JPH073332B2 - Surface inspection device - Google Patents
Surface inspection deviceInfo
- Publication number
- JPH073332B2 JPH073332B2 JP1035499A JP3549989A JPH073332B2 JP H073332 B2 JPH073332 B2 JP H073332B2 JP 1035499 A JP1035499 A JP 1035499A JP 3549989 A JP3549989 A JP 3549989A JP H073332 B2 JPH073332 B2 JP H073332B2
- Authority
- JP
- Japan
- Prior art keywords
- light
- sample
- color
- surface inspection
- inspection apparatus
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
- Length Measuring Devices By Optical Means (AREA)
Description
【発明の詳細な説明】 発明の目的； （産業上の利用分野） この発明は、表面検査装置に関し、例えば光ディスク，
半導体ウエハー等の鏡面物体を試料の対象とした表面検
査装置に関する。The present invention relates to a surface inspection apparatus, for example, an optical disc,
The present invention relates to a surface inspection device for a sample of a mirror-finished object such as a semiconductor wafer.
（従来の技術） 従来より、例えば光ディスク，半導体ウエハー等の鏡面
物体の表面を検査する装置は種々実用化されている。(Prior Art) Conventionally, various devices for inspecting the surface of a mirror-like object such as an optical disk and a semiconductor wafer have been put into practical use.
第５図（Ａ）及び（Ｂ）は、表面検査装置を説明するた
めの原理図である。FIGS. 5A and 5B are principle diagrams for explaining the surface inspection apparatus.
同図（Ａ）は、試料表面にへこみが存在する場合であ
り、その形状を球面と仮定すると、このへこみは球面の
凹面鏡として振舞い、平行光線を照射した場合に反射光
線は焦点f1に集光される。また、同図（Ｂ）は試料表面
に突起が存在する場合であり、反射光線は凸面鏡の焦点
−f2からの発散光となる。尚、球面の場合、曲率半径ｒ
と焦点距離ｆの間には次の関係がある。In the same figure (A), there is a dent on the sample surface, and assuming that the shape is a sphere, this dent behaves as a concave mirror of a spherical surface, and when parallel rays are emitted, the reflected rays are focused at the focal point f1. To be done. Further, FIG. 6B shows the case where a protrusion is present on the surface of the sample, and the reflected light beam is divergent light from the focus −f2 of the convex mirror. In the case of a spherical surface, the radius of curvature r
And the focal length f have the following relationship.
ｆ＝r/2 第４図は、従来における代表的な表面検査装置を示す図
である。f = r / 2 FIG. 4 is a diagram showing a typical conventional surface inspection apparatus.
同図において、点光源からの光は、レンズ21で平行光線
となり試料３に照射される。試料３からの反射光はレン
ズ22を通過し、そのレンズ22の焦点f0に集光される。と
ころが、この焦点f0を通過する光線は、試料３の表面に
おける凹凸のない完全な平面からの反射光成分のみであ
り、この図に示すような凹面で反射した光成分は、焦点
f0よりも内側のfuで集光される。また、図示しないが凸
面を有する場合は、その凸面で反射した光成分は焦点f0
よりも外側で集光される。In the figure, light from the point light source is irradiated onto the sample 3 becomes parallel light by the lens 2 1. Light reflected from the sample 3 passes through the lens 2 2, is focused on the focal point f 0 of the lens 2 2. However, the light ray passing through the focal point f 0 is only the reflected light component from a perfect flat surface on the surface of the sample 3, and the light component reflected by the concave surface as shown in this figure is the focal point.
It is focused at f u inside f 0 . Further, although not shown, when it has a convex surface, the light component reflected by the convex surface has a focal point f 0.
It is focused on the outside.
そこで、このとき焦点fu付近に受光面14を設置すると、
試料３の表面が完全に平面であれば受光面での照度は均
一であるが、例えば図のように凹面を有する場合には、
受光面14での照度分布は同図（Ｂ）に示すようになる。
また、凸面を有する場合でも、受光面14の位置に応じて
照度分布は均一ではなくなる。Therefore, if the light-receiving surface 14 is installed near the focal point f u at this time,
If the surface of the sample 3 is completely flat, the illuminance on the light receiving surface is uniform, but if the surface has a concave surface as shown in the figure,
The illuminance distribution on the light receiving surface 14 is as shown in FIG.
Further, even if it has a convex surface, the illuminance distribution is not uniform depending on the position of the light receiving surface 14.
従って、このように従来においては、試料からの反射光
の明暗を観測することにより試料の凹凸を検査してい
た。Therefore, as described above, conventionally, the unevenness of the sample is inspected by observing the brightness of the reflected light from the sample.
（発明が解決しようとする課題） ところで、試料表面の凹凸は実際には球面ではなく複雑
な形状をしており、集光位置において完全な点にはなら
ずボケが生ずる。故に、上述したような明暗観測による
従来の表面検査装置では、検査試料が完全な表面に近づ
くに従って表面の凹凸による明暗比が小さくなり、その
観測が困難になるという問題点があった。(Problems to be Solved by the Invention) By the way, the unevenness on the surface of the sample is not a spherical surface but a complicated shape, and it does not become a perfect point at the focusing position, resulting in blurring. Therefore, in the conventional surface inspection apparatus based on the light / dark observation as described above, there is a problem that the light / dark ratio due to the unevenness of the surface becomes smaller as the inspection sample comes closer to the perfect surface, and the observation becomes difficult.
この発明は上述したような事情から成されたものであ
り、この発明の目的は、微細な凹凸を高精度に検出でき
る表面検査装置を提供することにある。The present invention has been made under the circumstances as described above, and an object of the present invention is to provide a surface inspection apparatus capable of detecting fine irregularities with high accuracy.
発明の構成； （課題を解決するための手段） この発明は、例えば光ディスク，半導体ウエハー等の鏡
面物体を試料の対象とした表面検査装置に関し、この発
明の上記目的は、２波以上の波長成分を含む光を発光す
る発光手段と、その発光手段からの光を集光して試料に
照射し、その試料からの反射光を集光する集光レンズ系
と、その集光された反射光をカラー投影する投影手段と
を備え、前記投影手段に投影された前記反射光について
前記波長成分による色彩の変化を観測することによって
達成される。(Structure of the Invention) (Means for Solving the Problems) The present invention relates to a surface inspection apparatus which targets a mirror surface object such as an optical disk or a semiconductor wafer as a sample, and the above object of the present invention is to provide two or more wavelength components. A light emitting means for emitting light, a light collecting means for collecting the light from the light emitting means and irradiating the sample, and collecting the reflected light from the sample, and the collected reflected light. This is achieved by observing a change in color due to the wavelength component of the reflected light projected on the projection means, the projection means performing color projection.
（作用） この発明にあっては、２波長以上の波長成分を含む光を
集光して試料に照射し、その試料からの反射光を集光し
てカラー投影し、その投影された反射光について各波長
成分の屈折率の差による色彩の変化を観測することによ
り、微細な凹凸を高精度に検出できる。(Operation) In the present invention, the light including the wavelength components of two or more wavelengths is condensed and irradiated to the sample, the reflected light from the sample is condensed and color projected, and the projected reflected light By observing the change in color due to the difference in the refractive index of each wavelength component, fine irregularities can be detected with high accuracy.
（実施例） 以下、図面に基づいてこの発明の実施例について詳細に
説明する。Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings.
第１図は、この発明の表面検査装置の一実施例を示す図
である。第２図は、この発明の原理を説明するための図
である。FIG. 1 is a diagram showing an embodiment of the surface inspection apparatus of the present invention. FIG. 2 is a diagram for explaining the principle of the present invention.
先ず、第２図に基づいてこの発明の基本となる原理を説
明すると、試料３の凹面に照射された白熱球からの平行
光線（図示せず）は、反射してレンズ２で集光される。
そのとき白熱球からの白色光のうち、屈折率の小さい赤
色光は焦点距離が長くなり（Ａ点）、屈折率の大きい青
色光は焦点距離が短くなる（Ｂ点）。従って、同図
（ｂ）に示すようにＢ点での像を観測すれば、中心部に
紫が現われてその外側に円形状に赤が現われる。尚、こ
のように白色光を用いた場合でも、色彩の変化として現
われるのは長波長側の赤と短波長側の紫だけである。First, the basic principle of the present invention will be described with reference to FIG. 2. The parallel rays (not shown) from the incandescent sphere irradiated on the concave surface of the sample 3 are reflected and condensed by the lens 2. .
At this time, of the white light from the incandescent bulb, red light having a small refractive index has a long focal length (point A), and blue light having a large refractive index has a short focal length (point B). Therefore, when the image at the point B is observed as shown in FIG. 9B, purple appears in the central portion and red appears in a circular shape outside the central portion. Even when white light is used in this way, only red on the long wavelength side and purple on the short wavelength side appear as changes in color.
ところで、人間の視覚は明暗に対しては倍以上の光度差
がないと識別が不可能とされているが、色彩の変化に対
しては非常に敏感である。このことから、上述した原理
に基づいてこの発明はより微細な凹凸を感度よく識別す
るために、従来の明暗の変化を観測する替わりに色彩の
変化を観測しようとするものである。By the way, human vision is indistinguishable unless there is a light intensity difference more than double for light and dark, but it is very sensitive to changes in color. Therefore, based on the above-described principle, the present invention intends to observe a change in color instead of observing a conventional change in brightness and darkness in order to identify finer unevenness with high sensitivity.
そこで、第１図の実施例に基づいて以下説明を行なう。
先ず、点光源としての白熱球１からの光は、レンズ２に
よりほぼ平行光線となり試料３に照射される。試料３か
らの反射光はレンズ２で集光される。このとき、同図に
示すように例えば試料３の表面にくぼみがあれば、この
凹面からの反射光はレンズ２の焦点よりも内側で集光さ
れる。従って、このとき図のＡ点の近傍にピントを合せ
たカラーのテレビカメラ４を配置することにより、この
くぼみを第２図に示したような色彩の変化として観測す
ることができる。Therefore, the following description will be given based on the embodiment of FIG.
First, the light from the incandescent sphere 1 as a point light source is converted into almost parallel rays by the lens 2 and is applied to the sample 3. The reflected light from the sample 3 is condensed by the lens 2. At this time, if there is a dent on the surface of the sample 3 as shown in the figure, the reflected light from this concave surface is condensed inside the focal point of the lens 2. Therefore, at this time, by disposing the focused television camera 4 in the vicinity of the point A in the figure, this depression can be observed as a change in color as shown in FIG.
尚、光源は白熱球に限られることはなく、最低２種類の
波長成分を含むものであればよい。従って、白熱球の替
わりに、例えば赤と緑の２色同時発光のLEDを使用する
ことも可能である。また第３図に、赤と緑の２つのLED5
1,LED52を用いて、ハーフミラー６で２つの波長の光を
合成するようにした装置の例を示した。The light source is not limited to the incandescent bulb, and may be any light source containing at least two types of wavelength components. Therefore, instead of the incandescent bulb, it is possible to use, for example, LEDs that simultaneously emit two colors of red and green. Also, in Fig. 3, two red and green LEDs 5
1, LED 5 2 was used to show examples of apparatus that synthesizes the light of the two wavelengths by the half mirror 6.
（発明の効果） 以上のようにこの発明の表面検査装置によれば、試料に
２波長以上の波長成分を含む光を照射し、その反射光を
集光レンズを通してカラー投影して前記波長成分による
色彩の変化を観測することにより、従来の明暗の変化の
観測では識別が不可能であった微細な凹凸面を高精度に
検出できるので、実用的には極めて有用である。(Effects of the Invention) As described above, according to the surface inspection apparatus of the present invention, the sample is irradiated with light containing wavelength components of two or more wavelengths, and the reflected light is color-projected through the condensing lens to produce the wavelength components. By observing the change in color, it is possible to detect with precision the minute uneven surface that could not be identified by the conventional observation of change in brightness and darkness, which is extremely useful in practice.
第１図はこの発明の表面検査装置の一実施例を示す図、
第２図はこの発明の原理を説明するための図、第３図は
他の実施例を示す図、第４図は従来の表面検査装置を示
す図、第５図（Ａ）及び（Ｂ）は表面検査装置を説明す
るための原理図である。 １…白熱球、２…レンズ、３…試料、４…テレビカメ
ラ、５…LED、６…ハーフミラー、14…受光面。FIG. 1 is a diagram showing an embodiment of the surface inspection apparatus of the present invention,
FIG. 2 is a diagram for explaining the principle of the present invention, FIG. 3 is a diagram showing another embodiment, FIG. 4 is a diagram showing a conventional surface inspection apparatus, and FIGS. 5 (A) and 5 (B). FIG. 3 is a principle diagram for explaining a surface inspection device. 1 ... Incandescent bulb, 2 ... Lens, 3 ... Sample, 4 ... Television camera, 5 ... LED, 6 ... Half mirror, 14 ... Light receiving surface.
Claims (2)
面に平行光線を照射してその反射光の部分的収束又は発
散によって生ずる明暗像を観測することにより表面状態
を検査する鏡面物体の表面検査装置において、２波長以
上の波長成分を含む光を発光する発光手段と、その発光
手段からの光を集光して試料に照射し、その試料からの
反射光を集光する集光レンズ系と、その集光された反射
光をカラー投影する投影手段とを備え、前記投影手段に
投影された前記明暗像に対し、前記集光レンズ系におけ
る各波長成分の屈折率の差による色彩の変化を観測する
ようにしたことを特徴とする表面検査装置。1. A mirror-like object for inspecting the surface condition by irradiating parallel light rays on the surface of a mirror-like object and observing a light-dark image produced by partial convergence or divergence of the reflected light. In a surface inspection apparatus, a light emitting unit that emits light containing a wavelength component of two or more wavelengths, and a condenser lens that collects the light from the light emitting unit and irradiates the sample, and collects the reflected light from the sample. A system and projection means for color-projecting the condensed reflected light, and for the bright and dark image projected on the projection means, a color of a color due to a difference in refractive index of each wavelength component in the condenser lens system is provided. A surface inspection device characterized by observing changes.
モニターから成る請求項１に記載の表面検査装置。2. The surface inspection apparatus according to claim 1, wherein the projection means comprises a color television camera and a monitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1035499A JPH073332B2 (en) | 1989-02-15 | 1989-02-15 | Surface inspection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1035499A JPH073332B2 (en) | 1989-02-15 | 1989-02-15 | Surface inspection device |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02213710A JPH02213710A (en) | 1990-08-24 |
| JPH073332B2 true JPH073332B2 (en) | 1995-01-18 |
Family
ID=12443444
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1035499A Expired - Fee Related JPH073332B2 (en) | 1989-02-15 | 1989-02-15 | Surface inspection device |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH073332B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP6531579B2 (en) * | 2015-09-10 | 2019-06-19 | 株式会社Sumco | Wafer inspection method and wafer inspection apparatus |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS60135918A (en) * | 1983-12-26 | 1985-07-19 | Casio Comput Co Ltd | Method and device for color reading |
-
1989
- 1989-02-15 JP JP1035499A patent/JPH073332B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02213710A (en) | 1990-08-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| LAPS | Cancellation because of no payment of annual fees |