JP2004271944A - Method for manufacturing three-dimensional photonic crystal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a three-dimensional photonic crystal which manufactures the three-dimensional photonic crystal while adjusting the positions of two-dimensional patterning plates stacked on each other by nano manipulation. <P>SOLUTION: The method for manufacturing the three-dimensional photonic crystal comprises a process of laminating the formed two-dimensional patterning plates 10 and roughly adjusting their positions in a two-dimensional direction by utilizing cylinders, a process of coupling the respective two-dimensional patterning plates 10 to a microactuator and adjusting the intensity of diffracted light by finely adjusting the positions to the two-dimensional direction, and a process of gluing and fixing the laminated two-dimensional patterning plates 10 to each other. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
[Industrial applications]
The present invention relates to a method for manufacturing a three-dimensional photonic crystal, and more particularly, to a method for manufacturing a three-dimensional photonic crystal by adjusting the band gap of a stacked two-dimensional plate by nanomanipulation in a photonic crystal manufacturing process. The present invention relates to a method for producing a nick crystal.
[0002]
[Prior art]
2. Description of the Related Art Internet access and data transmission technologies are rapidly developing, and research and development of optical circuit elements made of photonic crystals are proceeding as optical circuit elements corresponding to this technology. The photonic crystal refers to an artificial crystal in which two types of transparent media having significantly different refractive indexes are regularly and alternately arranged at a cycle of a light wavelength. In a photonic crystal having a periodic structure and a refractive index ratio satisfying specific conditions, a phenomenon occurs in which light in a certain frequency range does not propagate at all. The spectrum band of the light that cannot propagate, that is, the forbidden light, is called a photonic band gap. This photonic crystal bends, directs, and handles light on a sub-millimeter scale, and has the ability to constitute a composite device with a large number of integrated light control functions. The photonic crystal will be briefly described with reference to FIG.
[0003]
5 (a) is a one-dimensional photonic crystals constituted by one-dimensional periodic array medium and medium of index n ₂ of the refractive index n ₁ alternately. 5 (b) is a photonic crystal constituted by two-dimensional periodic array medium and medium of index n ₂ of the refractive index n ₁ alternately. Figure 5 (c) is a three-dimensional photonic crystal arranged constituted by three-dimensional periodic the medium and the medium of refractive index n ₂ of the refractive index n ₁ alternately. Photonic crystals have a refractive index period on the order of λ / 2. Here, λ is the light wavelength.
Since the first development of the three-dimensional photonic bandgap structure, especially in the last decade of the twentieth century, research and development have been enthusiastically performed on photonic crystals. It is expected that photonic crystals can be used to realize amplification, traps, non-threshold lasers, optical integrated circuits, and other circuit elements. Practical research on one-dimensional and two-dimensional photonic crystals is proceeding more rapidly than research on practical use of three-dimensional photonic crystals. This is because one-dimensional and two-dimensional photonic crystals are relatively easy to manufacture. On the other hand, manufacturing a three-dimensional photonic crystal is not so easy.
[0004]
Referring to FIG. 6, a conventional example of a method of manufacturing a three-dimensional photonic crystal will be described. This method includes a self-organization method of a colloid crystal, a three-axis dry etching method, and a two-dimensional periodic structure for each layer. Methods such as a method of stacking and multiplexing are employed in combination. By stacking and multiplexing the two-dimensional periodic structure for each layer, a woodpile structure shown in FIG. 6A is formed, and a three-dimensional photonic crystal is formed. FIG. 6B is a diagram showing the woodpile structure of FIG. 6A viewed from above (see Non-Patent Document 1).
[0005]
A method different from the previous method of completing a photonic band gap in the near-infrared region by laminating a two-dimensional periodic structure layer by layer has also been implemented. The first reported technology is a technology employing silicon micro-electromechanical system (MEMS) and integrated circuit technology. This technique is based on filleting technology, which deposits a thin film of raw material on the surface of the step, performs reactive ion etching, and then leaves a thin strip of raw material along the side of the step. (See Non-Patent Document 2).
[0006]
As a second reported technique, a three-dimensional photonic crystal is also constructed by laminating strip wafers and fusing them together (see Non-Patent Document 3).
Then, by observing the change in the intensity of the diffraction spot of the laser beam incident on the laminated strip at right angles, the alignment state of the wafer is accurately recognized (see Non-Patent Document 4).
In addition, a micromanipulation technology itself has been developed as the third reported technology, and a two-dimensional photonic crystal can be stacked using polystyrene microspheres as a stopper (see Non-Patent Document 4).
[0007]
[Non-patent document 1]
SCIENCE VOL 289 28 JULY2000 P.S. 605
[Non-patent document 2]
OPTICS LETTERS / Vol. 24, no. 1 / January 1, 1999 / P. 50
[Non-Patent Document 3]
S. Noda, K .; Tomada, N.M. Yamamoto and A. Chutinan, Science, 289 (2000) 604.
[Non-patent document 4]
K. Aoki, H .; Hirayama and Y. Aoyagi, RIKEN Review, 33 (2001) 24-27.
[0008]
[Problems to be solved by the invention]
There is an increasing need to develop a reproducible manufacturing process suitable for manufacturing three-dimensional photonic crystals. For light of a wavelength being studied in the optical communication technology field, that is, light of a wavelength of 1310 nm to 1550 nm, a photonic band gap is obtained when the lattice spacing is about 400 nm. It is not easy to manufacture a three-dimensional photonic crystal spatially maintaining a periodicity with a lattice spacing of about 400 nm, and it is more difficult to actually manufacture a thick three-dimensional photonic crystal. The thickness of the eight dielectric thin film layers is the thickest as a three-dimensional photonic crystal as far as the inventor of the patent application knows, but the conventional manufacturing method has a three-dimensional photonic crystal having a greater thickness. This indicates that it is difficult to easily produce crystals.
[0009]
The present invention provides a method for manufacturing a three-dimensional photonic crystal in which a three-dimensional photonic crystal is manufactured while finely adjusting the position of the stacked two-dimensional patterning plates by nanomanipulation.
[0010]
[Means for Solving the Problems]
Stacking the formed two-dimensional patterning plates, coarsely adjusting the position in the two-dimensional direction using a cylinder, connecting each two-dimensional patterning plate to a microactuator, and fine-tuning the position in the two-dimensional direction; A method for manufacturing a three-dimensional photonic crystal, comprising the step of bonding and fixing the stacked two-dimensional patterning plates to each other, was configured.
Here, when finely adjusting the position of each two-dimensional patterning plate in the two-dimensional direction, the stacked two-dimensional patterning plates are irradiated with light at a plurality of different incident angles to control the microactuator while detecting the transmitted light. Thus, a method for manufacturing a three-dimensional photonic crystal was constructed.
[0011]
BEST MODE FOR CARRYING OUT THE INVENTION
A major advantage of the present invention is that a three-dimensional photonic crystal is formed based on a plate layer obtained by patterning at least eight or more dielectric thin films by employing a laminating method including a method of laminating dielectric thin films layer by layer. The point is that it can be manufactured with high precision. Adjustment of the lamination and position of the two-dimensional patterning plate of the dielectric thin film is performed by two separate steps. The lamination process of the two-dimensional patterning plate is a very easy process. Then, the step of adjusting the position between the plates is an extremely difficult step in the conventional example, but according to the present invention, the necessary position adjustment can be easily performed in real time. Since the positions of the two-dimensional patterning plates formed in different types of holes can be easily adjusted, a woodpile structure can be adopted as in the conventional example.
[0012]
【Example】
An embodiment of the present invention will be described with reference to FIG.
The three-dimensional photonic crystal can be manufactured by first stacking the two-dimensional patterning plate 10. The two-dimensional patterning plate 10 is manufactured using a dielectric semiconductor material such as silicon, indium phosphide, or gallium arsenide as a raw material. The two-dimensional patterning plate 10 has a surface area on the order of several mm ^{2 to} several cm ² and a thickness of several 100 nm. The two-dimensional patterning plate 10 includes four main parts, that is, a lattice part 11, a central round hole 12, a projection part 13, and a square hole 14. The grating portion 11 has a structure in which rods having a square cross section and slits formed between the rods are alternately arranged, which are formed by etching a thin plate made of the semiconductor material as a raw material. At the time of this etching, the raw material thin plate is etched while leaving the frame part around and the center part remaining. The width of the rods of the grating portion 11 and the dimensions of the slits between the rods are on the order of several 100 nm, and are formed to have dimensions that function at the optical communication wavelength. The center round hole 12 is a hole formed at the center and facilitates minute displacement of the two-dimensional patterning plate 10 when the two-dimensional patterning plate 10 is stacked and manipulated to form a photonic crystal. The diameter of the central round hole 12 is formed to be several hundred μm to several mm. The protrusion 13 is a key to positioning of the two-dimensional patterning plate 10 during manipulation on a nano scale. The protrusion 13 has a width of about several hundred nm and a length of the order of several mm to cm, and has a tip whose width is substantially equal to the inner space of the U-shaped arm 41 of the three-arm microactuator 4 described later. The engaging portion 131 is provided. The square holes 14 are formed in the corners of the frame by etching, and are used to integrally bond and fix the laminated two-dimensional patterning plates 10 after assembling a photonic crystal described later. The square hole 14 has a size of several mm ² .
[0013]
The procedure for assembling and manufacturing a three-dimensional photonic crystal will be described with reference to FIG.
(First step)
As a first step, the two-dimensional patterning plates 10 are sequentially stacked. The two-dimensional patterning plate 10 is stacked while inserting a long cylinder 2 made of a synthetic resin material into the central round hole 12, whereby the two-dimensional patterning plate 10 can be stably brought close to the two-dimensional photonic crystal 1. Become. The diameter of the cylinder 2 is smaller than the diameter of the central round hole 12 of the two-dimensional patterning plate 10 by about one period of the lattice of the lattice part 11. The two-dimensional patterning plate 10 used in the above stacking includes a two-dimensional patterning plate A having a lattice orientation shown in FIG. 1 and a two-dimensional patterning plate except that the lattice orientation is perpendicular to the plate A direction. A, two types of two-dimensional patterning plates B similar to A, which are alternately stacked, and eventually, a stack in which the lattice portions 11 in the two-dimensional patterning plate A and the lattice portions 11 in the two-dimensional patterning plate B intersect. Is configured.
[0014]
(Second step)
Next, with reference to FIG. 3, the second step will be described using 16 two-dimensional patterning plates 10 for convenience of description. Here, the number of the two-dimensional patterning plates 10 can be more than sixteen. FIG. 3 is a diagram showing a three-arm microactuator that performs nanomanipulation. FIG. 3 (a) is a diagram showing a top view, and FIG. 3 (b) is a diagram showing a side view. It is.
[0015]
The three-arm microactuator 4 shown in FIG. 3 can perform a nanoscale operation. The arm of the three-arm microactuator 4 is a U-shaped arm 41 having a diameter smaller than the thickness of the two-dimensional patterning plate 10. The three-arm microactuator 4 is driven with the accuracy of performing nanoscale operation positioning. Piezoelectric actuators and electric motors can be used for nanoscale operation. By providing a high-resolution glass scale encoder, it is possible to improve the control performance of positioning that is repeatedly performed on the nanoscale.
[0016]
The three U-shaped arms 41 of the three-arm microactuator 4 are inserted and positioned in the arm engaging portion 131 at the tip of the projection 13 of the two-dimensional patterning plate 10. In this case, a machine vision device having a camera, a frame grabber, or other machine vision hardware is used. The distance between the arm engaging portion 131 of the two-dimensional patterning plate 10 and the U-shaped arm 41 of the three-arm microactuator 4 must have an accuracy of at least ± 3 nm.
[0017]
Here, the following operation is performed. The first and third two-dimensional patterning plates 10A are positioned and fixed in a state where the arm engaging portions 131 of the protrusions 13 are inserted into the U-shaped arm 41 of the three-arm microactuator 4, and the second two-dimensional patterning plate 10B Is displaced by the U-shaped arm 41 via the arm engaging portion 131 in a state where the arm engaging portion 131 of the projection 13 is inserted into the U-shaped arm 41. That is, the second two-dimensional patterning plate 10B is displaced by a few hundred nm in the y direction by the U-shaped arm 41 to form a woodpile structure. Then, the second two-dimensional patterning plate 10B is displaced in the x direction by the U-shaped arm 41 and pressed against the cylinder 2, and then the U-shaped arm 41 is slightly displaced in the y direction to move the second two-dimensional patterning plate 10B. The bandgap that slightly rotates and satisfies the orthogonal condition close to 90 ° with each other is maximized with a precision of a few nm in sensitivity, and the second two-dimensional patterning plate 10B is positioned here. I do.
[0018]
4, the manufacturing process is controlled by an adjustment control unit having a computer in which software is stored. The first to third two-dimensional patterning plates 10A, 10B, and 10A are irradiated with light, and when the position between the plates is optimized, the transmitted light is detected by the light detection element 51 and the intensity of the diffracted light is reduced. The two-dimensional patterning plate 10 is read in real time by the spectrum detection device 5 and the nano displacement adjustment is completed. The nano displacement adjustment ends when a predetermined diffracted light intensity is confirmed.
[0019]
Subsequently, the fourth two-dimensional patterning plate 10B is stacked, and the second, third, and fourth two-dimensional patterning plates 10 are similarly adjusted to adjust the third two-dimensional patterning plate 10A to adjust the intensity of the diffracted light. The operation is performed, which is easier than the previous adjustment operation. If complete planarization is achieved in the processing step of thinning the semiconductor material substrate as a raw material, displacement adjustment in the z direction is not required.
Further, the fifth two-dimensional patterning plate 10A is stacked, and the third, fourth, and fifth two-dimensional patterning plates 10 are similarly adjusted to adjust the fourth two-dimensional patterning plate 10B to adjust the diffracted light intensity. do. Hereinafter, the same operation is continued. Finally, optimization of the crystal arrangement of the three-dimensional photonic crystal is achieved.
[0020]
(Third step)
When the positions of all the two-dimensional patterning plates 10 have been adjusted to maximize the diffraction intensity of the incident light, a third step of injecting the photocurable synthetic resin into the large square holes 14 is performed. In this case, the square hole 14 of the two-dimensional patterning plate 10 at the lowermost surface of the stacked body is not penetrated by etching about half the thickness. By curing the photocurable synthetic resin injected into the square holes 14, the laminate of the three-dimensional patterning plate 10 is fixed by four synthetic resin rods, and the production of the three-dimensional photonic crystal is completed.
[0021]
【The invention's effect】
As described above, according to the present invention, it is possible to easily manufacture a three-dimensional photonic crystal, which has conventionally been difficult to manufacture.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a two-dimensional patterning plate.
FIG. 2 is a perspective view illustrating how to assemble a two-dimensional patterning plate.
FIG. 3 is a diagram illustrating a three-arm microactuator.
FIG. 4 is a diagram illustrating an adjustment control unit used for assembling a two-dimensional patterning plate.
FIG. 5 illustrates a photonic crystal.
FIG. 6 is a diagram illustrating a conventional example of a three-dimensional photonic crystal.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Two-dimensional photonic crystal 10 Two-dimensional patterning plate 11 Lattice part 12 Center round hole 13 Projection part 131 Arm engaging part 14 Square hole 2 Cylinder 4 Three-arm microactuator 41 U-arm 5 Spectrum detection device 51 Light detection element 6 Adjustment Control unit

Claims (2)

Stacking the formed two-dimensional patterning plates, and roughly adjusting the position in the two-dimensional direction using a cylinder;
Connecting each two-dimensional patterning plate to a microactuator and fine-tuning the position in the two-dimensional direction to maximize the diffraction intensity of the incident light;
A step of bonding and fixing between the laminated two-dimensional patterning plates,
A method for producing a three-dimensional photonic crystal, comprising: The method for manufacturing a three-dimensional photonic crystal according to claim 1,
When finely adjusting the position of each two-dimensional patterning plate in the two-dimensional direction, the laminated two-dimensional patterning plates are irradiated with light having a plurality of different incident angles,
A method for manufacturing a three-dimensional photonic crystal, comprising controlling a microactuator while detecting transmitted light.

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