JPH05105485A - Working method for photosensitive glass - Google Patents

Abstract

PURPOSE:To easily work grooves different in depth or a groove having an inclined face by etching treatment of one time. CONSTITUTION:A hole 2a for exposure of a photomask 18 oppositely provided on the parts 3c, 3d desiring etching of a photosensitive glass plate 3. A reflective plate 4 is parallel arranged to the downside of the part 3c desiring deep etching of the photosensitive glass plate 3 and then exposed from the upper part of the photosensitive glass plate 3. Light is transmitted through the photosensitive glass plate 3 at a time of exposure and, thereafter, transmitted light is reflected by the reflective plate 4. The part 3c of the photosensitive glass plate 3 is reexposed and exposure thereof is more than the part 3d. When the parts 3c, 3d of the photosensitive glass plate 3 are heat-treated, crystallized and etched, grooves 3e, 3f different in depth are formed by etching treatment of one time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of processing photosensitive glass by etching.

[0002]

2. Description of the Related Art As a processing method for forming grooves or holes having different depths on a photosensitive glass plate, a method of using a masking material, and an exposure, a heat treatment, and an etching treatment are respectively performed.
There are ways to do it more than once.

In the former method, a masking material having a mask portion formed on a portion where a shallow groove is to be formed is placed on a photosensitive glass plate which has been exposed and crystallized in a predetermined pattern, is etched, and finally the masking material is removed. By etching, a groove having a deep groove, a shallow groove, and an inclined surface in a continuous portion between the both is formed.

In the latter method, a photosensitive glass plate is sequentially exposed and heat-treated to form an exposed portion of a deep groove, followed by crystallization and etching. Then, a re-exposure process, a re-heat treatment, and a re-etching process are performed to form a shallow groove, whereby a groove having a deep groove and a shallow groove is formed.

[0005]

SUMMARY OF THE INVENTION In the above-mentioned conventional method using a masking material, the masking material is formed, processed,
Suitable for this, because there are many steps such as removal, and since etching is performed with an etching solution such as a hydrofluoric acid aqueous solution while the masking material is in close contact, the adhesion to the photosensitive glass and hydrofluoric acid resistance must be satisfied. Limited things,
Further, considering the fine workability, it is preferable to use photolithography, but there is a problem that irregular reflection at the crystal part of the photosensitive glass may have an adverse effect.

The method of performing exposure and heat treatment twice has a problem that the heat treatment takes a very long time.

Therefore, an object of the present invention is to make it possible to easily process a groove having a different depth or a groove having an inclined surface by one etching process.

[0008]

In order to achieve the above object, a method for processing a photosensitive glass of the present invention comprises a step of exposing one surface of the photosensitive glass through an exposure hole of a photomask, Light passing through the photosensitive glass is reflected by the light reflecting means provided on the opposite side of the exposed surface of the photosensitive glass so as to face a part of the exposure hole of the photomask through the photosensitive glass. , A step of re-exposing the above-mentioned portion of the photosensitive glass by making it incident on the other surface of the portion of the photosensitive glass facing the exposure hole of the photomask and the light reflecting means, and heat treating the exposed portion and the re-exposed portion And a step of etching the crystal part are included.

[0009]

According to the present invention, when the photosensitive glass is exposed, the light is reflected by the light reflecting means and the exposure amount is changed depending on the location of the photosensitive glass.

That is, in the photosensitive glass, the light reflecting means is juxtaposed to the portion to be deeply etched. In this portion, the parallel light rays at the time of exposure are transmitted through the photosensitive glass, and then the parallel light rays transmitted by the reflecting plate are reflected and are made incident again on the photosensitive glass, so that the exposure amount is increased.

In the photosensitive glass, the light reflecting means is not juxtaposed to a shallow portion to be etched, so that the exposure amount of this portion is small. When the exposed area is heat treated and etched,
Grooves having different depths can be formed by one etching.

When it is desired to form a groove having an inclined surface on the photosensitive glass, a light reflecting means having a pattern of a reflecting plate formed on a transparent plate is used. In the photosensitive glass, the density of the pattern or the size of the dots of the pattern is decreased so that the reflection amount of light gradually decreases from the deep part to the shallow part of the groove.

As a result, an exposed portion in which the amount of exposure is changed is formed on the photosensitive glass. Then, a groove having an inclined surface can be formed by one etching.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

First, as shown in FIG. 1, both upper and lower surfaces 3a,
A photomask is provided above the plate-shaped photosensitive glass 3 whose 3b is polished. The photomask is composed of a transparent substrate 1 and a mask pattern 2, and the mask pattern 2 is formed so that the exposure holes 2a are opposed to the portions 3c and 3d of the photosensitive glass 3 where etching is desired.

A light source (not shown) is provided above the photomask.

The reflection plate 4 is juxtaposed below the portion 3c of the photosensitive glass 3 to be deeply etched. The reflector 4 is not juxtaposed below the shallowly etched portion 3d.

As a result, the deeply etched portion 3c of the photosensitive glass 3 faces the exposure hole 2a and the reflection plate 4.

The reflection plate 4 is for changing the exposure amount of the photosensitive glass plate 3 depending on the location.

To explain the operation, the photosensitive glass 3 is irradiated with parallel rays (XeCl excimer laser) from the light source through the exposure hole 2a of the photomask. The parallel rays are incident on the upper surface 3a of the photosensitive glass 3 and
Penetrates inside. After that, the parallel rays that have passed through the shallowly etched portion 3d of the photosensitive glass 3 proceed downward as they are, while the parallel rays that have passed through the deeply etched portion 3c of the photosensitive glass 3 are reflected by the reflector 4. Then, the light enters the photosensitive glass 3 again from the lower surface 3b. Then, the parallel rays are generated on the lower surface 3b of the photosensitive glass 3.
Permeate toward the upper surface 3a and travel upward. Due to the reciprocating laser light, the deeply etched portion 3c of the photosensitive glass 3 is re-exposed and the total exposure amount becomes larger than that of the portion 3d of the photosensitive glass 3.

Here, the exposure dose of the shallow etching portion 3d and the deep etching portion 3c of the photosensitive glass 3 will be described.

FIG. 8 shows the relationship between the total exposure amount and the etching rate of the photosensitive glass when the photosensitive glass is exposed to an XeCl excimer laser having an energy intensity per pulse of 1 mj / cm ² as an example.

As can be seen from FIG. 8, when the photosensitive glass is irradiated with XeCl excimer laser for 200 pulses or more, that is, when the total exposure is 200 (mJ / cm ² ) or more, the photosensitive glass is increased even if the total exposure is increased. There is almost no change in the etching rate. Total exposure is 85-200 (mJ
In the range A of / cm ² ), the etching rate decreases as the total exposure dose decreases.

In order to make the etching rate different between the shallow etching portion 3d of the photosensitive glass 3 and the deep etching portion 3c, the total exposure amount of the shallow etching portion 3d of the photosensitive glass 3 is shown in FIG. Range A
The exposure amount is adjusted so that the total exposure amount of the portion 3c to be deeply etched is within the range A or larger than the range A.

When the exposure is completed, the photosensitive glass 3 is heated to 50
A heat development step of heating the exposed portions 3c and 3d to a high temperature of about 0 to 700 ° C. is performed.

Next, the photosensitive glass 1 is subjected to etching by showering an etching solution composed of a hydrofluoric acid (HF) solution of 5 to 10% in a shower shape.

Since the portion 3c of the photosensitive glass 3 has a larger total exposure amount than the portion 3d, the etching rate of the crystal is higher. Therefore, in the same etching time, the portion 3c of the photosensitive glass 3 can be etched deeper than the portion 3d.

As a result, the grooves 3e and 3f having different depths can be formed by one etching process as shown in FIG.

The second embodiment of the present invention will be described below with reference to FIGS.

Photosensitive glass 1 as shown in FIGS.
3, a light reflecting means 14 is provided below the light reflecting means 14 and the light reflecting means 14 is composed of a light reflecting means 14a and a dot pattern 14b of a reflecting plate at the end of the light reflecting means 14a. The amount of light reflected is changed.

That is, the pattern 14b of the reflection plate gradually reflects the amount of light as it goes to the right in FIGS. 3 and 4 so that the grooves 13e and 13f having different depths of the photosensitive glass 13 are smoothly connected by the inclined surface. The size of the dots on the reflector is reduced so as to decrease.

The light reflecting means 14 is formed by a photolithographic method in which a film of Al, Cr, Ag or the like is formed on the surface of the transparent plate 5 by vapor deposition and a resist is applied thereon.

When the photosensitive glass plate 13 is exposed to light, an exposed portion in which the exposure amount is sequentially changed is formed inside the portion of the photosensitive glass plate 13 facing the pattern 14b of the reflection plate.

As a result, as shown in FIG. 5, the grooves 13e and 13f having different depths and the gently sloping surface 13g connecting these can be processed by one etching process.

The third embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 6, a pattern 24 of a reflecting plate for forming an inclined groove in the photosensitive glass 23 is provided below the photosensitive glass 23.

That is, a dot-shaped pattern 24 of a reflective plate similar to the dot-shaped pattern of the reflective plate of the second embodiment of the present invention is formed on the transparent plate 7. This pattern 2
4 is a photosensitive glass 2 when placed under the photosensitive glass 23
It is formed to have an area facing the exposure hole 2a through 3.

Therefore, in the pattern 24 of the reflecting plate, the pattern of the maximum dot having the maximum light reflectance faces the position corresponding to the deep part 23e of the groove of the photosensitive glass plate 23, and the shallow groove part. The pattern having the smallest light reflectance and the smallest pattern of dots is opposed to the position corresponding to 23f.

The pattern 24 of the reflecting plate is the photosensitive glass 2
The dot size of the reflector is reduced so that the reflection amount of light gradually decreases as it goes to the right in FIG. 6 so that the portions 23e and 23f of No. 3 are smoothly connected by the inclined surface.

As a result, by exposing the photosensitive glass 23, an exposed portion in which the exposure amount is sequentially changed is formed inside the portion of the photosensitive glass plate 23 corresponding to the pattern 24 of the reflection plate.

As a result, as shown in FIG. 7, a groove having a gently inclined surface can be formed in the photosensitive glass 23 by one etching process.

As the light reflection means for changing the light reflectance, a pattern in which the dot density of the reflection plate is changed may be formed on the transparent plate, and a linear pattern is formed on the transparent plate. It may be formed by changing the array density.

The light source for exposing the photosensitive glass is Xe.
The excimer laser is not limited to Cl excimer laser, and may not be strictly parallel rays, for example, ultraviolet rays from an ultra-high pressure mercury lamp.

[0044]

As described above, according to the method for processing a photosensitive glass of the present invention, the light-reflecting means juxtaposed on the photosensitive glass can form exposed portions having different exposure amounts on the photosensitive glass. By performing the etching process once, it is possible to process grooves having different depths or grooves having a gently sloping surface, which simplifies the processing, shortens the processing time, and achieves cost reduction.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a processing step of a processing method according to the present invention.

FIG. 2 is a cross-sectional view of a photosensitive glass to which the above processing method is applied.

FIG. 3 is a cross-sectional view showing a processing method of a second embodiment.

FIG. 4 is a plan view showing a light reflecting means according to a second embodiment.

FIG. 5 is a sectional view of a photosensitive glass to which the processing method of the second embodiment is applied.

FIG. 6 is a cross-sectional view showing the processing method of the third embodiment.

FIG. 7 is a sectional view of photosensitive glass to which the processing method of the third embodiment is applied.

FIG. 8 is a diagram showing the relationship between the total exposure of photosensitive glass and the etching rate.

[Explanation of symbols]

 2 Photomask 2a Exposure hole 3,13,23 Photosensitive glass 3c Re-exposure part 3d Exposure part 4,14,24 Light reflection means

Claims (1)

[Claims] 1. A step of exposing one surface of a photosensitive glass through an exposure hole of a photomask, and a step of facing a part of the exposure hole of the photomask through the photosensitive glass, The light reflecting means provided on the side opposite to the exposed surface of the photosensitive glass reflects the light transmitted through the photosensitive glass, and opposes the exposure hole of the photomask and the light reflecting means. Making the other surface of the photosensitive glass part incident and re-exposing the above-mentioned part of the photosensitive glass; heat-treating the exposed part and the re-exposed part to form a crystal part; And a step of etching the photosensitive glass.