JPH0363601A - Method and device for forming microlens array - Google Patents

Abstract

PURPOSE:To produce the high-quality lens arrays with high efficiency by using a laser CVD method by converting an exit beam by an intensity distribution converter to a uniform intensity and subjecting a substrate to deflection irradiation perpendicularly thereto via a deflection optical system. CONSTITUTION:The exit beam of a laser light source 1 is passed, shut off or modulated by an optical switch 2. This beam is converted to the intensity distribution uniform in the sectional direction of the optical axis by an intensity distribution conversion system 4. The beam is then deflected at a prescribed angle by the deflecting optical system 5 and the substrate 9 is perpendicularly irradiated with the deflected beam through a window part 7 of a CVD reaction cell 8 by a condenser lens 6. A gaseous material is previously introduced into the CVD reaction cell 8 is discharged to a discharge treating system 12 after the CVD reaction. The substrate 9 is, therefore, irradiated with the exit beams at a specified scanning speed with the uniform energy of the respective spots and the microlens arrays having a uniform shape are efficiently formed thereon.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for manufacturing a microlens, and particularly to a method and apparatus for manufacturing a small and high-performance microlens array.

[Conventional technology]

In recent years, demand for compact, lightweight, high-performance lenses has increased in response to the miniaturization and high density of light receiving and emitting elements such as LDs, LEDs, and CCDs.

Ion exchange method, EB drawing method, laser C
It has been proposed to use dielectric thin film technology such as the VD method.

Among them, the laser CVD method has excellent directivity of the laser beam, so it can obtain good spatial selectivity and concentrate energy in a specific area, so it is used in the mask process required in the photolithography method. This method has the advantage of eliminating the need for direct, spatially selective formation of thin films.

Further, the laser beam can be easily narrowed down using a lens or the like, and the beam spot can be narrowed down to a level corresponding to the wavelength of the laser.

For example, when a CO2 laser is used as a light source, a microlens with a diameter of about 10 μm can be obtained. In addition, by appropriately changing the composition of the material gas during the CVD process,
It is also easy to provide a refractive index distribution in the thickness direction of the film.

Furthermore, among laser CVD methods, in a thermal CVD process, the film growth rate depends on the surface temperature of the substrate. Therefore, by laser irradiation with a Gaussian beam intensity distribution, a temperature distribution with the peak at the center of the irradiation spot is formed on the substrate surface. Therefore, the surface shape of the grown film has curvature, and it can be used as a lens. The surface shape of the grown film can be made into a shape suitable for a -layer lens by applying etching treatment or the like.

As a technique for forming microlenses by such a laser CVD method, for example, Japanese Patent Application Laid-Open No. 62-26010
No. 4 is known. In this technique, the shape of the deposit is controlled to create a desired lens shape, such as a Fresnel lens.
To obtain flat lenses, holographic lenses, etc.
It has been shown that the energy distribution for irradiating the substrate is changed according to a predetermined program, and in this case, as an example, two laser beams are provided in the same optical path, and the movement program of these laser beams is changed. It is stated that.

[Problem to be solved by the invention]

Under the above-mentioned technical background, the integration of light emitting elements such as LDs is progressing from single units to arrays, and matrix-like devices have also appeared. and,
The microlenses used in conjunction with these lenses are also moving toward array formation.

However, a technique suitable for efficiently producing an array of microlenses using the laser CVD method has not yet been established.

The present invention provides a method and apparatus suitable for efficiently producing high-quality microlens arrays using laser CVD.

[Problem to be solved by the invention]

In order to achieve the above object, the present invention provides a microlens array forming method that includes a laser light source, an optical system that guides an emitted beam from the laser light source to a substrate, and a gas that causes a CVD reaction by irradiation with the emitted beam. a reaction cell comprising a gas supply system that guides the gas onto the substrate and an exhaust treatment system that exhausts the gas; the reaction cell includes a mechanism that holds the substrate in the gas atmosphere within the reaction cell; In a microlens array forming device equipped with a window for introducing light, the beam emitted from the laser light source is passed through, blocked, or modulated by an optical switch, and then the emitted beam is uniformly distributed over the cross-sectional direction of the optical axis by an intensity distribution conversion system. The optical path of the output beam from the intensity distribution conversion system is deflected within a predetermined angle by a deflection optical system, and the deflected beam that has passed through the deflection optical system is deflected perpendicularly to the substrate surface by a condenser lens. It is characterized by guiding and focusing light.

Further, the present invention provides a microlens array forming apparatus that includes a laser light source, an optical system that guides an emitted beam from the laser light source to a substrate, and a CVD process by irradiation with the emitted beam.
A reaction cell includes a gas supply system that guides a gas that causes a reaction onto a substrate, and an exhaust treatment system that exhausts the gas, and the reaction cell has a mechanism that holds the substrate in the gas atmosphere within the reaction cell. and a window for introducing the emitted beam, the emitted beam from the laser light source is placed in an optical path leading to the introduction window of the reaction cell,
an optical switch that passes through, blocks, or modulates the output beam; an intensity distribution conversion system that converts the intensity distribution in the optical axis cross-sectional direction of the output beam that has passed through the optical switch into a uniform distribution; A deflection optical system that deflects the optical path of an emitted beam within a predetermined angle, and a condenser lens that guides and focuses the deflected beam that has passed through the deflection optical system perpendicularly to the surface of the substrate. It is something to do.

[For production]

With the configuration of the present invention, the beam emitted from the laser light source is
Uniform energy irradiation is applied to each spot on a predetermined area on the substrate in the CVD reaction cell at a constant beam scanning speed, and the energy distribution within each spot can be controlled appropriately, allowing efficient production of microlens arrays. can do.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 shows the basic configuration of a microlens forming apparatus to which the configuration of the present invention is applied, in which 1 is a laser light source;
Reference numeral 2 denotes an optical switch, and the operation of the optical switch 2 corresponds to the operation of the deflection optical system described later.

The beam that has passed through the optical switch 2 is reflected by a mirror 3.
The intensity distribution conversion system 4 is then reached. The arrangement of the folding mirrors 3, the number of mirrors 3, etc. can be changed depending on the shape of the device, etc. The intensity distribution conversion system 4 can convert an incident beam having a Gaussian intensity distribution into a flat uniform intensity distribution.

The emitted beam that has passed through the intensity distribution conversion system 4 reaches a deflection optical system 5 , and the group of deflected beams from the deflection optical system 5 reaches a condenser lens system 6 . At this time, it is preferable that the optical arrangement of the condenser lens system 6 is telecentric with respect to the deflection center of the deflected beams from the deflection optical systems 5 to (7).

All of the deflected beams from the condenser lens system 6 become parallel, and after passing through the window 7, they are incident on the surface of the substrate 9 in the CVD reaction cell 8 at the same angle.

Inside the CVD reaction cell 8, a substrate 9 is held perpendicularly to the incident beam by a substrate holding mechanism 10, and the substrate holding mechanism 10 is provided with a mechanism for moving in three-wheel directions.

The CVD reaction cell 8 includes a gas supply system 1 provided at one end.
1, a material gas is introduced in advance, and after the CD reaction, the material gas is exhausted by a gas exhaust treatment system 12 provided at the other end of the CVD reaction cell 8.

After the substrate 9 is attached to a predetermined position of the substrate holding mechanism 10 in the CVD reaction cell 8, the CVD reaction cell 8 is sealed and evacuated, and then a gas supply system 11 is installed in the CVD reaction cell 8.
The CVD reaction cell 8 is maintained under predetermined CVD reaction conditions by operating the gas exhaust treatment system 12 while supplying material gas from the CVD reaction cell 8 .

Next, a specific configuration of the present invention will be explained with reference to FIG. Components that are the same as those shown in FIG. 1 are designated by the same reference numerals.

As mentioned above, in order to form microlenses on the surface of the substrate 9 in the CVD reaction cell 8 maintained under predetermined CVD reaction conditions, an AO modulator is used as the optical switch 2, and an AO modulator is used as the intensity distribution conversion system 4. , an afocal optical system consisting of at least a first group with positive power and a second group with negative power, and an optical system that converts the luminous flux density distribution by utilizing spherical aberration. Further, as the deflection optical system 5, a galvanometer 5A operated by a galvanometer drive system 5a is used, and as the condensing lens system 6, an arc-si
An n lens system 6A is used.

In addition, in order to efficiently perform the alignment work of each optical element in the apparatus, a guide He-Ne laser light source 13.
A half mirror 15 made of a Zn5e plate is provided, and an optical switch 2. A synchronous circuit 16 is provided between the galvanometer drive system 5a and the galvanometer drive system 5a. He-Ne for the guide
Other lasers may be used instead of the laser light source 13.

The light from the laser light source 13 is ξ 14. It is guided to the same optical path as the laser light source 1 through a half-layer 15 made of a Zn5e plate.

In this example, arc for galvanometer 5A
The arrangement of the -sin lens 6A is a telecenter link as described above, and when the galvanometer 5A is caused to vibrate sinusoidally, the arc-sin lens 6A causes the lens system 6 to
The beam scanning speed of the group of deflected beams from A can be kept constant on the surface of the substrate 9. Therefore, arc-
The group of deflected beams emitted from the sine lens 6A can irradiate only a predetermined area on the surface of the substrate 9 at a constant beam scanning speed, and the modulation control of the optical switch 2 such as an AO modulator can be simplified. can.

In the microlens array forming apparatus of the present invention, a beam with a Gaussian intensity distribution is converted into a uniform intensity distribution, a galvanometer 5A and an arc-sin lens 6 are used.
Due to the relationship with A, the control efficiency of the beam irradiation area on the substrate 9 is improved, so that the spot array in a predetermined area for forming a lens can give uniform power to each irradiation spot. Furthermore, the intensity distribution within each irradiation spot can be controlled.

Furthermore, since the reproducibility of the shape of the microlens depends on the temperature distribution given to the substrate 9, improving the uniformity of the power given to each irradiation spot in the spot row will increase the yield of the microlens array. I can do it.

Further, in the configuration of the present invention including means for optimizing the intensity distribution within each irradiation spot, each element lens can be controlled to have an arbitrary shape.

FIG. 3 shows another embodiment of the invention for forming a microlens array. Components that are the same as those in the embodiment shown in FIG. 2 are designated by the same reference numerals.

A CO2 laser light source IA is used as a laser light source, and the galvanometer deflection optical system 5A and its drive system 5 of the embodiment described above are used.
A polygon mirror 5B is placed in place of a. Further, an fθ lens 6B is used instead of the arc-sin lens 6A.

With this configuration of the polygon -58 and the fθ lens 6B, a predetermined area on the surface of the substrate 9 can be irradiated at a constant beam scanning speed.

〔effect〕

In the configuration of the present invention, by arranging the above-mentioned optical system in a microlens forming apparatus that uses a laser CVD method, it is possible to efficiently deflect and irradiate a laser beam with good parallelism to a substrate, and therefore to each irradiation spot. It has the effect of uniformly supplying energy and efficiently forming microlenses with a uniform shape.In addition, the intensity distribution within each irradiation spot can be adjusted arbitrarily, and the temperature of the spot irradiation area can be adjusted. Since the distribution can be controlled, it has the advantage that a spherical or aspherical element lens having a desired curvature can be formed.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the microlens array forming device of the present invention, FIG. 2 is a schematic diagram showing another embodiment of the microlens array forming device of the present invention, and FIG. 3 is a schematic diagram showing another embodiment of the microlens array forming device of the present invention. FIG. 7 is a schematic diagram showing still another embodiment of the lens array forming apparatus. 1. IA...Laser light source, 2... Optical switch, 4.
...Intensity distribution conversion system, 5.5A, 5B... Deflection optical system, 6.6A, 6B... Condensing lens system, 7... Window section,
8...CVD reaction cell, 9...Substrate.

Claims (2)

[Claims] (1) A laser light source, an optical system that guides the emitted beam from the laser light source to the substrate, and a
A reaction cell includes a gas supply system that guides a gas that causes a VD reaction onto a substrate, and an exhaust treatment system that exhausts the gas, and the reaction cell holds a substrate in the gas atmosphere within the reaction cell. In a microlens array forming device comprising a mechanism and a window for introducing the emitted beam, the emitted beam from the laser light source is passed through, blocked, or modulated by an optical switch, and then the emitted beam is changed to an optical axis by an intensity distribution conversion system. The intensity distribution is converted to a uniform intensity distribution over the cross-sectional direction, the optical path of the output beam from the intensity distribution conversion system is deflected within a predetermined angle by a deflection optical system, and the deflected beam that has passed through the deflection optical system is deflected by a condenser lens. A method for forming a microlens array, comprising guiding and condensing light perpendicularly to the surface of the substrate. (2) A laser light source, an optical system that guides the emitted beam from the laser light source to the substrate, and a
A reaction cell includes a gas supply system that guides a gas that causes a VD reaction onto a substrate, and an exhaust treatment system that exhausts the gas, and the reaction cell holds a substrate in the gas atmosphere within the reaction cell. In a microlens array forming device comprising a mechanism and a window for introducing the emitted beam, light that passes through, blocks, or modulates the emitted beam from the laser light source in an optical path leading to the introduction window of the reaction cell. a switch; an intensity distribution conversion system that converts the intensity distribution in the optical axis cross-sectional direction of the output beam that has passed through the optical switch into a uniform distribution; and an intensity distribution conversion system that converts the optical path of the output beam from the intensity distribution conversion system within a predetermined angle. A microlens array forming apparatus comprising: a deflection optical system that deflects the beam; and a condenser lens that guides and focuses a deflected beam that has passed through the deflection optical system perpendicularly to the surface of the substrate.