JPH05323586A - Antireflection pellicle for wall surface of pellicle frame - Google Patents

Abstract

PURPOSE:To prevent the reflection of unnecessary light by mounting on the surface of a wall to be irradiated a foam so that a very fine foreign substance such as kneaded compounds does not appear to reduce light intensity with the bubble of the foam and the like. CONSTITUTION:Light is directly or indirectly incident upon a foam 3 mounted on the surface of the wall of a pellicle frame 2 to irradiate. The radiated light enters into the bubble of the foam 3 to make irregular reflection, and the irregularly reflected light is finally brought into the absorbed state to reach such a state as not to exert a bad influence upon externals. That is, the foam 3 absorbs light and does not reflect light by itself. Then, a pellicle 4 is applied on the reticle pattern surface of a reticle 1 for the prevention of sticking very fine foreign substances and however when a laser beam enters into the inner wall surface of the pellicle frame 2, it is irregularly reflected in the case of the foam 3 being not provided there. Therefore, the foam 3 is stuck by a bonding agent in a particular position to absorb light, thereby eliminating erronous detection.

Description

Detailed Description of the Invention

[0001]

[Field of Industrial Application] The performance of the exposure apparatus is deteriorated as stray light such as when the wall surface of the pellicle attached to the reticle is directly or indirectly irradiated with light. By using the reticle with a pellicle having the above structure for preventing the reflection of the light, a semiconductor is manufactured with high accuracy.

[0002]

2. Description of the Related Art The current pellicle frame is blackened for the purpose of antireflection, and is provided with an adhesive. However, since this is a direct metal surface treatment, it is not completely antireflection. Absent. In particular, when laser light or the like is directly applied to this frame, the light is diffusely reflected and becomes scattered light, and other portions are adversely affected by this light.

Therefore, by attaching a foam to the wall surface of this frame, it becomes possible to absorb light and prevent irregular reflection.

[0004]

In an in-line foreign matter inspection apparatus used as an accessory to a reduction projection exposure apparatus,
In order to detect foreign matter on the reticle glass surface and pellicle surface, a semiconductor laser is generally radiated obliquely to the inspection surface. Therefore, the glass side of the reticle is not a problem, but the pellicle side can be mounted on the pellicle side. The laser beam that has passed through the pellicle may irradiate the wall surface of the attached frame. The laser beam is reflected and becomes scattered light, and even if there is no foreign matter, it may be as if there was a foreign matter, and the in-line foreign matter inspection device may erroneously detect.Therefore, it is necessary to take anti-reflection measures. is there.

[0005]

[Means for Solving the Problem] As a measure against diffused reflection of a pellicle frame, a foam is attached to a wall surface irradiated with light so that fine foreign matter such as kneading does not come out, and the foam of the foam causes The strength is reduced until the device is unaffected. A conventional adhesive may be applied on top of this.

[0006]

The light incident on the foam mounted on the wall surface of the pellicle frame is directly or indirectly irradiated. The radiated light enters the foam bubbles, and the light diffusely reflected therein finally reaches a state where it is absorbed and does not adversely affect the outside.

In other words, the foam absorbs light, but does not reflect light itself.

[0008]

EXAMPLE FIG. 1 shows a concrete example of a foam attached to a pellicle frame.

On the reticle pattern surface of reticle 1,
A pellicle is attached to prevent the adhesion of minute foreign matter.
On the inner wall surface of the pellicle frame, from the direction as shown,
It is assumed that laser light enters at an angle of 0 °. Then, when the foam 3 is not present, the light is radiated to the wall surface of the pellicle frame 2 and the light is diffusely reflected, and only the light in a certain fixed direction is received.
Unnecessary light enters, causing false detection. Therefore, the foam 3 is attached to the illustrated position with an adhesive to absorb light and eliminate the erroneous detection as described above.

Further, not only in this place but also in other places, this foam is attached at a position where light reflection is desired to be eliminated, so that diffuse reflection can be prevented.

In this example, since the incident light is only in one direction,
It is affixed to only one wall surface that is affected by this, and the countermeasure is taken, but it goes without saying that it is affixed to the inside and outside of the four wall surfaces as necessary.

Originally, the in-line foreign matter inspection apparatus which has been a problem is an apparatus for inspecting the foreign matter on the pellicle film 4.
The focal point of the optical system is on the pellicle surface, but since light passes through the pellicle, it irradiates the chrome surface of the reticle and the wall surface of the pellicle frame, and is diffusely reflected.

[0013]

According to the present invention, it is possible to prevent unnecessary reflection of light from the wall surface of the pellicle frame,
It can be made very effective for a device utilizing light reflection such as an in-line foreign matter inspection device.

Further, since the foam as the antireflection material has various types and colors, it is possible to properly use the foam depending on the influence of the reflected light and the situation.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a reticle with a pellicle to which a foam is attached for antireflection.

[Explanation of symbols]

1 ... Reticle, 2 ... Pellicle frame, 3 ... Antireflection foam, 4 ... Pellicle film.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Nashiro 882 Ichimo, Katsuta-shi, Ibaraki Hitachi, Ltd., Measuring Instruments Division (72) Inventor Ryozo Akabane 882 Ichige, Katsuta, Ibaraki Hitachi, Ltd. Measurement Inside the equipment division

Claims (1)

[Claims] 1. A pellicle for preventing dust from adhering to a pattern surface of a reticle used as an exposure mask in semiconductor manufacturing, wherein an inner wall surface or an outer wall surface of a pellicle frame to which the pellicle film is attached is an antireflection material (for example, an IC. An antireflection pellicle for a wall surface of a pellicle frame, which has a polyethylene foam such as a mat) or an antireflection structure.