Application of Thin-Film Micromachining on Glass

1998 ◽  
Vol 507 ◽  
Author(s):  
M. Boucinha ◽  
V. Chu ◽  
J.P. Conde
Keyword(s):  
Thin Film ◽  
Etch Rate ◽  
Sacrificial Layer ◽  
Three Dimensional ◽  
Electrical Characteristics ◽  
Microcrystalline Silicon ◽  
Large Area ◽  
Glass Substrates ◽  
Bridge Structures ◽  
Hydrogenated Amorphous

ABSTRACTThree dimensional microstructures have been made on glass substrates using surface micromachining techniques. Bridge structures were fabricated using both hydrogenated amorphous silicon and microcrystalline silicon. A low density silicon nitride with an etch rate of 100 Å/s in buffered HF was used as the sacrificial layer. As an example of how micromachining can be applied to large area electronics, thin film transistors (TFT) with the dielectric replaced by an air-gap were fabricated. The electrical characteristics of the first working devices are presented.

Application of Thin-Film Micromachining for Large-Area Substrates

1999 ◽  
Vol 557 ◽  
Author(s):  
M. Boucinha ◽  
V. Chu ◽  
V. Soares ◽  
J. P. Condee
Keyword(s):  
Thin Film ◽  
Silicon Nitride ◽  
Sacrificial Layer ◽  
Microcrystalline Silicon ◽  
Large Area ◽  
Aluminum Films ◽  
Glass Substrates ◽  
Low Temperature Processing ◽  
Device Applications ◽  
Silicon Silicon

AbstractSurface micromachining is used with amorphous silicon, microcrystalline silicon, silicon nitride and aluminum films as structural materials to form bridge and cantilever structures. Low temperature processing (between 110 and 250 °C) allowed fabrication of structures and devices on glass substrates. Two processes involving different materials as the sacrificial layer are presented: silicon nitride and photoresist. The mechanical integrity of the fabricated structures is discussed. As examples of possible device applications of this technology, air-gap thin film transistors and the electrostatic actuation of bridges and cantilevers are presented.

Thin Film Microelectromechanical Systems

2002 ◽  
Vol 715 ◽  
Author(s):  
V. Chu ◽  
J. Gaspar ◽  
J.P. Conde
Keyword(s):  
Thin Film ◽  
Microelectromechanical Systems ◽  
Absolute Calibration ◽  
Quality Factors ◽  
Large Area ◽  
Glass Substrates ◽  
Resonance Frequencies ◽  
Bridge Structures ◽  
On Chip

AbstractThis paper presents the fabrication and characterization of MEMS structures on glass substrates using thin film silicon technology and surface micromachining. The technology developed to process bridge and cantilever structures as well as the electromechanical characterization of these structures is discussed. This technology can enable the expansion of MEMS to applications requiring large area and/or flexible substrates. The main results for the characterization of the movement of the structures are as follows: (1) in the quasi-DC regime and at low applied voltages, the response is linear with the applied dc voltage. Using an electromechanical model which takes into account the constituent materials and geometry of the bilayer, it is possible to extract the deflection of the structures. This estimate suggests that it is possible to control the actuation of these structures to deflections on the sub-nanometric scale; (2) resonance frequencies of up to 20 MHz have been measured on hydrogenated amorphous silicon (a-Si:H) bridge structures with quality factors (Q) of 70-100 in air. The frequency depends inversely on the square of the structure length, as predicted by the mechanical model; and (3) using an integrated permanent magnet/magnetic sensor system, it is possible to measure the structure movement on-chip and to obtain an absolute calibration of the deflection of the structures.

Integrated Magnetic Sensing of Electrostatically Actuated Thin-Film Microbridges

2002 ◽  
Vol 729 ◽  
Author(s):  
J. Gaspar ◽  
Haohua Li ◽  
P.P. Freitas ◽  
V. Chu ◽  
J.P. Conde
Keyword(s):  
Thin Film ◽  
Low Temperatures ◽  
Counter Electrode ◽  
Spin Valve ◽  
Metal Gate ◽  
Electrostatically Actuated ◽  
Glass Substrates ◽  
Hydrogenated Amorphous ◽  
Bridge Length ◽  
The Magnetic Field

AbstractBilayer microbridges of aluminum and hydrogenated amorphous silicon are fabricated using thin film technology and surface micromachining at low temperatures on glass substrates. The microstructure is electrostatically actuated by applying a voltage between the bridge and a metal gate counter electrode placed beneath it. The movement is measured with a precision close to 0.1 Å by sensing the magnetic field of a permanent magnet, deposited and patterned on top of the microbridge, with an integrated spin valve magnetic sensor. The deflection of the bridge is at the same time monitored using an optical setup. The deflection of the structures is studied as a function of the driving applied gate voltage and bridge length and experimental results are analyzed with an electromechanical model.

CuxSbySz THIN FILMS PRODUCED BY ANNEALING CHEMICALLY DEPOSITED Sb2S3-CuS THIN FILMS

2001 ◽  
Vol 15 (17n19) ◽  
pp. 667-670 ◽  
Author(s):  
Y. RODRÍGUEZ-LAZCANO ◽  
M. T. S. NAIR ◽  
P. K. NAIR
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Band Gap ◽  
Deposition Method ◽  
Photovoltaic Devices ◽  
Large Area ◽  
Electrical And Optical Properties ◽  
Ternary Compounds ◽  
Glass Substrates ◽  
Different Temperatures

The possibility of generating ternary compounds through annealing thin film stacks of binary composition has been demonstrated before. In this work we report a method to produce large area coating of ternary compounds through a reaction in solid state between thin films of Sb2S3 and CuS. Thin films of Sb2S3 -CuS were deposited on glass substrates in the sequence of Sb2S3 followed by CuS (on Sb2S3 ) using chemical bath deposition method. The multilayer stack, thus produced, of approximately 0.5 μm in thickness, where annealed under nitrogen and argon atmospheres at different temperatures to produce films of ternary composition, CuxSbySz . An optical band gap of ~1.5 eV was observed in these films, suggesting that the thin films of ternary composition formed in this way are suitable for use as absorber materials in photovoltaic devices. The results on the analyses of structural, electrical and optical properties of films formed with different combinations of thickness in the multilayers will be discussed in the paper.

Large-Area Hydrogenated Amorphous and Microcrystalline Silicon Double-Junction Solar Cells

2004 ◽  
Vol 808 ◽  
Author(s):  
Baojie Yan ◽  
Guozhen Yue ◽  
Arindam Banerjee ◽  
Jeffrey Yang ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Deposition Time ◽  
High Rate ◽  
Microcrystalline Silicon ◽  
Large Area ◽  
Area Efficiency ◽  
Rf Glow Discharge ◽  
Double Junction ◽  
Junction Structure ◽  
Hydrogenated Amorphous

ABSTRACTHydrogenated amorphous silicon (a-Si:H) and hydrogenated microcrystalline silicon ( c-Si:H) double-junction solar cells were deposited on a large-area substrate using a RF glow discharge technique at various rates. The thickness uniformity for both a-Si:H and c-Si:H is well within ± 10% and the reproducibility is very good. Preliminary results from the large-area a-Si:H/m c-Si:H double-junction structures show an initial aperture-area efficiency of 11.8% and 11.3%, respectively, for 45 cm2 and 461 cm2 size un-encapsulated solar cells. The 11.3% cell became 10.6% after encapsulation and stabilized at 9.5% after prolonged light soaking under 100 mW/cm2 of white light at 50°C. High rate deposition of the c-Si:H layer in the bottom cell was made using the high-pressure approach. An initial active-area (0.25 cm2) efficiency of 11.3% was achieved using an a-Si:H/m c-Si:H double-junction structure with 50 minutes of c-Si:H deposition time.

scholarly journals Thin Film Encapsulation for RF MEMS in 5G and Modern Telecommunication Systems

Sensors ◽  
2020 ◽  
Vol 20 (7) ◽  
pp. 2133 ◽  
Author(s):  
Anna Persano ◽  
Fabio Quaranta ◽  
Antonietta Taurino ◽  
Pietro Aleardo Siciliano ◽  
Jacopo Iannacci
Keyword(s):  
Thin Film ◽  
Microelectromechanical Systems ◽  
Rf Mems ◽  
Sacrificial Layer ◽  
Three Dimensional ◽  
Telecommunication Systems ◽  
Rf Performance ◽  
Three Dimensional Finite Element ◽  
The Impact ◽  
Thin Film Encapsulation

In this work, SiNx/a-Si/SiNx caps on conductive coplanar waveguides (CPWs) are proposed for thin film encapsulation of radio-frequency microelectromechanical systems (RF MEMS), in view of the application of these devices in fifth generation (5G) and modern telecommunication systems. Simplification and cost reduction of the fabrication process were obtained, using two etching processes in the same barrel chamber to create a matrix of holes through the capping layer and to remove the sacrificial layer under the cap. Encapsulating layers with etch holes of different size and density were fabricated to evaluate the removal of the sacrificial layer as a function of the percentage of the cap perforated area. Barrel etching process parameters also varied. Finally, a full three-dimensional finite element method-based simulation model was developed to predict the impact of fabricated thin film encapsulating caps on RF performance of CPWs.

Combined Electron Beam Induced Current Imaging (EBIC) and Focused Ion Beam (FIB) Techniques for Thin Film Solar Cell Characterization

2010 ◽  
Author(s):  
Frank Altmann ◽  
Jan Schischka ◽  
Vinh Van Ngo ◽  
Stacey Stone ◽  
Laurens F. Tz. Kwakman ◽  
...  
Keyword(s):  
Thin Film ◽  
Electron Beam ◽  
Focused Ion Beam ◽  
Surface Defects ◽  
Ion Beam ◽  
Three Dimensional ◽  
Region Of Interest ◽  
Induced Current ◽  
Large Area ◽  
Electron Beam Induced Current

Abstract A novel analytical method applying combined electron beam induced current (EBIC) imaging based on scanning electron microscopy (SEM) and focused ion beam (FIB) cross sectioning in a SEM/FIB dualbeam system is presented. The method is demonstrated in several case studies for process characterization and failure analysis of thin film technology based Solar cells, including Silicon (CSG), Cadmium Telluride (CdTe) and Copper Indium Selenide (CIS) absorbers. While existing techniques such as electro-, photoluminescence spectroscopy and lock-in thermography are able to locate the larger, electrically active defects reasonably fast on a large area, the FIB-SEM EBIC system is uniquely capable of detecting sub-micron, sub-surface defects and of analysing these defects in the same system. In combination with a FIB, the localized region of interest can be easily cross sectioned and additional EBIC analysis can be applied for a three dimensional analysis of the p/n junction.

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