scholarly journals Selective W for Coating and Releasing MEMS Devices

1999 ◽  
Vol 605 ◽  
Author(s):  
S. S. Mani ◽  
J. G. Fleming ◽  
J. J. Sniegowski ◽  
M. P. de Boer ◽  
L. W. Irwin ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Microelectromechanical Systems ◽  
Process Integration ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Tungsten Coating ◽  
Mems Devices ◽  
Selective Deposition ◽  
Small Areas ◽  
Conformal Coating

AbstractTwo major problems associated with Si-based MEMS (MicroElectroMechanical Systems) devices are stiction and wear. Surface modifications are needed to reduce both adhesion and friction in micromechanical structures to solve these problems. In this paper, we will present a CVD (Chemical Vapor Deposition) process that selectively coats MEMS devices with tungsten and significantly enhances device durability. Tungsten CVD is used in the integrated-circuit industry, which makes this approach manufacturable. This selective deposition process results in a very conformal coating and can potentially address both stiction and wear problems confronting MEMS processing. The selective deposition of tungsten is accomplished through the silicon reduction of WF6. The self-limiting nature of this selective W deposition process ensures the consistency necessary for process control. The tungsten is deposited after the removal of the sacrificial oxides to minimize stress and process integration problems. Tungsten coating adheres well and is hard and conducting, requirements for device performance. Furthermore, since the deposited tungsten infiltrates under adhered silicon parts and the volume of W deposited is less than the amount of Si consumed, it appears to be possible to release stuck parts that are contacted over small areas such as dimples. The wear resistance of selectively coated W parts has been shown to be significantly improved on microengine test structures.

scholarly journals Chemical Vapor Deposition Coating for Micromachines

2000 ◽  
Vol 616 ◽  
Author(s):  
S. S. Mani ◽  
J. G. Fleming ◽  
J. J. Sniegowski ◽  
M. P. De Boer ◽  
L. W. Irwin ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Integrated Circuit ◽  
Vapor Deposition ◽  
Process Integration ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Tungsten Coating ◽  
Mems Devices ◽  
Selective Deposition ◽  
Small Areas

AbstractTwo major problems associated with Si-based MEMS devices are stiction and wear. Surface modifications are needed to reduce both adhesion and friction in micromechanical structures to solve these problems. In this paper, we will present a process used to selectively coat MEMS devices with tungsten using a CVD (Chemical Vapor Deposition) process. The selective W deposition process results in a very conformal coating and can potentially solve both stiction and wear problems confronting MEMS processing. The selective deposition of tungsten is accomplished through silicon reduction of WF6, which results in a self-limiting reaction. The selective deposition of W only on polysilicon surfaces prevents electrical shorts. Further, the self-limiting nature of this selective W deposition process ensures the consistency necessary for process control. Selective tungsten is deposited after the removal of the sacrificial oxides to minimize process integration problems. This tungsten coating adheres well and is hard and conducting, requirements for device performance. Furthermore, since the deposited tungsten infiltrates under adhered silicon parts and the volume of W deposited is less than the amount of Si consumed, it appears to be possible to release stuck parts that are contacted over small areas such as dimples. Results from tungsten deposition on MEMS structures with dimples will be presented. The effect of wet and vapor phase cleans prior to the deposition will be discussed along with other process details. The W coating improved wear by orders of magnitude compared to uncoated parts. Tungsten CVD is used in the integrated-circuit industry, which makes this approach manufacturable.

scholarly journals Strength Reliability of Micro Polycrystalline Silicon Structure

2007 ◽  
Vol 345-346 ◽  
pp. 777-780
Author(s):  
Shigeru Hamada ◽  
Kenji Hashizume
Keyword(s):  
Polycrystalline Silicon ◽  
Microelectromechanical Systems ◽  
Bending Strength ◽  
Chemical Vapor ◽  
Material Strength ◽  
Mems Devices ◽  
Bending Tests ◽  
Average Value ◽  
Micron Size ◽  
Mechanical Movement

In order to evaluate strength reliability of micron size polycrystalline silicon (poly-Si) structure, bending tests of cantilever beam and Weibull analysis are performed. Recently, the importance of microelectromechanical systems (MEMS) in society is increasing, and the number of production is also increasing. The MEMS devices, which contain mechanical movement, have to maintain their reliability in face of external shock, thermal stress and residual stress from manufacturing processes. In greeting the mass production era of the MEMS, in case the material strength design of MEMS is performed, required strength data is not average value but the variation, especially minimum value of the material. Micron size poly-Si structure is widely employed in the MEMS such as microsensor, switching device and so on. Then, in order to evaluate strength reliability of micron size poly-Si structure, tests and analysis are performed. The specimen is made by chemical vapor deposition (CVD) process and thickness is 3.5, 6.4 and 8.3 micrometer and the specimen has notch. The test specimen used for the test changed characteristics of (1) film thickness (2) stress concentration, and investigation about the influence each effects of the variation in a bending strength are discussed.

Studies of SiH2Ci2/H2 Gas Phase Chemistry for Selective Thin Film Growth of Crystalline Silicon, c-Si, Using Remote Plasma Enhanced Chemical Vapor Deposition

1991 ◽  
Vol 220 ◽  
Author(s):  
J. A. Theil ◽  
G. Lucovsky ◽  
S. V. Hattangady ◽  
G. G. Fountain ◽  
R. J. Markunas
Keyword(s):  
Gas Phase ◽  
Film Growth ◽  
Crystalline Silicon ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Film Deposition ◽  
Selective Deposition ◽  
Gas Phase Chemistry ◽  
Phase Chemistry

ABSTRACTConventional high temperature, >800°C, CVD processes, utilizing SiH2Ci2 promote selective deposition of c-Si onto c-Si, but not on SiO2 surfaces. We show that low temperature, 300°C remote PECVD, with rf-excited He plasmas, and SiH2Ci2 and H2 injected downstream, also selectively deposits c-Si on c-Si and not SiO2 surfaces. This preliminary study employs in-situ mass spectrometry, MS, to determine the species responsible for selective deposition process reaction pathways. These MS studies suggest that species responsible for film deposition are Si-containing fragments of the SiH2Ci2 molecule, e.g., SiH2Ci, SiCi2H, etc., while the species responsible for inhibiting deposition on the SiO2 surfaces are by-products of the break-up of the SiH2Ci2 molecule in the gas phase, e.g., H-atoms, HCI and H2Ci+ ions.

scholarly journals Device Process Integration: A New Device Fabrication Approach

2010 ◽  
Vol 4 (2) ◽  
Author(s):  
Viswanadam Gautham ◽  
Agarwal Ajay
Keyword(s):  
Integrated Circuits ◽  
Manufacturing Industry ◽  
Yield Loss ◽  
Microelectromechanical Systems ◽  
Process Integration ◽  
Device Fabrication ◽  
Mems Devices ◽  
New Device ◽  
Device Processing ◽  
The Cost

Microelectromechanical systems (MEMS) devices have gained considerable attention in medical and automotive applications due to their vast advantages in fault detection. However, the cost for MEMS devices has been a challenge for the device manufacturing industry due to the final packaging of the devices. It is considered expensive compared with device fabrication in certain applications. Majority of MEMS devices are still housing traditional packaging methods due to difficulty in handling and yield loss. The advanced interconnect solutions based on thin silicon carrier and through silicon via are being developed to interconnect integrated circuits and other devices at high densities. Can such technologies be used for MEMS device interconnections? It is really a challenge for MEMS designers and engineers due to the MEMS elements present in the devices. In this paper, we present a device fabrication process to realize interconnects that are fabricated prior to the MEMS elements are defined and processed in the device wafer. The interconnects are filled by doped polysilicon and device wafers with such prefabricated vertical interconnects can be used as the starting wafers for any device processing including optoelectronic and MEMS. The process details and their characterization are elaborated along with the physical and electrical analysis of such interconnections.

scholarly journals Area Selective Deposition of Iron Films Using Temperature Sensitive Masking Materials and Plasma Electrons as Reducing Agents

2021 ◽  
Author(s):  
Hama Nadhom ◽  
Yusheng Yuan ◽  
Polla Rouf ◽  
Niclas Solin ◽  
Henrik Pedersen
Keyword(s):  
Photoelectron Spectroscopy ◽  
Film Growth ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Reducing Agents ◽  
Film Deposition ◽  
Chemical Vapor Deposition Method ◽  
Temperature Sensitive ◽  
Film Material ◽  
Selective Deposition

<p>potential of area selective deposition (ASD) with a newly developed chemical vapor deposition method, which utilize plasma electrons as reducing agents for deposition of metal-containing films, is demonstrated using temperature sensitive polymer-based masking materials. The masking materials tested were polydimethylsiloxane (PDMS), polymethylmethacrylate (PMMA), polystyrene (PS), parafilm, Kapton tape, Scotch tape, and office paper. The masking materials were all shown to prevent film growth on the masked area of the substrate without being affected by the film deposition process. X-ray photoelectron spectroscopy analysis confirms that the films deposited consist mainly of iron, whereas no film material is found on the masked areas after mask removal. SEM analysis of films deposited with non-adhesive masking materials show that film growth extended for a small distance underneath the masking material, indicating that the CVD process with plasma electrons as reducing agents is not a line-of-sight deposition technique. The reported methodology introduces an inexpensive and straightforward approach for ASD that opens for exciting new possibilities for robust and less complex area selective metal-on-metal deposition. </p>

Packaging Options for MEMS Devices

MRS Bulletin ◽  
2003 ◽  
Vol 28 (1) ◽  
pp. 51-54 ◽  
Author(s):  
Erik Jung
Keyword(s):  
Integrated Circuit ◽  
Microelectromechanical Systems ◽  
Mems Devices ◽  
Single Chip ◽  
Wafer Level ◽  
Product Failure ◽  
Product Success ◽  
Microelectronics Industry ◽  
The Right ◽  
Crucial Part

AbstractMicroelectromechanical systems (MEMS) devices can be delicate structures sensitive to damage from handling or environmental influences. Their functionality may furthermore depend on sealing out the environment or being in direct contact with it. Stress, thermal load, and contaminants may change their characteristics. Here, packaging technology is challenged to extend from microelectronics toward MEMS and optoelectronic MEMS (MOEMS). Today's approaches rely on modified single-chip packages derived from the microelectronics industry, wafer-level capping to enable the device to be packaged like an integrated circuit, or highly specialized packages designed to complement the function of the MEMS device itself. Selecting the proper packaging method may tip the scale toward a product success or a product failure. Choosing the right technology, therefore, is a crucial part of the product design.

Design Considerations for Manufacturability of MEMS Comb Actuators

1996 ◽  
Author(s):  
Hrishikesh Dixit ◽  
Dean L. Taylor ◽  
Srikanth Kannapan
Keyword(s):  
Integrated Circuit ◽  
Design Space ◽  
Parametric Design ◽  
Chemical Vapor ◽  
Analytical Models ◽  
Optimal Solutions ◽  
Mems Devices ◽  
Design Considerations ◽  
Complex Process ◽  
Actuator Design

Abstract Comb actuators are electrostatic drives commonly used in micro-electromechanical systems (MEMS). These devices are typically fabricated using standard Integrated Circuit (IC) fabrication techniques such as lithography, oxidation, chemical vapor deposition and etching. The design of MEMS devices such as comb actuators is a complex process due to the dimensionality of the parametric design space and the parametric interdependencies imposed by performance, manufacturability and reliability constraints. We present a study aimed at the decomposition and structured organization of the various design and manufacturability considerations for comb actuators. The value of this knowledge organization is illustrated by the formulation and solution of a design problem that ensures optimal parametric design and layout of a comb actuator on a silicon wafer. We combine analytical models and specialized fabrication “design rules” to obtain optimal solutions for two interesting problems in MEMS comb actuator design.

MOCVD-TiN Barrier Layers for ULSI Applications

1992 ◽  
Vol 260 ◽  
Author(s):  
Ivo J. Raaijmakers ◽  
Raymond N. Vrtis ◽  
Jack Yang ◽  
Seshadri Ramaswami ◽  
Andre Lagendijk ◽  
...  
Keyword(s):  
Diffusion Barrier ◽  
Integrated Circuit ◽  
Metalorganic Chemical Vapor Deposition ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Al Alloy ◽  
Tin Films ◽  
Integrated Circuit Manufacturing ◽  
Barrier Performance ◽  
Tin Thin Films

ABSTRACTMaterial properties are reported of high quality TiN thin films, deposited by a low temperature (400 – 450 C) and low pressure (10 Torr) metalorganic chemical vapor deposition process using tetrakis(diethylamino)Ti and ammonia. Layer resistivities of less than 200 μΩ cm are achieved in 300 to 500 A thick films. The carbon and oxygen content in the films is found to be low (<3% C, <0.5% O). Conformality of the films in small contact holes is sufficient for the films to be applicable as diffusion barrier and adhesion layers in integrated circuit manufacturing at the 0.25 μΩgeneration.Integration of the MOCVD-TiN films in a Ti/TiN/Al-alloy metallization scheme is also reported. The diffusion barrier performance of the MOCVD-TiN layers is found to exceed that of PVD-TiN layers.

Reaction couples of ceramic thin films prepared by CVD

1988 ◽  
Vol 46 ◽  
pp. 798-799
Author(s):  
D.W. Susnitzky ◽  
S.R. Summerfelt ◽  
C.B. Carter
Keyword(s):  
Thin Film ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Solid State Reactions ◽  
Spatial Distributions ◽  
Diffusion Couples ◽  
Kinetics Studies ◽  
Ceramic Thin Films ◽  
Initial Stage

Solid-state reactions have traditionally been studied in the form of diffusion couples. This ‘bulk’ approach has been modified, for the specific case of the reaction between NiO and Al2O3, by growing NiAl2O4 (spinel) from electron-transparent Al2O3 TEM foils which had been exposed to NiO vapor at 1415°C. This latter ‘thin-film’ approach has been used to characterize the initial stage of spinel formation and to produce clean phase boundaries since further TEM preparation is not required after the reaction is completed. The present study demonstrates that chemical-vapor deposition (CVD) can be used to deposit NiO particles, with controlled size and spatial distributions, onto Al2O3 TEM specimens. Chemical reactions do not occur during the deposition process, since CVD is a relatively low-temperature technique, and thus the NiO-Al2O3 interface can be characterized. Moreover, a series of annealing treatments can be performed on the same sample which allows both Ni0-NiAl2O4 and NiAl2O4-Al2O3 interfaces to be characterized and which therefore makes this technique amenable to kinetics studies of thin-film reactions.

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