Processing of Thick Dielectric Films for Power MEMS: Stress and Fracture

2000 ◽  
Vol 657 ◽  
Author(s):  
Kuo-Shen Chen ◽  
Xin Zhang ◽  
S. Mark Spearing
Keyword(s):  
Residual Stress ◽  
Oxide Films ◽  
Intrinsic Stress ◽  
Dielectric Films ◽  
Mixed Mode Fracture ◽  
Strong Function ◽  
Deformation And Fracture ◽  
Power Mems ◽  
Theoretical Predictions ◽  
Critical Cracking Temperature

ABSTRACTThis paper presents residual stress characterization and fracture analysis of thick silane based PECVD oxide films. The motivation for this work is to elucidate the factors contributing to residual stress, deformation and fracture of oxide films so as to refine the fabrication process for power MEMS. It is shown that residual stress in oxide films strongly depended on thermal processing history. Dissolved gases were found to play an important role in governing intrinsic stress. The tendency to form cracks is a strong function of film thickness and annealing temperature. Mixed mode fracture mechanics was applied to predict critical cracking temperature, and there is a fairly good match between theoretical predictions and experimental observations.

In Situ Thin Film Stress Measurements – A Path to Understanding the Structure and Morphology of Electron Beam Evaporated ZnS

2002 ◽  
Vol 749 ◽  
Author(s):  
Vincent Barrioz ◽  
Stuart J. C. Irvine ◽  
D. Paul
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Electron Beam ◽  
Stress Reduction ◽  
Float Glass ◽  
Film Stress ◽  
Intrinsic Stress ◽  
Ex Situ ◽  
Stress Measurements

ABSTRACTZnS is a material of choice in the optical coating industry for its optical properties and broad transparency range. One of the drawbacks of ZnS is that it develops high compressive intrinsic stress resulting in large residual stress in the deposited layer. This paper concentrates on the evolution of residual stress reduction in ZnS single layers, depending upon their deposition rate or the substrate temperature during deposition (i.e. 22 °C and 133 °C). The substrate preparation is addressed for consideration of layer adhesion. Residual stress of up to − 550 MPa has been observed in amorphous/poor polycrystalline ZnS layers, deposited on CMX and Float glass type substrates, by electron beam evaporation at 22 °C, with a surface roughness between 0.4 and 0.8 nm. At 133 °C, the layer had a surface roughness of 1 nm, the residual stress in the layer decreased to − 150 MPa, developing a wurtzite structure with a (002) preferred orientation. In situ stress measurements, using a novel optical approach with a laser-fibre system, were carried out to identify the various sources of stress. A description of this novel in situ stress monitor and its advantages are outlined. The residual stress values were supported by two ex situ stress techniques. The surface morphology analysis of the ZnS layers was carried out using an atomic force microscope (AFM), and showed that stress reduced layers actually gave rougher surfaces.

A study on the residual stress measurement methods on chemical vapor deposition diamond films

1998 ◽  
Vol 13 (11) ◽  
pp. 3027-3033 ◽  
Author(s):  
Jung Geun Kim ◽  
Jin Yu
Keyword(s):  
Residual Stress ◽  
Chemical Vapor Deposition ◽  
Tensile Stress ◽  
Residual Stresses ◽  
Vapor Deposition ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Peak Shift ◽  
Intrinsic Stress ◽  
Chemical Vapor Deposition Diamond

Diamond films were deposited on the p-type Si substrate with the hot filament chemical vapor deposition (HFCVD). Residual stresses in the films were measured in air by the laser curvature, the x-ray diffraction (XRD) dϕψ − sin2ψ, and the Raman peak shift methods. All of the measuring methods showed similar behaviors of residual stress that changed from a compressive to a tensile stress with increasing the film thickness. However, values of residual stresses obtained through the Raman and XRD methods were 3–4 times higher than those of the curvature method. These discrepancies involved the setting of materials constants of CVD diamond film, and determination of a peak shifting on the XRD and Raman method. In order to elucidate the disparity, we measured a Young's moduli of diamond films by using the sonic resonance method. In doing so, the Raman and XRD peak shift were calibrated by bending diamond/Si beams with diamond films by a known amount, with stress levels known a priori from the beam theory, and by monitoring the peak shifts simultaneously. Results of each measuring method showed well coincidental behaviors of residual stresses which have the stress range from −0.5 GPa to +0.7 GPa, and an intrinsic stress was caused about +0.7 GPa with tensile stress.

Residual Stress Measurements on Cr/Ni Pads Evaporated on Polyimide Thin Films

1992 ◽  
Vol 36 ◽  
pp. 203-212
Author(s):  
C. C. Goldsmith ◽  
C. Van Buskirk
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Thermal Processing ◽  
Polyimide Film ◽  
Metal Films ◽  
Dielectric Films ◽  
Nickel Layer ◽  
Polyimide Films ◽  
Layer Structures ◽  
Deposited Metal

AbstractPolyimide films are becoming more important in multi-layer structures, acting as dielectric films to separate conductive layers. High thin film residual stresses can cause problems with the polyimide film, leading to loss of adhesion between the metal film and the polyimide or can cause cracking in the polyimide.In this paper, we examine the residual stresses in “as deposited” metal films evaporated onto BTDA-APB polyimide films and follow the change in residual stress of the nickel layer during subsequent thermal processing. We will show that the change in residual stresses can be correlated to the glass transition temperature of the polyimide film.

Thermo-mechanical behavior of thick PECVD oxide films for power MEMS applications

2003 ◽  
Vol 103 (1-2) ◽  
pp. 263-270 ◽  
Author(s):  
Xin Zhang ◽  
Kuo-Shen Chen ◽  
S. Mark Spearing
Keyword(s):  
Mechanical Behavior ◽  
Oxide Films ◽  
Power Mems
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