SU1409862A1 - Method of checking thickness of film in process of application - Google Patents

Abstract

The invention relates to a measurement technique and is intended to control the thickness of films applied in the process of spraying through grids. The purpose of the invention is to improve the accuracy of the control process and expand the range of controlled thicknesses by eliminating background highlights. A luminous flux is directed towards the sensor in the sprayed area from the light source. Luminous flux is obtained in the wavelength region in which the applied material and the mesh material are opaque and reflect no more than 50% of the incident light, and the distance between the filaments and the dimensions of the cross sections of the filaments are chosen from a range of 0.1-1000 µm and closer to the thicknesses applied films. During the deposition process on the substrate. and on the filaments of the grid you precipitate a nano. material, free for the passage of the luminous flux, the cross-sectional area of the grid is reduced, in accordance with which the intensity of the transmitted luminous flux through the grid decreases, judging the film thickness, for which the luminous flux should form some angle from Gouskostoyo grid or a fragment of the grid. 3 -il. (L

Description

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The invention relates to a measuring technique and can be used mainly in the production of targets for vacuum devices, elements of thin-film electronic devices and integrated circuits 1TU for film deposition

The purpose of the invention is to increase the accuracy of the control process and to expand the range of monitored film thicknesses by eliminating background highlights and maintaining the relationship between the deposited thicknesses and the intensity of the light flux transmitted through the grid.

Figure 1-3 shows schematically the method of controlling the thickness of the gtenka according to the Invention,

The method is carried out as follows.

25

thirty

When carrying out the process of spraying films in high vacuum, when the free path of molecules is much longer than the melody distance of the evaporator and the substrate of the evaporated substance molecules fly along straight lines and only those surfaces in the sprayed zone are dusty geometric shadows from the vaporizer. When a substance is sprayed at a low gas pressure (forvacouku1-1e); when the mean free path is less than or close to the distance between the evaporator and the substrate, 35 are filled and the surface2 is found in a geometric shadow from the evaporator. During the deposition process5 films from the gas Hanpm-Sep is chemically deposited from the gas phase, all surfaces in the anesenergation zone are comparatively evenly distributed.

Part of the light rays of the light flux 3 otletshets from the surface

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B - ratio of: the yield of the mesh material or film; dg - the thickness of the mesh on the film

in a plane perpendicular to the CBeToBONry flow; Ig - the width of the cross section of the mesh thread

in the plane, 5 perpendicular to the light}, - in t 5 h - the distance between the nit; t-2i., For the grid 4, consisting of Western-Dao rows of threads intersecting in the same plane, the image of one-square cells, the equality remains valid for. erected the 1st right part of the formula CD into a power.

When using a grid with filaments, the dimensions of the cross section of which and the distance between them are close to that of the applied films, the intensity of the background reflective illumination can increase with the ratio of the filaments to the unit pl, the thickness of the grid.

When implementing the invention using a single-channel system for controlling the thickness of the gshenok, the mesh 4 with the applied material 45 is used, the shaft is 1.0-1000 μm, in which lies 5 and runs out parallel

most of the film thickness used in the construction of vacuum devices and other objects of the invention.

the transmitted light flux 3. The intensity of this background reflective component of the light flux 3 transmitted through the grid 4 strongly depends on the surface structure of the applied films, which can complicate the connection between the intensity of the transmitted light flux and the bulk films.

The intensity of this reflective component can be accurately calculated by summing the integral expressions of a complex form, taking into account the multiple

reflections and reflections from a number of adjacent filaments. But this value can be estimated by the formula, taking into account the most significant contribution of twofold reflection. This formula for the grid of lguey parallel and lying in the same plane filaments

- A.n-B. () (H, -lg - d, -), where F

(one)

the intensity of the original light flux;

D1 is the intensity of the reflected background component; A - coefficient taking into account

shape and location of threads; n is the ratio of the number of threads to the grid;

B - ratio of: the yield of the mesh material or film; dg - the thickness of the mesh on the film

in a plane perpendicular to the CBeToBONry flow; Ig - the width of the cross section of the mesh thread

in the plane, 5 perpendicular to the light}, - in t 5 h - the distance between the nit; t-2i., For the grid 4, consisting of Western-Dao rows of threads intersecting in the same plane, the image of one-square cells, the equality remains valid for. erected the 1st right part of the formula CD into a power.

When using a grid with filaments, the dimensions of the cross section of which and the distance between them are close to that of the applied films, the intensity of the background reflective illumination can increase with the ratio of the filaments to the unit pl, the thickness of the grid.

When implementing the invention using a single-channel system, the interval of 1.0-1000 µm, in which the

most of the film thickness used in the construction of vacuum devices and other objects of the invention.

By heating the evaporator 6 with the drunk material 5, a stream of sprayed substance 7 was obtained which fell at an angle of 45 ° to the glass substrate 8 and at an angle of 45 to the grid 4 formed by crossing the dies and fortified in the mandrel (not shown). The grid 4 and the substrate 8 was placed above the evaporator 6 and on equal

five

Gui 5 () mm from the axis and distance

par 6. The light flux 3 was directed onto the grid at an angle of 90 ° to the grid plane 4. Next, the light flux passing through the grid 4 was focused with a lens on a photocell and its intensity was measured (light source, light filters and lenses are not shown).

During the process of applying the mesh to the filaments, 1 material is sprayed, the free area for the passage of the luminous flux is reduced, therefore, the intensity of the luminous flux 3 incident on the photocell, which is judged on the film thickness on the grid ds and the thickness

Claims (1)

film on the substrate dp. Invention Formula The method of controlling the film thickness during the application process, consisting in 09862 that a flat grid is installed in the control zone, the light flux with a wavelength for which the film material and the mesh is opaque is directed to the mesh, the intensity of the light flux passing through the mesh is recorded, and the intensity of the film is measured by the intensity - in order to improve the accuracy of the process of monitoring and expanding the range of the control In the case of film thicknesses, the directional light flux is chosen with a wavelength for which the applied material and the mesh material reflect no more than 50% of the incident light, and the distance between the filaments and the dimensions of the filament section forming the mesh are chosen from the interval of 0.1-1000 microns determined in accordance with the required thickness of the applied films. fa8.1