JP2000019135A - Surface property inspection device for test body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface property inspection device for body to be tested, capable of detecting an abnormality of very small and very feeble uneven sur face property in a wide range easily and with high sensitivity, and capable of recording as surface information. SOLUTION: This surface property inspection device for body to be tested is equipped with a supersaturated gas generator 1 for spraying supersaturated gas 7 to a body to be tested 12 loaded on a moving stage 11 or held by some method and for producing a dew-condensed surface 13 on the surface of the body to be tested 12. The supersaturated gas generator 1 is a vessel 2 having such a characteristic that it has a blowing-in opening 4 of misty-liquid mixed gas 6 and a blowing-off opening 5 of the supersaturated gas 7 and that heaters 3A, 3B are installed near the blowing-off opening 5 therein. And, this surface property inspection device of the body to be tested also has such as characteristic that it is equipped with the moving state 11 and a camera 16 for picking up the an image of the surface of the body to be tested 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of inspecting the surface properties of a glass substrate for liquid crystal, a semiconductor wafer, etc., such as cleaning unevenness, contamination unevenness, and abrasion unevenness, on the basis of a dew state on the surface of the object. The present invention relates to a surface property inspection device.

[0002]

2. Description of the Related Art In a panel manufacturing process of a liquid crystal display, an abnormality in surface properties such as unevenness of cleaning, contamination, and abrasion on the surface of a glass substrate for liquid crystal has a great adverse effect on product performance and yield. Therefore, inspection for dirt and scratches is performed with an accuracy of several microns or less, and automatic defect inspection using an optical inspection device that observes light scattering of defective parts using laser light or UV light and image processing technology related thereto. This is handled by a device or by a visual sensory test. In addition, elemental analysis of the detected attached foreign matter and the like has become possible even for an extremely small area.

As an inspection method different from the above, there is a method of exposing to the surface of an object to be inspected. That is, when the test object is exposed to water vapor generated from a heated water surface in the container and is exposed to the surface of the test object, the surface condition of the test object (cleaning unevenness, contamination unevenness, scratch unevenness, etc.) causes the exposure. The contact angles and the sizes of the condensed liquids are different, and the appearance of the dew surface is different. There is known a method of inspecting unevenness (non-uniformity) of surface properties by observing the state. For example, "Surface Chemistry of Glass" (Shoji Dohashi, Nanedo, published in 1956), "Physical Chemistry of Glass Surface" (Shoji Dohashi, Kodansha, published in 1974), and Japanese Patent Application Laid-Open (A) Hei 2 -168150, JP-A-6-43127, JP-A-7
181468.

A conventional example will be described with reference to FIG. Container 31
And water is heated by the heater 33 until steam 35 is generated. Next, the test object 3 is placed above the water 32.
When the inspection surface of the inspection object 34 is exposed to the water vapor 35 generated by positioning the position 4, if the surface temperature of the inspection object 34 is lower than the dew point of the water vapor 35, the surface exposed to the water vapor 35 is exposed. The result occurs. The contact angle and size of the condensed liquid vary depending on the surface properties of the inspection object 34, and as a result, the appearance of the dew surface varies, resulting in uneven cleaning, contamination, and scratches on the surface of the inspection object 34. Abnormalities in surface properties such as unevenness can be detected with high sensitivity.

However, the particles of the liquid of the water vapor 35 generated by the above-mentioned method are large, from several μm to several tens of microns.
μm. When the water vapor droplets having such a large particle diameter are condensed and adhere to the surface of the inspection object 34, it is difficult to detect a surface abnormality finer than the particle diameter, and the detection sensitivity is low. Observation of the dew surface 36 formed on the surface of the inspection object 34 in this manner is performed by the illumination light 3 of the illumination device 37.
Irradiation 8 is performed by the observer 39. When the test object 34 is transparent, the test object 34 is observed from the back side as shown in FIG. 3, and when the test object 34 is opaque, the test object 34 is turned upside down and the dew surface 36 is observed. The observation result is sketched and recorded by the observer 39 based on the observation memory.

[0006]

According to the inspection method using the above-mentioned automatic defect inspection apparatus, the dimensional accuracy for detecting foreign matters, scratches and pinholes on a substrate or a wafer is quite good. It is difficult to cope with the detection of surface information in the case of surface contamination such as cleaning unevenness or organic contamination unevenness. On the other hand, in the inspection method by dew condensation of the conventional method,
Although such problems can be solved to some extent, the detection sensitivity is insufficient when the irregularities in the irregular surface properties are extremely small and extremely weak because the dew particles are too large or unstable. Is difficult. Furthermore, the recording of the abnormality of the surface property cannot be recorded in detail because it is performed by manual sketching. The present invention has been made in view of such circumstances, and it is possible to easily and highly sensitively detect a wide range of extremely minute and extremely weak irregular surface texture abnormalities, and record detailed surface information without relying on manual sketching. It is to provide a device.

[0007]

According to the present invention, a supersaturated gas is blown onto a test object placed on a moving stage (11) or held by some method to form a dew surface on the surface of the test object. A surface property inspection device for an object to be inspected provided with a supersaturated gas generator, wherein the supersaturated gas generator has an inlet for a mist-like liquid mixture gas and an outlet for a supersaturated gas, and the outlet A container (2) in which a heater is installed in the vicinity of the object, a moving stage, and a camera for imaging the surface of the object to be inspected. In the present invention, the term "supersaturated gas" refers to a gas that is supersaturated at the temperature of the test object.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail with reference to FIGS. The supersaturated gas generator 1 includes a heater 3A near a blowout port 5 of a container 2 having a blowout port 4 for mixed gas 6 and a blowout port 5 for supersaturated gas 7.
Is installed. The mixed gas 6 blown from the blowing port 4 is usually a gas obtained by atomizing pure water, and the particle size of the pure water is about several μm to several tens μm. This gas flows in the container 2, passes near a heater 3A using a halogen lamp heater or a sheath heater, and is heated at the time of the passage to become a mixed gas having a particle size of submicron or less.

The gas mixture blown out from the outlet 5 becomes a supersaturated gas 7 in a supersaturated state with respect to the surface temperature of the inspection object 12 such as a glass substrate. When the supersaturated gas 7 hits the surface of the test object 12, the dew point 13 is formed on the surface of the test object 12 because the supersaturated gas 7 is cooled to a temperature equal to or lower than the dew point.

On the other hand, the supersaturated gas 7 which has been blown
As it gets farther away, it mixes with the surrounding air and becomes supersaturated. As a result, the dew surface 13 does not form on the surface of the inspection object 12 as the distance from the outlet 5 increases. Therefore, if the moving stage 11 is stopped, the observer 16 observes the dew surface 13 generated only in the vicinity of the outlet 5 by the illumination light 15 of the illumination device 14. However, since it is necessary to inspect the entire surface of the inspection object 12,
The test object 12 is placed on the moving stage 11 and the outlet 5
The observation area or the image of the plane information is recorded by the observer 16 or the camera 16 while moving the generation area of the dew surface 13 by moving the exposure area 13 with respect to the position. By processing the image information captured by the camera 16, it is possible to emphasize and display the surface property abnormality of the inspection object 12.

FIG. 2 is a sectional view of a supersaturated gas generator 1 according to a modification of the embodiment. In the case of FIG. 1, since the outlet 5 is far from the heater 3A, the wall surface temperature of the outlet 5 may be equal to or lower than the dew point of the supersaturated gas 7, and in that case, the wall surface of the outlet 5 is also exposed. A surface is generated, which drops as water droplets on the surface of the test object 12 to hinder observation and causes a problem that the surface of the test object 12 is contaminated. This problem can be solved by the method of FIG. That is, in this case, the heater 3B is provided in close contact with the outside of the outlet 5 of the container 2, and no dew condensation surface is formed on the inner wall surface of the outlet 5 or the outer wall surface of the container 2. In this way, extremely minute and extremely weak irregularities in the surface properties (cleaning irregularities, contamination irregularities, scratches and irregularities) on the entire surface of the object to be inspected can be easily detected with high sensitivity, and the surface information can be manually sketched. It is possible to record in detail without depending.

[0012]

According to the present invention, a supersaturated gas is generated by spraying a supersaturated gas onto a test object placed on a moving stage or held in some way to form a dew surface on the surface of the test object. A device for inspecting the surface properties of an object to be inspected, comprising a container, wherein the supersaturated gas generator has a liquid mixture gas inlet and a supersaturated gas outlet, and a heater is installed near the outlet. The surface property inspection device for the object to be inspected is characterized in that the particle size of the liquid particles of the supersaturated gas can be reduced to submicron or less, and the ultra-fine and extremely weak There is an effect that irregularities in the surface properties of irregularities can be easily detected with high sensitivity. Furthermore, the provision of the moving stage and the camera for imaging the surface of the object to be inspected has the effect that the detected surface information of the surface properties can be recorded in detail without manual sketching.

[Brief description of the drawings]

FIG. 1 is a sectional view of a surface texture inspection apparatus according to an embodiment.

FIG. 2 is a partial sectional view of a modification of the embodiment.

FIG. 3 is a cross-sectional view of a conventional surface texture inspection device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Supersaturated gas generator 2 Container 3A heater 3B heater 4 Inlet 5 Outlet 6 Liquid mixture 7 Supersaturated gas 11 Moving stage 12 Inspection object 13 Dew surface 14 Lighting equipment 15 Illumination light 16 Observer or camera 31 Container 32 Water 33 Heater 34 Inspection object 35 Water vapor 36 Dew surface 37 Lighting fixture 38 Illumination light 39 Observer

Claims (2)

[Claims] A supersaturated gas (7) is sprayed on a test object (12) mounted on a moving stage (11) or held in some way, and the surface of the test object is exposed to a dew surface (1).
3) A device for inspecting the surface properties of an object to be inspected, comprising a supersaturated gas generator (1) for generating 3), wherein the supersaturated gas generator (1) is an inlet (4) for a mist-like liquid mixture gas (6). ) And a supersaturated gas (7) outlet (5) comprising a heater (3A, 3B) near the supersaturated gas (7) outlet (5). A surface property inspection device for an object to be inspected, which is an installed container (2). 2. A moving stage (11) and an object to be inspected (1).
2. The apparatus according to claim 1, further comprising a camera (16) for imaging the surface of (2).