Measurement of Elastic Modulus and Residual Stress of Diamond Thin Films

Despite great advancements in diamond thin film growth and deposition techniques, determination of the residual stress and Young’s modulus for diamond films has continued to be a challenge. The bulge test is a potentially powerful tool for characterizing the mechanical properties of diamond film. In a bulge tester, pressure is applied on a thin membrane and the out-of-plane deflection of the membrane center is measured. The Young’s Modulus and the residual stress are simultaneously determined by using the load-deflection behavior of a membrane. By means of electron-enhanced hot filament chemical vapor deposition (HFCVD), a diamond film was deposited on silicon slice (100), and the free-standing window sample of diamond thin films was fabricated by means of photolithography and anisotropic wet etching. The deflection of the membranes is measured using a laser interferometry system. The elastic modulus and residual stress were measured using a self-designed bulge equipment. In addition, the distortion of diamond thin films under different pressure was simulated using finite element analysis and the contrast was made with experimental data. The research indicated that the Young’s Modulus of diamond thin films is 937.8GPa and the residual stress is -10.53MPa. The elastic modulus and the residual stress coincide with the report in the literature and the value tested by X-ray diffraction, respectively. This method uses a simple apparatus, and the fabrication of samples is very easy, and it has provided an effective means for precise measure the mechanical properties of other thin films.

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Measuring the elastic modulus and residual stress of freestanding thin films using nanoindentation techniques

Journal of Materials Research ◽

10.1557/jmr.2009.0360 ◽

2009 ◽

Vol 24 (9) ◽

pp. 2974-2985 ◽

Cited By ~ 14

Author(s):

Erik G. Herbert ◽

Warren C. Oliver ◽

Maarten P. de Boer ◽

George M. Pharr

Keyword(s):

Thin Films ◽

Mechanical Properties ◽

Residual Stress ◽

Thermal Expansion ◽

Elastic Modulus ◽

Dimensional Analysis ◽

Experimental Verification ◽

Cu Films ◽

Proposed Model ◽

The Difference

A new method is proposed to determine the elastic modulus and residual stress of freestanding thin films based on nanoindentation techniques. The experimentally measured stiffness-displacement response is applied to a simple membrane model that assumes the film deformation is dominated by stretching as opposed to bending. Dimensional analysis is used to identify appropriate limitations of the proposed model. Experimental verification of the method is demonstrated for Al/0.5 wt% Cu films nominally 22 µm wide, 0.55 µm thick, and 150, 300, and 500 µm long. The estimated modulus for the four freestanding films match the value measured by electrostatic techniques to within 2%, and the residual stress to within 19.1%. The difference in residual stress can be completely accounted for by thermal expansion and a modest change in temperature of 3 °C. Numerous experimental pitfalls are identified and discussed. Collectively, these data and the technique used to generate them should help future investigators make more accurate and precise measurements of the mechanical properties of freestanding thin films using nanoindentation.

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Enchancement of Mechanical Properties in BaTiO3 Ferroelectric Thin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.150-151.599 ◽

2010 ◽

Vol 150-151 ◽

pp. 599-602 ◽

Cited By ~ 1

Author(s):

Cheng Lu ◽

Xiang Yun Deng ◽

Xiao Fen Guan ◽

Zhong Wen Tan ◽

Yan Jie Zhang ◽

...

Keyword(s):

Thin Films ◽

Mechanical Properties ◽

Residual Stress ◽

Elastic Modulus ◽

Sintering Temperature ◽

Sol Gel ◽

Ferroelectric Thin Films ◽

Fabrication Method ◽

Maximum Hardness ◽

Sol Gel Process

Surface structure and mechanical properties of BaTiO3 thin films prepared by sol-gel process were investigated by XP-2 profiler and nano-indention. The results indicated that the thickness of thin films got thicker with sintering temperature and the thickness-increasing rate differ from different solvent. The hardness and elastic modulus were enhanced due to the presence of residual stress which was compression and probably induced by fabrication method. The maximum hardness is 9.98GPa when the Young’s modulus is 127.41GPa with ethanol as solvent sintered at 1000oC.

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INVESTIGATION OF INDENTATION METHODS FOR PROPERTIES DETERMINATION IN HARD FILM – SOFT SUBSTRATE SYSTEMS

MRS Proceedings ◽

10.1557/proc-841-r12.7 ◽

2004 ◽

Vol 841 ◽

Author(s):

M. S. Kennedy ◽

N. R. Moody ◽

D. F. Bahr

Keyword(s):

Thin Films ◽

Residual Stress ◽

Elastic Modulus ◽

Loading Frequency ◽

Soft Substrate ◽

Dynamic Motion ◽

Pile Up ◽

Unloading Rate ◽

Indentation Methods ◽

Cr Film

ABSTRACTElastic modulus values of the thin films utilized in three different hard film- soft substrate systems were measured using a combination of traditional and continuous stiffness indentation. These systems were chosen to represent typical systems currently utilized in MEMS and included Si/SU8/W, Si/SiO2/Ti/Pt/PZT, and Si/SiO2/Ti/Pt. The last system was coated with either a compressive or nonstressed Cr film. By taking into account ratio between the creep due to the polymer substrate, SU8, to the unloading rate, the modulus of W was measured to be 400 GPa. The modulus of the SU8 was also determined to be 6 GPa. Comparing both the CSM and traditional indentation for the Si/SiO2/Ti/Pt/PZT system showed that the dynamic motion of the indenter caused pile-up in the PZT and resulting in the overestimation of the PZT modulus. This pile-up is a function of the sinusoidal loading frequency. Instead, the modulus of the PZT was measured by shallow depths of traditional indentation that resulted in the PZT modulus of 100 GPa. The hard film-soft substrate systems were show to follow the same trend as stressed soft-film hard-substrate systems with residual stress. The modulus was over estimated for compressively stressed Cr films.

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Raman analyses of residual stress in diamond thin films grown on Ti6Al4V alloy

Materials Research ◽

10.1590/s1516-14392003000100010 ◽

2003 ◽

Vol 6 (1) ◽

pp. 51-56 ◽

Cited By ~ 9

Author(s):

Adriana F. Azevedo ◽

Evaldo J. Corat ◽

Nélia F. Leite ◽

Neidenei G. Ferreira ◽

Vladimir J. Trava-Airoldi

Keyword(s):

Thin Films ◽

Residual Stress ◽

Ti6al4v Alloy ◽

Diamond Thin Films

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Electron microscopic characterization of diamond thin films and substrates for diamond heteroepitaxial growth

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100154937 ◽

1989 ◽

Vol 47 ◽

pp. 592-593

Author(s):

J.B. Posthill ◽

R.P. Burns ◽

R.A. Rudder ◽

Y.H. Lee ◽

R.J. Markunas ◽

...

Keyword(s):

Thin Films ◽

Wide Band ◽

Deposition Process ◽

Heteroepitaxial Growth ◽

Electron Microscopic ◽

Wide Band Gap ◽

Lattice Matching ◽

Different Types ◽

Diamond Thin Films

Because of diamond’s wide band gap, high thermal conductivity, high breakdown voltage and high radiation resistance, there is a growing interest in developing diamond-based devices for several new and demanding electronic applications. In developing this technology, there are several new challenges to be overcome. Much of our effort has been directed at developing a diamond deposition process that will permit controlled, epitaxial growth. Also, because of cost and size considerations, it is mandatory that a non-native substrate be developed for heteroepitaxial nucleation and growth of diamond thin films. To this end, we are currently investigating the use of Ni single crystals on which different types of epitaxial metals are grown by molecular beam epitaxy (MBE) for lattice matching to diamond as well as surface chemistry modification. This contribution reports briefly on our microscopic observations that are integral to these endeavors.

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