JP2886408B2 - Double-sided pattern forming method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a double-sided pattern suitable for forming a hologram or the like. More specifically, the present invention relates to a method for forming a predetermined pattern on the front surface and the back surface of a single substrate, with the pattern positions corresponding between the front surface and the back surface.

[0002]

2. Description of the Related Art Conventionally, when a substrate having a pattern on both surfaces is formed, a predetermined pattern is formed on one surface (front surface) of two glass wafer substrates, and the back surface of each glass wafer substrate is bonded to each other. It was a single substrate.

For example, as shown in FIG. 5A, a resist 107 is applied to the surface 108A of a glass wafer substrate 108, and as shown in FIG. 5B, the resist 107 is exposed to ultraviolet rays 109 through a photomask 101A. I do. Here, the photomask 101A is, as shown in FIG.
A plurality of unit patterns 102A are provided at a predetermined pitch on one surface (in the area 103A) of a substantially rectangular glass plate.
The alignment marks 104A and 104A 'in the shape of a letter are provided symmetrically in the figure. As shown in FIG. 5 (c), the exposed portion of the resist 107 is removed by developing, and as shown in FIG. 5 (d), the pattern 107 is etched on the surface 108A of the glass wafer substrate 108.
2A and alignment marks 124A, 124A '. Thereafter, as shown in FIG.
7 is removed by ashing. On the other hand, a resist 157 is applied to the surface 158A of the glass wafer substrate 158 as shown in FIG.
57 is exposed to ultraviolet light 159 through the photomask 101B. Here, as shown in FIG. 6B, the photomask 101B has one surface (a region 103B) of a substantially rectangular glass plate.
(Inner) are provided with a plurality of unit patterns 102B at a predetermined pitch, and alignment marks 104B, 10
4B 'is provided symmetrically in the figure.
As shown in FIG. 5H, the exposed portion of the resist 157 is removed by developing, and as shown in FIG.
And the pattern 152A and the alignment marks 154B, 1
54B '. Thereafter, the resist 107 is removed by ashing, as shown in FIG. next,
As shown in FIG. 7 (k), the glass wafer substrate 108 is turned upside down and an ultraviolet curable resin 115 is used as an adhesive on the back surface 108B.
Is applied, and a glass wafer substrate 158 is laid on top of this as shown in FIG. By moving the glass wafer substrates 108 and 158 in the horizontal direction by the alignment jigs 116 and 116 ', the alignment marks 154B' and 124A and the alignment marks 154B and 124A respectively move up and down as shown in FIG. It is adjusted so as to overlap, and then, ultraviolet rays 117 are irradiated.
Thereby, the resin 115 is cured and the glass wafer substrates 108 and 158 are completely bonded (the process is completed).

[0004]

However, in the above-mentioned conventional forming method, since the glass wafer substrates 108 and 158 are bonded to each other, there is a problem that the operation is extremely troublesome. Further, at the time of bonding, air bubbles may enter between the glass wafer substrates 108 and 158, resulting in a defective product. Further, alignment jigs 116, 116 '
After the alignment is performed by the method described above, the glass wafer substrates 108 and 158
May be displaced from each other, resulting in a defective product. As described above, conventionally, there has been a problem that the number of steps is increased due to the step of bonding the glass wafer substrates 108 and 158, defects are caused, and the yield is reduced.

Therefore, an object of the present invention is to omit the step of bonding a glass wafer substrate and to make a predetermined pattern correspond to the front and back surfaces of one substrate and to correspond the pattern position between the front and back surfaces. It is an object of the present invention to provide a method for forming a double-sided pattern that can be formed by using the above method.

[0006]

In order to achieve the above object, a double-sided pattern forming method of the present invention has a predetermined pattern on one side of a glass plate and a predetermined alignment mark at two places on the one side. Using the first and second photomasks, the patterns of the first and second photomasks are made to correspond to the front and back surfaces of one transparent substrate and the pattern positions between the front and back surfaces. A method of forming a double-sided pattern by transferring, wherein a first resist is applied to the surface of the transparent substrate, the first resist is exposed through the first photomask, and subsequently developed. Patterning the first resist and performing etching using the first resist as a mask to form a pattern and an alignment mark on the surface of the transparent substrate on the transparent substrate; Transferring and forming a second resist on the back surface of the transparent substrate, and then mounting the transparent substrate on the stage of a predetermined alignment device with the back surface side up, and the transparent substrate The second photomask is disposed in parallel on the substrate, and the second photomask is placed in a state where the focus of the objective lens of the microscope of the alignment apparatus is adjusted to the height of the pattern surface of the second photomask. Moving the two photomasks in a horizontal plane to align the two alignment marks of the second photomask with reference marks provided in the field of view of the microscope; and setting the focal point of the objective lens of the microscope to the transparent position. The stage is moved in a horizontal plane in this state according to the height of the surface of the substrate, and the two alignment marks transferred to the surface of the transparent substrate are aligned with the field of view of the microscope. A step of aligning each of the reference marks provided therein, and a step of exposing the second resist through the second photomask, followed by developing to pattern the second resist. Etching is performed using the second resist as a mask, and the second resist is masked on the back surface of the transparent substrate.
In which the pattern of the photomask is transferred and formed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The double-sided pattern forming method of the present invention will be described below in detail with reference to embodiments.

A first photomask 1A shown in FIG.
And the second photomask 1B shown in FIG. The first photomask 1A is provided with a plurality of unit patterns 2A at a predetermined pitch on one surface (within the area 3A) of a substantially rectangular glass plate, and has a substantially L-shaped alignment mark 4A, 4A 'and a linear Alignment mark 5A, 5
A 'is provided symmetrically in the figure. On the other hand, the first photomask 1B is provided with a plurality of unit patterns 2B at a predetermined pitch on one surface (in the area 3B) of a substantially rectangular glass plate, and has a substantially L-shaped alignment mark 4B,
4B 'is provided symmetrically in the figure.
The alignment marks 4B, 4B 'are rectangular transparent areas 6
B, 6B '.

The patterns of the first and second photomasks 1A and 1B are applied to the front surface 8A and the back surface 8B of a single transparent substrate (for example, a glass plate) 8 shown in FIG. Formed.

First, as shown in FIG. 1A, a first resist 7 is applied to a surface 8A of a transparent substrate 8. Figure (b)
As shown in FIG. 2, the transparent substrate 8 is placed on a stage 10 of a predetermined alignment device, and the first photomask 1A
To expose the first resist 7 (light is indicated by an arrow 9). Subsequently, as shown in FIG.
Is patterned.

Next, as shown in FIG. 1D, etching is performed using the first resist 7 as a mask, and the pattern 8 of the first photomask 1A is formed on the surface 8A of the transparent substrate 8.
A is transferred to the alignment marks 4A and 4A '. Here, the transferred pattern is represented by 22A, and the transferred alignment marks are represented by 24A and 24A '. After this,
As shown in FIG. 4E, ashing is performed to remove the resist 7.
Is removed.

Next, as shown in FIG. 1F, a second resist 17 is applied to the back surface 8B of the transparent substrate 8. As shown in FIG. 1G, the transparent substrate 8 is placed on the stage 10 of the alignment apparatus with the back side facing up, and the second photomask 1B is arranged on the transparent substrate 8 in parallel.

Here, the alignment apparatus shown in FIG.
As shown in (h), a pair of left and right objective lenses 11, 11 'is provided. Also, as shown in FIG. 1 (i), the field of view of the microscope of the above alignment apparatus (in this example, the left half corresponds to the objective lens 11 and the right half corresponds to the objective lens 11 ′) 12 Scope line 13 is provided. Among the scope lines 13, the vertical lines 14, 14 'and the horizontal line 15 are selected as reference lines. A vertical line 14 in the left half of the field of view 12
And the horizontal line 15 constitute one fiducial mark, and the intersection of the vertical line 14 'and the horizontal line 15 in the right half of the field of view 12 constitutes another fiducial mark. .

Next, as shown in FIG. 1 (j), the focal points of the objective lenses 11 and 11 'are adjusted to the height of the pattern surface of the second photomask 1B. At this time, usually,
As shown in the figure, the two alignment marks 4B and 4B 'of the second photomask 1B are aligned with the reference lines 14, 15;
4 'and 15', respectively. Then, the second photomask 1B is moved in a horizontal plane,
As shown in FIG. 11 (l), the L-shaped sides of the alignment marks 4B, 4B 'are aligned with the reference lines 14, 15; 14', 15, respectively. When the positions are aligned, the movement of the second photomask 1B in the horizontal plane with respect to the objective lenses 11, 11 'is stopped.

Next, as shown in FIG. 1 (m), the focal points of the objective lenses 11 and 11 'of the microscope are adjusted to the height of the surface 8A of the transparent substrate 8. At this time, usually
As shown in (n), the alignment marks 24A, 24A 'transferred to the front surface 8A in the process correspond to the reference lines 14, 1'.
5; 14, 15 '. Therefore, the stage 10 is moved in a horizontal plane to
As shown in (o), the alignment marks 24A, 24
Each side of the L-shape of A 'is defined as a reference line 14, 15; 14, 15'
Align with each other. When the positions are matched, the movement of the stage 10 in the horizontal plane with respect to the objective lenses 11, 11 'is stopped.

Next, as shown in FIG. 3 (p), the second resist 17 is exposed through the second photomask 1B.
(Light is represented by arrow 19). Subsequently, as shown in FIG. 3 (q), development is performed to pattern the second resist 17.

Next, as shown in FIG. 1 (r), etching is performed using the second resist 17 as a mask to transfer the pattern 2B of the second photomask 1B to the back surface 8A of the transparent substrate 8. Here, the transferred pattern is
B (note that the transferred patterns of the alignment marks 4B and 4B 'are omitted). After this, the same figure (s)
As shown in FIG. 7, the resist 17 is removed by ashing.

In this manner, the first and second photomask patterns 22A and 22B can be transferred and formed on the front surface 8A and the back surface 8B of one transparent substrate 8 in correspondence with the pattern positions. it can.

In this double-sided pattern forming method, a glass wafer substrate is not bonded, but a pattern is formed on the front and back surfaces of a single substrate. Can be. Further, since the bonding is not performed, there is no possibility that air bubbles enter between the glass wafer substrates or the glass wafer substrate is displaced, resulting in defective products. Therefore, the number of steps can be reduced and the yield can be increased.

[0020]

As is clear from the above, in the double-sided pattern forming method of the present invention, the patterns of the first and second photomasks are made to correspond to the pattern positions of the front and back surfaces of one transparent substrate. It can be formed by transferring. Rather than bonding glass wafer substrates together, patterns can be formed on the front and back surfaces of a single transparent substrate.
Work can be greatly reduced. Further, since the bonding is not performed, there is no possibility that air bubbles enter between the glass wafer substrates or the glass wafer substrate is displaced, resulting in defective products. Therefore, the number of steps can be reduced and the yield can be increased.

[Brief description of the drawings]

FIG. 1 is a process diagram illustrating a double-sided pattern forming method according to an embodiment of the present invention.

FIG. 2 is a process diagram illustrating a double-sided pattern forming method according to one embodiment of the present invention.

FIG. 3 is a process diagram illustrating a double-sided pattern forming method according to an embodiment of the present invention.

FIG. 4 is a view showing a photomask used in the double-sided pattern forming method.

FIG. 5 is a process chart for explaining a conventional double-sided pattern forming method.

FIG. 6 is a view showing a photomask used in the conventional double-sided pattern forming method.

[Explanation of symbols]

 1A, 1B Photomask 2A, 2B Unit pattern 4A, 4A ', 4B, 4B' Alignment mark 6B, 6B 'Transparent area 8 Transparent substrate 8A Front surface 8B Back surface 22A, 22B Transferred pattern 24A, 24A' Transferred position Alignment mark

Claims (1)

(57) [Claims] 1. A method according to claim 1, wherein the first and second photomasks have a predetermined pattern on one surface of the glass plate and have predetermined alignment marks at two locations on the one surface. A double-sided pattern forming method for transferring and forming a pattern of a mask on a front surface and a back surface of one transparent substrate in correspondence with a pattern position between the front surface and the back surface. Applying the first resist, exposing the first resist through the first photomask, and subsequently performing development to pattern the first resist; and using the first resist as a mask. A step of performing etching to transfer and form the pattern of the first photomask and the alignment mark on the surface of the transparent substrate; and applying a second resist on the back surface of the transparent substrate. Placing the transparent substrate on the stage of a predetermined alignment device with the back side facing up, arranging the second photomask in parallel with the transparent substrate, and setting the objective lens of the microscope of the alignment device. With the focal point of the second photomask being adjusted to the height of the pattern surface of the second photomask.
Moving the two photomasks in a horizontal plane to align the two alignment marks of the second photomask with reference marks provided in the field of view of the microscope; The focal point was adjusted to the height of the surface of the transparent substrate. In this state, the stage was moved in a horizontal plane, and two alignment marks transferred to the surface of the transparent substrate were provided in the field of view of the microscope. A step of respectively aligning with the reference mark, a step of exposing the second resist through the second photomask, and a step of performing development to pattern the second resist; A step of performing etching by using a resist as a mask to transfer and form the pattern of the second photomask on the back surface of the transparent substrate. Sided pattern forming method according to.