JP2001201627A - Method for manufacturing diffraction element - Google Patents

Abstract

(57) [Problem] To provide a method for manufacturing a diffraction element capable of forming a diffraction grating of a predetermined three-dimensional shape in a short time even on a material having a high melting point (softening point) such as quartz. When a workpiece is irradiated with an energy beam through a stencil mask having a predetermined shape (pattern) and etched, a diffraction element having a predetermined three-dimensional diffraction grating formed on the workpiece is manufactured. it can.

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 diffraction element, and more particularly to a method for manufacturing a diffraction element capable of easily forming a diffraction grating having a predetermined three-dimensional shape.

[0002]

2. Description of the Related Art As one of fine processing in a semiconductor device manufacturing process, there is a processing method utilizing photolithography technology. In this method, first, a photoresist is applied to a substrate 41 shown in FIG. 6A, as shown in FIG. 6B, and a photoresist film 42 is formed. As shown in FIG. 6C, the photoresist film is exposed to an arbitrary shape using the photomask pattern 43. Thereafter, the photoresist film 42 is developed (FIG. 6D).
).

As a developing method, there are a method of dipping in a developing solution, a method of spraying the developing solution in a mist state, and the like. By the development, the exposed portion of the photoresist remains on the substrate 41 in the case of a negative photoresist, and the unexposed portion of the photoresist remains on the substrate 41 in the case of a positive photoresist. FIG. 6D shows the case of a positive photoresist.

After development, the substrate 41 is etched using the photoresist film 42 remaining on the substrate 41 as a protective film (FIG. 6E).
). For the wet etching, for example, a mixed aqueous solution of hydrogen fluoride and ammonium fluoride is used, and for the dry etching, for example, plasma generated by causing high-frequency discharge in a gas containing fluorine gas is used. Finally, the photoresist film 42 is removed using a stripping solution or oxygen plasma, and the first step of the fine processing is completed (FIG. 6 (f)).

In such a process, the above operation is repeated several tens of times to form a complicated three-dimensional diffraction grating as shown in FIG. Problem. In addition, in the photolithography technique, in addition to the complexity of the operation, the photomask pattern 43 must be prepared in advance, and if a different pattern is to be produced, another photomask pattern 43 must be newly produced. Further, there is a problem that contamination by a resist residue occurs.

In addition to such a method, Japanese Patent Laid-Open No. 10-78504 discloses a method of forming a diffraction grating having a predetermined three-dimensional shape by a molding method using a mold. However, in this method, it is difficult to form a material having a high melting point such as quartz, and in particular, there is a problem that transfer from a roller mold cannot be performed well to form a right angle portion.

Accordingly, an object of the present invention is to provide a method of manufacturing a diffraction element which can form a diffraction grating having a predetermined three-dimensional shape in a short time even on a material having a high melting point (softening point) such as quartz.

[0008]

Means for Solving the Problems In view of the above problems, as a result of intensive studies, the present inventors have found that when a workpiece is irradiated with an energy beam through a stencil mask having a predetermined shape (pattern) and is etched, The present inventors have found that a diffraction element in which a predetermined three-dimensional diffraction grating is formed on a workpiece can be manufactured, and arrived at the present invention.

That is, a method of manufacturing a diffraction element according to the present invention is a method of manufacturing a diffraction element which irradiates a workpiece with an energy beam through a stencil mask having a slit of a predetermined shape and etches the surface thereof. While irradiating the energy beam having passed through the slit of the stencil mask, at least one of the workpiece and the stencil mask is relatively moved with respect to the other to form a predetermined three-dimensional diffraction grating on the surface thereof. It is characterized by the following.

In the method of manufacturing a diffraction element according to the present invention, it is preferable that the workpiece is provided on a piezo stage having a minute moving mechanism. The stencil mask has a width of 1 to
A plurality of slits each having a thickness of 100 μm are provided, and are preferably made of a single crystal silicon wafer. Further, the energy beam is preferably a fast atom beam.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [1] Manufacturing Apparatus for Diffraction Element FIG. 1 shows a schematic configuration of a manufacturing apparatus used for manufacturing a diffraction element according to the present invention. The apparatus shown in FIG. 1 includes an energy beam source 6 for generating an energy beam, a piezo stage 3 which supports a workpiece (diffraction element) 2 at a position facing the energy beam source, and has a minute moving mechanism, Stencil mask 1 is provided between source 6 and workpiece 2. The stencil mask 1 is fixed by a holding device 4. The piezo stage 3 and the holding device 4 are provided on a support 5.

As the energy beam, any of a fast atomic beam, an ion beam, an electron beam, a laser, radiation, X-rays, an atomic beam and a molecular beam can be used. Among them, a fast atomic beam is preferred. A fast atom beam is a neutral energy particle beam and a beam having a very good directivity, so that it can be applied to any material. Workpiece 2
When providing an ultra-fine pattern on the surface, the beam easily reaches the ultra-small holes and gaps, improving the processing accuracy.
A processing bottom with high flatness and a vertical processing wall can be manufactured.

As an etching gas supplied to the energy beam source 6, a fluorine-based gas such as CF ₄ , CHF ₃ or SF ₆ is used. The workpiece 2 includes a metal, a semiconductor,
In addition to insulators, graded materials, etc., especially the melting point (softening point) of quartz etc.
Higher materials can also be used.

The piezo stage 3 is a rotation / translation stage, which can be freely moved by a control device (not shown), and the movement distance can be controlled in the range of 100 to 1000 nm. Accordingly, a diffraction grating having a complicated three-dimensional shape can be formed on the surface of the workpiece 2 by moving the piezo stage 3 on which the workpiece 2 is placed in a state where the workpiece 2 is irradiated with the energy beam.

Further, the gripping device 4 is provided with a function of freely moving the stencil mask 1, and at least one of the workpiece 2 and the stencil mask 1 is relatively moved with respect to the other. A diffraction grating having a predetermined three-dimensional shape can be formed. According to such an apparatus, continuous processing can be performed while irradiating an energy beam, so that a plurality of steps such as a photoresist step need not be repeated.

The stencil mask 1 is provided with a slit 1a of a predetermined shape such as a rectangle as shown in FIG. The irradiated energy beam is blocked by a stencil mask having a shielding property, but a part of the energy beam is irradiated to the workpiece 2 through a slit 1a provided in the stencil mask. The surface of the workpiece 2 is etched by the energy beam emitted from the slit 1a.

As the stencil mask 1, various materials such as single crystal silicon, glass, polyethylene, tungsten, and SUS can be considered. Among them, single crystal silicon is preferably used. Single crystal silicon has a hard crystal plane
A slit 1a having a fine shape of not more than μm and perpendicular to the surface can be easily formed. As a result, the beam diameter of the energy beam applied to the workpiece 2 through the slit 1a also becomes 5 μm or less, so that a very fine diffraction grating can be formed on the workpiece 2.

Here, the slit 1a of a predetermined shape provided in the stencil mask 1 is obtained by subjecting the stencil mask 1 to a reactive ion etching through-etching.

The width of the slit 1a is preferably 1 to 100 μm. If the width is larger than 100 μm, the diameter of the beam irradiated on the workpiece 2 increases, and it takes time to form a fine three-dimensional shape. On the other hand, if it is less than 1 μm, it is difficult to actually form the slit 1a, which is not preferable.

Further, not only one slit 1a is provided in one stencil mask, but a plurality of slits 1a are provided as shown in FIG. At this time, the interval between the slits 1a, 1a is
Determined according to the pitch of the periodic pattern of the desired shape. For example, in order to form a pattern that is repeated at a period of 30 μm on the workpiece 2, the slit interval is also set to 30 μm. By providing a plurality of slits 1a in this way,
A plurality of diffraction gratings having the same shape can be efficiently formed on the workpiece 2.

[2] Method of Manufacturing Diffractive Element A method of manufacturing a diffractive element of the present invention using the apparatus shown in FIG. 1 will be described with reference to FIG.

As shown in FIG. 2A, the workpiece 2 is set on the piezo stage 3, and the stencil mask 1 is set on the holding device 4. After the stencil mask 1 is set, the piezo stage 3 is moved to perform alignment with the workpiece 2. Thereafter, as shown in FIG. 2B, an energy beam is irradiated through the stencil mask 1.

Although the beam emitted from the energy beam source 6 is blocked by the stencil mask 1, the stencil mask 1 is provided with a slit 1a having a predetermined width. Is irradiated on the workpiece 2 on the piezo stage 3 and its surface is etched. As a result, a minute concave portion 2a is formed on the surface of the workpiece 2.

Here, if a single crystal silicon wafer is used for the stencil mask 1, a slit having a narrower slit width than that of a stencil mask made of glass, SUS, or the like can be provided.
(Slits of μm or less can be easily formed.)
Therefore, the diameter of the beam irradiated through the slit 1a can be set to 5 μm or less. As a result, a finer three-dimensional shape can be formed as compared with the conventional beam processing, and the concave portion 2a formed by the irradiation of the energy beam becomes finer than that obtained by the conventional processing. If a high-speed atomic beam is used as an energy beam, a vertical machined wall can be formed with high accuracy.

The control device moves at least one of the workpiece 2 on the piezo stage 3 and the stencil mask 1 relative to the other. Since the moving amount and moving speed of the stencil mask 1 provided on the piezo stage 3 or the holding device 4 are set in advance, a predetermined three-dimensional shape is continuously formed on the workpiece 2 while irradiating the energy beam. (FIG. 2 (c)).

The beam irradiation time on each part of the surface of the workpiece 2 is controlled by the trajectory and the moving speed of the movement of the piezo stage 3 or the stencil mask 1. Therefore, the part irradiated with the beam depends on the irradiation time. Etched,
Since the portion blocked by the stencil mask 1 is not irradiated for that time, it remains as a projection, and a predetermined three-dimensional diffraction grating is formed on the workpiece 2.

If the moving speed is changed in this manner, a different shape can be formed on the surface of the workpiece 2. Therefore, even when a different shape is formed, another photomask pattern needs to be newly formed. There is no.

Further, according to such a method, continuous processing while irradiating an energy beam becomes possible.
It is not necessary to go through a plurality of steps such as a photoresist step, and since the sequential control is performed, a desired three-dimensional shape can be accurately formed on the workpiece 2. Therefore, FIG.
A complicated-shaped concave portion as shown in (d) can be easily formed.

[0029]

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

[0030] was placed a workpiece made of quartz on the piezo stage 3 of the apparatus shown in Example Figure 1 (diffractive element) 2 (1mm thick by 20 mm × 20 mm). A single crystal silicon wafer shown in FIG. 3 as a stencil mask 1 in a gripping device 4 (a total of 20 mm × 20 mm and a thickness of 0.1 m)
m, slit width 5 μm, slit length 3 mm, slit interval (between 1a, 1a) 32 μm). Stencil mask 1
Was set, and the piezo stage 3 was moved to perform alignment with the workpiece 2.

The relationship between the etching time and the position of the stencil mask 1 was calculated by deconvolution as shown in FIG. 4 from the desired processing shape and slit width. In other words, the pitch is set to 1 μm, and the piezo stage 3 is moved in the horizontal direction as a whole by 32 μm. Since the etching amount is proportional to the etching time, by setting the moving speed to a predetermined value, the shape as shown in FIG. On the surface of the workpiece 2.

The piezo stage 3 was moved by a very small amount by the control device, and fine processing was performed while irradiating a high-speed atomic beam.

When the processed shape of the workpiece 2 was observed using an AFM (atomic force microscope), it was found that it had almost the same shape as in FIG. Therefore, according to the method of the present invention, it has been found that a predetermined shape can be accurately formed on the workpiece 2.

[0034]

As described above in detail, according to the method for manufacturing a diffraction element of the present invention, complicated operations such as a photoresist step are not required, so that the operation time and cost can be greatly reduced. Also, a diffraction grating having a predetermined three-dimensional shape can be accurately formed on a material having a high melting point such as quartz. Further, there is no problem of contamination by the resist residue.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a configuration of a diffraction device manufacturing apparatus for performing a method of the present invention.

FIG. 2 illustrates the steps of the method of the present invention.

FIG. 3 is a top view showing an example of a stencil mask used in the method of the present invention.

FIG. 4 is a diagram showing a slit position and an etching amount when deconvolution is performed in the example.

FIG. 5 is a view showing a target shape in the embodiment.

FIG. 6 is a diagram showing an example of a conventional photoresist process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Stencil mask 1a ... Slit 2 ... Workpiece 3 ... Piezo stage 4 ... Grasping device 5 ... Support base 6 ... Energy beam source

Claims (6)

[Claims] 1. A method of manufacturing a diffraction element for irradiating a workpiece with an energy beam through a stencil mask having a slit of a predetermined shape and etching a surface of the workpiece, the energy beam having passed through the slit of the stencil mask is provided. A method for manufacturing a diffraction element, wherein at least one of the workpiece and the stencil mask is relatively moved with respect to the other while irradiating, and a diffraction grating having a predetermined three-dimensional shape is formed on the surface thereof. 2. The method for manufacturing a diffraction element according to claim 1, wherein the workpiece is provided on a piezo stage having a minute movement mechanism. 3. The method of manufacturing a diffraction element according to claim 1, wherein a width of the slit provided in the stencil mask is 1 to 100 μm. 4. The method of manufacturing a diffraction element according to claim 1, wherein a plurality of slits are provided in the stencil mask. 5. The method for manufacturing a diffraction element according to claim 1, wherein the stencil mask is a single crystal silicon wafer. 6. The method for manufacturing a diffraction element according to claim 1, wherein the energy beam is a high-speed atomic beam.