scholarly journals Nanoporous Layers and the Peculiarities of Their Local Formation on a Silicon Wafer

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 163
Author(s):  
Vitali Vasil’evich Starkov ◽  
Ekaterina Alexanrovna Gosteva ◽  
Dmitry Dmitry Zherebtsov ◽  
Maxim Vladimirovich Chichkov ◽  
Nikita Valerievich Alexandrov
Keyword(s):  
Stem Cells ◽  
Porous Silicon ◽  
Silicon Wafer ◽  
High Resistivity ◽  
Local Formation ◽  
Biological Objects ◽  
Intermediate Ring ◽  
Close Proximity ◽  
Sensor Devices ◽  
P Type

This review presents the results of the local formation of nanostructured porous silicon (NPSi) on the surface of silicon wafers by anodic etching using a durite intermediate ring. The morphological and crystallographic features of NPSi structures formed on n- and p-type silicon with low and relatively high resistivity have also been investigated. The proposed scheme allows one to experiment with biological objects (for example, stem cells, neurons, and other objects) in a locally formed porous structure located in close proximity to the electronic periphery of sensor devices on a silicon wafer.

scholarly journals Monolithically Integrated Diffused Silicon Two-Zone Heaters for Silicon-Pyrex Glass Microreactors for Production of Nanoparticles: Heat Exchange Aspects

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 818
Author(s):  
Milena Rašljić Rafajilović ◽  
Katarina Radulović ◽  
Milče M. Smiljanić ◽  
Žarko Lazić ◽  
Zoran Jakšić ◽  
...  
Keyword(s):  
High Temperature ◽  
Silicon Wafer ◽  
Titanium Dioxide Nanoparticles ◽  
Pyrex Glass ◽  
High Resistivity ◽  
Glass Wafer ◽  
Monolithically Integrated ◽  
Different Temperatures ◽  
And Performance ◽  
P Type

We present the design, simulation, fabrication and characterization of monolithically integrated high resistivity p-type boron-diffused silicon two-zone heaters in a model high temperature microreactor intended for nanoparticle fabrication. We used a finite element method for simulations of the heaters’ operation and performance. Our experimental model reactor structure consisted of a silicon wafer anodically bonded to a Pyrex glass wafer with an isotropically etched serpentine microchannels network. We fabricated two separate spiral heaters with different temperatures, mutually thermally isolated by barrier apertures etched throughout the silicon wafer. The heaters were characterized by electric measurements and by infrared thermal vision. The obtained results show that our proposed procedure for the heater fabrication is robust, stable and controllable, with a decreased sensitivity to random variations of fabrication process parameters. Compared to metallic or polysilicon heaters typically integrated into microreactors, our approach offers improved control over heater characteristics through adjustment of the Boron doping level and profile. Our microreactor is intended to produce titanium dioxide nanoparticles, but it could be also used to fabricate nanoparticles in different materials as well, with various parameters and geometries. Our method can be generally applied to other high-temperature microsystems.

scholarly journals First blood: the endothelial origins of hematopoietic progenitors

Angiogenesis ◽  
2021 ◽  
Author(s):  
Giovanni Canu ◽  
Christiana Ruhrberg
Keyword(s):  
Stem Cells ◽  
Molecular Mechanisms ◽  
Vascular Endothelial Cells ◽  
Fetal Liver ◽  
Cell Types ◽  
Yolk Sac ◽  
Vascular Endothelial ◽  
Hematopoietic Stem ◽  
Close Proximity ◽  
Clinical Interest

AbstractHematopoiesis in vertebrate embryos occurs in temporally and spatially overlapping waves in close proximity to blood vascular endothelial cells. Initially, yolk sac hematopoiesis produces primitive erythrocytes, megakaryocytes, and macrophages. Thereafter, sequential waves of definitive hematopoiesis arise from yolk sac and intraembryonic hemogenic endothelia through an endothelial-to-hematopoietic transition (EHT). During EHT, the endothelial and hematopoietic transcriptional programs are tightly co-regulated to orchestrate a shift in cell identity. In the yolk sac, EHT generates erythro-myeloid progenitors, which upon migration to the liver differentiate into fetal blood cells, including erythrocytes and tissue-resident macrophages. In the dorsal aorta, EHT produces hematopoietic stem cells, which engraft the fetal liver and then the bone marrow to sustain adult hematopoiesis. Recent studies have defined the relationship between the developing vascular and hematopoietic systems in animal models, including molecular mechanisms that drive the hemato-endothelial transcription program for EHT. Moreover, human pluripotent stem cells have enabled modeling of fetal human hematopoiesis and have begun to generate cell types of clinical interest for regenerative medicine.

Temperature effect on the roughness of the formation interface of p-type porous silicon

1998 ◽  
Vol 84 (6) ◽  
pp. 3129-3133 ◽  
Author(s):  
S. Setzu ◽  
G. Lérondel ◽  
R. Romestain
Keyword(s):  
Porous Silicon ◽  
Temperature Effect ◽  
P Type

Beamforming Lens Antenna on a High Resistivity Silicon Wafer for 60 GHz WPAN

2010 ◽  
Vol 58 (3) ◽  
pp. 706-713 ◽  
Author(s):  
Woosung Lee ◽  
Jaeheung Kim ◽  
Choon Sik Cho ◽  
Young Joong Yoon
Keyword(s):  
Silicon Wafer ◽  
High Resistivity ◽  
60 Ghz ◽  
Lens Antenna ◽  
High Resistivity Silicon

Utilization of Low Wavelength Laser Linking with Electrochemical Etching to Produce Nano-Scale Porous Layer on p-Type Silicon Wafer with High Luminous Flux

2021 ◽  
Vol 10 (1) ◽  
pp. 016003
Author(s):  
Philip Nathaniel Immanuel ◽  
Chao-Ching Chiang ◽  
Tien-Hsi Lee ◽  
Sikkanthar Diwan Midyeen ◽  
Song-Jeng Huang
Keyword(s):  
Silicon Wafer ◽  
Porous Layer ◽  
Electrochemical Etching ◽  
Luminous Flux ◽  
Nano Scale ◽  
Type Silicon ◽  
P Type

Structural, Surface Morphological and Photoluminescence Properties of Nanostructured Porous Silicon Material for Optoelectronics Application

2012 ◽  
Vol 584 ◽  
pp. 290-294 ◽  
Author(s):  
Jeyaprakash Pandiarajan ◽  
Natarajan Jeyakumaran ◽  
Natarajan Prithivikumaran
Keyword(s):  
Porous Silicon ◽  
Current Density ◽  
Light Emission ◽  
Electrochemical Etching ◽  
Light Emitting Diode ◽  
Radiative Transition ◽  
Sem Images ◽  
Optoelectronic Application ◽  
Gap Opening ◽  
P Type

The promotion of silicon (Si) from being the key material for microelectronics to an interesting material for optoelectronic application is a consequence of the possibility to reduce its device dimensionally by a cheap and easy technique. In fact, electrochemical etching of Si under controlled conditions leads to the formation of nanocrystalline porous silicon (PS) where quantum confinement of photo excited carriers and surface species yield to a band gap opening and an increased radiative transition rate resulting in efficient light emission. In the present study, the nanostructured PS samples were prepared using anodic etching of p-type silicon. The effect of current density on structural and optical properties of PS, has been investigated. XRD studies confirm the presence of silicon nanocrystallites in the PS structure. By increasing the current density, the average estimated values of grain size are found to be decreased. SEM images indicate that the pores are surrounded by a thick columnar network of silicon walls. The observed PL spectra at room temperature for all the current densities confirm the formation of PS structures with nanocrystalline features. PL studies reveal that there is a prominent visible emission peak at 606 nm. The obtained variation of intensity in PL emission may be used for intensity varied light emitting diode applications. These studies confirm that the PS is a versatile material with potential for optoelectronics application.

Optical Studies of porous Silicon

1993 ◽  
Vol 298 ◽  
Author(s):  
T. Lin ◽  
M. E. Sixta ◽  
J. N. Cox ◽  
M. E. Delaney
Keyword(s):  
Optical Properties ◽  
Fourier Transform ◽  
Steady State ◽  
Porous Silicon ◽  
Ftir Spectroscopy ◽  
Optical Studies ◽  
Etched Silicon ◽  
Bending Modes ◽  
P Type ◽  
Over Time

AbstractThe optical properties of both electrochemically anodized and chemically stain-etched porous silicon are presented. Fourier transform infrared (FTIR) spectroscopy showed that absorbance in stain-etched samples was 3x and 1.7x greater than in anodized samples for the SiH/SiH2 stretch and scissors-bending modes, respectively. Also, oxygen is detected in stain-etched samples immediately after formation, unlike anodized samples. Photoluminescence measurements showed different steady state characteristics. Electrochemical-etched silicon samples stored in air increased in photoluminescent intensity over time, unlike the stain-etched samples. A photoluminescent device made by anodization on epitaxial p-type material (0.4 Ωm) on n-type substrate (0.1 Ω-cm) did not exhibit electroluminescence.

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