JPH10160912A - Production of light scattering plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for producing a light scattering plate having a desired light scattering characteristic. SOLUTION: This light scattering plate has at least a substrate 1 and plural scattering bodies 3 arranged in the form of patterns on this substrate 1 and scatters incident light. This process for production consists in forming the material of the substrate 1 of a reaction initiation material which is the catalyst for an electroless plating reaction or providing the surface of the substrate with a reaction initiation layer 1b and further forming non-reaction initiation layers 4 which have plural apertures 1a and are not the catalysts for the electroless plating reaction on its surface. Plating films 3' are respectively grown by an electroless plating method on the respective apertures 1a, by which the scattering bodies 3 described above are formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a light-scattering plate for scattering incident light.
The present invention relates to a method for manufacturing a light scattering plate suitable as a light scattering plate for calibration in an inspection device for detecting minute dust from the intensity of scattered light when a sample is irradiated with light.

[0002]

2. Description of the Related Art A dust inspection apparatus for inspecting the size and the number of dusts present on a substrate member such as a photomask or a silicon wafer used in a manufacturing process of a semiconductor element or the like is a scattered light generated when a sample is irradiated with light. This is an inspection device that detects minute dust from the intensity of light, and a light scattering plate for calibration is used to adjust the sensitivity and the like.

The light scattering plate is, for example, one in which a scattering member is provided on a substrate. The scattering member preferably exhibits the same scattering characteristics as the dust to be inspected. For example, it is preferable that a plurality of fine particles (scatterers) having the same size as the dust and having relatively isotropic scattering characteristics are arranged on the substrate. As shown in FIG. 3, a conventional light-scattering plate has fine particles 12 (for example, scatterers of true spherical beads made of polystyrene or the like) adhered on a substrate 11 of glass or the like as shown in FIG. Has been used.

Since the spherical beads (scatterers) 12 have a spherical shape, incident light is isotropically scattered. The conventional light scattering plate has been manufactured by spraying true spherical beads (scatterers) 12 onto the substrate 11 by spraying or the like. As a conventional method of manufacturing a light scattering plate, in addition to the method of spraying true spherical beads (scattering body) onto a substrate, there is a method of forming a scattering body on a substrate by etching to form a light scattering plate. is there. FIG. 4 shows an example of the manufacturing process.

[0005] A thin film layer 13 'is formed on a substrate 11, and a resist pattern layer 14 is formed on the surface thereof.
a). Further, a part of the thin film layer 13 'is removed by an etching method (FIG. 3B).
Is obtained, a light scattering plate in which the scatterers 13 are arranged on the substrate 11 is obtained. By the way, the light scattering plate for calibration is required to have a predetermined scattering characteristic, and when manufacturing a plurality of light scattering plates, all of them have the same scattering characteristic, or have substantially the same scattering characteristics. Is required.

[0006] In order to satisfy such requirements, it is necessary to make the shape, size, and distribution density of the scatterers provided on the substrate equal or substantially equal. Further, the distribution of the light scattering characteristics in the substrate surface must be uniform or have a desired distribution.

[0007]

However, since the light scattering plate using the spherical beads sprays the spherical beads, which are the scatterers, with a spray, the amount of the spherical beads adhered to the substrate per unit area. Was difficult to control. That is, the number (total number) of true spherical beads or the number per unit area (density) differs from a desired value due to the difficulty in controlling the amount of adhesion, and the light scattering characteristics often vary. There was a problem.

In addition, since it is difficult to control the distribution of the amount of the adhered particles by spraying, the number of fine particles per unit area differs at each point on the substrate even if the distribution is to be uniform. And it is difficult to obtain a desired distribution by spraying. Next, the scatterer preferably has a desired shape, for example,
When isotropic light scattering characteristics are required, the shape of the scatterer needs to be spherical.

However, in the case of the light scattering plate manufactured by the etching process, the cross-sectional shape of the scatterer is rectangular,
In many cases, the shape becomes triangular, trapezoidal, etc., and it is particularly difficult to work into a spherical shape, and furthermore, it is difficult to control the shape of the scatterer, so that the light scattering characteristics vary. Had a point. As described above, the light scattering plate manufactured by the conventional manufacturing method often has a light scattering characteristic different from a desired value, and the dust inspection apparatus calibrated using the light scattering plate has a measurement sensitivity. Has a problem that the variation in the size is large.

The present invention has been made in view of the above problems, and has as its object to provide a method for manufacturing a light scattering plate having desired light scattering characteristics.

[0011]

Therefore, the present invention firstly provides a light scattering device which comprises at least a substrate and a plurality of scatterers arranged in a pattern on the substrate, and scatters incident light. In the method of manufacturing a board, the material of the substrate may be a reaction starting material serving as a catalyst for an electroless plating reaction, or a reaction starting material layer may be provided on the surface of the substrate, and the surface may have a plurality of openings. A non-reaction starting material layer that does not become a catalyst for the electroless plating reaction is formed in correspondence with the pattern, and the scatterer is formed by growing a plating film in each opening by an electroless plating method. To provide a light scattering plate manufacturing method (Claim 1).

[0012] The present invention also provides a second method, wherein "the material of the plating film is Ag, Au, Co, Cu, Fe, Ir, Ni, O
s, Pd, Pt, Rh, or Ru; and a manufacturing method according to claim 1 (claim 2). Further, the present invention is characterized in that the third aspect is that “a spherical, roughly spherical, hemispherical or roughly hemispherical scatterer is formed in the opening by making the shape of the opening circular or roughly circular. The manufacturing method according to claim 1 or 2 (claim 3) "is provided.

Further, the present invention fourthly provides "a manufacturing method according to claim 3 (claim 4), wherein the size of the opening is smaller than the size of the scatterer." Further, the present invention fifthly provides that "the non-reaction starting material layer is formed of one or more layers, and at least one layer is formed of a resist material or a material containing silicon oxide as a main component. To (4) (Claim 5). "

The present invention is also directed to a sixth aspect of the present invention in which "the reaction starting material layer is formed of one or more layers, or the substrate is made of a reaction starting material, and at least Pd, Co, Fe, Ir, Ni, Os, Pt, R
h or Ru is used.
The manufacturing method (claim 6) described above "is provided. Further, the present invention seventhly provides a feature that `` the size of the scatterer is controlled by at least one of the size of the opening, the amount of plating current, the plating solution immersion time, and the plating solution composition. The manufacturing method according to claims 1 to 6 (claim 7) "is provided.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention relates to a method for producing a light-scattering plate comprising at least a substrate and a plurality of scatterers arranged in a pattern on the substrate and scattering incident light. According to the present invention, the material of the substrate is used as a reaction starting material serving as a catalyst for the electroless plating reaction, or a reaction starting material layer is provided on the surface of the substrate, and the surface thereof has a plurality of openings and the electroless plating reaction is performed. The non-reaction starting material layer which does not become a catalyst is formed corresponding to the pattern, and a plating film is grown in each opening by an electroless plating method to form the scatterer.

That is, according to the method of manufacturing the light scattering plate of the present invention, the plurality of openings are formed in a desired pattern, and the scatterers are formed in each of the openings by electroless plating. A desired number, distribution, size, and shape can be provided on the substrate, and as a result, a light scattering plate having desired light scattering characteristics can be manufactured (claim 1).

The substrate according to the present invention can easily grow a plating film by an electroless plating method as long as at least the surface thereof is made of the above-mentioned reaction initiating substance. At this time, the entire substrate may be composed of a reaction initiating substance, or a reaction initiating substance layer may be formed on the surface of the substrate. FIG. 1 shows some steps of a method (one example) of manufacturing a light scattering plate according to the present invention. In FIG. 1, a part of the light scattering plate is enlarged and its cross section is shown.

First, a non-reaction-initiating substance layer 4 is formed in a pattern on the substrate 1 (at least on the reaction-initiating substance layer 1b) whose surface is at least made of a reaction-initiating substance (FIG. 1A). Further, a plating film 3 'is grown on the portion 1a (opening) where the reaction starting material layer 1b is exposed by the electroless plating method (FIG. 1B) to form the scatterer 3 (FIG. 1C). ). As described above, the scatterer according to the present invention is formed by the electroless plating method. In order to control the formation (size and shape) of the scatterer by the electroless plating method with good controllability, the material of the plating film is made of Ag. , Au, Co, Cu, Fe, Ir, Ni, Os,
Pd, Pt, Rh or Ru is preferable (claim 2).

In the scatterer according to the present invention, the shape of the opening is circular or approximately circular so that light can be scattered isotropically. It is preferable to form a scatterer of a shape or a substantially hemisphere (claim 3). The scatterer according to the present invention is formed in each opening by an electroless plating method. At this time, in each opening, the thickness of the plating film 3 ′ is non-uniform as shown in FIG. After growing until the thickness becomes equal to the thickness of the reaction-initiating substance layer 4, it is further grown isotropically as shown in FIG. Can be easily formed.

At this time, the scatterer 3 is composed of the non-reaction starting material layer 4
It is preferable that the size of the opening 1 a be smaller than the desired size of the scatterer 3. That is, it is preferable that the size of the opening is smaller than the size of the scatterer so that a spherical, roughly spherical, hemispherical or roughly hemispherical scatterer is easily formed in each opening (claim 4). .

In the present invention, it is preferable that the non-reaction starting material layer is formed of one or more layers, and at least one layer is formed of a resist material or a material containing silicon oxide as a main component. The non-reaction-initiating substance layer according to the present invention may be a single layer, or may be composed of a plurality of layers so as to facilitate the pattern formation of the openings.

It is preferable that at least one of the layers constituting the non-reaction-initiating substance layer is formed of a resist material because an opening pattern can be easily formed by a lithography process. Alternatively, it is preferable that at least one of the layers constituting the non-reaction starting material layer is formed of a material containing silicon oxide as a main component, because an opening pattern can be easily formed by an etching process or the like (claim 5).

According to the fifth aspect of the present invention, the position, size and shape of the opening can be easily controlled, and the scatterers are formed only in the openings.
The distribution (position and density), size and shape can be easily controlled. In the present invention, the reaction starting material layer is formed of one or a plurality of layers, or the substrate is formed of a reaction starting material, and at least Pd, Co, Fe, Ir, Ni, Os, Pt, It is preferable to use Rh or Ru (claim 6).

The reaction-initiating substance layer according to the present invention may be a single layer, or may be composed of a plurality of layers including a layer for improving the adhesion to the substrate. Further, as a reaction starting material, for example, Pd, Co, Fe, Ir, Ni, O
When s, Pt, Rh, or Ru is used, the plating film 3 ′
Is preferable because it grows easily.

According to the present invention, the size of the scatterer can be easily controlled. For example, the size (or area) of the opening, the amount of plating current, the plating solution immersion time,
By controlling at least one of the plating solution compositions, a scatterer having a desired size can be obtained (claim 7). In addition, the size of the formed scatterer largely depends on the immersion time during plating (plating solution immersion time) or the plating solution composition.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to the following examples.

[0027]

Embodiment 1 FIG. 1 shows some steps of a method for manufacturing a light scattering plate according to this embodiment. In FIG. 1, a part of the light scattering plate is enlarged and its cross section is shown. First, a thin film layer of Pt was formed as a reaction starting material layer 1b serving as a catalyst for an electroless plating reaction on a substrate 1 made of quartz glass having a size of 5 inches by a sputtering method. Furthermore, P
After applying a resist on the surface of the thin film layer, the resist was processed into a pattern by an electron beam drawing process to form a resist pattern 4 (FIG. 1A).

At this time, the resist pattern 4 has a diameter of 0.2
It was formed so that a plurality of circular openings of μm or more were arranged.
The resist pattern 4 is a non-reaction starting material layer that does not act as a catalyst for the electroless plating reaction. Next, using the resist pattern 4 as a stencil mask, a Ni plating film 3 ′ is formed in each opening 1a of the resist pattern 4 by an electroless plating method.
Was grown (FIG. 1 (b)). As a result, a roughly spherical scatterer 3 having a diameter of 0.5 μm or more was formed in a desired distribution pattern according to the pattern of the aperture 1a (FIG. 1 (c)).

At this time, the size of the scatterer 3 depends on the plating area (the area of the opening), the plating current, the plating solution immersion time,
Alternatively, the error could be suppressed to 0.05 μm or less by controlling the composition of the plating solution. As a result, a scatterer 3 having a desired shape (generally spherical or approximately hemispherical) and size could be obtained. Incidentally, the resist pattern 4 used as the stencil mask may be peeled off if necessary. The plating solution used for the electroless plating is an aqueous solution of 30 g / l of nickel chloride, 10 g / l of sodium hypophosphite, and 10 g / l of sodium citrate. The bath temperature was 90 ° C.

When a plurality of light-scattering plates were manufactured through the above steps and their light-scattering characteristics were examined, they all exhibited the same light-scattering characteristics, and the characteristic values were the desired light-scattering characteristics. When the sensitivity of the dust inspection apparatus was calibrated using the light scattering plate, the sensitivity could be adjusted to a desired value.

[0031]

Embodiment 2 FIG. 2 shows some steps of a method for manufacturing a light scattering plate according to this embodiment. In FIG. 2, a part of the light scattering plate is enlarged and a cross section is shown. First, a thin film layer of Pd was formed on a substrate 1 made of quartz glass having a size of 5 inches as a reaction starting material layer 1b serving as a catalyst of an electroless plating reaction by a sputtering method (FIG. 2).
(A)).

On the surface of the Pd thin film layer, a silicon oxide thin film layer 2 'is formed by a sputtering method as a non-reaction starting material layer 2 which does not act as a catalyst for the electroless plating reaction, and a resist is formed on the surface of the silicon oxide thin film layer 2'. Then, the resist was processed into a pattern by an electron beam drawing process to form a resist pattern 4 (FIG. 2B). At this time, the resist pattern 4 was formed such that a plurality of circular openings having a diameter of 0.2 μm or more were arranged. Next, resist pattern 4
By a reactive ion etching method.
To form a pattern of the opening 1a (see FIG. 2).
(C)). Thereafter, the resist pattern 4 may be peeled off if necessary, or may be left as it is.

Further, as a result of growing a Ni plating film in each opening 1a of the silicon oxide thin film layer 2 by electroless plating, a roughly spherical scatterer 3 having a diameter of 0.5 μm or more is formed according to the pattern of the opening 1a. , In a desired distribution pattern. At this time, the size of the scatterer 3 could be suppressed to an error of 0.05 μm or less by controlling the plating area (the area of the opening), the plating current, the plating solution immersion time, or the plating solution composition. As a result, a scatterer 3 having a desired shape (a shape having a part of a sphere or a sphere) and a size could be obtained.

The silicon oxide thin film layer 2 used as a stencil mask may be peeled off as required. Also,
The plating solution used for the electroless plating was nickel chloride 3
It was an aqueous solution of 0 g / l, sodium hypophosphite 10 g / l, and sodium citrate 10 g / l. The electroless plating conditions were a plating bath pH of 4 to 6 and a bath temperature of 90 ° C. When a plurality of light-scattering plates were manufactured through the above steps and the light-scattering characteristics thereof were examined, they all exhibited the same light-scattering characteristics, and the characteristic values were the desired light-scattering characteristics. When the sensitivity of the dust inspection apparatus was calibrated using the light scattering plate, the sensitivity could be adjusted to a desired value.

[0035]

As described above, according to the present invention, it is possible to provide a desired number, distribution, size, and shape of scatterers on a substrate, and as a result, the scatterers have desired light scattering characteristics. The light scattering plate can be manufactured with a high yield. Further, when the sensitivity of the dust inspection device is calibrated using the light scattering plate manufactured by the manufacturing method of the present invention, the sensitivity of the device can be calibrated to a desired sensitivity.

According to the present invention, a light scattering plate having a spherical, approximately spherical, hemispherical or approximately hemispherical scatterer can be easily produced. Further, since the size of the scatterer can be easily controlled, a light scattering plate having desired scattering characteristics can be manufactured with a high yield. In addition, by using the light scattering plate manufactured according to the present invention, it is possible to use the light scattering plate as a sample for calibrating the photomultiplier sensitivity of a dust inspection device, and it is possible to minimize variations in photomal sensitivity between devices. It is.

The light scattering plate manufactured according to the present invention is:
Compared to the conventional light scattering plate using spherical beads, it is extremely unlikely that the scatterer will fall or move due to the handling of the light scattering plate. Can be used as well.

[Brief description of the drawings]

FIG. 1 is a process chart showing some steps of a method (one example) of manufacturing a light scattering plate according to Example 1.

FIG. 2 is a process diagram illustrating some steps of a method (an example) of manufacturing a light scattering plate according to Example 2.

FIG. 3 is a side view showing a conventional light scattering plate manufactured by spraying true spherical beads (scatterers) on a substrate.

FIG. 4 is a process chart showing steps (part) of a method of forming a scatterer on a substrate by etching to form a light scattering plate.

[Description of Signs of Main Parts]

 DESCRIPTION OF SYMBOLS 1 ... Substrate 1a ... Opening 1b ... Reaction initiation material layer 2 ... Patterned non-reaction initiation material layer 2 '... Non-reaction initiation material layer 3 ... Scattering body (electroless 3 ′ ·· Plating film 4 ··· Patterned resist layer 11 ··· Substrate 12 ·· Spherical beads 13 ··· Scatterer (formed by etching) 13 ′ ··· Thin film layer 14 ... patterned resist layer

Continued on the front page (72) Inventor Tetsuya Oshino Nikon Corporation, 2-3-2 Marunouchi, Chiyoda-ku, Tokyo

Claims (7)

[Claims] 1. A method for manufacturing a light-scattering plate that includes at least a substrate and a plurality of scatterers arranged in a pattern on the substrate, and that scatters incident light. A non-reaction starting material which is used as a reaction starting material serving as a catalyst for an electroplating reaction, or a reaction starting material layer is provided on the surface of the substrate and further has a plurality of openings on the surface thereof and does not serve as a catalyst for the electroless plating reaction. A method for manufacturing a light-scattering plate, comprising: forming a layer corresponding to the pattern; and forming a scatterer by growing a plating film in each opening by an electroless plating method. 2. The material of the plating film is made of Ag, Au, C
o, Cu, Fe, Ir, Ni, Os, Pd, Pt, R
The method according to claim 1, wherein h or Ru is used. 3. A scatterer having a spherical shape, a substantially spherical shape, a hemispherical shape, or a substantially hemispherical shape is formed in the opening by making the shape of the opening circular or substantially circular. 2. The production method according to 2. 4. The method according to claim 3, wherein the size of the opening is smaller than the size of the scatterer. 5. The method according to claim 1, wherein the non-reaction starting material layer is formed of one or more layers, and at least one layer is formed of a resist material or a material containing silicon oxide as a main component. Production method. 6. The reaction-initiating substance layer is formed of one or more layers, or the substrate is composed of a reaction-initiating substance, and at least Pd, Co, and F are used as the reaction-initiating substance.
The method according to claim 1, wherein e, Ir, Ni, Os, Pt, Rh, or Ru is used. 7. The method according to claim 1, wherein the size of the scatterer is controlled by at least one of the size of the opening, the amount of plating current, the immersion time of the plating solution, and the composition of the plating solution. 7. The method according to any one of claims 1 to 6.