Solid State Phenomena Vol. 371

Abstract: This study investigates the effects of laser spot size and sizing threshold parameters in Surface Scanning Inspection Systems (SSIS) on defect cluster identification in 300 mm silicon wafers. Reducing the laser spot size enhances the detection of smaller point defects, increasing cluster counts by up to 45% depending on the scan mode. Similarly, lowering the sizing threshold improves point defect capture rates, raising cluster probability by over 30%. However, these optimizations involve trade-offs: smaller spot sizes limit the search distance, while lower thresholds encourage cluster merging, resulting in a net decrease in identified clusters by 10%-20% in some cases. These findings underscore the need for a precise balance between sensitivity and resolution in SSIS configurations to achieve effective defect management. This work offers critical insights for optimizing silicon wafer quality, an essential factor in advanced integrated circuit manufacturing. Furthermore, it establishes a foundation for integrating machine learning-based defect feature analysis, paving the way for next-generation automated and predictive inspection systems in semiconductor fabrication. By addressing the challenges of defect clustering and providing data-driven solutions, this study contributes to the advancement of more reliable and efficient inspection technologies for the evolving demands of the semiconductor industry.

Abstract: The proliferation of X-band microwaves across wireless networks, satellite communications, and radar systems has raised global concerns regarding their potential impact on human health and communication security. Additionally, advancements in radar detection technology have diminished the effectiveness of military equipment in modern warfare, driving a heightened demand for materials capable of absorbing microwaves across the X-band spectrum in both civilian and military sectors. Effective microwave absorbing materials (MAM) ideally exhibit lightweight construction, robust absorption capabilities, and a broad effective absorption band. Among the array of reported MAM, rubber-based microwave absorbers emerge as particularly promising for practical application. Their exceptional flexibility, environmental resilience, favorable mechanical properties, versatility, and ease of processing distinguish them in this domain. Cobalt Titanate (CoTiO₃), a common perovskite with the ABO₃ structure, showcases remarkable magnetic and semiconducting characteristics, including outstanding photochemical stability, efficient light absorption, and high carrier mobility. These attributes render it versatile for various applications, spanning catalysis, adsorption, dielectric ceramics, magnetic recording, gas sensors, and pigments. A composite material comprising Cobalt Titanate and Natural Rubber holds significant promise as a microwave absorbing material in the X-band spectrum. Its potential lies in leveraging the synergistic properties of both constituents to achieve enhanced microwave absorption performance, offering substantial implications for various civilian and military applications.

Abstract: This research discusses synthesizing and characterizing magnetic hard-soft composite materials (Ba_0.6Sr_0.4Fe_11.5Al_0.5O₁₉/NiFe₂O₄) applied as microwave absorbers at S-band and C-band frequencies. The mechanical alloying method for sample synthesis uses a high-energy ball mill and sintering at high temperatures. Characterization of the crystal structure was done using an X-ray diffractometer. The Ba_0.6Sr_0.4Fe_11.5Al_0.5O₁₉ sample (hard magnetic) has a hexagonal structure, while the NiFe₂O₄ (soft magnetic) has a cubic structure. SEM analysis revealed a heterogeneous form with particle sizes ranging from 0.4 to 0.8 µm. Magnetization at room temperature was characterized using a vibrating-sample magnetometer (VSM). The magnetization saturation (Ms), magnetic remanent (Mr), and field coercivity (Hc) are 54.22 emu/g, 21.68 emu/g, and 0.876 kOe, respectively. Microwave absorption characterized using vector network analysis (VNA) shows that the hard-soft magnetic composite sample (Ba_0.6Sr_0.4Fe_11.5Al_0.5O₁₉/NiFe₂O₄) has a minimum reflection loss (RLmin) value of -29.86 dB for the S-band and -18.76 dB for the C-band area with an effective bandwidth reaching 2.34 GHz.

Abstract: This research has successfully synthesized Fe₃O₄/SWCNT/TiO₂ nanocomposite as a radar absorber for stealth technology applications in the Ka-band. The study aimed to investigate the nanocomposite's crystal structure, morphology, functional groups, magnetic properties, and radar absorption performance at a frequency Ka-Band range from 26.5 GHz to 40.0 GHz. The X-ray diffraction analysis revealed a crystalline phase of Fe₃O₄ with a crystallite size of 14.26 nm and two crystalline phases of TiO₂ (anatase and rutile) with crystallite sizes of 5.12 nm and 27.51 nm, respectively. The scanning electron microscopy image showed SWCNT as a matrix with diameters of several nanometers and lengths of several micrometers, along with Fe₃O₄ and TiO₂ particles as fillers with a particle size of 46.56 nm, consistent with the XRD characterization. Furthermore, the infra-red spectrum confirmed the presence of Fe₃O₄ through octahedral and tetrahedral Fe-O bonds. C-O, C-C, and C=O indicated the presence of SWCNT. Meanwhile, -OH bonds also validated the success of their functionalization. Ti-O and Ti-O-C bonds stated the presence of TiO₂ bound to SWCNTs. The hysteresis curve exhibited superparamagnetic properties of the nanocomposite with a saturation magnetization of 9.38 emu/g. Furthermore, radar absorption measurement demonstrated that the nanocomposite absorbs radar with a maximum reflection loss of –1.51 dB at an effective frequency of 33.16 GHz, showing a potency for Fe₃O₄/SWCNT/TiO₂ nanocomposite as radar absorber in the Ka-Band Region, inspiring potential applications in stealth technology.

Abstract: The lithium aluminium titanium tantalum phosphates compounds Li₁₊xAl_xT_2-x-yTa_y(PO₄)₃ (LATTaP) with different compositions (x = 0.3; 0.02 ≤ y ≤ 0.05) were synthesized using a solid-state synthesis approach. The synthesized samples were characterized through various methods. TGA/DTG results indicate the thermal stability and complete breakdown of the stoichiometric compositions. This ensures LATTaP solid electrolytes remain stable under battery cycling, high-temperature environments, and battery applications. This was corroborated by the FTIR findings, which showed the total decomposition of volatile substances, including water molecules, CO₂, and HN₃; the wave bands associated with hydroxyl or carboxylic compounds were completely absent, with only the bands corresponding to the vibration of the PO₄ ionic group detected. This identifies chemical bonding, confirming the stability of the phosphate framework which determines structural integrity for long-term battery cycling without material degradation. The samples were successfully produced with an R-3c space group for structural characterization, assuming a hexagonal crystal structure, as referenced in the ICSD database 98-006-9677. XRD analysis demonstrated the presence of a single-phase NASICON-type crystal structure, which is essential for high ionic conductivity. The findings showed that the thermal properties of the materials are important to identify proper applicability of the material as a solid electrolyte.