Method For Determination Of Thickness Research Articles

Possibilities and limitations of the film thickness determination method based on white light interference

The usefulness of the film thickness determination method based on the principle of white light interference is tested numerically in a wide range of optical constants and thicknesses of a thin film of interest. Numerous cases occurring in practice are included. The factors which could influence the results obtained by the method are analysed. Some limitations of the method are found resulting from both experimental errors and the factors discussed.

Observation of dependent to independent Bloch wave transition in Kikuchi patterns

The transition from dependent to independent Bloch waves in high-energy electron diffraction theory is demonstrated by observing the disappearance of subsidiary fringes in Kikuchi patterns as the crystal thickness is increased. Comparison is made between experimental and computed Kikuchi band profiles in Si. It is shown that the subsidiary fringes provide a method for thickness determination in zone axis convergent-beam electron diffraction patterns from relatively thin crystals.

Absolute method for determination of metallic film thickness by X‐ray fluorescence

AbstractAn absolute method for the determination of the thickness of a nickel film on iron has been developed. The mass absorption coefficient of nickel for the effective wavelength has been determined empirically and mathematically. The found values were in agreement. To perform this method only one intensity measurement of the fluorescent substrate emission is required (Fe Kα). The method was tested using iron sheets with different thicknesses of nickel obtained by chemical deposition. Thicknesses between 6 and 25 μm produced relative differences from gravimetric values of 1.8‐1.1%.

A reflectance method for quantification of immunological reactions on surfaces

A simple optical method for determination of thicknesses of organic layers on solid substrates is described. The method is based on the use of a substrate with a high refractive index, e.g., silicon, and reflection of light at an angle of incidence close to the pseudo-Brewster angle. Under these conditions, a reflectance minimum is obtained for light polarized in the plane of incidence. The presence of an organic layer on the surface will increase the reflectance, which is used to determine the thickness of the layer. The physical basis of the method is described briefly, and the application to immunology is demonstrated.

A new method of thickness determination for targets of powdered materials prepared by centrifugal precipitation

Targets of powdered materials for nuclear experiments prepared by centrifugal precipitation from suspensions in liquid paraffin contain some amounts of residual liquid paraffin which play the role of binder. Such a target has two unknown quantities concerning its thickness, the amount of target material itself and also that of the residual paraffin. To solve this problem we must have two-sided information concerning the thickness. An apparent thickness observed with an α -ray thickness gauge and another apparent thickness observed with a β -ray thickness gauge with 14 C β -rays were proved to play the role of the above mentioned two-sided information. Thciknesses of target materials and those of residual paraffin could thus be determined separately.

Thickness determination of thin films by electron backscattering: principles, problems, and applications

For thin films with thicknesses D ≪ R/2 (R: range of primary electrons within the film material) the total electron backscattering ratio η = Ir/IO proved to be proportional to λ4NAZ2D for mean and high atomic numbers Z (λ: electron wavelength, NA: atomic number density), from which a thickness determination method has been developed.The observed high values of the backscattering ratio can only be explained by assuming multiple scattering starting very rapidly at thicknesses of about 10 nm even at low atomic numbers thus increasing the backscattered intensity from single scattering events (fig. 1) and by using the Mott scattering cross-section for high atomic numbers (fig. 2). For very thin films of low atomic numbers single Rutherford scattering seems to be applicable.By focusing the electron beam into the film plane and scanning the beam across the film the thickness distribution of self-supporting crystalline films can be determined.

The Determination of the Thickness of Anodic Al2O3 Film

To compare the properties of anodized aluminium oxide layers an easy thickness determination method is wanted. Crevecoeur and De Wit used a method expressing the thickness in terms of peak voltages obtained by forming again after annealing. The aim of the work described here is to relate the value of the peak voltage to the thickness of the layer measured by ellipsometry.On specimens formed in an aqueous solution of b oric acid and ammonium hydroxide the following relation is found between the thickness d (nm) and peak voltage Vp (volt):d = 1.020 Vp + (0.00044 ± 0.00011) Vp2. On specimens formed in a solution of ammonium pentaborate in ethylene glycol the squared Vp term is of a lower value. however when Vp is less than 150 V the above relation holds for layers formed in both electrolytes, the systematic error then being less than 1%.

On projected widths of stacking faults used for foil thickness determinations

Abstract Transmission electron microscopy studies of stacking faults in a Co-based alloy show that under some microscopy conditions the width of the bright-field image of a fault is significantly less than the width of the corresponding weak-beam dark-field image, the latter providing a good indication of the true fault width. Further microscopy studies and examination of the equations describing the contrast caused by a stacking fault in a perfect crystal demonstrate that the discrepancy in observed width exists for faults with a negative phase angle α, when the deviation of the foil from the perfect Bragg reflecting position is greater than zero. An additional condition is that the foil thickness must be in the range ξ g ≤t≤2ξ g , where t is the thickness and ξ g the extinction distance. This effect can lead to serious errors in the calculation of foil thickness in materials of low stacking fault energy, where a common method of thickness determination is based upon the projected width of stacking fault...

1174. An emission method for determination of thickness of free thin films: A S Dolgov,phys electronics, rep interdiscipl scient-tech coll, no 7, 1974, 91–92 ( in Russian)

1174. An emission method for determination of thickness of free thin films: A S Dolgov,phys electronics, rep interdiscipl scient-tech coll, no 7, 1974, 91–92 ( in Russian)

Complexometric method for determination of thickness in vacuum deposited thin metallic films: G Masse and J Dunoyer, Le Vide, 26 (154), July–Aug–Sept–Oct 1971, 174–177 ( in French)

Complexometric method for determination of thickness in vacuum deposited thin metallic films: G Masse and J Dunoyer, Le Vide, 26 (154), July–Aug–Sept–Oct 1971, 174–177 ( in French)

Specimen preparation for quantitative microradiography.

The great importance of the pretreatment of biological objects for quantitative microradiography is discussed. Freeze-drying was proved a suitable method in obtaining dehydrated sections without any measurable change in the dry substance. The different steps of the freeze-drying procedure are analyzed with special reference to their effects on mass determinations. The most important errors are the effects of shrinkage and incomplete drying, their magnitude being discussed. For microradiographic determination of dry mass per unit volume the thickness of the freeze-dried tissue sections must be measured. Different methods for thickness determination are discussed and for freeze-dried sections a procedure for focusing in a microscope proved appropriate, the error in a single determination being less than 1 μm.

Determination of the thickness of electron microscopy sections

An interference microscopical method of thickness determination for ultramicrotome sections is described. Thicknesses are determined for methacrylate sections before and after exposure to vacuum and electron beam. Exposure to electron beam is observed to occasion a marked loss of section material (approximately 60%). Thicknesses have been measured and compared for sections cut at two different microtome advance rates, 100 Å and 250 Å. The mean value of the section thickness in the 100 Å series is 326 Å and in the 250 Å series 493 Å. The thinnest section in the 100 Å series is 190 Å. The distortion of the sections, as revealed by comparison between microtome advance and the actual thickness of the sections, is briefly discussed.

A New Method for Determination of Thickness of Microtome Sections

A METHOD for determining the thickness of microtome sections with the same accuracy as the rest of the analytical procedure has long been required in quantitative cytochemistry. Hitherto this has not been possible, and it has generally been necessary to estimate thickness from the microtome setting, a rather unsatisfactory method.