JP3100154B2 - Composite line for optoelectronic devices - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial applications]

The present invention relates to an optical element, a semiconductor element, and an OEIC of an optoelectronic device.
The present invention relates to a composite line connecting between (optical integrated circuits) and the like, capable of transmitting an optical signal, transmitting an electric signal, and flowing a power supply current.

[0002]

[Prior art]

2. Description of the Related Art In recent years, as a device aiming at high-speed information processing, research on an optoelectronic device, which is mounted with an optical element, an OEIC, etc. together with a semiconductor element, has been actively conducted. OEIC refers to a hybrid integrated circuit including an optical element and a semiconductor element. Conventionally, in this optoelectronic device, a signal line for transmitting an electric signal or a power supply line for transmitting a power supply current, which connects between a semiconductor element, an optical element, an OEIC, or the like mounted thereon, and an optical waveguide for transmitting an optical signal are referred to as an optoelectronic device. Are separately arranged in a plane on the substrate.

[0003]

[Problems to be solved by the invention]

By the way, in the above optoelectronic device, when a signal line, a power supply line, and an optical waveguide are separately arranged in a plane on the substrate, the total number of the lines increases, and the number of the lines increases on the substrate. In addition, the arrangement of the lines becomes difficult, and the wiring space of those lines on the substrate is increased, so that the optoelectronic device cannot be simplified and downsized.

In order to solve these problems, a signal line, a power supply line, and an optical waveguide are formed to have a very small width, and a large number of such lines are arranged at a small pitch on a substrate at high density. It is possible to do.

However, in such a case, the conductor resistance of the signal line or the power supply line increases, and the conductor loss of an electric signal or power supply current transmitted or flowing through those lines increases.
An optical signal easily leaks out of the optical waveguide, and the optical signal cannot be transmitted efficiently through the optical waveguide. At the same time, crosstalk occurs between signal lines arranged at a small pitch, or an optical signal leaked from one adjacent optical waveguide arranged at a small pitch mixes with an optical signal transmitted through the other optical waveguide. In addition, so-called optical signal crosstalk occurs between optical waveguides.

[0006] The present invention has been made in view of such problems,
On a substrate of an optoelectronic device, a signal line, a power supply line, and an optical waveguide that connect between a semiconductor element, an optical element, an OEIC, and the like, increase a conductor resistance value of the line, or crosstalk between the lines. The purpose of the present invention is to provide a composite line of an optoelectronic device (hereinafter, referred to as a composite line) which can be provided at a high density without causing a wiring space or causing a crosstalk of optical signals or optical signals. I have.

[0007]

In order to achieve the above object, a first composite line according to the present invention comprises an optical waveguide for transmitting an optical signal having the same width and a signal line or a signal line formed on a substrate for an optoelectronic device. A metal line used as a power supply line is alternately stacked in three or more layers so as to be vertically overlapped with the optical waveguide disposed in the lowermost layer, and the refractive index n ₁ of the light of the substrate. The refractive index n ₂ of the light of the optical waveguide and the refractive index n ₃ of the light of the gas in contact with both side surfaces or the upper surface of the optical waveguide have a relationship of n ₁ <n ₂ and n ₃ <n _2. It is characterized by:

A second composite line according to the present invention is provided on a substrate for an optoelectronic device,
A metal line used for a signal line or a power supply line formed to have the same width and an optical waveguide for transmitting an optical signal are formed in three or more layers so that the metal lines are arranged in the lowermost layer and overlap vertically. The refractive index n ₂ of the light of the optical waveguide and the refractive index n ₃ of the gas of the gas contacting both side surfaces or the upper surface of the optical waveguide are n ₃ <
is characterized in that a relationship of n _2.

In the first or second composite line according to the present invention, a material that covers an upper surface or a lower surface of the optical waveguide formed between the metal line and the optical waveguide and having the same width as the optical waveguide and the metal line. A material layer in which the refractive index n ₄ of the light is n ₄ <n ₂ with respect to the refractive index n ₂ of the light of the optical waveguide, and the material layer is vertically overlapped with the optical waveguide and the metal line. It is preferable to adopt a structure in which the layers are stacked as described above.

[0010]

[Action]

In the first or second composite line having the above-described configuration, an optical signal that is about to leak out from the inside of the optical waveguide to the outside is converted into a metal line covering the upper surface or the lower surface of the optical waveguide, and the refractive index of light is reduced. n ₁ of the substrate, material layer with a refractive index of light n _4, or both sides, or the refractive index of the upper surface is in contact light of the optical waveguide a gas n _3, the refractive index of the light waveguide n ₂ Then n ₁ <
A metal line, a substrate, a material layer, or a gas such as air having a relationship of n ₂ , n ₃ <n ₂ , and n ₄ <n ₂ can be reflected into the optical waveguide or totally reflected. Then, the optical signal can be transmitted without leaking the inside of the optical waveguide to the outside.

In the first or second composite line in which a material layer is laminated between the optical waveguide and the metal line, the upper surface or the lower surface of the optical waveguide is directly covered with the metal line. In comparison, the refractive index n _{4 of the} light is n ₄ <n ₂ , and the material layer having a relationship of n ₄ <n ₂ allows the optical signal to leak out from the inside of the optical waveguide to the outside through the upper surface or the lower surface of the optical waveguide. Everything,
Total reflection can be reliably performed inside the optical waveguide without irregular reflection. Then, the optical signal transmitted through the optical waveguide is
The inside of the optical waveguide can be efficiently transmitted to the other end with little transmission loss. The reason is that the inner surface of the metal line that is in contact with the upper surface or the lower surface of the optical waveguide is difficult to be formed into a mirror-like shape, and when the inner surface is enlarged, fine irregularities are formed on the inner surface of the metal line. There are many. Therefore, when an optical signal that is about to leak out from the upper surface or the lower surface of the optical waveguide to the outside is reflected by the inner surface of the metal line into the optical waveguide, a part of the optical signal becomes a metal. This is because irregular reflection occurs due to minute irregularities existing on the inner side surface of the line. Then, all the optical signals that are about to leak out from the upper surface or the lower surface of the optical waveguide are totally reflected inside the optical waveguide, and the inside of the optical waveguide can be efficiently and accurately transmitted to the other side. Because you can't.

Also, a metal line laminated between optical waveguides laminated in two or more layers above and below it, or a material layer in addition thereto,
It is possible to reliably prevent optical signals transmitted through one of the upper and lower optical waveguides from being mixed into the other optical waveguide and to cause crosstalk of the optical signal between the upper and lower optical waveguides.

In addition, a metal line laminated between optical waveguides laminated in two or more layers above and below it, or a material layer in addition thereto,
Unnecessary external light from the upper surface of the optical waveguide below the metal line or the material layer enters the inside of the optical waveguide as noise, or unnecessary external light enters from the lower surface of the optical waveguide above the metal line or the material layer. External light can be prevented from entering the inside of the optical waveguide as noise.

Further, each of the optical waveguides stacked in two or more layers above and below it can be independently used as an optical waveguide for transmitting an optical signal. Alternatively, each of the metal lines stacked in two or more layers above and below the metal lines can be independently used as a signal line for transmitting an electric signal, or can be independently used as a power supply line for flowing a power supply current.

In the first or second composite line, an optical waveguide and a metal line having the same width are formed, and a material layer having the same width as the optical waveguide and the metal line is laminated between them. Because they are alternately stacked on the substrate in three or more layers so that they are vertically stacked without being stacked or stacked, they are used as optical waveguides for transmitting optical signals, signal lines for transmitting electric signals, or power supply lines for flowing power supply current. The metal lines to be formed can be arranged on the substrate in two or more layers not vertically in the horizontal direction but three-dimensionally in the vertical direction. And the optoelectronic device having the optical waveguide and the metal line used for the signal line or the power supply line can be made compact.

In the second composite line, since a metal line or a material layer is additionally provided between the substrate and the optical waveguide, the refractive index of light of the substrate may be made irrelevant. it can.
In addition, substrates made of various materials can be used.

[0017]

【Example】

Next, embodiments of the present invention will be described with reference to the drawings. 1 to 3 show a preferred embodiment of the first composite line of the present invention. FIG. 1 is a partial perspective view thereof, and FIG. 2 or 3 is an enlarged side sectional view thereof. Hereinafter, an embodiment of this figure will be described.

[0018] In FIG, 10 is a substrate made of ceramic or the like in which the plate, the refractive index of the light is formed of alumina ceramics or the like of n _1. Reference numeral 20 denotes a narrow-band optical waveguide having a refractive index of light.
It is formed of quartz glass or the like of n _2. Numeral 30 is a strip-shaped metal line used for a signal line for transmitting an electric signal or a power supply line for flowing a power supply current,
It is made of aluminum, gold or the like. The optical waveguide 20 and the metal line 30 are alternately laminated on the substrate 10 in three or more layers (six layers in FIGS. 1 and 2 and five layers in FIG. 3). In the first composite line shown in FIGS. 1 and 2, the upper surface of the uppermost optical waveguide 20 is covered with a metal line 30. On the other hand, in the first composite line shown in FIG. 3, the upper surface of the uppermost optical waveguide 20 is exposed to a gas such as air. The optical waveguide 20 and the metal line 30 are formed to have the same width. An optical waveguide 20 is arranged at the lowermost layer in contact with the substrate 10. The optical waveguides 20 and the metal lines 30 are alternately stacked on the substrate 10 so as to overlap each other without any irregularities.

The refractive index n ₁ of light of the substrate 10 and the refractive index n ₂ of light of the optical waveguide 20
If, the both side surfaces or the refractive index n ₃ of the gas such as air light its upper surface in contact with the optical waveguide _{20, n 1 <n 2,} n 3 < as a relationship of n _2, the substrate 10 and the optical waveguide Twenty components are each selected. The first composite line shown in FIGS. 1 to 3 is configured as described above.

In the first composite line, when an optical signal is transmitted through the optical waveguide 20, the light that leaks from the inside of the optical waveguide 20 to the outside through the upper surface, the lower surface, or both side surfaces of the optical waveguide 20. The signal, the inner surface of the metal line 30 covering the upper surface or the lower surface of the optical waveguide 20, the gas such as air in contact with both side surfaces or the upper surface of the optical waveguide 20, or the lower surface of the optical waveguide 20 is in contact. The light can be reflected inside the optical waveguide 20 by the substrate 10. Then, the optical signal can be transmitted to the optical waveguide 20 without leaking from the inside to the outside.

An optical waveguide 20 for transmitting an optical signal or a metal line 30 for transmitting an electric signal or flowing a power supply current is connected to the substrate 10.
In addition, it is not three-dimensionally arranged in the horizontal direction but two- or more layers in the vertical direction. Further, the size of the optoelectronic device having the optical waveguide 20 and the metal line 30 for transmitting an electric signal or flowing a power supply current can be reduced.

Further, each of the optical waveguides 20 stacked in two or more layers above and below it can be independently used as an optical waveguide for transmitting an optical signal. Alternatively, each of the metal lines 30 stacked in two or more layers above and below the metal lines 30 may be independently used as a signal line for transmitting an electric signal, or may be independently used as a power supply line for flowing a power supply current.

The metal line 30 reliably prevents unnecessary light noise from entering the inside of the optical waveguide 20 from outside the optical waveguide 20 through the upper or lower surface of the optical waveguide 20 covered by the metal line 30. be able to.

Further, the optical signal transmitted through one optical waveguide 20 of the optical signal transmitted through the optical waveguide 20 stacked in two or more layers above and below it is mixed into the other optical waveguide 20, and the optical signal is transmitted between the two. Optical waveguides stacked on top of each other
The metal line 30 laminated between the two can surely prevent this.

FIGS. 4 to 7 show other preferred embodiments of the first composite line of the present invention, and specifically show enlarged side sectional views thereof. Hereinafter, an embodiment of this figure will be described.

In the first composite line shown in the figure, between the optical waveguide 20 and the metal line 30, a material layer 40 covering the upper surface or the lower surface of the optical waveguide 20 formed to have the same width as the optical waveguide 20 and the metal line 30. Are stacked so as to overlap the optical waveguide 20 and the metal line 30 without any irregularities in the vertical direction. In the first composite line shown in FIGS. 4 and 6, a material layer 40 is laminated on all the upper surfaces or lower surfaces of the optical waveguide 20 which are in contact with the metal line 30. On the other hand, in the first composite line shown in FIGS. 5 and 7, the material layer 40 is laminated on a part of the upper surface or lower surface of the optical waveguide 20 which is in contact with the metal line 30, and the other optical waveguide 20 has one layer. The upper or lower surface of the part is in direct contact with the metal line 30. The material layer 40 is formed of quartz glass or the like having a light refractive index n ₄ lower than the light refractive index n ₂ of the optical waveguide 20. The rest is configured in the same way as the first composite line shown in FIGS. 1 to 3 described above, and its operation is the same as that of the first composite line shown in FIGS. 1 to 3 except for the following points. It is the same as the composite line.

In the first composite line, when an optical signal is transmitted to the optical waveguide 20, from the inside to the outside of the optical waveguide 20 through the upper or lower surface of the optical waveguide 20 covered by the material layer 40. The optical signal to be leaked is entirely reflected inside the optical waveguide 20 without being irregularly reflected by the smooth inner surface of the material layer 40 covering the upper surface or the lower surface of the optical waveguide 20. Can be reflected. Then, the optical signal can be efficiently transmitted from the inside of the optical waveguide 20 to the other end thereof with little transmission loss.

Also, through the upper or lower surface of the optical waveguide 20 covered by the metal line 30 or the material layer 40, unnecessary light noise entering the optical waveguide 20 from the outside of the optical waveguide 20 is prevented. Alternatively, it can be surely prevented by the material layer 40.

Further, the optical signal transmitted through one optical waveguide 20 of the optical signal transmitted through the optical waveguide 20 stacked in two or more layers above and below it is mixed into the other optical waveguide 20, and the optical signal is transmitted between the two. Optical waveguides stacked on top of each other
A metal line 30 or material layer stacked between 20
40 can be surely prevented.

8 to 10 show a preferred embodiment of the second composite line of the present invention, FIG. 8 is a partial perspective view thereof, and FIG. 9 or 10 is an enlarged side sectional view thereof. Hereinafter, an embodiment of this figure will be described.

In the second composite line shown in the figure, a metal line 30 in the form of a narrow band made of aluminum, gold, or the like, and a quartz having a refractive index of light of n ₂ are formed on a plate-shaped substrate 10 made of alumina ceramic or the like. An optical waveguide 20 in the form of a strip made of glass or the like is alternately 3
The layers are stacked in layers or more (six layers in FIGS. 8 and 9 and five layers in FIG. 10). The optical waveguide 20 and the metal line 30 are formed to have the same width. The metal line 30 is arranged in the lowermost layer in contact with the substrate 10. The optical waveguides 20 and the metal lines 30 are alternately stacked on the substrate 10 so as to overlap each other without any irregularities. In the first composite line shown in FIGS. 8 and 9, the upper surface of the uppermost optical waveguide 20 is exposed to a gas such as air. On the other hand, in the first composite line shown in FIG. 10, the upper surface of the uppermost optical waveguide 20 is covered with the metal line 30. The refractive index n ₂ of the light of the optical waveguide 20 and the refractive index n ₃ of the light of a gas such as air on which both side surfaces of the optical waveguide 20 or the upper surface thereof are in contact,
The constituent members of the optical waveguide 20 are selected so that n ₃ <n ₂ .

The second composite line shown in FIGS. 8 to 10 is configured as described above. In this second composite line,
When an optical signal is transmitted to the optical waveguide 20, the optical waveguide
An optical signal that is about to leak out from the inside of the optical waveguide 20 to the outside through both side surfaces or the upper surface of the optical waveguide 20 is a gas such as air that is in contact with both side surfaces or the upper surface of the optical waveguide 20, or the optical waveguide 20.
The light can be reflected inside the optical waveguide 20 by the metal line 30 covering the upper or lower surface of the optical waveguide 20. Then, the optical signal can be transmitted to the optical waveguide 20 without leaking from the inside to the outside.

Further, since the metal line 30 is laminated between the substrate 10 and the optical waveguide 20, the refractive index of light of the substrate 10 can be made irrelevant. The substrate 10 can be made of various materials.

An optical waveguide 20 for transmitting an optical signal or a metal line 30 for transmitting an electric signal or flowing a power supply current is connected to the substrate 10.
In addition, it is not three-dimensionally arranged in the horizontal direction but two- or more layers in the vertical direction. Further, the size of the optoelectronic device having the optical waveguide 20 and the metal line 30 for transmitting an electric signal or flowing a power supply current can be reduced.

Further, each of the optical waveguides 20 stacked in two or more layers above and below it can be independently used as an optical waveguide for transmitting an optical signal. Alternatively, each of the metal lines 30 stacked in two or more layers above and below the metal lines 30 may be independently used as a signal line for transmitting an electric signal, or may be independently used as a power supply line for flowing a power supply current.

The metal line 30 reliably prevents unnecessary light noise from entering the inside of the optical waveguide 20 from outside the optical waveguide 20 through the upper or lower surface of the optical waveguide 20 covered by the metal line 30. be able to.

Further, the optical signal transmitted through one optical waveguide 20 of the optical signal transmitted through the optical waveguide 20 laminated in two or more layers above and below it is mixed into the other optical waveguide 20, and the optical signal is transmitted between the two. Optical waveguides stacked on top of each other
The metal line 30 laminated between the two can surely prevent this.

FIGS. 11 to 14 show another preferred embodiment of the second composite line according to the present invention, and specifically show a partially enlarged side sectional view thereof. Hereinafter, an embodiment of this figure will be described.

In the second composite line shown in the figure, between the metal line 30 and the optical waveguide 20, a material layer covering the upper surface or the lower surface of the optical waveguide 20 and the optical waveguide 20 formed to have the same width as the metal line 30. 40 are laminated so as to overlap with the optical waveguide 20 and the metal line 30 without any irregularities. In the second composite line shown in FIGS. 11 and 13, a material layer 40 is laminated on all the upper surfaces or lower surfaces of the optical waveguide 20 which are in contact with the metal line 30. On the other hand, in the second composite line shown in FIGS. 12 and 14, the material layer 40 is laminated on a part of the upper surface or lower surface of the optical waveguide 20 which is in contact with the metal line 30, and one of the other optical waveguides 20 is formed. The upper or lower surface of the part is in direct contact with the metal line 30. The material layer 40 is formed of quartz glass or the like having a light refractive index n ₄ lower than the light refractive index n ₂ of the optical waveguide 20. The rest is configured similarly to the second composite line shown in FIGS. 8 to 10 described above, and the operation thereof is the same as that of the second composite line shown in FIGS. 8 to 10 except for the following points. It is the same as the composite line.

In the second composite line, when an optical signal is transmitted to the optical waveguide 20, light that is about to leak from the upper or lower surface of the optical waveguide 20 that is in contact with the inner surface of the material layer 40. The signal can be totally reflected inside the optical waveguide 20 without being irregularly reflected by the smooth inner mirror surface of the material layer 40. Then, the optical signal can be efficiently transmitted from the inside of the optical waveguide 20 to the other end thereof with little transmission loss.

Further, through the upper surface or the lower surface of the optical waveguide 20 covered with the metal line 30 or the material layer 40, unnecessary light noise from entering the inside of the optical waveguide 20 from the outside of the optical waveguide 20 can be prevented. Alternatively, it can be surely prevented by the material layer 40.

Further, the optical signal transmitted through one optical waveguide 20 of the optical signal transmitted through the optical waveguide 20 laminated in two or more layers above and below it is mixed into the other optical waveguide 20, and the optical signal is transmitted between the two. Optical waveguides stacked on top of each other
A metal line 30 or material layer stacked between 20
40 can be surely prevented.

The first or second composite line described above is formed on the substrate 10 by, for example, the following first or second method.

In the first method, the thin film layer for forming the optical waveguide 20 and the thin film layer for forming the metal line 30 are provided with or without the thin film layer for forming the material layer 40 interposed therebetween. Next, three or more layers are alternately and widely formed on the substrate 10 formed into a smooth mirror surface by sputtering or the like. Next, the thin film layers laminated and formed on those substrates 10 are formed in a predetermined pattern shape by an etching process. And
The optical waveguide 20 and the metal line 30, with or without the material layer 40 interposed between the optical waveguide 20 and the metal line 30,
A first or second composite line formed by alternately laminating three or more layers with the same width is formed on a substrate 10.

On the other hand, in the second method, the thin film layer for forming the optical waveguide 20 or the thin film layer for forming the metal line 30 is formed on the smooth mirror-like substrate 10 by sputtering or the like. Thereafter, the thin film layer is formed in a predetermined pattern shape by an etching process. Next, on the substrate 10 on which the optical waveguide 20 or the metal line 30 formed by forming the thin film layer in a predetermined pattern shape, a thin film layer for forming the metal line 30, or a thin film layer for forming the optical waveguide 20, With or without intervening a thin film layer for forming the material layer 40 between them,
After alternately forming two or more layers by sputtering or the like, the thin film layer for forming the metal line 30 or the thin film layer for forming the optical waveguide 20 or the thin film layer for forming the material layer 40 is etched by an etching process. Optical waveguide 20 formed on substrate 10
Alternatively, it is formed in the same width as the metal line 30 in a predetermined pattern shape.

When the thin film layer for forming the optical waveguide 20, the thin film layer for forming the metal line 30, or the thin film layer for forming the material layer 40 is formed by the above-described first or second method, After the upper surface of the thin film layer for forming the metal line 30 or the thin film layer for forming the material layer 40 or the thin film layer for forming the optical waveguide 20 formed on the top 10 is finished into a smooth mirror-like surface by lapping or the like, the thin film layers are formed. It is preferable to form a thin film layer for forming the optical waveguide 20, a thin film layer for forming the metal line 30, and a thin film layer for forming the material layer 40 on the upper surface. And
It is preferable that the inner surface of the material layer 40 directly covering the upper surface or the lower surface of the optical waveguide 20 or the inner surface of the metal line 30 be formed into a smooth mirror surface or a state close thereto. Then, by the inner surface of the material layer 40 and the inner surface of the metal line 30, the optical signal that is about to leak out from the inside of the optical waveguide 20 to the outside is totally reflected by the inner surface of the material layer 40 or the metal line 30 is not reflected. It is desirable to be able to reflect light with less irregular reflection on the inner surface of the lens. Then, it is preferable that the optical signal can be efficiently transmitted from the inside of the optical waveguide 20 to the other end thereof with little transmission loss.

In the first or second composite line shown in FIGS. 1 and 8, the optical waveguide 20, the metal line 30, and the material layer 40 are formed linearly. The 30 and the material layer 40 may be formed in a shape in which a halfway portion is bent, or may be formed in a curved shape. Also in this case, it is possible to provide a first or second composite line having an operation similar to that of the first or second composite line formed linearly.

[0048]

【The invention's effect】

As described above, according to the first or second composite line of the present invention, the optical signal transmitted through the optical waveguide is prevented from leaking to the outside of the optical waveguide, and the transmission loss is reduced to the tip of the optical waveguide toward the end thereof. I can tell them well. Further, each of the optical waveguides stacked in two or more layers above and below it can be independently used as an optical waveguide for transmitting an optical signal. Alternatively, each of the metal lines stacked in two or more layers above and below the metal lines can be independently used as a signal line for transmitting an electric signal, or can be independently used as a power supply line for flowing a power supply current.

In addition, since an optical waveguide for transmitting an optical signal or a metal line used for a signal line or a power supply line is vertically stacked in two or more layers and provided on a substrate, the optical waveguide and the signal line or the power supply line are provided. The optical waveguides, the signal lines, or the power supply lines can be densely arranged in two or more layers in the vertical direction on the substrate, as compared with the case where the optical waveguides or the signal lines or the power supply lines are arranged horizontally on the substrate. In addition, the optoelectronic device having the optical waveguide, the signal line, and the power supply line can be reduced in size and density.

In the case of the first or second composite line in which the material layer is stacked between the optical waveguide and the metal line stacked above and below the first and second compound lines, the material layer is smoothed like a mirror surface of the material layer. By the formed inner surface without fine irregularities, without irregularly reflecting the optical signal that is about to leak from the inside of the optical waveguide to the outside,
The light can be totally reflected inside the optical waveguide. Then, the optical signal can be efficiently transmitted inside the optical waveguide with little transmission loss.

In the first or second composite line in which the optical waveguides are vertically stacked in two or more layers, an optical signal transmitted through the upper and lower optical waveguides is transmitted from one of the optical waveguides to the other optical waveguide. A metal line laminated between an optical waveguide laminated above and below and a metal line, or a material layer in addition to the above, reliably prevents crosstalk of an optical signal from invading into a wave path between them. Can be.

In the case of the first or second composite line in which the upper surface or the lower surface of the optical waveguide is covered with a metal line or a material layer in addition thereto, the optical waveguide is formed by the metal line or the material layer in addition thereto. Unnecessary external light from the upper surface or the lower surface of the waveguide can be reliably prevented from becoming noise inside the optical waveguide and entering the optical waveguide.

According to the second composite line of the present invention, the refractive index of light of the substrate can be made irrelevant, and substrates made of various materials can be used for the substrate for forming the optoelectronic device.

[Brief description of the drawings]

FIG. 1 is a partial perspective view of a first composite line of the present invention.

FIG. 2 is an enlarged side sectional view of a first composite line of the present invention.

FIG. 3 is an enlarged side sectional view of the first composite line of the present invention.

FIG. 4 is an enlarged side sectional view of the first composite line of the present invention.

FIG. 5 is an enlarged side sectional view of the first composite line of the present invention.

FIG. 6 is an enlarged side sectional view of the first composite line of the present invention.

FIG. 7 is an enlarged side sectional view of the first composite line of the present invention.

FIG. 8 is a partial perspective view of a second composite line of the present invention.

FIG. 9 is an enlarged side sectional view of the second composite line of the present invention.

FIG. 10 is an enlarged side sectional view of a second composite line of the present invention.

FIG. 11 is an enlarged side sectional view of a second composite line of the present invention.

FIG. 12 is an enlarged side sectional view of a second composite line of the present invention.

FIG. 13 is an enlarged side sectional view of a second composite line of the present invention.

FIG. 14 is an enlarged side sectional view of a second composite line of the present invention.

[Explanation of symbols]

 10 substrate 20 optical waveguide 30 metal line 40 material layer

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-290409 (JP, A) JP-A-2-90108 (JP, A) JP-A 55-55595 (JP, A) JP-A 52-90 52587 (JP, A) JP-A-1-18110 (JP, A) JP-A-1-102506 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/12-6 / 14 G02F 1/00-1/125 H01L 27/15 H01S 5/00-5/50 H05K 1/02

Claims (3)

(57) [Claims] An optical waveguide for transmitting an optical signal having the same width and a metal line used for a signal line or a power supply line are formed on a substrate for an optoelectronic device, and the optical waveguide is disposed in a lowermost layer thereof. In this state, three or more layers are alternately laminated so as to overlap with each other, and the refractive index n ₁ of light of the substrate and the refractive index of light of the optical waveguide
and n _2, the refractive index n ₃ of the light of both side surfaces or the upper surface is in contact gas in the optical waveguide, the composite of the optoelectronic device, characterized in that a relationship of _{n 1 <n 2, n 3} <n 2 line. 2. A metal line used for a signal line or a power supply line having the same width and an optical waveguide for transmitting an optical signal are disposed on the lowermost layer of a substrate for an optoelectronic device. In this state, three or more layers are alternately stacked so as to overlap each other, and the refractive index n ₂ of the light of the optical waveguide and the refractive index n _{3 of the} gas light in contact with both side surfaces of the optical waveguide or the upper surface thereof. And n ₃ <n ₂
A composite line for an optoelectronic device, characterized in that: 3. A material layer for covering an upper surface or a lower surface of an optical waveguide formed to have the same width as the optical waveguide and the metal waveguide between the metal waveguide and the optical waveguide, wherein the refractive index of the light is n.
_{4. The} optical waveguide according to claim 1, wherein a material layer having a relation of n ₄ <n ₂ with respect to a refractive index n ₂ of light of the optical waveguide is laminated so as to vertically overlap the optical waveguide and the metal line. A composite line for the optoelectronic device according to any of the preceding claims.