scholarly journals A Stochastic Model to Describe the Scattering in the Response of Polysilicon MEMS

2021 ◽  
Vol 2 (1) ◽  
pp. 95
Author(s):  
Luca Dassi ◽  
Marco Merola ◽  
Eleonora Riva ◽  
Angelo Santalucia ◽  
Andrea Venturelli ◽  
...  
Keyword(s):  
Silicon Film ◽  
Micro Fabrication ◽  
Micro Electro Mechanical Systems ◽  
Local Fluctuations ◽  
Stochastic Framework ◽  
On Line ◽  
Chip Testing ◽  
On Chip ◽  
Time Required ◽  
Polycrystalline Silicon Film

The current miniaturization trend in the market of inertial microsystems is leading to movable device parts with sizes comparable to the characteristic length-scale of the polycrystalline silicon film morphology. The relevant output of micro electro-mechanical systems (MEMS) is thus more and more affected by a scattering, induced by features resulting from the micro-fabrication process. We recently proposed an on-chip testing device, specifically designed to enhance the aforementioned scattering in compliance with fabrication constraints. We proved that the experimentally measured scattering cannot be described by allowing only for the morphology-affected mechanical properties of the silicon films, and etch defects must be properly accounted for too. In this work, we discuss a fully stochastic framework allowing for the local fluctuations of the stiffness and of the etch-affected geometry of the silicon film. The provided semi-analytical solution is shown to catch efficiently the measured scattering in the C-V plots collected through the test structure. This approach opens up the possibility to learn on-line specific features of the devices, and to reduce the time required for their calibration.

A Deep Learning-Based Approach to Uncertainty Quantification for Polysilicon MEMS

2021 ◽  
Vol 4 (1) ◽  
pp. 27
Author(s):  
José Pablo Quesada-Molina ◽  
Stefano Mariani
Keyword(s):  
Deep Learning ◽  
Voronoi Tessellation ◽  
Characteristic Size ◽  
Micro Electro Mechanical Systems ◽  
Polysilicon Film ◽  
Polysilicon Films ◽  
Chip Testing ◽  
On Chip ◽  
Micromechanical Characterization ◽  
Local Stiffness

The path towards miniaturization for micro-electro-mechanical systems (MEMS) has recently increased the effects of stochastic variability at the (sub)micron scale on the overall performance of the devices. We recently proposed and designed an on-chip testing device to characterize two sources of variability that majorly affect the scattering in response to the external actions of inertial (statically determinate) micromachines: the morphology of the polysilicon film constituting the movable parts of the device, and the environment-affected over-etch linked to the microfabrication process. A fully stochastic model of the entire device has been set to account for these two sources on the measurable response of the devices, e.g., in terms of the relevant C-V curves up to pull-in. A complexity in the mentioned model is represented by the need to assess the stochastic (local) stiffness of polysilicon, depending on its unknown (local) microstructure. In this work, we discuss a deep learning approach to the micromechanical characterization of polysilicon films, based on densely connected neural networks (NNs). Such NNs extract relevant features of the polysilicon morphology from SEM-like Voronoi tessellation-based digital microstructures. The NN-based model or surrogate is shown to correctly catch size effects at a varying ratio between the characteristic size of the structural components of the device, and the morphology-induced length scale of the aggregate of silicon grains. This property of the model looks to indeed be necessary to prove the generalization capability of the learning process, and to next feed Monte Carlo simulations resting on the model of the entire device.

scholarly journals On-Chip Assessment of Scattering in the Response of Si-Based Microdevices

2021 ◽  
Vol 4 (1) ◽  
pp. 18
Author(s):  
Aldo Ghisi ◽  
Stefano Mariani
Keyword(s):  
Stochastic Model ◽  
Silicon Film ◽  
Testing Device ◽  
Micro Structure ◽  
Progressive Reduction ◽  
Research Activities ◽  
Compliant Part ◽  
Beam Bending ◽  
Chip Testing ◽  
On Chip

The response of micromachines to the external actions is typically affected by a scattering, which is, on its own, induced by their microstructure and by stages of the microfabrication process. The progressive reduction in size of the mechanical components, forced by a path towards (further) miniaturization, has recently enhanced the outcomes of the aforementioned scattering, and provided a burst in research activities to address issues linked to its assessment. In this work, we discuss the features of an on-chip testing device that we purposely designed to efficiently estimate the two major sources of scattering affecting inertial, polysilicon-based micromachines: the morphology of the silicon film constituting the movable parts of the device, and the etch defect or over-etch induced by microfabrication. The coupled electro-mechanical behavior of the statically determinate movable (micro)structure of the on-chip device has been modeled via beam bending theory, within which the aforementioned sources of scattering have been accounted for through local fluctuating fields in the compliant part of the structure itself, namely the supporting spring. The proposed stochastic model is shown to outperform former ones available in the literature, which neglected the simultaneous and interacting effects of the two mentioned sources on the measure response. The model can fully catch the scattering in the C–V plots up to pull-in, hence, also in the nonlinear working regime of the device.

scholarly journals Synthesis of Boron-Doped Silicon Film Using Hot Wire Chemical Vapor Deposition Technique

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 237
Author(s):  
M. Abul Hossion ◽  
B. M. Arora
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Polycrystalline Silicon ◽  
Silicon Film ◽  
Chemical Vapor ◽  
Hot Wire ◽  
Deposition Technique ◽  
Boron Doped ◽  
Vapor Deposition Technique ◽  
Polycrystalline Silicon Film

Boron-doped polycrystalline silicon film was synthesized using hot wire chemical vapor deposition technique for possible application in photonics devices. To investigate the effect of substrate, we considered Si/SiO2, glass/ITO/TiO2, Al2O3, and nickel tungsten alloy strip for the growth of polycrystalline silicon films. Scanning electron microscopy, optical reflectance, optical transmittance, X-ray diffraction, and I-V measurements were used to characterize the silicon films. The resistivity of the film was 1.3 × 10−2 Ω-cm for the polycrystalline silicon film, which was suitable for using as a window layer in a solar cell. These films have potential uses in making photodiode and photosensing devices.

Pulsed Laser-Induced Amorphization of Polycrystalline Silicon Film

1990 ◽  
Vol 29 (Part 2, No. 4) ◽  
pp. L548-L551 ◽  
Author(s):  
Toshiyuki Sameshima ◽  
Masaki Hara ◽  
Setsuo Usui
Keyword(s):  
Polycrystalline Silicon ◽  
Silicon Film ◽  
Pulsed Laser ◽  
Polycrystalline Silicon Film

Initial stage of semiinsulating polycrystalline silicon film growth

2008 ◽  
Vol 37 (6) ◽  
pp. 349-355
Author(s):  
A. S. Turtsevich ◽  
O. Yu. Nalivaiko ◽  
V. A. Solodukha ◽  
V. V. Glukhmanchuk ◽  
N. G. Tsirkunova ◽  
...  
Keyword(s):  
Polycrystalline Silicon ◽  
Film Growth ◽  
Silicon Film ◽  
Initial Stage ◽  
Polycrystalline Silicon Film
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