Ion-implantation has many applications in the fabrication and processing of microelectronic devices from semiconductors, but thermal treatments are required to remove defects produced by the implant and to electrically activate dopants. Recently, pulsed laser annealing has been used to activate surface layers of GaAs that have been heavily doped with 28Si+ by ion implantation, and carrier concentrations of > 1 x 1019 cm-3 have been achieved (Ref. 1). Double-crystal x-ray diffraction techniques are very sensitive to strains and defects in single crystals and provide a means for characterizing and quantifying the damage produced by ion-implantation and the subsequent relief of damage by pulsed laser annealing.

Synthesizing thin diamond films by chemical vapor deposition (CVD) is the most recent and technologically important development in the thin-film field. Thin diamond films are useful in many applications because of their unique physical, chemical, optical, and electronic properties.

To assess thin diamond films’ suitability for support membranes in X-ray lithography, X-ray diffraction was used to characterize the crystal structure and orientation of these films deposited on silicon wafers by hot-filament assisted CVD. X-ray transmission properties of free-standing thin diamond films prepared by selectively etching silicon substrates were characterized by X-ray fluorescence in short and long wavelength regions.

This paper discusses conventional and grazing incidence diffraction techniques used to study the crystal structure of thin diamond films and compares the results with film morphology. It also describes X-ray transmission properties of these films in terms of Beer's Law, the mass absorption coefficient, and the wavelength of attenuated radiation. Finally, it reveals the long wavelength regions for optimum X-ray lithography operations using polycrystalline diamond (PCD) film.

A series of nanostructured Fe/Ag metal films were produced at various substrate temperatures to determine their magnetic characteristics. The magnetic coercivity was found to increase with the diffracting-particle size which is process controlled. The films produced at low substrate temperature (<200°C) consisted of small metallic clusters of Ag (<100 Å). As the substrate temperature was increased, the films exhibited increased crystallinity and larger diffracting-particle size. The position of the maximum in the particlesize distribution function and the width of the function increased with substrate temperature.

There are many investigations about thin film. However, these are limited to the surface layer thin film on substrates. It Is very important to know the characteristics of the extremely thin film itself such as surface layer thin film.

In the present paper, the first part deals with the thickness measurements of the surface layer film and substrate by means of x-ray method, and then the measurement method of their stress - strain curves and the procedure of the measurement are described. The results obtained are discussed on the basis of their stress — strain curves.

Precision lattice parameter measurement by the X-ray diffraction method of Bond [1] has been examined as a substitutional method for IR in determining the oxygen concentration in silicon single crystals. Asymmetric 444 CuKai reflections were measured for undoped (100) oriented silicon wafers to obtain the correlation curve between the silicon lattice parameter and oxygen concentration. Precise adjustment of the optical system and computer fitting in determining the peak position allow a minute lattice dilation of silicon due to oxygen to be detected by the Bond method. The precision of this measurement system was of the order of 10-6. The lattice expansion of silicon by dissolved oxygen was determined to be at the rate of 3.2X10-24 atoms of oxygen per cm3. Furthermore, the oxygen concentrations of heavily Sb-doped silicon wafers were determined nondestructively.

Residual stresses are a major factor in the reliable operation of multi-layer thin film structures. These stresses form due to various causes. Defect incorporation during deposition, rccrystallization, second-phase precipitation, coefficient of thermal expansion (CTE) mismatch, etc., can all cause the formation of residual stress fields. These stress fields can also change during the operation of the device, depending on the temperature excursions seen during the operation. Again, the stress change may be due to any of the factors listed above, brought about by the temperature excursions.

In this paper we examine the formation and relaxation of residual stresses in “blanket” Al, Cu and Ni films subjected to temperature cycling. Comparison of the stress dependency on temperature to the total retained strain (measured by a micro-grid technique) is then used to determine the location of plastic flow within the film.

Although widely recognized in the research community as one of the most accurate non-destructive methods for the determination of . residual stress in polycrystalline structural materials, x-ray diffraction has not been widely adopted in the field. This is partly due to the fact that such measurements require, most often, a well trained user with knowledge in both materials and mechanical sciences in addition to the specific know-how of the instrument. We believe that computer assistance could contribute to the promotion of this technique by increasing the productivity and accuracy of these measurements. We have developed a prototype expert system, using Nexpert Object's shell, to assist a non-trained operator in the validation and interpretation of X-ray diffraction residual stress data.

The present work describes this prototype which has been designed to confirm the feasibility of the concept. Its knowledge base contains relevant examples of the rules necessary for data validation. The prototype has also confirmed most of the concepts required for the implementation of a full-scale version by evaluating all of the major technical features such as graphics representation, external routines and database access.

A new failure criterion for discriminating good and bad (overheated) railroad car wheels is proposed using X-ray residual stress data. The procedure for the new discrimination criterion is based on the fluctuations of the azimuthal residual stress in the tread of the wheel. This criterion is based on a maximum likelihood statistical analysis of stress data obtained from six different wheels as determined by x-ray diffraction. Of these locations, the analysis showed the tread, and perhaps a critical point on the top of the flange, to be the most sensitive to residual stress. The variance analysis showed that fluctuations in stress a.l the most sensitive location in the tread to be related to the service history. The residual stresses showed an oscillatory pattern in the hoop direction around the wheels. Extension of the measurement technology to the use of faster residual stress measurements is proposed. To validate our x-ray residual stress data, residual stresses were also measured by hole drilling. Excellent agreement between two techniques was found.

Simulated heat-affected zones (HAZs) were made in austenitic sta.inless steel specimens using a Gleeble. The samples were heated to temperatures as high as 1100°C by computer controlled resistance heating. By controlling the heating rate, maximum temperature, and cooling rate, a wide range of residual stresses were introduced in the specimens. Stress measurements were made using X-ray diffraction. It was found that significant stress gradients were produced in the simulated HAZs, and that all stresses were compressive in nature, both in the longitudinal and transverse directions. These results are not representative of the residual stresses determined in the HAZs of real welds, thus calling into question some aspects of the role of the Gleeble in such simulations.

Plastic deformation of metals will broaden the x-ray diffraction line. The diffraction line around its peak can he approximated by a Gaussian function. The broadness of the diffraction line can be evaluated by the standard deviation, called Gaussian curve parameter (GCP), of a Gaussian function approximating the diffraction peak. Plastic strains applied to mild steels by simple and combined tension, compression, and tortion were correlated with GCP. Two kinds of GCP's were determined; the one, GCP α', was determined from the diffraction line corrected for the background counts, and the other, GCP α, was from the line uncorrected for the background, The GCP α' can be obtained from the GCP α as

α' = 0.936α + 0.011

This equation shows that the background subtraction can be omitted in determining GCP. The equivalent plastic strain ɛeq can be evaluated from the GCP a as

ɛeq - 0.000108 x 103.97α

This x-ray method allows rapid measurement of complex plastic strain without touching specimens.

X-ray elastic constants for the 511+333 and the 422 reflections of β-SiC were calculated from the single crystal data of Tolpygo using the Voigt-Reuss, Eshelby-Kroner and x-ray methods. Agreement was satisfactory for the 511+333, but less so for the 422. A hot-pressed α-Al2O3/ 29 vol % β-SiC (whisker) composite was investigated on its 3 principal faces. The total residual strains were found to be consistently anisotropic on all 3 faces suggesting that texture was present in the whiskers as a result of hot-pressing. Assuming no texture in the matrix, it was found possible to determine the average residual microstresses in the whiskers using the theory of Noyan and Cohen, without needing to know the whisker elastic constants or texture. The average microstresses were determined in each phase as well as the average residual macrostresses on each face.

X-ray fractography is a new method which utilizes X-ray diffraction observation of the fracture surface for the analysis of micromechanisms and mechanics of fracture. The line broadening of X-ray diffraction profiles and the residual stress left on the surface are two of the important parameters.

The residual stress distribution of a ceramic-metal joint specimen was determined by both two- and three-dimensional thermoelastoplastic stress analyses using the finite element method (FEM). The residual stress on the surface of the specimen was also measured by x-ray diffraction. A specimen was prepared by brazing a silicon nitride plate to a carbon steel plate. The highest tensile stress σx perpendicular to the interface appeared at the corners of the silicon nitride adjacent to the interface. The maximum compressive stress σy parallel to the interface occurred at the center of the interface of the silicon nitride. The residual stresses in the silicon nitride and the steel plates distribute antisymmetrically with respect to the center of the specimen. Around the interface, the high stress concentration occurs and the residual stress distributes three-dimensionally, giving a wrong result by the two-dimensional FEM. The residual stress distribution measured by x-rays was similar to that calculated from the three-dimensional FEM.

Unidirectional continuous fiber composites fabricated from 20 μm diameter α-AI2O3 fibers (duPont FP) and 5 different silicate glass matrices (Corning 9013 and 7740, Owns Illinois N51A and Schott 8229 and 8228) were examined for residual strain and stress in the fibers using x-ray diffraction and the results compared with the predictions of two simple residual stress models. The glasses were chosen to have thermal expansion coefficients ranging from 1.3 to 10.2 x 10-6 /°C, compared with 7.2 x 10-6 /°C for the fiber, so as to produce a range of residual stresses. The magnitudes of the measured normal strains and stresses increased with increasing fiber/matrix thermal expansion mismatch in the order expected except for the sample containing Corning glass 7740 which showed extensive microcracking. Small shear strains were also detected in most of the samples due to the fibers not lying precisely along the presumed uniaxial direction. Agreement with the models was qualitative only but revealed that the residual stresses in the samples containing Corning 7740 and Schott 8229 glasses were substantially less than expected, possibly due to microcracking and/or fiber degradation.

Machine parts made of ceramics are usually finished by grinding. Residual stresses as well as defects introduced by grinding will influence the fracture strength and the function of the ceramic parts. Although several investigators measured the grinding residual stresses by the X-ray diffraction method, their grinding conditions were rather limited.

Residual stress values in a material are governed by the measurements of the atomic spacings in a specific crystallographic plane and the elastic constant for that plane. It has been reported that the value of the elastic constant depends on microstructure, preferred orientation, plastic deformation and morphology [1], Thus, the theoretical calculation of the elastic constant may deviate from the intrinsic value for a real alloy.

Zn-Ni-alloy electroplated steels are used for the parts of automob iles because of their high corrosion resistance. in the x-ray stress measurement of this material, some unique experimental results were observed: (i) The sin2Φ diagrams were severely curved, and (ii) the influence of the wave length of x-ray radiations upon the shape of the d-sin2Φ diagram was very slight. As no strong texture or the gradients of composition were observed in this material, the above experimental results suggested the existence of steep stress gradients in the direction of depth, and a theoretical problem on the difference in the effective penetration depth of x-rays and the weighted mean of the lattice strain between thin films and ordinary thick materials.

Fracture accidents of engineering structures and machines in operation sometimes result from defects. One of the purposes of fracture analysis are to determine the causes of failure, and to use the information to prevent similar failure accidents. It is important to obtain quantitative analysis from the fracture surface. X-ray diffraction technique as well as Electron Fraotography has been widely used for fracture analysis of engineering structures and machines.

The residual stress left on the fracture surface is one of the important parameters in X-ray fractographic study. It has been used to analyze fracture mechanisms in fracture toughness and fatigue tests especially of high strength steels.

In this paper, X-ray fractography was applied to brittle fracture of alumina (Al2O3) and zirconia (ZΓO2) ceramics.