Methods for latent image simulations in photolithography with a polychromatic light attenuation equation for fabricating VIAs in 2.5D and 3D advanced packaging architectures

As demand accelerates for multifunctional devices with a small footprint and minimal power consumption, 2.5D and 3D advanced packaging architectures have emerged as an essential solution that use through-substrate vias (TSVs) as vertical interconnects. Vertical stacking enables chip packages with increased functionality, enhanced design versatility, minimal power loss, reduced footprint and high bandwidth. Unlocking the potential of photolithography for vertical interconnect access (VIA) fabrication requires fast and accurate predictive modeling of diffraction effects and resist film photochemistry. This procedure is especially challenging for broad-spectrum exposure systems that use, for example, Hg bulbs with g-, h-, and i-line UV radiation. In this paper, we present new methods and equations for VIA latent image determination in photolithography that are suitable for broad-spectrum exposure and negate the need for complex and time-consuming in situ metrology. Our technique is accurate, converges quickly on the average modern PC and could be readily integrated into photolithography simulation software. We derive a polychromatic light attenuation equation from the Beer-Lambert law, which can be used in a critical exposure dose model to determine the photochemical reaction state. We integrate this equation with an exact scalar diffraction formula to produce a succinct equation comprising a complete coupling between light propagation phenomena and photochemical behavior. We then perform a comparative study between 2D/3D photoresist latent image simulation geometries and directly corresponding experimental data, which demonstrates a highly positive correlation. We anticipate that this technique will be a valuable asset to photolithography, micro- and nano-optical systems and advanced packaging/system integration with applications in technology domains ranging from space to automotive to the Internet of Things (IoT).

Invisible Images and Indeterminacy: Why We Need a Multi-stage Account of Photography

Some photographs show determinate features of a scene because the photographed scene had those features. This dependency relation is, rightly, a consensus in philosophy of photography. I seek to refute many long-established theories of photography by arguing that they are incompatible with this commitment. In Section II, I classify accounts of photography as either single-stage or multi-stage. In Section III, I analyze the historical basis for single-stage accounts. In Section IV, I explain why the single-stage view led scientists to postulate “latent” photographic images as a technical phenomenon in early chemical photography. In Section V, I discredit the notion of an invisible latent image in chemical photography and, in Section VI, extend this objection to the legacy of the latent image in digital photography. In Section VII, I appeal to the dependency relation to explain why the notion of a latent image makes the single-stage account untenable. Finally, I use the multi-stage account to advance debate about “new” versus “orthodox” theories of photography.

An Efficient Blind Image Deblurring Using a Smoothing Function

This paper introduces an efficient deblurring image method based on a convolution-based and an iterative concept. Our method does not require specific conditions on images, so it can be widely applied for unspecific generic images. The kernel estimation is firstly performed and then will be used to estimate a latent image in each iteration. The final deblurred image is obtained from the convolution of the blurred image with the final estimated kernel. However, image deblurring is an ill-posed problem due to the nonuniqueness of solutions. Therefore, we propose a smoothing function, unlike previous approaches that applied piecewise functions on estimating a latent image. In our approach, we employ L2-regularization on intensity and gradient prior to converging to a solution of the deblurring problem. Moreover, our work is based on the quadratic splitting method. It guarantees that each subproblem has a closed-form solution. Various experiments on synthesized and real-world images confirm that our approach outperforms several existing methods, especially on the images corrupted by noises. Moreover, our method gives more reasonable and more natural deblurred images than those of other methods.

STUDY OF HOLOGRAPHIC PROTECTIVE ELEMENTS USED ON DRIVER'S LICENSE AND VEHICLE REGISTRATION CERTIFICATES ON PLASTIC BASIS AND AN EXAMPLE OF THEIR FORGERY

The article deals with the current situation in the study by forensic experts of holographic protective elements (hereinafter – HPE). Over the past 30 years, HPE have been actively developing and widespread, they are used both as design elements and to protect various types of documents. In its manufacture, application software and equipment are used, which provides high-resolution images and allow encoding large amounts of information. Although there are several scientific works included in the Register of methodologies for conducting forensic examinations of the Ministry of Justice of Ukraine, but it was written more than 20 years ago. Therefore, to conduct an expert study of HPE, it is necessary to update the methodological base, revise the approaches to its research and issues to be solved. The article briefly outlines the design features, techniques and methods of protecting HPE that are used by its manufacturers. It is emphasized that latent images are introduced into the structure of holograms to control its authenticity, which are checked by various detectors. There are described examples of latent image decoding. It is also described an example of detecting a fake film with holographic elements that are very similar to the original. At the same time, when examining the fake film, it was found that there are no microtext and the hidden abbreviation “MBС” (in Ukrainian). As a result of the research carried out, the author proposes to accept the results of verification of the elements of control of the authenticity of the HPE, in order to substantiate the probable conclusion about the conformity or inconsistency of the hologram. In addition, the presence of significant differences in the common features of the studied HPE and the sample, in the author's opinion, is a sufficient basis for the conclusion about the discrepancy between the holographic images and the sample. Therefore, experts of the questioned document examination can carry out such studies, with certain restrictions.