JPH0545147A - Method for measuring film thickness of multilayer film and tool for monitoring film thickness - Google Patents

Abstract

PURPOSE:To enable a film thickness of a first-layer thin film to be measured by forming a film on a base with an improved transmission property of X rays simultaneously with formation of a film of a product and then measuring the film thickness of a lower-layer film through the base by the fluorescent X-rays method with it as a sample. CONSTITUTION:In this film thickness measuring tool, a heat-resistance X-rays transmission film 5 is laminated on an SUS plate 1 with a hole 1a. A first-layer thin film 2 and a second-layer thick film 3 are formed on the heat-resistance X-rays transmission film 5, X rays 4 for measuring film thickness are emitted onto the film 5, and then a film thickness of the first-layer thin film 2 is measured according to intensity of the fluorescent X rays 4a. Since the X rays 4 can be emitted to the first-layer thin film 2 through the film 5, the film thickness can be measured without causing the strength of a fluorescent rays 4a to be attenuated and without being affected by the second-layer thick film 3, thus enabling the film thickness of the first-layer thin film 2 to be measured accurately.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to film thickness measurement in a sputtering / vapor deposition apparatus, and more particularly to a measuring method suitable for measuring a multilayer film thickness and a jig used therefor.

[0002]

2. Description of the Related Art Conventionally, this type of multi-layer film thickness measurement is performed by, for example, forming a first layer thin film 2 and a second layer thick film 3 directly on the surface of a silicon wafer 6 as shown in FIG. Thick film 3
The film thickness was measured by irradiating the X-ray 4 for film thickness measurement from above and measuring the intensity of the fluorescent X-rays generated.

[0003]

By the way, according to the above-mentioned conventional method for measuring the multilayer film thickness, when measuring the multilayer film thickness, the X-ray 4 for film thickness measurement is irradiated from above the second layer thick film 3. Since the measurement of the multilayer film thickness was performed, the intensity of the X-rays 4 and the fluorescent X-rays 4a was attenuated by the film thickness of the second layer thick film 3, so that the variation of the thickness of the second layer film caused There is a drawback that the film thickness measurement accuracy is reduced.

[0004]

The film thickness measuring method of the present invention is a method of forming a film on a base material having good X-ray transmission at the same time as the film formation of a product, and using this as a sample to measure the lower layer of the lower layer by the fluorescent X-ray method. It is characterized in that the film thickness of the film is measured through the substrate.

Further, as a jig used as a base material having good X-ray transmission, a jig having a heat-resistant X-ray transmission film attached to a metal plate having holes similar to the shape of the product is used.

[0006]

According to the above structure, since the X-ray for measuring the film thickness can be directly irradiated from above the first thin film, the film thickness measuring fluorescent X-ray is not affected by the second thick film. Since the strength is not attenuated, the film thickness of the first thin film can be accurately measured.

Further, as the jig for the monitor, a metal plate having a hole to which a heat-resistant X-ray transparent film is attached is used, so that it can be easily attached to the film-forming equipment like the product and after use. Can be used by changing the film.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing a schematic structure of a film thickness measuring jig to which a heat resistant X-ray transparent film (for example, a heat resistant polyimide tape) of one embodiment of the present invention is attached. In the figure, 1 is a SUS plate with holes 1a, 2 is a first layer thin film, 3
Is a second thick film, 4 is an X-ray, 4a and 4b are fluorescent X-rays for film thickness measurement, and 5 is a heat-resistant X-ray transparent film (for example, a heat-resistant polyimide tape).

Next, a film thickness measuring jig to which the heat resistant X-ray transparent film 5 is attached will be described. In this film thickness measuring jig, a heat resistant X-ray transparent film 5 is attached to a SUS plate 1 having holes 1a.

The SUS plate 1 has the same shape as that of a semiconductor wafer as a product and has the same film thickness as that of the product.

That is, the outer diameter was set to 300 μ, which is substantially equal to the diameter of the product semiconductor wafer and the thickness of the laminated plate. The heat-resistant polyimide tape used was 40 μm. Since the polyimide tape is self-adhesive, no adhesive is needed. If another film is used, an adhesive may be used. The first thin film 2 and the second thick film 3 are formed on the heat-resistant X-ray transparent film 5, and the film thickness measuring X-ray 4 is irradiated on the heat-resistant X-ray transparent film 5. The film thickness of the first thin film 2 is measured by the intensity of the fluorescent X-ray 4a. According to this embodiment, it is possible to irradiate the film thickness measuring X-ray 4 from above the first layer thin film 2 through the heat-resistant X-ray transparent film 5, so that it is not affected by the second layer thick film 3. The film thickness can be measured without attenuating the intensity of the fluorescent X-ray 4a for film thickness measurement.
There is an advantage that the film thickness of the second layer thin film 2 can be accurately measured.

This measuring method is not limited to only the lowermost layer, but can be applied to the measurement of the thickness of the second layer or more when X-ray attenuation is small because the thickness of the lower layer is thin. ..

[0013]

As described above, according to the present invention, the heat-resistant X-ray transparent film (for example, heat-resistant polyimide tape) 5
Was attached to a SUS plate 1 having holes, and a thin film 1 for the first layer and a thick film 3 for the second layer were formed.
Since the X-rays 4 can be irradiated from above the first thin film 2, the intensity of the X-rays 4 and the fluorescent X-rays 4a for film thickness measurement is not attenuated, and the film thickness of the first thin film 2 can be accurately measured. effective.

[Brief description of drawings]

FIG. 1 is a sectional view showing a film thickness measuring method of the present invention.

FIG. 2 is a sectional view showing a conventional film thickness measuring method.

[Explanation of symbols]

 1 Perforated SUS plate 2 1st layer thin film 3 2nd layer thick film 4 X-rays for film thickness measurement 4a, 4b Fluorescent X-ray 5 Heat-resistant X-ray transparent film 6 Silicon wafer

Claims (2)

[Claims] 1. A film is formed on a base material having good X-ray transmission at the same time as the film formation of a product, and the film thickness of the lower layer film is measured through the base material by a fluorescent X-ray method using this as a sample. Multilayer film thickness measurement method. 2. A film thickness monitor jig comprising a heat-resistant X-ray transparent film attached to a metal plate having holes.