Characterisation of residual stress in dielectric films studied by automated wafer mapping

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.

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Research on some Key Mechanical Properties of Silicon Nitride Thin Films Deposited by PECVD

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.742.773 ◽

2015 ◽

Vol 742 ◽

pp. 773-777

Author(s):

Qun Feng Yang ◽

Jian Yi Zheng ◽

Jun Qing Wang ◽

Jun Hui Lin ◽

Xue Nan Zhao ◽

...

Keyword(s):

Thin Films ◽

Mechanical Properties ◽

Residual Stress ◽

Silicon Nitride ◽

Mechanical Characteristics ◽

Dielectric Films ◽

Rotating Beam ◽

Atomic Force ◽

Scanning Electron

The purpose of this work is to study the mechanical characteristics of the silicon nitride(SiNx) thin films prepared by PECVD technique, some researches as follows were carried out. First, the SiNx thin films were deposited on the two different substrates. Then, the atomic force microscope (AFM) was adopted to test the surface quality of the SiNxfilms, and the scanning electron microscope (SEM) was used to test the section morphology of the SiNxthin films. Finally, the rotating beam structures was applied to measure the residual stress in the SiNx films. The SiNxthin films with low stress can be fabricated through PECVD, in which the surface roughness values(Ra) are 1.261 nm and 2.383nm, and the residual stress is 43.5 kPa. Therefore, the SiNxthin films deposited by PECVD are suitable for the preparation of device dielectric films in MEMS.

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

MRS Proceedings ◽

10.1557/proc-657-ee8.4 ◽

2000 ◽

Vol 657 ◽

Cited By ~ 2

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.

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Residual stress and fracture of thick dielectric films for power MEMS applications

Technical Digest. MEMS 2002 IEEE International Conference. Fifteenth IEEE International Conference on Micro Electro Mechanical Systems (Cat. No.02CH37266) ◽

10.1109/memsys.2002.984230 ◽

2003 ◽

Cited By ~ 2

Author(s):

X. Zhang ◽

K.-S. Chen ◽

S.M. Spearing

Keyword(s):

Residual Stress ◽

Dielectric Films ◽

Power Mems

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Study of PZT Film Stress in Multilayer Structures for MEMS Devices

MRS Proceedings ◽

10.1557/proc-605-287 ◽

1999 ◽

Vol 605 ◽

Cited By ~ 6

Author(s):

E. Zakar ◽

M. Dubey ◽

R. Polcawich ◽

B. Piekarski ◽

R. Piekarz ◽

...

Keyword(s):

Residual Stress ◽

Lead Zirconate Titanate ◽

Sol Gel ◽

Lead Zirconate ◽

Film Stress ◽

Dielectric Films ◽

Mems Devices ◽

Annealing Conditions ◽

Pzt Film ◽

Final Stress

AbstractResidual stress in the multilayer Si/Dielectric/Pt/PZT/Pt stack was measured as a function of annealing conditions, sol-gel derived PZT (Lead Zirconate Titanate -52/48) thickness, SiO2 and/or Si3N4 dielectric films thickness. Residual stress in the Si3N4 layer varied from -201 to +1275 MPa and from -430 to + 511 MPa in the Si02 layer. Furnace annealing of the bottom Pt film reduced the stress over rapid thermal annealing (RTA). Stress due to PZT films was the controlling factor for the final stress of the stack. Upon increasing PZT thickness, stress became less tensile for Si3N4 dielectric and more tensile for Si02. The deposition of the top Pt on PZT followed by RTA at 300°C in nitrogen had a minimal effect on the final stress of the stack. The average tensile stress for the Si/Si02 /Pt/PZT/Pt and Si/Si3N4/Pt/PZT/Pt stacks was 140 ± 25 and 476±235 MPa respectively.

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Electron microscopy studies of PZT ferroelectric film capacitor structures

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100131450 ◽

1992 ◽

Vol 50 (2) ◽

pp. 1364-1365

Author(s):

V. Kaushik ◽

P. Maniar ◽

J. Olowolafe ◽

R. Jones ◽

A. Campbell ◽

...

Keyword(s):

Electric Fields ◽

Sol Gel ◽

Ferroelectric Material ◽

Dielectric Constants ◽

Dielectric Films ◽

Lead Zirconium Titanate ◽

Si Substrate ◽

Film Capacitor ◽

Pzt Films ◽

High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

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TEM investigations of surface residual stress relaxation in A12O3 and Al2O3-SiC nanocomposite

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100170876 ◽

1994 ◽

Vol 52 ◽

pp. 628-629

Author(s):

J. Fang ◽

H. M. Chan ◽

M. P. Harmer

Keyword(s):

Residual Stress ◽

Single Phase ◽

Stress Relief ◽

Stress Recovery ◽

Surface Residual Stress ◽

Microscopic Mechanism ◽

Sic Particles ◽

Annealing Procedure ◽

The Difference ◽

Nano Size

It was Niihara et al. who first discovered that the fracture strength of Al2O3 can be increased by incorporating as little as 5 vol.% of nano-size SiC particles (>1000 MPa), and that the strength would be improved further by a simple annealing procedure (>1500 MPa). This discovery has stimulated intense interest on Al2O3/SiC nanocomposites. Recent indentation studies by Fang et al. have shown that residual stress relief was more difficult in the nanocomposite than in pure Al2O3. In the present work, TEM was employed to investigate the microscopic mechanism(s) for the difference in the residual stress recovery in these two materials.Bulk samples of hot-pressed single phase Al2O3, and Al2O3 containing 5 vol.% 0.15 μm SiC particles were simultaneously polished with 15 μm diamond compound. Each sample was cut into two pieces, one of which was subsequently annealed at 1300° for 2 hours in flowing argon. Disks of 3 mm in diameter were cut from bulk samples.

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