JPH02222909A - Manufacture of waveguide type optical device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for manufacturing a waveguide optical device, and more particularly, to a method for manufacturing a waveguide optical device, and more specifically, a waveguide optical device that is incorporated into an optical integrated circuit and is equipped with a channel optical waveguide and various passive elements. The present invention relates to a method for manufacturing a waveform optical device in a simple and short number of steps.

(Prior Art) In a waveguide optical device incorporated into an optical integrated circuit, a channel optical waveguide with a predetermined pattern and various waveguide passive elements are formed on a semiconductor substrate such as a Si substrate.

For example, conventional channel optical waveguides are typically manufactured by laminating a cladding layer and a core layer in this order over the entire surface of a predetermined substrate, and then applying photolithography to the core layer.

To explain this with respect to a ridge-shaped channel optical waveguide, first, a cladding layer with a desired refractive index is formed on the surface of the substrate, and then a core layer made of a material having a refractive index higher than that of the cladding layer is formed on top of this. .

Next, after applying a resist material to the entire surface of this core layer,
A mask in which a desired channel optical waveguide pattern is hollowed out is placed here, and exposure and development processing is performed.

Then, after removing the mask, the undeveloped portions of the resist material are etched. Thereafter, the core layer portion exposed from below the removed portion of the resist material is etched away, and finally the developed portion of the resist material (
(same pattern as the channel optical waveguide pattern) is removed. In this way, a channel optical waveguide with a desired pattern is formed on the cladding layer.

In addition, grading of a production example of a waveguide passive element will be explained.

First, for grading, the refractive index modulation type, the cross section of which is shown in Fig. 19(a), Fig. 19(Φ), and Fig. 19(C), and Fig. 20(a), Fig. 20( b), and a relief type as illustrated in FIG. 20(C).

In the case of refractive index modulation type grading, portions t2a having a different refractive index from other portions are periodically formed in the optical waveguide 12 formed on the two substrates 11. In the case of relief-type grading, an optical waveguide 12 is formed on the substrate 11, and convex reliefs 13 made of a material with a higher refractive index than the optical waveguide 12 are periodically formed on the optical waveguide 12. is formed (Fig. 20(a)
, FIG. 20 (Q))) There is also a type in which convex reliefs 13 are periodically formed directly on the optical waveguide 12, as shown in FIG. 20 (C).

Conventionally, when creating a refractive index modulation type of these gradings, the sensitivity to these beams is increased by direct exposure using two-beam interference of a laser beam or direct exposure with an electron beam on the optical waveguide 12 formed on the substrate 11. Refractive index modulation is periodically recorded in the medium of the optical waveguide 12.

However, if the medium of the optical waveguide 12 is a material that has no sensitivity to the beam, the above method cannot be applied, so in that case, the grading is formed by periodically patterning using the photolithography technique described above, , by applying ion exchange and thermal diffusion to achieve refractive index modulation in that area.

In the case of relief-type grading, it is formed by a combination of periodic patterning of the grading using photolithography and thin film deposition or etching of a relief material.

(Problems to be Solved by the Invention) However, in the case of the above-mentioned conventional method for manufacturing a channel optical waveguide, the number of steps required to complete the channel optical waveguide is extremely large and complicated, so the productivity is low. The problem is that it is low.

In addition, since the formation of the channel optical waveguide is progressed by etching, the side portions of the channel optical waveguide to be formed are likely to be eroded by the etching and become rough.
As a result, a problem arises in that the transmission loss of the formed channel optical waveguide increases.

In addition, in the case of waveguide optical devices explained using grading as an example, since these waveguide optical devices are formed on the circuit pattern of the optical waveguide,
This requires the steps of forming an optical waveguide in advance and forming a circuit pattern thereon.

Therefore, this case also causes an increase in the number of steps. In particular, in the case of forming a waveguide optical element using photolithography, the productivity is extremely low because the photolithography itself requires many steps, as described above.

The present invention solves the above-mentioned problems when manufacturing waveguide optical devices, and provides a method for easily manufacturing channel guides and waveguide optical elements with reduced transmission loss using a small number of steps. In particular, in the production of a waveguide type optical element, the object is to provide a method that can form a waveguide type optical element at the same time as creating an optical waveguide.

(!Means for Solving Problem I) In order to achieve the above-mentioned object, in the present invention, raw material A of material A having a desired refractive index is jetted onto the substrate surface from a jetting jig having a predetermined diameter. Step of forming a fine particle layer by depositing (hereinafter referred to as the first step); A step of forming a fine particle layer on the surface of the formed fine particle layer or at a predetermined location within the fine particle layer in the formation process from the jetting jig to have a desired refractive index. Step of forming a precursor of the target element by ejecting and depositing raw material B of material B (hereinafter referred to as the second step):
and a step of converting the raw material A and the raw material B into the raw material A and the raw material B, respectively, to transform the fine particle layer and the precursor into an optical waveguide and a target element, respectively (hereinafter referred to as the third step). Provided is a method for manufacturing a waveguide optical device, characterized by comprising;

In the method of the present invention, the first step and the second step described above are continuous steps performed using the same ejection jig.

In addition, the above-mentioned target element refers to a channel optical waveguide and a waveguide type optical element of each scale such as grading, lens, and prism. Therefore, the waveguide type optical device in the present invention refers to the above-mentioned channel optical waveguide. An optical circuit component in which a waveguide type optical element is integrally formed.

Material A and material B in the present invention are materials having a desired refractive index, and specifically, they are preferably glass containing quartz as a main component. B is subjected to predetermined processing, for example,
Preferably, it can be formed by performing a heat treatment at a high temperature.

Although the composition of raw materials A and B is not particularly limited, it is preferable that they are fine particles of glass, for example.
ni, 5iej! gyaTICj! It is preferable that the glass particles be obtained by a flame hydrolysis reaction in which a metal chloride such as 08 or Ht is converted into an oxide using a flame of 08 or Ht.

Further, the ejection jig for ejecting the raw material A or the raw material Bt is preferably a microtorch having an aperture approximately equal to the width of the channel when the target element to be formed is a channel optical waveguide. When the element is a waveguide type photodynamic element, it is preferable to use a microtorch having a diameter necessary for shaping the shape of the element.

In the first step of the present invention, raw material A is deposited on the surface of the substrate to form a fine particle layer. In this case, the substrate and the ejection jig may be moved relative to each other, such as by fixing the substrate and scanning the ejection jig on its surface, or vice versa, by fixing the ejection jig and moving the substrate. By doing so, the formation of a fine particle layer is advanced.

The second step is a step of forming a precursor of the target element on the fine particle layer formed in the first step.

In this case, the raw material B of the material B having a refractive index higher than that of the material A is spouted onto the surface of the fine particle layer of the raw material A of the material A, and the raw material B of the material B has a refractive index higher than that of the material A, and the material B is spouted along the pattern of the channel optical waveguide to be formed. By sweeping the ejection jig, a precursor of the channel optical waveguide pattern is formed. Further, by ejecting the raw material B, a precursor of the waveguide passive element is formed in the fine particle layer of the raw material A so that the intended waveguide passive element is formed.

In the third step, the fine particle layer (raw material A) is transformed into material A by performing a predetermined process on the fine particle layer formed through the first and second steps and the precursor of the target element. A precursor (raw material B) is converted to material B.

For example, if you use the glass particles mentioned above as raw materials A and B and apply heat treatment as the treatment, the material A,
Both B become glass, but at that time, part of material B diffuses to material A located below, and as a result, part of material B is located on the surface of material A and other parts A channel optical waveguide and a waveguide-type passive element located within the material B are formed in the portion.

(Embodiments of the Invention) The method of the present invention will be explained in more detail below based on the accompanying drawings.

Example 1 FIGS. 1 to 3 are process diagrams illustrating a method for forming a ridge-shaped channel optical waveguide.
On the entire surface of the material, fine particles N2 of a predetermined thickness are formed by ejecting raw material A, which will become a crund glass (material A) with a predetermined refractive index, from the microtorch 3.

While moving the microtorch 3 in accordance with the pattern of the desired channel optical waveguide with respect to the fine particle layer 2, the core glass fine particles (material B having a higher refractive index than material A) obtained by the flame hydrolysis reaction are transferred from the microtorch 3 to the fine particle layer 2. The raw material B) is spouted to form a pattern 4 of the raw material B (first
Fig. 2).

This is then heated at a high temperature. As a result of this treatment, as shown in FIG. 3, the fine particle layer 2 for the raw material and the pattern 4 for the raw material B are changed to a glass layer 2° and a glass layer pattern 4'', respectively. pattern 4”
A part of it diffuses into the glass layer (cladding N) 2°. Thus, a desired pattern of wedge-shaped channel optical waveguide is formed on the ground layer 2.

Embodiment 2 FIGS. 4 to 6 are process diagrams illustrating the case of forming a buried channel optical waveguide by the method of the present invention.

In the figure, a predetermined substrate 1 is first prepared.

Then, from the microtorch 3, crushed glass fine particles (raw material A) obtained by the flame hydrolysis reaction of S i C1a are
) is ejected onto the surface of the substrate 1. At this time, the fine particle layer 2 of the raw material A is formed by scanning the microtorch 3 so that a groove pattern 5 having the same pattern as the desired channel optical waveguide is formed on the surface (FIG. 4).

Next, while changing the composition of the ejected glass particles from the microtorch 3 to core glass particles (raw material B) and ejecting them, the microtorch 3 is moved along the groove pattern 5 to inject the core glass particles into the groove pattern 5. is filled to form a layer pattern 4 of raw material B (FIG. 5).

Thereafter, the microtorch 3 is moved over the entire surface while the raw material ejected from the microtorch 3 is changed into crushed glass fine particles (raw material A) and spouted again to form a fine particle layer 6 (FIG. 6).

Finally, by heating the whole, the fine particle layers 2.6 are vitrified and changed into cladding layers, and the raw material B
The layer pattern 4 changes into a core pattern. Thus,
A waveguide optical device having a buried channel optical waveguide is obtained.

Embodiment 3 FIGS. 7 to 10 are process diagrams for forming another buried channel optical waveguide.

In the figure, first, a substrate 1 is prepared, and on the surface of this substrate 1, the aforementioned microtorch is moved to deposit clad glass fine particles (raw material A) to form a fine particle layer.
Subsequently, core glass fine particles (raw material B) are deposited on the half surface in an amount corresponding to the thickness of the channel optical waveguide to be formed, thereby forming a first fine particle layer 2 having a stepped portion 2b.
form a (Figure 1).

Next, core glass fine particles (raw material B) are ejected from the microtorch onto the stepped portion 2b of the first fine particle layer 2a,
Form a desired layer pattern 4 using raw material B (Fig. 8)
, Then, while ejecting the clad glass fine particles (raw material A) from the microtorch again, the first fine particles F12a
The remaining surface is scanned to make the entire surface flat (Figure 9).

Next, while ejecting clad glass fine particles (raw material A) from the same microtorch, second fine particles [2c] are formed on the surface shown in FIG. 9 (FIG. 10). By performing such heat treatment, both of the layer pattern 4° fine particle layers 2a and 2c of raw material B are vitrified, and a buried channel optical waveguide is formed therein.

Example 4 FIGS. 11 and 12 are process diagrams showing an example of manufacturing relief-type grading.

In FIG. 11, fine particles N2 are formed on the surface of the substrate 1 by the microtorch 3. As shown in FIG. At this time, Example 1
~By the method shown in Example 3, in the fine particle layer,
A channel optical waveguide (not shown) having a desired pattern is formed in advance.

Next, by changing the raw material ejected from the microtorch 3, a relief-shaped grading raw material is deposited on the channel optical waveguide in a predetermined shape to form a relief precursor 7 on the fine particle layer 2. (Figure 11).

This operation is periodically repeated to form a desired number of groups of relief precursors on the fine particle layer 2.

Finally, the whole is heated to vitrify the fine particle layer 2 (the cladding layer and the core layer contained therein) and the relief-shaped precursor 7.

A waveguide optical device with relief-shaped grading is thus obtained.

Example 5 FIGS. 13 to 16 are process diagrams showing a manufacturing example of refractive index modulation type grading.

First, in FIG. 13, the microtorch 3 is scanned over the surface of the substrate 1 to form a fine particle layer 8a of a predetermined thickness from the raw material A. A channel optical waveguide (not shown) having a desired pattern is formed in this fine particle layer 8a by the method of Examples 1 to 3. Next, the raw material A is again ejected onto the fine particle layer 8a so as to have the same thickness as the grading to be formed, and is deposited halfway (FIG. 13).

Subsequently, the raw material ejected from the microtooth 3 is converted into raw material B for grading, which is deposited in a predetermined shape to form a precursor 9 for grading (FIG. 14). The ejected raw material is again used as raw material A for fine particle NBa.
and continue scanning (Fig. 15).

By repeating such operations, a desired number of grading precursors 9 arranged periodically in parallel are formed in the fine particle layer 8 (FIG. 16).

Finally, the fine particle layer 8 and the grading precursor 9 are vitrified all at once by heating the whole. (Thus, a waveguide optical device with index-modulated grading is obtained.

Example 6 FIGS. 17 and 18 are process diagrams for manufacturing a two-dimensional convex lens as a waveguide optical element.

In this case as well, a fine particle layer 8a is formed on the substrate 1 in the same manner as in Example 5, and a lens-shaped high refractive region 1 is formed on the fine particle layer 8a by changing the scanning mode of the microtorch 3.
form 0. Then, the entire structure is heated and vitrified to obtain a waveguide optical device in which a convex lens is embedded in the glass layer (cladding layer) 8.

(Effects of the Invention) As is clear from the above explanation, according to the method of the present invention, the channel optical waveguide and the Various waveguide type optical elements can be formed. Therefore, it is possible to create an optical waveguide, a channel optical waveguide, and a waveguide optical element in a continuous process.
Since the number of steps is significantly reduced compared to the conventional method, its industrial value is extremely large.

4゜Also, since no enchantment is used in creating the channel optical waveguide, surface roughening of the formed channel optical waveguide is suppressed, and as a result, a channel optical waveguide with reduced transmission loss can be manufactured. .

[Brief explanation of the drawing]

Figures 1 to 3 are process diagrams illustrating an example method for forming a ridge-type channel optical waveguide, and Figures 4 to 6 illustrate an example method for forming a buried-type channel optical waveguide. Illustrative process diagrams, FIGS. 7 to 10 are process diagrams illustrating other embodiment methods for forming a buried channel optical waveguide, and FIGS. 11 and 12 are embodiments for forming relief-type grading. Process diagrams illustrating the method, Figures 13-1
FIG. 6 is a process diagram illustrating an example method of forming a refractive index modulation type grading, FIGS. 17 and 18 are process diagrams illustrating an example method of forming a two-dimensional convex lens, and FIG.
The figure is a schematic diagram showing the grading of the refractive index modulation type.
Figure 0 is a schematic diagram showing relief-shaped grading. DESCRIPTION OF SYMBOLS 1...Substrate, 2, 6.8... Fine particle layer, 3... Microtorch, 4... Channel optical waveguide precursor, 5
... Concave groove pattern, 7... Precursor of relief type grading, 9... Precursor of refractive index modulation type grading, 10... Precursor of waveguide type convex lens.

Claims (5)

[Claims] (1) Step of forming a fine particle layer by ejecting and depositing raw material A of material A having a desired refractive index onto the substrate surface from a jetting jig with a predetermined diameter; a step of forming a precursor of a target element by ejecting and depositing raw material B of material B having a desired refractive index from the ejection jig at a predetermined location in a certain fine particle layer; and the raw material A and the raw material. A method for manufacturing a waveguide optical device, characterized in that the fine particle layer and the precursor are transformed into an optical waveguide and a target element, respectively, by performing a process of transforming B into the material A and the material B, respectively. (2) The guide according to claim 1, wherein the raw material A and the raw material B are glasses mainly made of quartz, the raw material A and the raw material B are glass particles obtained by a flame hydrolysis reaction, and the treatment is a heat treatment. A method for manufacturing a waveform optical device. (3) The method for manufacturing a waveguide optical device according to claim 1, wherein the target element is a channel optical waveguide or a waveguide passive element. (4) Fine particles formed by ejecting and depositing raw material A of material A having a desired refractive index on the substrate surface or thereon from an ejection jig having an aperture approximately equal to the width of the channel optical waveguide to be formed. On the surface of the layer, raw material B of material B having a desired refractive index larger than the refractive index of material A,
At least two raw material layers are formed by ejecting and depositing from the ejection jig, and then a treatment is performed to transform the raw material A and the raw material B into the raw material A and the raw material B, and the raw material A is deposited on the raw material A. 2. The method of manufacturing a waveguide optical device according to claim 1, wherein a channel optical waveguide made of said material B is formed. (5) The surface of a substrate, the surface of a fine particle layer formed by depositing raw material A of material A having a desired refractive index on the surface of the substrate by jetting it from a jetting jig of a predetermined diameter, or the surface of a fine particle layer that is in the process of being formed. A precursor of a waveguide passive element is formed by ejecting the raw material B having a desired refractive index from the ejection jig at a predetermined location in the layer, and then the raw material A and the raw material B are injected into the material B and the raw material B. 2. The method for manufacturing a waveguide optical device according to claim 1, wherein the fine particle layer and the precursor are transformed into an optical waveguide and a waveguide passive element, respectively, by performing a treatment to transform them into B.