scholarly journals Self-Controlled Cleaving Method for Silicon DRIE Process Cross-Section Characterization

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 534
Author(s):  
Dmitry A. Baklykov ◽  
Mihail Andronic ◽  
Olga S. Sorokina ◽  
Sergey S. Avdeev ◽  
Kirill A. Buzaverov ◽  
...  

Advanced microsystems widely used in integrated optoelectronic devices, energy harvesting components, and microfluidic lab-on-chips require high-aspect silicon microstructures with a precisely controlled profile. Such microstructures can be fabricated using the Bosch process, which is a key process for the mass production of micro-electro-mechanical systems (MEMS) devices. One can measure the etching profile at a cross-section to characterize the Bosch process quality by cleaving the substrate into two pieces. However, the cleaving process of several neighboring deeply etched microstructures is a very challenging and uncontrollable task. The cleaving method affects both the cleaving efficiency and the metrology quality of the resulting etched microstructures. The standard cleaving technique using a diamond scriber does not solve this issue. Herein, we suggest a highly controllable cross-section cleaving method, which minimizes the effect on the resulting deep etching profile. We experimentally compare two cleaving methods based on various auxiliary microstructures: (1) etched transverse auxiliary lines of various widths (from 5 to 100 μm) and positions; and (2) etched dashed auxiliary lines. The interplay between the auxiliary lines and the etching process is analyzed for dense periodic and isolated trenches sized from 2 to 50 μm with an aspect ratio of more than 10. We experimentally showed that an incorrect choice of auxiliary line parameters leads to silicon “build-up” defects at target microstructures intersections, which significantly affects the cross-section profile metrology. Finally, we suggest a highly controllable defect-free cross-section cleaving method utilizing dashed auxiliary lines with the stress concentrators.

2015 ◽  
Vol 20 (1) ◽  
pp. 1-26 ◽  
Author(s):  
Dong-Hyeon Kim ◽  
Shu-Chin Lin ◽  
Yi-Chen Wu

Recent empirical work on globalization and inflation analyzes multicountry data sets in panel and/or cross-section frameworks and reaches inconclusive results. This paper highlights their shortcomings and reexamines the issue utilizing heterogeneous panel cointegration techniques that allow for cross-section heterogeneity and dependence. It finds that in a sample of developing countries globalization of both trade and finance, on the average, exerts a significant and positive effect on inflation, whereas in a sample of developed countries there is, on the average, no significant impact of openness. Neither type of openness disciplines inflationary policy. Despite this, there are large variations in the effect across countries, due possibly to differences in the quality of political institutions, central bank independence, the exchange-rate regimes, financial development, and/or legal traditions.


2018 ◽  
Vol 9 (1) ◽  
pp. 56-65 ◽  
Author(s):  
M. A. Bezuglyi ◽  
N. V. Bezuglaya ◽  
S. Kostuk

The correct accounting of laser emitter parameters for improvement of diagnostic authenticity of methods of optical biomedical diagnostic is important problem for applied biophotonic tasks. The purpose of the current research is estimation of influence of energy distribution profile in transversal section of laser beam on light scattering by human skin layers at photometry by ellipsoidal reflectors.Biomedical photometer with ellipsoidal reflectors for investigation of biological tissue specimens in transmitted and reflected light uses laser probing radiation with infinitely thin, Gauss-type and uniform cross-section profile. Distribution of beams with denoted profiles, which consist of 20 million photons with wavelength 632.8 nm, was modeled by using of Monte-Carlo simulation in human skin layers (corneous layer, epidermis, derma and adipose tissue) of various anatomic thickness and with ellipsoidal reflectors with focal parameter equal to 16.875 mm and eccentricity of 0.66.The modeling results represent that illuminance distribution in zones of photometric imaging is significantly influenced by the laser beam cross-section profile for various thickness of corneous layer and epidermis in transmitted and reflected light, and also derma in reflected light. Illuminance distribution for adipose tissue in reflected and transmitted light, and also derma in transmitted light, practically do not depend of laser beam profile for anatomic thicknesses, which are appropriate for human skin on various sections of body.There are represented results of modified Monte-Carlo simulation method for biomedical photometer with ellipsoidal reflectors during biometry of human skin layers. For highly scattered corneous layer and epidermis the illumination of middle and external rings of photometric images changes depending from the laser beam profile for more than 50 % in transmitted and 30 % in reflected light. For weakly scattering skin layers (derma and adipose layer) the influence of profile can be observed only for derma in reflected layer and is equal not more than 15 %. 


Author(s):  
Mariana Bruno Rodrigues Benitez ◽  
Verônica Viana Vieira ◽  
Célia Maria Carvalho Pereira Araujo Romão

Background and objectives: Total parenteral nutrition (TPN) has great clinical importance in malnutrition treatment and prevention in patients with digestive problems. Although good practices for handling TPN are well established, contamination of these products still occurs, and this product remains listed as a higher risk drug by the Institute for Safe Medication Practices. The present study aimed to obtain an overview of the documentary data of the parenteral nutrition samples sent to the National Institute for Quality Control in Health (INCQS) of Fundação Oswaldo Cruz. Methods: This is a qualitative descriptive and quantitative study carried out based on a cross-section of TPN samples analyzed from 2000 to 2016. Results: A total of TPN 134 samples were sent during the study period. 11.20% of the samples were sent in 2001, 0.80% in 2005, 8.20% in 2006, 16.40% in 2007, 63.40% in 2013. Six samples (4.5%) were canceled and 113 submitted to sterility testing, resulting in 13.3% unsatisfactory samples. Conclusion: During the study period, four suspected events of enterobacterial contamination in TPNs administered to patients were reported, three of which have not yet been described in the scientific literature. For the safety of patients using TPN to be guaranteed, it is suggested that the norms that regulate TPN therapy be reviewed and updated, and programs to monitor the quality of these preparations should be established.


Mechanik ◽  
2018 ◽  
Vol 91 (7) ◽  
pp. 476-478
Author(s):  
Elżbieta Doluk ◽  
Józef Kuczmaszewski ◽  
Paweł Pieśko

Presented are results of the surface quality sandwich composites (aluminum alloy EN AW-2024 and CFRP) by using an abrasive water-jet. The experiments were conducted with different speed of cutting, pressure of the abrasive water, mass flow rates, entry side of the stream and quantity of composite layers. The analysis has been studied based on received bevel angle values.


2014 ◽  
Vol 68 (5) ◽  
pp. 629-641 ◽  
Author(s):  
Tatjana Djakov ◽  
Ivanka Popovic ◽  
Ljubinka Rajakovic

Micro-electro-mechanical systems (MEMS) are miniturized devices that can sense the environment, process and analyze information, and respond with a variety of mechanical and electrical actuators. MEMS consists of mechanical elements, sensors, actuators, electrical and electronics devices on a common silicon substrate. Micro-electro-mechanical systems are becoming a vital technology for modern society. Some of the advantages of MEMS devices are: very small size, very low power consumption, low cost, easy to integrate into systems or modify, small thermal constant, high resistance to vibration, shock and radiation, batch fabricated in large arrays, improved thermal expansion tolerance. MEMS technology is increasingly penetrating into our lives and improving quality of life, similar to what we experienced in the microelectronics revolution. Commercial opportunities for MEMS are rapidly growing in broad application areas, including biomedical, telecommunication, security, entertainment, aerospace, and more in both the consumer and industrial sectors on a global scale. As a breakthrough technology, MEMS is building synergy between previously unrelated fields such as biology and microelectronics. Many new MEMS and nanotechnology applications will emerge, expanding beyond that which is currently identified or known. MEMS are definitely technology for 21st century.


1990 ◽  
Vol 64 (1) ◽  
pp. 13-22 ◽  
Author(s):  
Michael Nelson ◽  
Donald J. Naismith ◽  
Victoria Burley ◽  
Sue Gatenby ◽  
Nicola Geddes

Children (227), aged 7–12 years, weighed and recorded all food and drink consumed for seven consecutive days. Each child completed tests of verbal and non-verbal intelligence, and was then randomly allocated to one of two groups after matching for age, sex, IQ and height. In a double-blind trial lasting for 28 d, one group received a vitamin-mineral supplement daily and the other group a placebo. On re-testing, there were no significant differences in performance between the two groups. Furthermore, there were no consistent correlations between test scores and micronutrient intakes based on the weighed records. Thus, we found no evidence that learning ability in a cross-section of British schoolchildren was limited by the quality of their diets.


Author(s):  
Huifen Wei ◽  
Wenping Geng ◽  
Kaixi Bi ◽  
Tao Li ◽  
Xiangmeng Li ◽  
...  

Abstract LiNbO3 (LN)-based micro-electro-mechanical systems (MEMS) vibration sensors exhibit giant prospection in extreme environments, where exist a great amount of irradiation. However, to the best of our knowledge, it is still unknown whether the irradiation affects the performance of LN-based piezoelectric MEMS sensors. Based on this consideration, it is necessary to model the irradiation environment to investigate the effect of high dosage irradiation on LN-based vibration sensors. Firstly, the theoretical work is done to study the Compton Effect on the Gamma-ray irradiation with Co-60 source. After irradiation, X-ray diffraction (XRD) characterization was performed to verify the effect of irradiation on the crystalline of LN thin film. Meanwhile, the performances of output voltages on the five MEMS devices under various dosage of irradiation are compared. As a result, a neglected shift of 0.02 degrees was observed from the XRD image only under maximum irradiation dosage of 100 Mrad(Si). Moreover, the output voltages of cantilever-beam vibration sensors decrease by 3.1%. Therefore, it is verified that the γ-ray irradiation has very little influence on the LN-based MEMS vibration sensors, which have great attraction on the materials and sensors under high-dose irradiation.


Author(s):  
Timothy Moulton ◽  
G. K. Ananthasuresh

Abstract There exists a need to stabilize the electrostatic actuation commonly used in Micro-Electro-Mechanical Systems (MEMS). Most electrostatically actuated MEMS devices act as variable capacitors with varying gap between the charged conductors. Electrostatic force in these devices is a nonlinear attractive force between the conductors resulting in a complex dynamic system. These systems are stable for only a small portion of the initial gap. In this paper a design method is presented for electrostatic micro-mirrors with improved stability. Controllable, stable electrostatic actuation can be achieved through surface contact between the two conductors. Once in contact with the surface, the compliance of the structure is used to stabilize the electrostatic actuation over a long range of motion. Beam based variable angle mirrors were designed and fabricated using the Multi-User MEMS Process at MCNC technology center. The design methods for stable electrostatic actuation were tested on these mirrors. Some characteristics are noted and their implementation into future designs is discussed.


Author(s):  
Airi Ifinedo ◽  
Princely Ifinedo

This study examines the influence of national IT policies, socio-economic and cultural factors on the network readiness of African countries. The capability and level of preparation of a nation to participate in and benefit from information and communication technologies (ICT) for socio-development is assessed by the network readiness index. Prior studies have shown that such factors have a significant influence on how a country benefits from its use of ICT products for development. Research on this topic with data from the African continent is rare. This study serves to fill this gap. It is based on data from a cross-section of twenty diverse African countries. The data suggested variability in the use of ICT for developmental purposes among the sampled countries. To that end, Africa should not be viewed as monolithic in such respects. The study showed that all the measures used to operationalize national IT policies, socio-economic and some cultural factors are positively related to the network readiness of the sampled African countries. Importantly, the quality of each country’s educational systems, its transparency (corruption) levels, its ICT regulatory framework, and its cross-cultural dimension of power distance (PDI) were found to have significant relevance to its network readiness. The implications of the study’s findings for research and policy making are discussed.


Author(s):  
Anis Nurashikin Nordin

Today’s high-tech consumer market demand complex, portable personal wireless consumer devices that are low-cost and have small sizes. Creative methods of combining mature integrated circuit (IC) fabrication techniques with innovative radio-frequency micro-electro-mechanical systems (RF-MEMS) devices has given birth to wireless transceiver components, which operate at higher frequencies but are manufactured at the low-cost of standard ICs. Oscillators, RF bandpass filters, and low noise amplifiers are the most critical and important modules of any wireless transceiver. Their individual characteristics determine the overall performance of a transceiver. This chapter illustrates RF-oscillators that utilize MEMS devices such as resonators, varactors, and inductors for frequency generation. Emphasis will be given on state of the art RF-MEMS components such as film bulk acoustic wave, surface acoustic wave, flexural mode resonators, lateral and vertical varactors, and solenoid and planar inductors. The advantages and disadvantages of each device structure are described, with reference to the most recent work published in the field.


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