Microfabrication of Crevice Corrosion Samples

2000 ◽  
Vol 657 ◽  
Author(s):  
Xiaoyan Wang ◽  
Robert G. Kelly ◽  
Jason S. Lee ◽  
Michael L. Reed
Keyword(s):  
Crevice Corrosion ◽  
Computational Models ◽  
Microelectromechanical Systems ◽  
Spatial Information ◽  
Semiconductor Device ◽  
Device Fabrication ◽  
Metal Electrodes ◽  
Electrical Connections ◽  
Microfabrication Techniques

ABSTRACTA major challenge in developing computer models for crevice corrosion lies in fabricating appropriate experimental crevice samples. The geometry and dimensions of these samples must be controlled to a high order of precision in order to be amenable for comparison to computational models. In this work we report an effort to construct crevice samples with rigorously defined dimensions by using microfabrication techniques developed for microelectromechanical systems (MEMS). These techniques include microfabrication with SU- 8, electroplating, and other standard semiconductor device fabrication techniques as well. The crevice substrates contain one-dimensional arrays of metal electrodes to be studied, which are isolated by walls of SU-8. The electrodes have individual electrical connections so that spatial information of the in-situ corrosion process can be obtained. The crevice formers with SU-8 posts were coupled to crevice substrates to maintain a uniform crevice gap. Further, crevice formers with regular rectangular subcrevices were fabricated to study the roles of subcrevices in crevice corrosion.

Fabrication of a Conductometric Sensor for Crevice Corrosion Studies

2002 ◽  
Vol 729 ◽  
Author(s):  
Xiaoyan Wang ◽  
Robert G. Kelly ◽  
Jason S. Lee ◽  
Michael L. Reed
Keyword(s):  
Thin Film ◽  
Real Time ◽  
Crevice Corrosion ◽  
Metal Ion ◽  
Microelectromechanical Systems ◽  
Spatial Information ◽  
Ion Concentration ◽  
Potentiometric Sensors ◽  
Conductometric Sensor

AbstractMicrofabricated crevice corrosion samples have been employed in experiments that provided important information necessary for developing an accurate, comprehensive, and reliable crevice corrosion model. Acquiring real-time spatial information of crevice corrosion is also essential in analyzing corrosion processes. Integration of arrays of solid-state microsensors, such as conductometric sensors, pH and other ion concentration potentiometric sensors, into the crevice corrosion samples will allow for in-situ real-time data acquisition. In the present work, crevice corrosion samples with conductometric sensor arrays are made using the techniques developed for thin film semiconductor processing and microelectromechanical systems (MEMS) fabrication. The crevice corrosion testing sample is constructed by coupling a crevice former to a crevice substrate and has a uniform crevice gap. A conductometric sensor array built on a silicon wafer is incorporated into the crevice former. Each of these sensors is composed of a pair of thin film gold electrodes, which enables in-situ spatial conductivity analysis of crevice corrosion. Information about metal ion concentration and active chemistry inside the crevice can also be obtained.

Polycrystalline Silicon Films for Microelectromechanical Devices

1995 ◽  
Vol 403 ◽  
Author(s):  
H. Kahn ◽  
S. Stemmer ◽  
R. L. Mullen ◽  
M. A. Huff ◽  
A. H. Heuer
Keyword(s):  
Residual Stress ◽  
Polycrystalline Silicon ◽  
Microelectromechanical Systems ◽  
Device Fabrication ◽  
Process Equipment ◽  
Boron Doped ◽  
Microelectromechanical Devices ◽  
Polysilicon Films ◽  
Polycrystalline Silicon Films

AbstractPolycrystalline silicon is the most widely used structural material for surface micromachined microelectromechanical systems (MEMS). There are many advantages to using thick polysilicon films; however, due to process equipment limitations, these devices are typically fabricated from polysilicon films less than 3 μm thick. In this work, microelectromechanical test structures were designed and processed from thick (up to 10 μm) in situ boron-doped polysilicon films. The elastic modulus of these films was about 150 GPa, independent of film thickness. The thermal oxidation of the polysilicon induced a compressive stress into the top surface of the films, which was detected as a residual stress in the polysilicon after the device fabrication was complete.

Advanced Single-Wafer Sequential Multiprocessing Techniques for Semiconductor Device Fabrication

1989 ◽  
Vol 146 ◽  
Author(s):  
Mehrdad M. Moslehi ◽  
Cecil Davis
Keyword(s):  
Microwave Plasma ◽  
Semiconductor Device ◽  
Future Trend ◽  
Device Fabrication ◽  
Manufacturing Cost ◽  
Layer Transition ◽  
Device Structures ◽  
Equipment Utilization ◽  
Process Energy

ABSTRACTSingle-Wafer Integrated in-situ Multiprocessing (SWIM) is recognized as the future trend for advanced microelectronics production in flexible fast turn-around computer-integrated semiconductor manufacturing environments. The SWIM equipment technology and processing methodology offer enhanced equipment utilization, improved process reproducibility and yield, and reduced chip manufacturing cost. They also provide significant capabilities for fabrication of new and improved device structures. This paper describes the SWIM techniques and presents a novel single-wafer advanced vacuum multiprocessing technology developed based on the use of multiple process energy/activation sources (lamp heating and remote microwave plasma) for multilayer epitaxial and polycrystalline semiconductor as well as dielectric film processing. Based on this technology, multilayer in-situ-doped homoepitaxial silicon and heteroepitaxial strained layer Si/GexSil-x/Si structures have been grown and characterized. The process control and the ultimate interfacial abruptness of the layer-to-layer transition widths in the device structures prepared by this technology will challenge the MBE techniques in multilayer epitaxial growth applications.

scholarly journals Precise in situ etch depth control of multilayered III−V semiconductor samples with reflectance anisotropy spectroscopy (RAS) equipment

2016 ◽  
Vol 7 ◽  
pp. 1783-1793 ◽  
Author(s):  
Ann-Kathrin Kleinschmidt ◽  
Lars Barzen ◽  
Johannes Strassner ◽  
Christoph Doering ◽  
Henning Fouckhardt ◽  
...  
Keyword(s):  
Secondary Ion Mass Spectrometry ◽  
Semiconductor Device ◽  
Device Fabrication ◽  
Etch Depth ◽  
Reflectance Anisotropy ◽  
Depth Control ◽  
Dry Etch ◽  
First Time ◽  
Secondary Ion

Reflectance anisotropy spectroscopy (RAS) equipment is applied to monitor dry-etch processes (here specifically reactive ion etching (RIE)) of monocrystalline multilayered III–V semiconductors in situ. The related accuracy of etch depth control is better than 16 nm. Comparison with results of secondary ion mass spectrometry (SIMS) reveals a deviation of only about 4 nm in optimal cases. To illustrate the applicability of the reported method in every day settings for the first time the highly etch depth sensitive lithographic process to form a film lens on the waveguide ridge of a broad area laser (BAL) is presented. This example elucidates the benefits of the method in semiconductor device fabrication and also suggests how to fulfill design requirements for the sample in order to make RAS control possible.

In Situ Stress Measurements During the Formation of TiSi2 C49 On Si Wafers

1990 ◽  
Vol 188 ◽  
Author(s):  
J. F. Jongste ◽  
G. C. A. M. Janssen ◽  
S. Radelaar
Keyword(s):  
Integrated Circuits ◽  
Semiconductor Device ◽  
Large Change ◽  
In Situ Stress ◽  
Device Fabrication ◽  
Intrinsic Stress ◽  
High Resistivity ◽  
Stress Measurements ◽  
In Situ Stress Measurements

In the microelectronics industry titanium disilicide (TiSi2) is used as a material for metallization and interconnection on silicon based integrated circuits. In the C54 structure (face centred orthorhombic) TiSi2 has important properties for application in electronic devices: low resistivity (16 μΩ cm), stability up to 900°C and compatibility with silicon processing. In thin films this phase is formed above approx. 700°C. However before this phase is formed, a metastable TiSi2 phase with the C49 (or ZrSi2) structure [1] is already formed at lower temperature. This C49 phase is unfavourable as metallization in IC applications because of the high resistivity (60–300 μΩ cm). From a technological point of view however it is important to realize that during the C49 formation the thin film is subject to a large change of the intrinsic stress. The occurrence of this stress can cause problems during semiconductor device fabrication. Gate oxides in MOSFETs (and other IC microstructures) may be deteriorated by stress. Also focussing problems in lithographic steps can arise because of wafer warpage. In this paper we present in situ stress measurements of the formation of TiSi2 C49 from Ti-Si multilayers. From these measurements the kinetics of the formation process is analyzed.

Microfabricated Crevice Former with a Sensor Array

2001 ◽  
Vol 687 ◽  
Author(s):  
Xiaoyan Wang ◽  
Robert G. Kelly ◽  
Michael L. Reed
Keyword(s):  
Real Time ◽  
Crevice Corrosion ◽  
Sensor Array ◽  
Microelectromechanical Systems ◽  
Spatial Information ◽  
Ph Sensor ◽  
Corrosion Testing ◽  
Array Configuration ◽  
Selective Membrane ◽  
Microsensor Arrays

AbstractMicrofabrication of crevice corrosion samples is of importance in developing an accurate, comprehensive, and reliable crevice corrosion model, and real-time acquisition of corrosion information is also essential. Solid-state microsensor arrays have been used for detecting potential, pH, and ion concentrations, and their integration into crevice corrosion testing samples will provide real-time spatial information of crevice corrosion. The crevice corrosion testing sample is constructed by coupling a crevice former to a crevice substrate and has a uniform crevice gap. In this paper we present a crevice former incorporating a potentiometric, ion- selective membrane microelectrode pH sensor array. The crevice former is built on a silicon wafer using microelectromechanical systems (MEMS) fabrication and thin film semiconductor processing techniques, and consists of an array of five independent sensing microelectrodes. The array configuration allows for in-situ spatial pH analysis of crevice corrosion based on information from each sensor. The fabrication details of the crevice former with microelectrode sensor will be elaborated.

Behavior of contact-silicided TFSOI gate structures

1994 ◽  
Vol 52 ◽  
pp. 860-861
Author(s):  
N. David Theodore ◽  
Juergen Foerstner ◽  
Peter Fejes
Keyword(s):  
Semiconductor Device ◽  
Series Resistance ◽  
Field Effect Transistors ◽  
Silicon Layer ◽  
Device Fabrication ◽  
Silicon On Insulator ◽  
Continuous Layer ◽  
Buried Oxide ◽  
Device Structures ◽  
Thin Silicon

As semiconductor device dimensions shrink and packing-densities rise, issues of parasitic capacitance and circuit speed become increasingly important. The use of thin-film silicon-on-insulator (TFSOI) substrates for device fabrication is being explored in order to increase switching speeds. One version of TFSOI being explored for device fabrication is SIMOX (Silicon-separation by Implanted OXygen).A buried oxide layer is created by highdose oxygen implantation into silicon wafers followed by annealing to cause coalescence of oxide regions into a continuous layer. A thin silicon layer remains above the buried oxide (~220 nm Si after additional thinning). Device structures can now be fabricated upon this thin silicon layer.Current fabrication of metal-oxidesemiconductor field-effect transistors (MOSFETs) requires formation of a polysilicon/oxide gate between source and drain regions. Contact to the source/drain and gate regions is typically made by use of TiSi2 layers followedby Al(Cu) metal lines. TiSi2 has a relatively low contact resistance and reduces the series resistance of both source/drain as well as gate regions

Analysis of movement of persons with disabilities during evacuation by lift

2020 ◽  
Vol 15 (1) ◽  
pp. 209-220
Author(s):  
Martin Szénay ◽  
Martin Lopušniak
Keyword(s):  
Computational Models ◽  
Persons With Disabilities ◽  
Entire Process ◽  
Injured Person ◽  
Impaired People ◽  
Movement Parameters ◽  
The Times ◽  
Mobility Impaired

Abstract Lifts are indispensable for the evacuation of mobility-impaired people from buildings in case of emergency. It is necessary to quantify the movement parameters of these people and describe the entire process using a suitable algorithm. The aim of the research was to quantify the times and speeds of movement for a person using a wheelchair and for an injured person. An experiment in situ was used. During the experiment, arrivals at the lift, cabin entries, and exits were monitored. The results include the times and speeds of a mobility-impaired person's movement. The experiments showed that a person using a wheelchair was slower than an injured person. The results can be used to expand computational models to account for the possibility of using lifts for evacuation.

Irradiation Induced Changes in Semiconducting Thin Films

2013 ◽  
Vol 341 ◽  
pp. 181-210 ◽  
Author(s):  
S.K. Tripathi
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Heavy Ions ◽  
Semiconductor Device ◽  
High Energy ◽  
Device Fabrication ◽  
Electrical Performance ◽  
Radiation Environment ◽  
Extended Defects ◽  
Semiconducting Thin Films

High-energy electron, proton, neutron, photon and ion irradiation of semiconductor diodes and solar cells has long been a topic of considerable interest in the field of semiconductor device fabrication. The inevitable damage production during the process of irradiation is used to study and engineer the defects in semiconductors. In a strong radiation environment in space, the electrical performance of solar cells is degraded due to direct exposure to energetically charged particles. A considerable amount of work has been reported on the study of radiation damage in various solar cell materials and devices in the recent past. In most cases, high-energy heavy ions damage the material by producing a large amount of extended defects, but high-energy light ions are suitable for producing and modifying the intrinsic point defects. The defects can play a variety of electronically active roles that affect the electrical, structural and optical properties of a semiconductor. This review article aims to present an overview of the advancement of research in the modification of glassy semiconducting thin films using different types of radiations (light, proton and swift heavy ions). The work which has been done in our laboratory related to irradiation induced effects in semiconducting thin films will also be compared with the existing literature.

Innovative Curriculum on Electronic Materials Processing and Engingeering

2001 ◽  
Vol 684 ◽  
Author(s):  
Jane P. Chang
Keyword(s):  
Semiconductor Manufacturing ◽  
Chemical Engineering ◽  
Materials Science ◽  
Semiconductor Device ◽  
Electronic Materials ◽  
Dynamic Environment ◽  
Complementary Metal Oxide Semiconductor ◽  
Device Fabrication ◽  
Oxide Semiconductor ◽  
Solid State Physics

Recognizing that the traditional engineering education training is often inadequate in preparing the students for the challanges presented by this industry's dynamic environment and insufficient to meet the empoyer's criteria in hiring new engineers, a new curriculum on Semiconductor Manufacturing is instituted in the Chemical Engineering Department at UCLA to train the students in various scientific and technologica areas that are pertinenet to the microelectronics industries. This paper describes this new mutidisciplinary curriculum that provides knowledge and skills in semiconductor manufacturing through a series ofcourses that emphasize on the application of fundamenta engineeering disciplines in solid-state physics, materials science of semiconductors, and chemical processing. The curriculum comprises three major components:(1)a comprehensive course curriculum in semiconductor manufacturing; (2) a laboratory for hands-on training in semiconductor device fabrication; (3) design of experiments. The capstone laboratory course is designed to strengthen students’ training in “unit operatins” used in semicounductor manufacturing and allow them to practice engineering principles using the state-of-the-art experimental setup. It comprises the most comprehensive training(seven photolithographic steps and numero0us chemical processes)in fabricating and testing complementary metal-oxide-semiconductor (CMOS) devices. This curriculum is recentyaccredited by the Accreditation Board for Engineering and Technology(ABET).

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