JP2002055063A - Measuring apparatus for slurry concentration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring apparatus for a slurry concentration, which can be installed without having to modify a slurry supply pipe itself, and which can measure the slurry concentration with high accuracy and automatically. SOLUTION: The measuring apparatus is provided with an X-ray generator 2 and a transmitted X-ray detector 3, which are installed at positions, sandwiching the slurry supply pipe 1 as well as a converter which converts an X-ray signal into the slurry concentration. Transmitted X-rays, which are radiated from the X-ray generator 2 and which transmit the inside of the pipe 1, are detected by the detector 3, and the X-ray signal from the detector 3 is converted into the slurry concentration by the converter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slurry concentration measuring device for measuring the concentration of a slurry such as a slurry for CMP (chemical mechanical polishing) of a semiconductor silicon wafer.

[0002]

2. Description of the Related Art The most typical conventional method for obtaining the concentration of a slurry liquid is to dry the slurry liquid and measure the weight of the slurry liquid before drying by a balance or the like in advance. In some cases, the value obtained by dividing by the above is used as the slurry concentration.

[0003]

However, in the above-described method, it takes a great deal of time and effort to extract only the slurry component from the slurry liquid, and the extraction of the slurry component is difficult due to the degree of drying. To be accompanied by large errors.

[0004] Other conventional methods include a light scattering method and a high-frequency dielectric constant method. In each case, the signal output response is linear with respect to the slurry concentration, especially when the concentration of the slurry liquid is high. Since the response becomes complicated (not monotonically decreasing or monotonically increasing), a reliable measurement result cannot be obtained.

The present invention has been made in consideration of the above-mentioned matters, and has as its object to be able to install the slurry supply pipe itself without any modification, to perform high-precision measurement, and also to enable automatic measurement. It is an object of the present invention to provide an apparatus for measuring a slurry concentration.

[0006]

To achieve the above object, a slurry concentration measuring apparatus of the present invention comprises an X-ray generator and a transmitted X-ray detector provided at a position sandwiching a slurry supply pipe; And a converter for converting a signal into a slurry concentration. The transmitted X-ray detector detects the transmitted X-rays emitted from the X-ray generator and transmitted through the slurry supply pipe. The converter converts the X-ray signal into a slurry concentration by the converter (claim 1).

[0007] An X-ray generator provided to irradiate the slurry supply pipe with X-rays, a fluorescent X-ray detector, and a converter for converting an X-ray signal into a slurry concentration are provided. Fluorescent X-rays emitted from the X-ray generator and generated in the slurry supply pipe are detected by the fluorescent X-ray detector, and an X-ray signal from the fluorescent X-ray detector is converted by the converter. Convert to slurry concentration (Claim 2).

According to the above configuration, it is possible to provide a slurry concentration measuring apparatus which can be installed without modifying the slurry supply pipe itself, can measure with high accuracy, and can also automatically measure.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are a perspective view and an explanatory view schematically showing a configuration of a slurry concentration measuring device D according to a first embodiment of the present invention. The slurry concentration measuring device D is, for example, a CM used in a CMP (chemical mechanical polishing) process of a semiconductor wafer.
An X-ray generator 2 and a transmitted X-ray detector 3 held at a position sandwiching the slurry supply pipe 1 for measuring the concentration of the slurry liquid for P, and a conversion for converting an X-ray signal into a slurry concentration. A container (not shown) is provided in the case 4.

The slurry supply pipe 1 is for sending a slurry liquid from a slurry supply device (not shown) to a polishing machine used for CMP of a semiconductor wafer, and is not corroded by the slurry liquid flowing inside. And a material that transmits X-rays, transmitted X-rays and fluorescent X-rays. Examples of the material include fluororesin and hard Teflon (registered trademark).

The slurry supply pipe 1 and the X-ray generator 2
X-ray convergence means 5 is provided between
The X-rays generated from the X-ray generator 2 are irradiated into the slurry supply pipe 1 with the divergence restricted by the X-ray convergence means 5. The X-ray convergence means 5 is, for example, an X-ray guide tube or an X-ray collimator.

The transmitted X-ray detector 3 measures a change in the transmitted X-ray intensity corresponding to a change in the concentration of the slurry liquid flowing in the slurry supply pipe 1, thereby obtaining a linear relationship with the slurry concentration. Is obtained.

The case 4 can be easily attached to and detached from the slurry supply pipe 1.
It has a display unit 4a and an operation unit 4b on the front,
The rear surface has a cutout portion 4c formed from the rear side toward the inner side, and a fitting body 4d that is detachable from the cutout portion 4c. Then, in order to attach the case 4 to the slurry supply pipe 1, all that is required is to bring the notch portion 4c into contact with a desired portion of the slurry supply pipe 1 and mount the fitting 4d.

In the case 4 attached to the slurry supply pipe 1, the X-ray generator 2 and the transmitted X-ray detector 3 are connected to the slurry supply pipe 1.
Is held at the position sandwiching.

The case 4 has a density signal output cable and a power supply cable (not shown).

The measurement of the slurry concentration using the slurry concentration measuring device D having the above-described structure is performed by the X-ray generator 2 and passing through the X-ray converging means 5 into the slurry supply pipe 1. Among the irradiated X-rays, transmitted X-rays transmitted through the slurry supply pipe 1 are detected by the transmitted X-ray detector 3, and a signal from the transmitted X-ray detector 3 is converted into a slurry concentration by the converter. This is done by conversion.

Here, the attachment of the slurry concentration measuring device D to the slurry supply pipe 1 is desirably performed on a straight portion of the slurry supply pipe 1 with little stagnation or accumulation.

FIG. 3 is a graph showing the data obtained by detecting the transmitted X-ray count value of the 30% stock solution of the CMP slurry used in the CMP process of the semiconductor wafer and the solution obtained by appropriately diluting the stock solution with an X-ray detector. Things. In the figure, the horizontal axis represents the weight% of the slurry concentration for CMP,
The vertical axis indicates the number of transmitted X-rays detected by the X-ray detector.

As shown in FIG. 3, there is a correlation between the slurry concentration and the number of transmitted X-rays.

In the slurry concentration measuring apparatus D having the above configuration, the transmitted X-ray transmitted through the slurry supply pipe 1 is detected by the transmitted X-ray detector 3, but instead of such a configuration, Even when a configuration is adopted in which X-rays emitted from the X-ray generator 2 are used to detect fluorescent X-rays generated in the slurry supply pipe 1 by a fluorescent X-ray detector (not shown). Good. At this time, the position where the fluorescent X-ray detector is provided may be appropriately set.

In the slurry concentration measuring apparatus D having the above configuration, since the slurry supply pipe 1 itself can be installed without any modification, stagnation or accumulation inside the slurry supply pipe 1 does not occur with installation. It is possible to measure the concentration of the slurry with high accuracy and high reliability from the outside of the slurry supply pipe 1 for a long period of time, and it is also possible to perform automatic measurement.

The slurry supply pipe 1 generally used is made of a material that transmits X-rays, transmitted X-rays, and fluorescent X-rays. It is highly likely.

[0023]

As described above, according to the present invention having the above configuration, the slurry supply pipe itself can be installed without any modification, the measurement can be performed with high accuracy, and the automatic measurement can be performed. It is possible to provide a slurry concentration measuring device that performs the following.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a configuration of a slurry concentration measuring apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram schematically showing the configuration of the embodiment.

FIG. 3 is a graph showing data obtained by detecting a transmitted X-ray count value of a 30% stock solution of a CMP slurry used in a CMP process of a semiconductor wafer and a solution obtained by appropriately diluting the stock solution with an X-ray detector. is there.

[Explanation of symbols]

1. Slurry supply pipe, 2. X-ray generator, 3. X-ray transmission
Line detector, D: Slurry concentration measuring device.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiichiro Tomioka 18 Koichimae-Kawaramachi, Kichijo-in, Kyoto, Kyoto, Japan (72) Inventor Keiko Sakuma 2-Higashi-cho, Kichijoin-gu, Minami-ku, Kyoto, Kyoto HORIBA, Ltd. (72) Inventor Junyo Ishikawa 2 Higashi-cho, Kichijoin-gu, Minami-ku, Kyoto, Kyoto F-term, Ltd. F-term (reference) 2G001 AA01 BA04 BA11 CA01 DA02 KA01 LA20 MA02 SA02

Claims (2)

[Claims] 1. An X-ray generator and a transmitted X-ray detector provided at a position sandwiching a slurry supply pipe, and a converter for converting an X-ray signal into a slurry concentration, and are irradiated from the X-ray generator. Wherein the transmitted X-ray transmitted through the slurry supply pipe is detected by the transmitted X-ray detector, and an X-ray signal from the transmitted X-ray detector is converted into a slurry concentration by the converter. Concentration measuring device. 2. An X-ray generator provided to irradiate a slurry supply pipe with X-rays, a fluorescent X-ray detector, and a converter for converting an X-ray signal into a slurry concentration, Fluorescent X-rays emitted from the X-ray generator and generated in the slurry supply pipe are detected by the fluorescent X-ray detector, and an X-ray signal from the fluorescent X-ray detector is converted by the converter. A slurry concentration measuring device for converting into a slurry concentration.