25%). The following are some benefits of using the electronic class record: accuracy (75%), less effort (100%), education (56.25%), increased systematicity (56.25%), and increased efficiency (81.25%) are all positives. The faculty's adoption of the Electronic Grading System is encouraged for efficiency. The faculty must be educated on the program's features to address users’ issues when using the electronic grading system. A seminar workshop could be planned for in-depth talks on using the electronic grading system. Researchers are encouraged to do a comparative study utilizing additional factors that affect how effectively people operate the computerized grading system.

Hexagonal Hybrid Bismuthene by Molecular Interface Engineering.

High-quality devices based on layered heterostructures are typically built from materials obtained by complex solid-state physical approaches or laborious mechanical exfoliation and transfer. Meanwhile, wet-chemically synthesized materials commonly suffer from surface residuals and intrinsic defects. Here, we synthesize using an unprecedented colloidal photocatalyzed, one-pot redox reaction a few-layers bismuth hybrid of "electronic grade" structural quality. Intriguingly, the material presents a sulfur-alkyl-functionalized reconstructed surface that prevents it from oxidation and leads to a tuned electronic structure that results from the altered arrangement of the surface. The metallic behavior of the hybrid is supported by ab initio predictions and room temperature transport measurements of individual nanoflakes. Our findings indicate how surface reconstructions in two-dimensional (2D) systems can promote unexpected properties that can pave the way to new functionalities and devices. Moreover, this scalable synthetic process opens new avenues for applications in plasmonics or electronic (and spintronic) device fabrication. Beyond electronics, this 2D hybrid material may be of interest in organic catalysis, biomedicine, or energy storage and conversion.

Towards net zero emissions, recovered silicon from recycling PV waste panels for silicon carbide crystal production

The high rate of PV adaptation around the world requires a strategy for recovery of the materials from PV waste panels and a circular market development. In particular, the silicon recovered from the PV cells can be used in different applications. A valuable acquisition is to refine the recovered silicon at metallurgical grade to a high level of purity namely electronic grade silicon which in conjunction with graphite can be the raw material for silicon carbide crystal production. Based on a comprehensive and critical review of the latest research and development of relevant technologies, a manufacturing process is proposed to increase the usage of renewable resources, reduce the energy consumption and CO2e emissions. The recovered silicon from recycling PV waste can reduce the CO2e emissions to a third of what is involved in the current carbothermic reduction of quartz in an induction furnace. Based upon the thorough evaluation of available evidence, a continuous coupled process is envisaged where the upgraded metallurgical grade silicon from recycling PV waste undergoes further vacuum and gas refining to the electronic grade silicon. Then the purified liquid silicon enters a vertical Bridgeman furnace for silicon carbide crystal production through a bottom seeded solution growth process. Considering the silicon melting point at 1410 °C, omitting a solidification/ meting step after vacuum/gas refining leads to energy and material saving. The continuous method can reduce the CO2e emissions up to 75% compared with the current silicon carbide production through Acheson process.

The adsorption behavior of BCl3SiHCl3 on aliphatic amine by DFT method

AbstractBackgroundThe removal of trace amount of BCl3 from SiHCl3 by adsorption is an efficient method in manufacture of electronic grade polysilicon.ObjectiveDFT simulations were used to investigate the adsorption mechanism of aliphatic amine adsorbents and to compare the performance of these adsorbents.MethodsThe adsorption energies, mulliken charges, dipole moments and FMOs of aliphatic amines on SiHCl3 and BCl3 were calculated using the DFT method at the B3LYP/6‐311++G (2d, p) level, and on this basis the factors affecting the adsorption capacity and selectivity were explored in depth.ResultsThe results indicates that these adsorbents show good adsorption performance and high separation efficiency for BCl3. In particular, (CH3)2NH has the highest adsorption capacity for BCl3 at 298 K and 1 atm and achieves effective desorption at high temperatures to allow the adsorbent to be reused.ConclusionsThe adsorption behaviors are strongly affected by frontier orbitals, dipoles and polarizabilities of aliphatic amines, among which HOMO of amines plays the decisive role for adsorbing BCl3, providing theoretical guidance for adsorbent design associated with removal of BCl3 from SiHCl3.

Iterative Learning-Based Predictive Control Method for Electronic Grade Silicon Single Crystal Batch Process

The growth process of silicon single crystal (SSC) is a typical batch production process, which has the characteristics of batch size, variety, complex process, and intensive technology. In order to accurately control the diameter and thermal field temperature of the Czochralski (Cz) SSC batch production process to ensure that the actual production requirements of electronic-grade SSC are met, this paper proposes an iterative learning-based batch process predictive control strategy Model Predictive Control -Iterative Learning Control -Extended State Observer (MPC-ILC -ESO). The control strategy consists of two parts. The time axis is a dual Model Predictive Control (MPC) controller, which is mainly used to deal with disturbance suppression and constraints in the production process of a single batch of SSC. The iterative axis is the Extended State Observer (ESO) based Iterative Learning Control (ILC) control algorithm to deal with uncertainty and disturbance estimation and compensation in the multi-batch production process. The control effects of the time axis and the batch axis are superimposed as the final controlled object input to ensure the crystal diameter and stable thermal field temperature. Finally, the effectiveness of the proposed control strategy is verified based on the data analysis of the semiconductor industry production process.

Highly-efficient third-harmonic generation from ultrapure diamond crystals

We report on a direct generation of efficient and wavelength-tunable third-harmonic generation (THG) from ultrapure electronic-grade (EG) diamond crystals. Under an ultrafast infrared excitation at 1280 nm, the considerably high optical conversion efficiency of ∼ 0.7% at a THG wavelength of 427 nm is obtained, and the THG signal can be tuned over ultra-broadband range from 420 to 730 nm. We argue that the THG efficiency is originating from minimum absorption loss and phase-matching conditions in EG diamond. Enhanced THG from EG diamond crystal represents a new paradigm for establishing efficient diamond-based frequency converters, quantum sensing, and quantum communications platforms.

Copper in compensated p- and n-type Czochralski silicon: Diffusivity, influence on the majority charge carrier density and mobility

Copper contamination risks are present throughout the whole crystalline silicon solar cell process flow, namely during ingot growth processes using recycled feedstock, wafer sawing and metallisation. Copper is a fast-diffusing impurity which can modify the carrier transport and recombination properties. The aim of this study is to present new insights into the properties of copper-contaminated highly doped and compensated silicon, with a focus on the copper diffusivity and the influence of this impurity on the majority carrier mobility and density. For this, compensated Czochralski silicon ingots were grown from electronic grade feedstock doped with boron and phosphorus, and the wafers intentionally contaminated with copper. Its concentrations were measured by Glow Discharge Mass Spectrometry, while the electrical properties were extracted from Hall Effect measurements. The dopant concentrations were used to compute the effective diffusivity of interstitial copper and important changes in the copper diffusivity are expected in the vicinity of the p-type/n-type transition. For the n-type compensated wafers, a strong migration of copper atoms towards the surface and a reduced copper bulk content were highlighted. Furthermore, the presence of precipitates was experimentally revealed. Both the equilibrium electron density and electron mobility were not influenced by the contamination. In p-type compensated material, copper atoms did not accumulate at the surface, probably due to both the limited copper precipitation in p-type silicon and the lower copper diffusivity. In addition, the equilibrium hole density was not influenced. However, the hole carrier mobility was affected, likely associated to the higher bulk copper content. • Highly doped compensated silicon was intentionally contaminated with copper. • Electrical properties were obtained from Hall Effect measurements. • Large differences in copper diffusivity close to the p-to n-type transition. • Strong migration of copper towards the surface in n-type compensated wafers. • Equilibrium electron density and mobility are not influenced by the contamination.