JPH0772685B2 - Multilayer film thickness measurement method and film thickness monitor jig - Google Patents

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 / evaporation apparatus, and more particularly to a measurement method suitable for multi-layer film thickness measurement and a jig used therefor.

[0002]

2. Description of the Related Art Conventionally, a multilayer film thickness measurement of this type has been performed by, for example, forming a first thin film 2 and a second thick film 3 directly on a surface of a silicon wafer 6 as shown in FIG. Thick film 3
The film thickness is 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 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]

Means for Solving the Problems The film thickness measuring method of the present invention is a method of forming a film on a base material having a 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 a fluorescent X-ray method. 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 metal plate having a hole having a shape close to that of a product and a heat-resistant X-ray transmission film attached thereto 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 layer thin film, the fluorescent X-rays for measuring the film thickness are not affected by the second layer thick film. Since the strength is not attenuated, the film thickness of the first thin film can be accurately measured.

Further, since the jig for monitoring uses a metal plate having a hole to which a heat-resistant X-ray transparent film is adhered, 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-layer 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 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. From the heat-resistant X-ray transparent film 5, the first thin film 2 and the second thick film 3 are formed, and the heat-resistant X-ray transparent film 5 is irradiated with the film thickness measuring X-ray 4. The film thickness of the first layer 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, and can be applied to the measurement of the film thickness of the second layer or more when the X-ray attenuation is small due to the lower film thickness. .

[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-ray 4 can be irradiated from above the first layer thin film 2, the intensity of the X-ray 4 and the film thickness measuring fluorescent X-ray 4a is not attenuated, and the film thickness of the first layer 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 product is formed, 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.