JPS60181703A - Production of halogram diffraction grating - Google Patents

Abstract

PURPOSE:To improve the strength and particularly moisture resistance of a pattern by providing an underlying layer consisting of a plastic or curable resin which is not attacked by the photoresist in the coating stage on a substrate and coating the photoresist thereon. CONSTITUTION:An underlying layer 33 consisting of a plastic resin or curable resin which is not attacked by photoresist in the coating stage is formed on a substrate 31 and the photoresist is coated thereon. For example, PVAL, epoxy resin, etc. are used for such layer 33 and the photoresist coating layer is subjected to hologram recording by the conventional method. The strength and particularly moisture resistance of a diffraction grating pattern 39 can be improved by forming the layer 33 by using the resin which is not attacked by the photoresist in the coating stage thereof in the above-mentioned way. The cracking of the diffraction grating pattern 39 occuring in high temp. and high humidity, dew condensation, etc. is thus prevented and the deterioration in diffraction efficiency is prevented. The diffraction grating is used for a laser printer, bar code reader for POS, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a method of manufacturing a diffraction grating using hologram recording, and particularly to a method of manufacturing a hologram diffraction grating used in hologram scanners for laser printers, barcode readers for POS, and the like.

Hologram scanners have been proposed in conjunction with conventional optical scanning means such as laser printers and barcode readers for POS (Japanese Patent Laid-Open Nos. 55-161211, 1983).
-120211, etc.).

A hologram scanner can be manufactured by applying a photoresist onto a glass disk, recording a hologram, and then developing it to form a diffraction grating in a desired pattern (Japanese Patent No. 120211/1999).

However, is the diffraction grating formed in this way exposed to environmental conditions over time? The problem is that cracks are likely to occur. Although photoresists have excellent properties such as high sensitivity and the ability to be microfabricated, they are essentially melted in the final process without damaging the substrate, and they are not stable in the environment or deteriorate over time. The current situation is that it has been neglected.

Purpose The present invention aims to provide a method for manufacturing a diffraction grating by holographic recording using a photoresist.

Structure The method for manufacturing a hologram diffraction grating according to the present invention includes
In a manufacturing method that includes the steps of applying a photoresist, disposing a hologram, and then developing, a base layer made of a plastic resin or a curable resin that will not be removed when applying the photoresist is formed on the substrate, and a base layer is formed on the base layer. It is characterized by applying photoresist to the surface.

The present invention will be explained in more detail below.

The plastic resin or curable resin used for the underlayer is one that can be dissolved in the photoresist solution (mainly in a solvent) during the photoresist coating process, and includes polyvinyl alcohol, alkyd resin, epoxy resin, and epoxy-modified acrylic resin. Examples include resin. A base layer is formed by dissolving these resins in a solvent and applying them, or by applying an oligomer together with a curing agent to form a thin film on a glass substrate. The thickness of the base layer is suitably about 0.01 to 10 μm, preferably 0.5 to 2 μm. Note that supports other than glass can also be used as the substrate.

Next, a photoresist is coated on the base layer thus formed by a conventional method using a suitable coating means such as a rotating spinner. The coating thickness of the photoresist is appropriately determined depending on the depth of the diffraction grating to be formed. However, it is usually about 0.1 to 10 μm, preferably 0.5 to 2.0 μm.
The degree is appropriate. As the photoresist, a positive type photoresist is suitable, and a naphthoquinone diazide type, such as phenol, novolatz, resin and 2.
Preferred are those containing a -diazo-1-naphthalenone derivative, and those containing a vinyl phenol resin and a 2-diazo-1-naphthalenone derivative. These photoresists include 0FPR series such as 0FPR-800 (manufactured by Tokyo Ohka Co., Ltd.), Shitsuplay AZ series C5hlplay
(manufactured by Kodal, Inc.), Kodak Microresist (manufactured by Kodal, Inc.), Merck Selective Resist (manufactured by CMark Inc.), etc. The photoresist can also be prebaked if necessary.

After forming the recording layer in this manner, an antireflection film is applied to the back surface of the substrate, if necessary, and hologram recording is performed on the photoresist. Hologram recording can be performed by a conventional method, for example, as shown in FIG. The laser light from the laser light source 11 is split by a beam sinter 13, and each split beam passes through a mirror 15.15', is focused on an objective lens 17.17', and passes through a pinhole 19°19'. The collimating lens 21, 21' converts the beam into a parallel light beam, and the glass substrate 23 on which the recording layer 22 is formed by coating photoresist.
The interference fringes of the two beams are recorded on the photoresist by irradiating the two beams so as to overlap each other. Next, this recording layer 22
By developing this, a diffraction grating having a desired grating spacing and grating depth is formed. If a positive type photoresist is used, the exposed areas become soluble and are removed by development, whereas if a negative type is used, the exposed areas become insolubilized and the unexposed areas are removed by development, resulting in a sinusoidal relief. It is formed.

FIG. 2 is a schematic cross-sectional view of a diffraction grating formed in this manner, in which a diffraction grating (photoresist relief) 35 is formed on a glass substrate 31 with a base layer 33 interposed therebetween. The grating spacing can be controlled according to the mutual angle of the two light beams interfering on the photoresist and the wavelength of the light beams, and the grating depth h is controlled by the Gribake conditions, the irradiation time, the development time, the development 11. Eri control is possible in controlling concentration, etc. In addition, as a laser light source, He-Cd laser (441.6 nm) and Ar laser (457.9 nm) are used.
, 488.0 nm), etc. are used.

Then, the diffraction grating of the present invention is obtained by performing necessary post-treatments such as washing with water, drying, and post-baking. FIG. 3 is a schematic plan view showing the hologram disk 36 used in the hologram scanner obtained in this way, in which a diffraction grating pattern 39 is formed on a disk-shaped glass substrate 37. Note that 41 is a mounting hole.

The present invention manufactures holograms using photoresist, and is suitable for holography in general, particularly for manufacturing hologram diffraction gratings, and is suitable for manufacturing hologram scanners for laser printers, barcode readers for PO8, hologram lenses, and diffraction gratings for spectrometers. Furthermore, it can be widely applied to the manufacture of four-gram application measuring instruments such as shape measurement of aspherical lenses and vibration analysis measurement.

Effects According to the present invention, when manufacturing a hologram using a photoresist, a base layer is formed using a tree l'd that is not damaged in the photoresist coating process. , especially the moisture resistance can be improved. This is thought to be because the underlayer improves the adhesion of the photoresist and acts as a buffer layer for internal stress.

Therefore, cracks can be effectively prevented from occurring in the diffraction grating pattern even under environmental conditions such as high temperature, high humidity, and dew condensation, and deterioration of desired characteristics such as diffraction efficiency can be effectively prevented.

Example 1 After thoroughly cleaning and drying a glass substrate with an outer diameter of 100 mm, a hole diameter of 3 mm, and a thickness of 31 nm, amino alkyd resin (Dainippon Ink Co., Ltd.) was applied using a rotary spinner.
was applied to a thickness of 0.2 μm and cured by heating and drying at 150° C. for 30 minutes to form a base layer.

A positive photoresist (Silapray AZ-1350) was coated on this underlayer with a dry coating to a thickness of 1.31 J fi, and was baked at 90° C. for 20 minutes to form a recording layer.

Next, after an antireflection coating (441.6 nm) was applied to the back surface, 10 holographic gratings with a grating number of 2200/+u were photographed using a He-Cd laser (441.6 nm).

Next, it is developed with a developer (Shippray AZ developer),
After thorough washing with water, it was post-baked at 105° C. for 1 hour to produce the hologram disk shown in FIG. 3.

Example 2 A hologram disk was produced in the same manner as in Example 1, except that a partially saponified polyvinyl alcohol solution was applied to a thickness of 0.3 μm and dried at 120° C. for 20 minutes to form a base 1-.

Example 3 A photo-linking initiator was added to epoxy-modified acrylate (Mitsubishi Rayon Store), coated to a thickness of 0.15 μm, and cured by irradiation for 20 minutes under a crystallizing mercury lamp to form a base layer. A hologram disk was created in the same manner as in Example 1.

Comparative Example A hologram disk was prepared in the same manner as in Example 1 except that a photoresist was applied directly onto a glass substrate without forming an underlayer.

Temperature-humidity cycle test For each of the 10 samples (hologram disks) obtained in Comparative Examples and Examples 1 to 3 as described above,
A temperature-humidity cycle test was conducted using the method specified in JI 5-C-5024 to determine the cause of cracked samples. It is shown in Table 1.

Male 1 table

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a hologram recording method. FIG. 2 is a schematic cross-sectional view showing a diffraction grating obtained by the present invention. FIG. 3 is a schematic plan view showing the hologram scanner. 11...Laser light source 13 beam splitter 17,1τ...Objective lens 21.21'-...Collimating lens 22...Recording layer 23.31.37...Glass substrate 33...Underlayer 35...Diffraction grating 36...Hologram scanner 39...Diffraction grating pattern patent applicant Ricoh Co., Ltd. - Purification of drawings':! -F (no change in content) 兇１圀I) １ 焔 20 foil 3 劔” 三次Ne 10 正ふ 4; (Method) % formula % ■, Indication of the incident 1982 Patent Application No. 36282 2, Invention Name: Method for manufacturing hologram diffraction gratings 3, Relationship with the case of the person making the amendment Patent applicant: 1-3-6 Nakamagome, Ota-ku, Tokyo (674) Ricoh Co., Ltd. Representative: Hama 1) Hiro 4, Agent May 211, 1980 1i-1i1i Correct subject drawing 7, contents of amendments Appropriate drawings are submitted as shown in the attachment.

Claims (1)

[Claims] 1. In a method for manufacturing a hologram diffraction grating, which includes the steps of applying a photoresist on a substrate, recording a hologram, and then developing it, an underlayer made of a plastic resin or a curable resin that is not left on the substrate during application of the photoresist. 1. A method for manufacturing a hologram diffraction grating, comprising forming a base layer and applying a photoresist on the base layer.