Principles and Applications of Wafer Curvature Techniques for Stress Measurements in Thin Films

1988 ◽  
Vol 130 ◽  
Author(s):  
Paul A. Flinn

AbstractMeasurement of the curvature induced in a wafer (or other flat plate) by the stress in a thin film has long been used as a convenient and accurate technique for the determination of the stress. Numerous improvements over the years have led to instruments that provide simple and rapid measurements of stress as a function of the time and temperature for any desired thermal history. A computer controlled instrument using laser scanning will be briefly described and its capabilities and limitations discussed.Applications of the technique to a variety of thin film materials will be discussed. In addition to the effects of differences in thermal expansion, stresses associated with various deposition techniques, gain or loss of material, phase transformations and flow will be considered. In aluminum based systems, themal expansion, plastic flow and phase transformation play major roles. Refractory metals show, in addition, large stresses associated with the deposition process. In inorganic dielectric systems thermal expansion effects are usually relatively small; deposition effects and the gain or loss of material are the dominant effects. Silica based glasses formed by chemical vapor deposition, for example, show large stress changes due to gain or loss of water, and plasma deposited silicon nitride films show large effects associated with hydrogen. Overall, determination of the stress as a function of time and temperature is a valuable part of the evaluation of a thin film material for use in a VLSI device.

Author(s):  
D.W. Susnitzky ◽  
S.R. Summerfelt ◽  
C.B. Carter

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.


1998 ◽  
Vol 508 ◽  
Author(s):  
A. Izumi ◽  
T. Ichise ◽  
H. Matsumura

AbstractSilicon nitride films prepared by low temperatures are widely applicable as gate insulator films of thin film transistors of liquid crystal displays. In this work, silicon nitride films are formed around 300 °C by deposition and direct nitridation methods in a catalytic chemical vapor deposition system. The properties of the silicon nitride films are investigated. It is found that, 1) the breakdown electric field is over 9MV/cm, 2) the surface state density is about 1011cm−2eV−1 are observed in the deposition films. These result shows the usefulness of the catalytic chemical vapor deposition silicon nitride films as gate insulator material for thin film transistors.


2012 ◽  
Vol 1 (1) ◽  
pp. 46 ◽  
Author(s):  
Amir Mahyar Khorasani ◽  
Mohammad Reza Solymany yazdi ◽  
Mehdi Faraji ◽  
Alex Kootsookos

Thin-film coating plays a prominent role on the manufacture of many industrial devices. Coating can increase material performance due to the deposition process. Having adequate and precise model that can predict the hardness of PVD and CVD processes is so helpful for manufacturers and engineers to choose suitable parameters in order to obtain the best hardness and decreasing cost and time of industrial productions. This paper proposes the estimation of hardness of titanium thin-film layers as protective industrial tools by using multi-layer perceptron (MLP) neural network. Based on the experimental data that was obtained during the process of chemical vapor deposition (CVD) and physical vapor deposition (PVD), the modeling of the coating variables for predicting hardness of titanium thin-film layers, is performed. Then, the obtained results are experimentally verified and very accurate outcomes had been attained.


MRS Bulletin ◽  
1989 ◽  
Vol 14 (10) ◽  
pp. 48-53 ◽  
Author(s):  
J.V. Mantese ◽  
A.L. Micheli ◽  
A.H. Hamdi ◽  
R.W. Vest

There are many methods of depositing thin film materials: thermal evaporation, sputtering, electron or laser beam evaporation, chemical vapor deposition (CVD), and molecular beam epitaxy (MBE). A good survey of many of the deposition methods appears in the 1988 November and December issues of the MRS BULLETIN. One method not included in that survey, however, is metalorganic deposition (MOD), a powerful method for depositing a variety of materials.Metalorganic deposition is not to be confused with metalorganic chemical vapor deposition (MOCVD), which is a gaseous deposition method. MOD is a nonvacuum, liquid-based, spin-on method of depositing thin films. A suitable organic precursor, dissolved in solution, is dispensed onto a substrate much like photoresist. The substrate is spun at a few thousand revolutions per minute, removing the excess fluid, driving off the solvent, and uniformly coating the substrate surface with an organic film a few microns thick. The soft metalorganic film is then pyrolyzed in air, oxygen, nitrogen, or other suitable atmosphere to convert the metalorganic precursors to their constituent elements, oxides, or other compounds. Figure 1 shows a schematic of the deposition process including a prebake and annealing (if necessary).


1983 ◽  
Vol 27 ◽  
pp. 397-404
Author(s):  
J. S. Pressnall ◽  
J. J. Fitzpatrick ◽  
Paul Predecki

AbstractA computer-controlled high temperature Guinier diffractometer system for accurate determination of lattice thermal expansion is described. A critical test of the system using α-Al2O3 (0.3μ polishing alumina) showed close agreement with the single crystal expansion data of Wachtman et al. Lattice thermal expansion of cordierite doped with the following dopants: Ge+4, P+5, Zn+2, Li+1 and Ca+2 was investigated. Of these the Li+1 at the 5% level (5% of Si+4 replaced by Li+1 + Al+3) produced the largest decrease in mean lattice expansion.


Author(s):  
Enboa Wu ◽  
Albert J. D. Yang ◽  
Ching-An Shao ◽  
C. S. Yen

Nondestructive determination of Young’s modulus, coefficient of thermal expansion, Poisson ratio, and thickness of a thin film has long been a difficult but important issue as the film of micrometer order thick might behave differently from that in the bulk state. In this paper, we have successfully demonstrated the capability of determining all these four parameters at one time. This novel method includes use of the digital phase-shifting reflection moire´ (DPRM) technique to record the slope of wafer warpage under temperature drop condition. In the experiment, 1-um thick aluminum was sputtered on a 6-in silicon wafer. The convolution relationship between the measured data and the mechanical properties was constructed numerically using the conventional 3D finite element code. The genetic algorithm (GA) was adopted as the searching tool for search of the optimal mechanical properties of the film. It was found that the determined data for Young’s modulus (E), Coefficient of Thermal Expansion (CTE), Poisson ratio (ν), and thickness (h) of the 1.00 um thick aluminum film were 104.2Gpa, 38.0 ppm/°C, 0.38, and 0.98 um, respectively, whereas that in the bulk state were measured to be E=71.4 Gpa, CTE=23.0 ppm/°C, and ν=0.34. The significantly larger values on the Young’s modulus and the coefficient of thermal expansion determined by this method might be attributed to the smaller dislocation density due to the thin dimension and formation of the 5-nm layer of Al2O3 formed on top of the 1-um thick sputtered film. The Young’s Modulus and the Poisson ratio of this nano-scale Al2O3 film were then determined. Their values are consistent with the physical intuition of the microstructure.


Author(s):  
Pradeep George ◽  
Hae Chang Gea ◽  
Yogesh Jaluria

Chemical Vapor Deposition (CVD) process is simulated and optimized for the deposition of a thin film of silicon from silane. The key focus is on the rate of deposition and on the quality of the thin film produced. The intended application dictates the level of quality need for the film. Proper control of the governing transport processes results in large area film thickness and composition uniformity. A vertical impinging CVD reactor is considered. The goal is to optimize the CVD system. The effect of important design parameters and operating conditions are studied using numerical simulations. Then Compromise Response Surface Method (CRSM) is used to model the process over a range of susceptor temperature and inlet velocity of the reaction gases. The resulting response surface is used to optimize the CVD system.


2007 ◽  
Vol 22 (4) ◽  
pp. 319-323 ◽  
Author(s):  
Jianfeng Fang ◽  
Jing Huo ◽  
Jinyuan Zhang ◽  
Yi Zheng

The structure of a chemical-vapor-deposited (CVD) diamond thin film on a Mo substrate was studied using quasi-parallel X-ray and glancing incidence techniques. Conventional X-ray diffraction analysis revealed that the sample consists of a diamond thin film, a Mo2C transition layer, and Mo substrate. The Mo2C transition layer was formed by a chemical reaction between the diamond film and the Mo substrate during the CVD process. A method for layer-thickness determination of the thin film and the transition layer was developed. This method was based on a relationship between X-ray diffraction intensities from the transition layer or its substrate and a function of grazing incidence angles. Results of glancing incidence X-ray diffraction analysis showed that thicknesses of the diamond thin film and the Mo2C transition layer were determined successfully with high precision.


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