Characterization Of Wafers Research Articles

Wafer and chip-level characterization of edge-coupled photonic integrated circuits by cascaded grating couplers and spot-size converters

This study presents an efficient testing process for characterizing silicon photonic ICs. This process utilizes a coupling structure that integrates grating couplers and spot-size converters for efficient testing both at the chip and wafer levels, respectively. By leveraging wafer-level testing to estimate the characteristics of final chip-level devices, we anticipate a reduction in testing costs. To demonstrate the validity of the proposed testing process, we fabricated and measured silicon-on-insulator ring resonator devices on both wafer and chip levels. The results showed good agreement between the two levels of measurement, validating the effectiveness of our proposed testing process.

Controllable Fabrication of Silicon Solar Cells with Inverted or Upright Pyramid Structures by a One-Step Copper Catalysis Method

Silicon has garnered significant attention as the primary material for solar cell preparation. Traditional alkaline etching solutions are limited to creating an upright pyramid structure on monocrystalline silicon surfaces. However, research indicates that an inverted pyramid structure exhibits superior light-trapping properties compared to the upright pyramid structure. In this study, we employed a one-step copper ion metal-assisted chemical etching process to fabricate an inverted pyramid structure on monocrystalline silicon wafers. This method allows for the customization of either inverted or upright pyramid structures by adjusting the concentration of specific solution components. Characterization of the textured silicon wafers reveals that the inverted pyramid structure exhibits lower reflectivity than both the upright pyramid structure and polished silicon. By integrating this texturing technique into the solar cell production line, we successfully produced solar cells with both inverted and upright pyramid structures. Evaluation of various solar cell parameters demonstrates that the inverted pyramid structure outperforms the upright pyramid structure, showcasing lower reflectivity and higher photoelectric conversion efficiency.

Defect characterization of SiC wafers by polarized light microscopy under a condition slightly deviated from crossed Nicols

Defect characterization of SiC wafers by polarized light microscopy under a condition slightly deviated from crossed Nicols

Development of High-Resolution Nuclear Emulsion Plates for Synchrotron X-Ray Topography Observation of Large-Size Semiconductor Wafers

Characterization of defects in semiconductor wafers is essential for the development and improvement of semiconductor devices, especially power devices. X-ray topography (XRT) using synchrotron radiation is a powerful methods used for defect characterization. To achieve detailed characterization of large-size semiconductor wafers by synchrotron XRT, we have developed nuclear emulsion plates reaching a high-resolution and wide dynamic range. We have shown that higher-resolution XRT images could be obtained using emulsions with smaller iodobromide crystals, and demonstrated clear observation of threading edge dislocations in a SiC epitaxial layer having small contrast. Furthermore, we demonstrated XRT image acquisition for almost all of a 150-mm SiC wafer with one plate. Our development will contribute to advances in electronic materials, especially in the field of power electronics, in which defect characterization is important for improving the performance and yield of devices.

A Medicated Wafers as a Novel Drug Delivery Carrier

Throughout the globe, pharmaceutical researchers seek to investigate medicated wafers as a novel instrument for drug delivery. As an alternative strategy to standard dosage forms, medicated wafers have been recognized. Wafers are regarded as convenient for swallowing, self-administering, and rapid dissolving dosage form, making it a versatile drug delivery platform. This delivery system was used through several paths such as oral, buccal, sublingual, and transdermal routes for both systemic and local intervention. The development of effective thin wafers needs an extensive understanding of the pharmacological and pharmaceutical properties of drugs and polymers together with a suitable choice of production procedures. The objective of this review is therefore to provide an overview of the new innovative formulation techniques, the various patents registered, the application in the pharmaceutical field, factors affecting the formulation of thin wafers, including the physicochemical properties of polymers and drugs, anatomical and physiological constraints, and the characterization of wafers. It also includes the latest trends and perspectives for designing thin wafers products and issues for different businesses developing thin wafers.

Fabrication, in Vitro, and in Vivo Characterization of Mucoadhesive Berberine-Loaded Blended Wafers for Treatment of Chemotherapy-Induced Oral Mucositis.

This study aims to design and characterize berberine-loaded wafers for the treatment of chemotherapy-induced oral mucositis. Wafers were prepared by lyophilization of hydrogels of various ratios of chitosan (CS)/sodium alginate (SA) as well as CS/hydroxypropyl methylcellulose (HPMC). In vitro release, in vitro mucoadhesion, porosity, and swelling studies were conducted to select the optimized formulations. Moreover, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and mechanical properties studies were also performed for further characterization. The efficacy of optimized berberine-loaded wafers in the treatment of oral mucositis was investigated in a 5FU-induced oral mucositis rat model. F2-CS-SA and F6-CS-HPMC wafers exhibited sustained release profile and excellent mucoadhesion strength. Therefore, these wafers were selected as the optimized formulations. SEM confirmed the porous structure of these wafers and is in agreement with the results of porosity and swelling studies. XRD and FTIR studies indicated that berberine was incorporated into the wafer matrix in the amorphous form. In vivo studies demonstrated that topical application of berberine-loaded optimized wafers reduced significantly the severity of 5FU-induced oral mucositis and decreased the expression of inflammatory markers (TNF-α and IL-1β). The results of in vitro and in vivo studies revealed that berberine-loaded F2-CS-SA and F6-CS-HPMC wafers can be effective in the treatment of chemotherapy-related oral mucositis.

Preparation and characterization of benzydamine hydrochloride-loaded lyophilized mucoadhesive wafers for the treatment of oral mucositis

Chemo/radiotherapy-induced oral mucositis (OM) has painful ulcers that can impair patients' lives. This study aimed to develop and characterize (in vitro and in vivo) benzydamine (BNZ) freeze-dried mucoadhesive wafers from chitosan (CS) in combination with different hydrophilic polymers as a locally controlled delivery system for OM treatment. The porous (69–83%) optimum wafers (0.02–0.03 g and 3.2–4.3 mm) released 90–95% of their drug content over 8 h and demonstrated 40–53 g mucoadhesion strength. Mechanical evaluations of F1 (CS) and F14 (CS/HPMC (3:1)) selected formulations showed modulus of elasticity, tensile strength, and % elongation at break ranging from 0.2 to 0.3 MPa, 0.01–0.02 MPa, and 15–18%, respectively. The antimicrobial efficacy of BNZ-loaded wafers was significantly higher than drug-free ones. The extract solutions of the drug-free and BNZ-loaded wafers revealed 100 and 20% viability in human gingival fibroblasts (HGFs) exposure. In vivo analysis demonstrated that BNZ-loaded wafers represented a significant reduction in macroscopic evaluation of OM and histopathological tests compared to positive and negative controls and drug-free wafers. Conclusively, lyophilized F1 and F14 mucoadhesive wafers had acceptable structural, mechanical, and biological properties and might be promising drug delivery systems for OM.

Observation of in-plane shear stress fields in off-axis SiC wafers by birefringence imaging.

For the nondestructive characterization of SiC wafers for power device application, birefringence imaging is one of the promising methods. In the present study, it is demonstrated that birefringence image contrast variation in off-axis SiC wafers corresponds to the in-plane shear stress under conditions slightly deviating from crossed Nicols according to both theoretical consideration and experimental observation. The current results indicate that the characterization of defects in SiC wafers is possible to achieve by birefringence imaging.

High Power Mid-Infrared Quantum Cascade Lasers Grown on GaAs

The motivation behind this work is to show that InP-based intersubband lasers with high power can be realized on substrates with significant lattice mismatch. This is a primary concern for the integration of mid-infrared active optoelectronic devices on low-cost photonic platforms, such as Si. As evidence, an InP-based mid-infrared quantum cascade laser structure was grown on a GaAs substrate, which has a large (4%) lattice mismatch with respect to InP. Prior to laser core growth, a metamorphic buffer layer of InP was grown directly on a GaAs substrate to adjust the lattice constant. Wafer characterization data are given to establish general material characteristics. A simple fabrication procedure leads to lasers with high peak power (>14 W) at room temperature. These results are extremely promising for direct quantum cascade laser growth on Si substrates.

Thermal characterization of direct wafer bonded Si-on-SiC

Direct bonded Si-on-SiC is an interesting alternative to silicon-on-insulator (SOI) for improved thermal management in power conversion and radio frequency applications in space. We have used transient thermoreflectance and finite element simulations to characterize the thermal properties of direct bonded Si-on-4H–SiC samples, utilizing a hydrophobic and hydrophilic bonding process. In both instances, the interface has good thermal properties resulting in TBReff values of 6 + 4/−2 m2 K GW−1 (hydrophobic) and 9 + 3/−2 m2 K GW−1 (hydrophilic). Two-dimensional finite element simulations for an equivalent MOSFET showed the significant thermal benefit of using Si-on-SiC over SOI. In these simulations, a MOSFET with a 200 nm thick, 42 μm wide Si drift region was recreated on a SOI structure (2 μm buried oxide) and on the Si-on-SiC material characterized here. At 5 W mm−1 power dissipation, the Si-on-SiC was shown to result in a >60% decrease in temperature rise compared to the SOI structure.

Design, Development and Characterization of Flash release wafers containing Levocetrizine hydrochloride and Montelukast sodium

The main objective of the current research investigation was to develop and characterize flash release wafers containing Levocetrizine hydrochloride and Montelukast sodium. The formulation of flash release wafers was done by the solvent casting method. HPMC E5 LV, HPMC E50 LV, HPMC Lab grade polymer and plasticizer like glycerol, di-butyl phthalate were screened for wafers formation. Amongst them, HPMC lab-grade as polymer basis and glycerol as plasticizer showed good smooth wafers, acceptable thickness, clear and easy to peel off from the Petri plate. There was no interaction found between drug-drug and drug-excipients by FT-IR spectral analysis and shown that the ingredients used for the formulation of wafers were highly compatible. Then the optimized flash release wafers were evaluated for main parameters like disintegration time, drug content, surface pH, thickness and percentage drug release. Batch ML-7 was found to be optimized formulation of wafers which showed the satisfactory acceptable results of drug content 99.56±1.03of Levocetrizine hydrochloride and 98.92±2.33 of Montelukast sodium, least disintegration time of about 15±0.68 seconds, surface pH was 6.78± 0.010 and percentage drug release of Levocetrizine hydrochloride and Montelukast sodium was 96% and 97.5% at 5th minute. Hence it was found that the optimized formulation ML-7 showed much faster drug release than the oral marketed immediate-release tablet formulation in a 5th minute. This depicted that the formulation containing a lower concentration of polymer and a higher concentration of superdisintegrates showed a positive effect on disintegration time and drug release.

Characterization of mosaic diamond wafers and hot-filament epilayers by using HR-EBSD technics

Tungsten (W) incorporated diamond film was homoepitaxially grown on a mosaic diamond wafer by hot-filament chemical vapor deposition. The crystallinity of the W incorporated epilayer and the original mosaic diamond wafer was characterized by using high-resolution electron backscatter diffraction (HR-EBSD). From kernel average misorientation maps (KAM) derived from HR-EBSD measurements, it was found that the numerical value of KAM and the width of coalescence boundary region (CBR) of W incorporated epilayers were much smaller than those of original mosaic diamond wafers and not only in the CBR but also in the bulk area, the crystalline quality of the W incorporated epilayer is better than that of the original mosaic diamond wafers. It is suggested that the primal role for the W incorporation is strain reduction near threading dislocations during growth.

Ultrafast nonlinear ultrasonic measurement using femtosecond laser and modified lock-in detection

Ultrafast ultrasonic techniques using picosecond/femtosecond lasers show promise for the nondestructive evaluation at fine spatial resolutions because the induced ultrasonic waves have an extremely high frequency range, from GHz to THz. However, most existing applications are based on the linear feature variation of the measured ultrafast ultrasonic waves; this is limited by the linearity assumptions in lock-in detection schemes adopted for ultrafast ultrasonic measurement. This study proposes a technique to measure ultrafast nonlinear ultrasonic waves using a femtosecond laser and a modified lock-in detection scheme. The advantages of the proposed technique are as follows. (1) The developed technique can measure nonlinear ultrasonic waves induced by a femtosecond laser; (2) linear and nonlinear ultrasonic responses can be decomposed and measured using a modified lock-in detection scheme; and (3) the decomposed nonlinear ultrasonic waves can be used for effective micro defect detection and microstructure characterization at sub-micrometer scale. The proposed technique was used to successfully perform validation tests on micro crack detection in a silicon wafer and microstructure characterization of an additively manufactured Ti-6Al-4V sample.

Surface Topography Measurement

AbstractWhen testing the surface quality of the finest structures, white‐light interferometers are in their element, both in production and development, as well as in laboratories and research. This measurement principle works on almost all materials, operates without contact, providing surface profiles in 3D with height resolutions in the nanometer range. Today, large‐area measurements are just as possible as detailed investigations with high lateral resolution, e.g. for surface characterization of wafers, optical components or in tribology.

Ultrafast pulse laser inscription and surface quality characterization of micro-structured silicon wafer

• Established an efficient methodology based on Ultrafast laser inscription principle for fabricating higher quality microchannels. • The proposed methodology will be an alternative technique for the usual industrial practice to attain higher ablation depth. • For the first time, ALF over the crystalline coating of Si3N4 on silicon was analysed and reported to be predominant on structural integrity. • The occurrence of the bulging phenomenon on coated silicon surface at low repetition rates were reported. • The surface temperature was predicted which justified the enhancement in surface integrity processed at a specific range of lasing parameters. We report the applicability of the ultrafast pulse laser inscription technique to achieve high ablation depth on uncoated silicon wafer despite its higher surface reflectivity. The proposed methodology of this research work can be an alternative approach for the usual industrial practice of coating silicon surface with highly reflective materials for increasing the absorption phenomenon. To unveil the potential of the proposed methodology, a comparative study was carried out by fabricating microchannels of higher depth on uncoated and coated silicon wafer by varying repetition rate from 10 kHz to 500 kHz at a constant pulse energy of 18 μJ. The formation of ablation depth, ablation width and amorphous layer thickness was taken as the standard for evaluating the effectiveness of the proposed methodology. The experimental results revealed the formation of a higher ablation depth of 6.6 μm and an amorphous layer thickness of 0.039 μm for uncoated silicon material. Whereas, in the case of coated silicon material the ablation depth was found to be 3.199 μm with an amorphous layer thickness of 0.101 μm. This justified the applicability of the ultrafast pulse laser inscription technique for achieving quality microchannels having higher depth on silicon material without any surface coating. The underlying mechanism for the improved performance is due to the low temporal separation (μs) property of ultrafast lasers which results in negligible heat diffusion into the bulk material, thereby minimizing the collateral thermal damages. This was further proved based on an analytical model by evaluating the surface temperature at various repetition rates. The experimental and analytical results from the present work will be highly beneficial for the electronic industry, where the laser micro structuring of MEMS components made of silicon material is highly challenging due to its reflective property.

Quality Characterization of Wafers Enriched with Fish Powder Developed from Small Bony Fish

ABSTRACT The study aimed to improve the nutritional quality of wafers by utilizing fish powder developed from small bony fish at 10%, 20%, and 30% inclusion levels. Quality evaluation of produced wafers in terms of nutritional, physical, sensory, and shelf life characteristics was performed. Results revealed a significant increase (p < .05) in protein (8.07 ± 0.34 to 23.34 ± 0.43 g/100 g), fat (1.08 ± 0.85 to 4.69 ± 0.78 g/100 g), and ash content (3.67 ± 0.47 to 8.33 ± 0.30 g/100 g) of wafers with increased supplementation of fish powder. No significant change in diameter, thickness, or weight per wafer was observed; however, water absorption capacity (212.67 ± 2.52 to 71.67 ± 2.89 ml/100 g), fat absorption capacity (164.00 ± 3.60 to 66.00 ± 5.29 ml/100 g), and linear expansion (139.17 ± 6.16 to 76.40 ± 2.11%) reduced significantly (p < .05) on increasing level of fish powder in the produced wafers. Color analyses revealed a significant decrease in L* (89.57 ± 1.25 to 46.89 ± 1.06) and b* (7.25 ± 0.09 to 18.59 ± 0.8) value and significant increase in a* value (−0.54 ± 0.01 to 3.87 ± 0.03) with increasing fish powder supplementation. There was no significant (p > .05) alteration in sensory attributes of wafers with fish powder incorporation up to 20%. The produced wafers also had good storage stability, with peroxide value, free fatty acid, and total plate count within acceptable limits up to two months of storage.

Improvement of extra low impact energy SIMS data reduction algorithm for process control

This work explores quantitative boron depth profiling in the top first nanometer using dynamic secondary ion mass spectrometry (SIMS). Dynamic SIMS measurements were performed with a magnetic sector CAMECA IMS Wf/SC Ultra, using extremely low impact energy O2+ (below 250 eV) sputtering. It was concluded that the modification of quantification protocol by the creation of a surface transient curve can provide a tool for the accurate characterization of low energy implantation wafers, including boron, under extremely low energy sputtering conditions with an oxygen beam.

Influence of Nonlinearity on Electronic Transport Characterization of Ion-Implanted Silicon Wafers with Photocarrier Radiometry

Two-layer linear and nonlinear models were employed to investigate the influence of the nonlinear dependence of photocarrier radiometry (PCR) signal on excitation power for ion-implanted silicon wafers on the determination of carrier transport parameters of ion-implanted layers in the frequency domain. Three silicon wafers were measured at 830 nm excitation wavelength, with the ion-implantation dose of 1011, 1013, and 1016 cm−2, respectively. The effect of nonlinear coefficient on the multi-parameter fitting for electronic transport parameter determination was analyzed via theoretical simulations and experimental measurements. Both simulation and experimental results showed that the multi-parameter fitted results obtained via the linear PCR model (ignoring the nonlinearity) were significantly different from that obtained via the nonlinear PCR model (taking into account the nonlinearity). With the linear PCR model, the fitting errors in the determination of transport parameters of ion-implanted layers were highly sensitive to the nonlinearity coefficient. For low-implantation-dose silicon wafers with high nonlinearity coefficients close to 2, the square variance increased drastically, and the fitting errors were non-acceptably high. Comparison of the electronic transport parameters determined via the two-layer linear and nonlinear PCR models clearly showed that two-layer nonlinear PCR model is much more suitable than the linear model for describing the PCR signals and is more accurately for characterizing the carrier transport parameters of ion-implanted silicon wafers.

Performance of Al–Mn Transition-Edge Sensor Bolometers in SPT-3G

SPT-3G is a polarization-sensitive receiver, installed on the South Pole Telescope, that measures the anisotropy of the cosmic microwave background (CMB) from degree to arcminute scales. The receiver consists of ten 150~mm-diameter detector wafers, containing a total of 16,000 transition-edge sensor (TES) bolometers observing at 95, 150, and 220 GHz. During the 2018-2019 austral summer, one of these detector wafers was replaced by a new wafer fabricated with Al-Mn TESs instead of the Ti/Au design originally deployed for SPT-3G. We present the results of in-lab characterization and on-sky performance of this Al-Mn wafer, including electrical and thermal properties, optical efficiency measurements, and noise-equivalent temperature. In addition, we discuss and account for several calibration-related systematic errors that affect measurements made using frequency-domain multiplexing readout electronics.

71Ga NMR characterization of an n-doped free-standing gallium nitride wafer

The crystallinity of an n-doped free-standing GaN wafer sliced from a GaN crystal grown on a GaN template with a mask pattern was characterized by 71Ga NMR. The quadrupolar frequency determined from the quadrupolar-split 71Ga spectra agreed with that of free-standing GaN single crystals reported in the literature. On the other hand, the broad satellite transition lines compared to the central transition line manifested structural deviation. The satellite linewidths were notably anisotropic with respect to the angle between the magnetic field and the crystalline axes; this phenomenon was attributed to the strain distribution inside the crystal. Assuming uniform deformation of the crystal as the main origin of the satellite linewidths, the longitudinal strain distribution was estimated to be on the order of 10−5. The strain distribution was also found to be slightly larger at the center of the wafer than at the edge.