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Trends for wafer thickness, wafer diameter, and die thickness. (Ó S. Savastiouk. Reproduced with permission from S. Savastiouk. 10 Permission to reuse must be obtained from the rightsholder.)
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Ultrathin silicon wafer technology is reviewed in terms of the semiconductor applications, critical challenges, and wafer pre-assembly and assembly process technologies and their underlying mechanisms. Mechanical backgrinding has been the standard process for wafer thinning in the semiconductor industry owing to its low cost and productivity. As th...
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Detection of wafer/die crack after the wafer dicing process is important for yield rate control prior to packaging. The traditional approach of microscopic examination is done after the dies are stripped from the dicing tape, and further crack propagation could result from this pick-and-place process. An on-tape crack inspection technique is propos...
Citations
... [4][5][6][7] Examples include wafer positioning in lithography systems, nanometric surface topography measurements with Atomic Force Microscopes (AFM), and angle measurements in magic-angle graphene. [8][9][10] To achieve accurate, reliable, and inter-comparable nanoscale measurements, traceability is essential so that the measurement results can be related to a reference standard through a documented unbroken chain of calibrations. 11) Establishing reference standards based on physical constants is a crucial element in the length traceability chain. ...
The nanometric length traceability chain is the foundation of cutting-edge research at the nanoscale. The current traceability chain has limitations in its applications. However, the application performance of the nanometric traceability chain based on the ⁷S3-⁷P4 transition in chromium atoms has been fully validated. Addressing the issue that the ⁷S3-⁷P4 transition frequency at the traceability side of this chain has not been measured in a vacuum environment, this study used the fluorescence symmetry method under vacuum conditions to measure the ⁷S3-⁷P4 transition frequency, obtaining the corresponding vacuum wavelength of 425.5533474 nm and the vacuum wave number of 23498.81645 cm⁻¹.
... However, creep-feed grinders use several (often three) cupshaped grinding wheels, each of which rotates on its axis, providing a decisive advantage. These wheels may include diamond grains of varying sizes, i.e., 320, 600, and 1700 mesh [51]. The diameter of these wheels is larger than that of the wafer. ...
... Grinding or lapping of the wafer results in surface and edge damage. To remove such damage from the surface of the wafer, etching of the wafer is done [51]. This step is important to clean of wafer surface before further processing. ...
... This results in a cheap total cost of ownership and little impact on the natural world. The dry polishing wheel utilizes either silicon dioxide or a combination of silicon dioxide and silicon carbide as its abrasive grain [51]. More investigation into the mechanism of dry polishing's material removal is necessary. ...
Silicon wafers are essential components in the production of various devices, including integrated circuits, microchips, and solar cells. The quality and characteristics of silicon wafers greatly influence the performance and reliability of these devices. Silicon wafers have been produced through processes like the Czochralski method, which involves growing a single crystal ingot of silicon and then slicing it into thin wafers. While effective, these methods have limitations in terms of scalability, cost, and uniformity. Recent advancements in silicon wafer production focus on improving efficiency, reducing costs, and enhancing quality. The innovations in silicon wafer production and finishing have significant implications for various industries, including electronics, telecommunications, automotive, and renewable energy. This article provides an overview of the production of high-purity silicon, a vital component in semiconductor device manufacturing. A comprehensive description related to the extraction of silicon from silica, the refinement of metallurgical grade silicon (MGS) to achieve high purity. Additionally, the article covers various processes involved in silicon wafer manufacturing, including cutting, shaping, polishing, and cleaning, and explores advancements in technology that could enhance wafer manufacturing capabilities.
... With the centralization and miniaturization of nanoelectromechanical systems [1,2], the manufacturing technology of integrated circuits has become increasingly demanding, requiring higher wafer processing efficiency and quality [3,4]. The importance of friction research at interfaces with nanoscale roughness related to wafer thinning [5] and equal curvature radii. ...
This review provides a comprehensive overview of recent advancements in molecular dynamics (MD) simulations of dry friction on rough substrates. While nanoscale roughness plays a crucial role in nanotribological investigations, the exploration of rough substrates remains insufficient based on MD simulations. This paper summarizes research on rough surfaces constructed from various descriptions, including the multi-asperity surface, groove-textured surface, fractal surface, Gaussian surface, stepped surface and randomly rough surface. In addition, the friction behavior of rough substrates coated with solid films is comprehensively elucidated. Present investigations on rough surfaces primarily focus on the effect of basic frictional variables, surface morphology characteristics and different motion types. The studies conducted on rough substrates exhibit a higher degree of resemblance to realistic interfaces, thereby offering valuable insight into the design of surface morphology to achieve enhanced frictional performance.
... One crucial milestone for achieving ultra-thin Si wafers of thicknesses below 100 μm was the adoption of laser dicing as a tool for wafer singulation instead of blade dicing. This innovation addressed the issue of chippage caused by blade dicing and increased the cost efficiency for small wafer thicknesses [4]. ...
Thin Silicon dies separated by laser dicing form a thin layer via redeposition of ablated silicon known as recast layer. This work analyzed the influence of the recast layer microstructure and nanoscale residual stress gradients on the bending strength of bare and metalized silicon dies <100 μm. Scanning and transmission electron mi-croscopy revealed an intricate microstructure of ablated silicon and elements of the wafer backside metallization within the recast layer. Refined silicon grains decorated by nanoscopic metallic precipitates at their grain boundaries were observed. Cross-sectional synchrotron X-ray nanodiffraction revealed that the altered micro-structure increased the tensile residual stress from 200 to 295 MPa for bare and metalized dies, respectively. Additionally, the metalized die exhibited gradients in residual stress and grain size between the die front-and backside. Despite their similar frontside bending strengths of ~340 MPa, observed in 3-point bending experiments , a considerable strengthening of the backside from 425 up to 957 MPa was measured for bare and metalized die, respectively. The origins of the tensile residual stress and the influence of the backside metalli-zation on the die bending strength are discussed.
... After ingot growth, the silicon ingots are sliced into thin wafers using wire saws or diamond saws [27]. These wafers typically have thicknesses ranging from 100 to 300 micrometers and diameters of 125 to 200 millimeters [28]. Diamond wire sawing has become the preferred method for wafering due to its higher throughput, lower kerf loss, and reduced consumable costs compared to traditional slurry-based sawing techniques [29]. ...
Solar energy has emerged as a promising alternative to traditional fossil fuels due to its abundant availability and sustainability. Solar cells, the fundamental units of solar energy conversion, have undergone significant advancements in fabrication techniques to enhance their efficiency, durability, and cost-effectiveness. This review aims to provide a comprehensive overview of various methods employed in the preparation of solar cells, including thin-film, crystalline silicon, organic, and perovskite-based technologies. By analyzing recent research developments, challenges, and future prospects, this article sheds light on the evolving landscape of solar cell fabrication, contributing to the ongoing efforts in achieving widespread adoption of solar energy.
... Integrated circuits play a crucial role in modern production and daily life, and their manufacturing process is complex and precise. Even slight changes in materials, environments, and process parameters can result in numerous wafer defects [1][2][3][4]. As a vital step in production, timely wafer defect detection is essential for improving chip productivity and yield [5][6][7]. ...
... In addition, we set up dedicated threads for the weight calculation module and load information collection module to ensure that each module can work independently. Meanwhile, we set the end flag endflag and the weight update flag wtflag to false (lines [1][2][3][4][5], indicating that the current task scheduling has not ended and the weight value does not need to be adjusted temporarily. Then, load-balancing scheduling (lines 7-16) is performed under the framework of SWRR, and the results of each scheduling are recorded in the sequence. ...
The increasing wafer yield and shrinking size pose challenges for real-time defect inspection using a single computer. To address this, we propose enhancing real-time performance by increasing computing devices. However, uneven load distribution due to device performance or defects variations can reduce inspection efficiency. We introduce computer cluster load balancing to solve this, utilizing a load-balancing model and an objective function. We propose the adaptive discrete quantum particle swarm optimization algorithm (ADQPSO) for efficient load balancing and implement the adaptive dynamic smooth weighted round-robin algorithm based on ADQPSO. Experimental results demonstrate that our algorithm achieves the fastest execution speed and up to a 24% improvement in performance. Our approach significantly improves real-time performance and efficiency in wafer surface defect inspection.
... Another alternative to improve the BSM to Si adhesion is the substrate's surface structuration through Si backside intentional roughening using a standard isotropic chemical etching process for stress relief after backside grinding [7][8][13][14][15][16]. While a lot of work has been done on the isotropic acidic etching of Si [13][14][15][16], scarce data exist in the literature related to the correlation between Si substrate surface tailoring using chemical etching and backside metallization. ...
... Another alternative to improve the BSM to Si adhesion is the substrate's surface structuration through Si backside intentional roughening using a standard isotropic chemical etching process for stress relief after backside grinding [7][8][13][14][15][16]. While a lot of work has been done on the isotropic acidic etching of Si [13][14][15][16], scarce data exist in the literature related to the correlation between Si substrate surface tailoring using chemical etching and backside metallization. In [7,13], the effects of different Si substrate chemical etching and TiNiAg BSM metallization schemes on the surface roughness and mechanical properties of thinned Si wafers and their impact on the dicing and soldering processes were studied. ...
... The starting substrates were 8-inch, 725µm thick, p-type (100) and ultra-flat (single-side polished) prime Si wafers. A standard hydrofluoric acid (HF) based isotropic wet etching process was used to roughen (Ra=200nm) the substrate backside [13][14][15][16]. Both flat (Ra=0nm) and structured (Ra=200nm) wafers were used for the metallization process. ...
... Normally, fly cutting or ultra-precision turning was usually applied to achieve high parallelism [7][8][9]. Nevertheless, the two surfaces of the workpiece are cut in turn during machining, and only the total thickness variation (TTV) can be guaranteed. The flatness as well as the parallelism cannot be improved, owing to the weak rigidity, which would cause deformation by the residual stress [10][11][12]. ...
Double-sided lapping (DSL) is a precision process widely used for machining flat workpieces, such as optical windows, wafers, and brake pads owing to its high efficiency and parallelism. However, the mechanism of parallelism error reduced by the DSL process was rarely investigated. Furthermore, the relationship between parallelism and the flatness was not clearly illustrated. To explain why the parallelism of workpieces becomes convergent by the DSL, a theoretical model has been developed in this paper by calculating the parallelism evolution with the consideration of variation contact situations between workpieces and lapping plates for the first time. Moreover, several workpieces, including a slanted one rendering the model close to the actual process, are taken to calculate the parallelism evolution, and the mechanism of the parallelism error reduced by the DSL process is clarified. The calculation result has indicated that the parallelism error was reduced from 100.0 μm to 25.6 μm based on the parallelism evolution model. The experimental results showed that the parallelism improved from 108.6 μm to 28.2 μm, which agreed with the theoretical results well.
... Moreover, bulk MOSFETs operate in the inversion mode and typical TFTs engage in the accumulation mode (Sharma et al., 2014). For comparison purposes, the semiconductor film thickness in TFTs ranges from 30 to 100 nm, though for single-crystal bulk silicon devices, the substrate depth usually is the silicon wafer thickness, spanning from ~100 μm to 1 mm (Marks et al., 2015). Figure 3 illustrates, in a) and b), silicon-on-insulator (SOI) technology often used devices and, in c), the TFT structure. ...
A study regarding the use of amorphous silicon compounds as the waveguiding materials for manufacturing photonic integrated circuits.
... Non-modification polishing refers to the removal of the workpiece material without material modification. Unlike other classification approaches (compliant and conventional polishing [51], dry and wet polishing [52], etc.), this classification is proposed to realize ACS efficiently on complex surfaces, namely freeform surfaces by serially combined processes of chemical modification polishing and non-modification polishing, as shown in Figure 3. ...
Roughness down to atomic and close-to-atomic scale is receiving an increasing attention in recent studies of manufacturing development, which can be realized by high-precision polishing processes. This review presents polishing approaches at atomic and close-to-atomic scale on planar and curved surfaces, including chemical mechanical polishing, plasma-assisted polishing, catalyst-referred etching, bonnet polishing, elastic emission machining, ion beam figuring, magnetorheological finishing, and fluid jet polishing. These polishing approaches are discussed in detail in terms of removal mechanisms, polishing systems, and industrial applications. The authors also offer perspectives for future studies to address existing and potential challenges and promote technological progress.
