JPH10270725A - Fine-wire, photoelectric conversion element with fine-wire, and their manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fine-wire capable of being applied to a photoelectric conversion element, etc. SOLUTION: In a fine-wire 10, forming a silicon fine-wire portion 11 on a silicon substrate 1, a silicon-dioxide fine-wire portion 12 is formed at the end of the silicon fine-wire portion 11 via a metallic portion 13. The silicon fine-wire portion 11 has a photoelectric conversion function and the silicon- dioxide fine-wire portion 12 has a light transferring function. After depositing gold as a catalyzer on the silicon substrate 1, they are heated to form a fused alloy drop. Then, feeding a silane gas to the intermediate, the silicon fine-wire portion 11 is grown under the fused alloy drop by the catalytic action of the fused alloy drop. Subsequently, heating the portion 11 in an oxygen atmosphere, the end portion of the silicon fine-wire portion 11 is oxidized by the catalytic action of the fused alloy drop.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin line which can be used as a photoelectric conversion element, a photoelectric conversion element provided with the thin line, and a method for manufacturing the same.

[0002]

2. Description of the Related Art In recent years, the density of integrated circuits and the like has been increased, and a technique for accurately observing an extremely fine region in a manufacturing process thereof has been required. In addition, as the density of optical memories has been increased, a technique for reading and writing data from and in an extremely small area has been required.

Heretofore, as a photoelectric conversion element for observing a fine area and performing reading and writing, an element using an optical fiber as an input / output unit of an optical signal has been proposed.
In this photoelectric conversion element, the tip of the optical fiber has a diameter of 10
Etching is performed down to about 0 nm, so that information of a minute region can be obtained or light can be irradiated to the minute region. The other end of the optical fiber is connected to an appropriate processing unit such as a light detecting unit and a light emitting unit. Further, the side surface of the optical fiber is coated with an appropriate metal so that there is no light input / output from other than the tip.

[0004]

However, conventionally, an optical fiber as an optical input / output unit is connected to a processing unit to constitute a photoelectric conversion element. The end portion must be made thicker to be connected to the processing section, and there is a problem that manufacturing is difficult. In addition, since the tip of the optical fiber is made thinner by etching, it is difficult to accurately make the diameter smaller than 100 nm, and there has been a problem that the diameter cannot be sufficiently reduced.

Therefore, it is desired to develop a new photoelectric conversion element. One of the means is, for example, silicon (S).
i) Use of thin lines is conceivable. The band gap of this silicon thin wire increases as the diameter of the thin wire decreases, and the indirect transition band gap in the bulk changes to a direct transition band gap in a thin wire having a thickness of several tens nm. I do. As a result, in the silicon wire, the efficiency of the recombination luminescence of the excited electrons and holes is significantly increased, and the emission wavelength is also shifted to the shorter wavelength side, so that visible light can be emitted.

[0006] This silicon thin wire is, for example, VL
S (Vapor-Liquid-Solid) method (E.
I. Givargizov, J. Vac. Sci. Techno. B11 (2), p. 449) can be grown on a silicon substrate. In the VLS method, gold (Au) is vapor-deposited on a silicon substrate to form a molten alloy droplet of silicon and gold on the surface of the silicon substrate, and then heated while supplying a silicon source gas to grow a silicon fine wire. It is a way to make it. Therefore,
If a new photoelectric conversion element using this silicon thin wire can be obtained, observation of a fine region becomes possible.

The present invention has been made in view of the above problems, and a first object of the present invention is to provide a thin wire having a new structure which can be used for a photoelectric conversion element and the like, and a method for manufacturing the same. .

It is a second object of the present invention to provide a photoelectric conversion element capable of observing a fine region with high accuracy and a method for manufacturing the same.

[0009]

A thin wire according to the present invention is formed on a silicon thin wire portion formed of silicon on one side in the length direction and on the other side opposite to the silicon thin wire portion in the length direction. And a silicon dioxide thin wire portion made of silicon dioxide.

A photoelectric conversion element according to the present invention converts an optical signal and an electric signal to each other, and has an optical input / output section formed on one side in the length direction, and the optical input / output section is connected to the optical input / output section. Is provided with a thin line having a photoelectric conversion portion formed on the other side on the opposite side in the length direction.

A method for manufacturing a thin wire according to the present invention is a method for manufacturing a thin wire including a silicon thin wire portion made of silicon and a silicon dioxide thin wire portion made of silicon dioxide, wherein the silicon thin wire portion is grown on a substrate. A vapor deposition step of vapor deposition of a catalyst at the time of the heating, and a growth step of heating the substrate on which the catalyst is vapor-deposited in an atmosphere containing a silicon source gas, and selectively growing a silicon thin wire portion on the surface of the substrate by the action of the catalyst.
An oxidizing step of selectively oxidizing a portion of the grown silicon fine wire portion on the tip side by the action of a catalyst to form a silicon dioxide fine wire portion.

[0012] The method for manufacturing a photoelectric conversion element according to the present invention comprises:
What is claimed is: 1. A method for manufacturing a photoelectric conversion element having a thin wire on which an optical input / output part and a photoelectric conversion part are formed, comprising: evaporating a catalyst on a substrate; A heating step in which the thin-film photoelectric conversion portion is selectively grown on the surface of the substrate by the action of a catalyst; And an oxidation step of forming an input / output unit.

In this fine wire, a silicon fine wire portion is formed on one side in the length direction, and a silicon dioxide fine wire portion is formed on the other side. This silicon thin line portion has a photoelectric conversion function. The silicon dioxide thin wire portion has a light transmitting function.

In this photoelectric conversion device, when an optical signal is input to the optical input / output unit, the optical signal is guided to the photoelectric conversion unit through the inside of the optical input / output unit. This optical signal is converted into an electric signal by the photoelectric conversion unit, and is taken out as an electric signal.
When a voltage is applied to the photoelectric conversion unit, the electric signal is converted into an optical signal by the photoelectric conversion unit, and is guided and output by the optical input / output unit.

In this method for producing a thin wire, a catalyst is deposited on a substrate and then heated in an atmosphere containing a silicon source gas. At this time, a thin silicon wire portion is selectively grown on the surface of the substrate by the action of the catalyst. Next, the silicon fine wire portion is oxidized. At this time, the tip of the silicon fine wire portion is selectively oxidized by the action of the catalyst, and a silicon dioxide fine wire portion is formed. Thus, a thin wire including the silicon thin wire portion and the silicon dioxide portion is manufactured.

In this method of manufacturing a photoelectric conversion element, after depositing a catalyst on a substrate, the substrate is heated in an atmosphere containing a raw material gas of a substance constituting the photoelectric conversion portion. At this time, a thin-line photoelectric conversion portion is selectively grown on the surface of the substrate by the action of the catalyst. Next, the fine wire is oxidized. At this time, the tip of the fine wire is selectively oxidized by the action of the catalyst, and a light input / output portion is formed. As a result, a photoelectric conversion element having a thin wire on which the light input / output unit and the photoelectric conversion unit are formed is manufactured.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 shows the configuration of a thin wire 10 according to a first embodiment of the present invention. The fine wire 10 has a silicon fine wire portion 11 made of single crystal silicon on one side in the length direction, and a silicon dioxide fine wire portion 12 made of amorphous silicon dioxide on the other side opposite to the silicon fine wire portion 11 in the length direction. It has. The silicon thin wire portion 11 has a photoelectric conversion function, and the silicon dioxide thin wire portion 12 has a light transmitting function. A metal portion 13 made of a suitable metal such as gold (Au) is provided between the silicon thin wire portion 11 and the silicon dioxide thin wire portion 12. The thin wire 10 is formed substantially vertically on the substrate 1 made of single crystal silicon with the silicon thin wire portion 11 facing the substrate 1. The thickness of the thin line 10 is 50 nm or less, preferably 30 nm or less, and more preferably 10 nm or less.

The thin wire 10 having such a configuration can be manufactured, for example, as follows.

FIG. 2 shows each manufacturing step in the method of manufacturing the thin wire 10. First, for example, when the specific resistance is 0.
The substrate 1 made of (111) single-crystal silicon having a thickness of 4 to 4 Ωcm is inserted into a reaction furnace (not shown), for example, 5 × 10 ⁻⁸ T.
The surface is cleaned by heating at 1000 ° C. in a vacuum of orr.

Next, as shown in FIG. 2A, the pressure inside the reaction furnace is reduced and the substrate 1 is appropriately heated (for example, 70 ° C.).
0 ° C.) and a metal (for example, gold (Au) or silver (Ag)) serving as a catalyst when the silicon thin wire portion 11 is grown on the surface of the substrate 1
And indium (In)) are deposited (a deposition step). Thereby, the catalyst layer 2 is formed on the substrate 1. On this occasion,
The heating of the substrate 1 is performed, for example, by passing a direct current along the long axis of the substrate 1. The metal is deposited by using, for example, a tungsten (W) filament.

After the catalyst layer 2 is formed, the substrate 1 is appropriately heated in a reaction furnace (not shown) (for example, at 700 ° C.).
Hold for an appropriate time (for example, 30 minutes) (heating step). As a result, the catalyst layer 2 on the substrate 1
Part of the silicon on the surface of FIG.
As shown in (1), a molten alloy droplet 2a is formed. Although the molten alloy droplets 2a are formed in the vapor deposition step, they are aggregated with each other by the heating step to have a certain size.

After forming the molten alloy droplets 2a, the substrate 1 is appropriately heated in a reaction furnace (not shown) (for example, 70
0 ° C.), for example, silane (Si
H ₄ ) gas is introduced (growth step). The amount of the silane gas to be introduced is adjusted, for example, so that the partial pressure of the silane gas in the reaction furnace is less than 0.5 Torr. Preferably, the adjustment is performed so as to be 0.15 Torr or less.
As a result, the silane gas is decomposed by the decomposition reaction shown in Formula 1 using the molten alloy droplet 2a as a catalyst to produce silicon.

[Formula 1] SiH ₄ → Si + 2H ₂

The silicon decomposed from the silane gas diffuses into the molten alloy droplet 2a and is epitaxially bonded to the interface between the molten alloy droplet 2a and the substrate 1. As a result, FIG.
As shown in (1), a thin silicon wire portion 11 having a thickness corresponding to the size of the molten alloy droplet 2a is selectively grown under the molten alloy droplet 2a.

After the growth of the silicon thin wire portion 11, an oxygen (O ₂ ) gas is introduced into a reaction furnace (not shown) and heated at 800 ° C. in an oxygen gas atmosphere of, for example, 500 Torr (oxidation step). Thereby, the silicon thin wire portion 1
At the front end of 1, selective oxidation occurs using the molten alloy droplet 2 a as a catalyst, and as shown in FIG. 2D, the molten alloy droplet 2 a moves toward the substrate 1 with the progress of oxidation.
Therefore, a part of the silicon thin wire portion 11 on the tip side is oxidized, and the silicon dioxide thin wire portion 12 is formed.

In this oxidation step, oxidation is also slightly generated on the side surface of the silicon thin wire portion 11. Therefore, as shown in FIG.
When this oxidation step is performed in a state where the entire side surface is exposed, a thin oxide film 3 is formed on the side surface of the silicon fine wire portion 11.
Although not shown, the oxidation is prevented by forming an antioxidant film on the side surface of the silicon thin wire portion 11 and performing an oxidation step.

When the tip of the silicon fine wire portion 11 is oxidized and cooled as described above, the molten alloy droplet 2a precipitates and solidifies the dissolved silicon, and the silicon thin wire portion 1
A metal part 13 is formed between the metal part 1 and the silicon dioxide thin wire part 12. This results in the thin line 10 shown in FIG.

As described above, according to the thin wire 10 according to the present embodiment, since the silicon dioxide thin wire portion 12 is provided at the tip of the silicon thin wire portion 11, light is guided by the silicon dioxide thin wire portion 12, and the silicon thin wire portion is also provided. The optical signal and the electric signal can be mutually converted by the unit 11. Therefore, it can be used as a photoelectric conversion element corresponding to a fine region.

Further, according to the method of manufacturing the thin wire 10 according to the present embodiment, the silicon thin wire portion 11 is formed on the substrate 1 by VL.
After the growth by the S method, the tip of the silicon fine wire portion 11 is oxidized using the molten alloy droplet 2a as a catalyst, so that the fine wire 10 according to the present embodiment can be easily manufactured. Therefore, the thin wire 10 according to the present embodiment can be realized.

(Second Embodiment) FIG. 3 shows a second embodiment of the present invention.
1 shows a configuration of a photoelectric conversion element 20 according to the embodiment. This photoelectric conversion element 20 uses the thin wire 10 described in the first embodiment. Therefore, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

The photoelectric conversion element 20 includes a silicon thin wire portion 11, a silicon dioxide thin wire portion 12, and a metal portion 13 on a substrate 1.
And a thin wire 10 having the following. The formation position and thickness of the thin line 10 are appropriately controlled. In this case, among the fine wires 10, the silicon fine wire portion 11 functions as a photoelectric conversion portion, the silicon dioxide fine wire portion 12 functions as a light input / output portion, and the metal portion 13 functions as an electrode portion.

On the substrate 1, an auxiliary film 21 made of silicon dioxide is formed. The auxiliary film 21 is provided with an opening 21a.
Are formed on the substrate 1 through the substrate. That is, the formation position and thickness of the thin line 10 are controlled by the auxiliary film 21. Incidentally, the auxiliary film 21 also has a role as an insulating layer for ensuring insulation between the metal part 13 and the substrate 1. The position of the metal portion 13 in the thin wire 10 substantially coincides with the position of the surface of the auxiliary film 21, and the silicon thin wire portion 11 is located in the opening 21 a of the auxiliary film 21.
The silicon dioxide fine wire portion 12 protrudes from the auxiliary film 21.

A coating film 2 made of a suitable metal such as gold or aluminum (Al)
2 are formed to prevent light from being input and output from the side surface and to guide light to be input and output from the front end. A wiring 23 made of a suitable metal such as gold or aluminum is connected to the metal part. Although not shown, a wiring connected to the silicon thin wire portion 11 is formed on the substrate 1. Through the wiring 23 and the like, a voltage can be applied to the silicon thin wire portion 11 and a current generated in the silicon thin wire portion 11 can be detected.

The photoelectric conversion element 20 having such a configuration
Can be manufactured, for example, as follows.

FIG. 4 to FIG. 7 show the respective manufacturing steps in the first manufacturing method of the photoelectric conversion element 20.
First, as shown in FIG.
The substrate 1 made of (111) single crystal silicon having a thickness of 4 to 4 Ωcm is inserted into a reaction furnace (not shown) and oxidized, and an oxide film having a thickness of, for example, about 1 μm is formed as an auxiliary film 21 on the surface of the substrate 1.

Next, as shown in FIG. 4B, a photoresist film 31 is applied and formed on the auxiliary film 21 and selectively exposed to light. Opening 31 having a large size (for example, a diameter of about 1 μm)
a is formed.

Subsequently, as shown in FIG. 5A, the auxiliary film 21 is etched using an etching solution containing hydrofluoric acid (HF) using the photoresist film 31 as a mask. As a result, an opening 21a having an appropriate size (for example, a diameter of about 1 μm) is formed in the auxiliary film 21 corresponding to the formation position of the fine wire 10 (the above-described auxiliary film forming step).

After forming the opening 21a in the auxiliary film 21,
For example, the photoresist film 31 is removed with acetone. After that, the substrate 1 is immersed in, for example, nitric acid (HNO ₃ ) heated to 70 ° C., and further etched with an etching solution containing hydrofluoric acid to remove the surface of the substrate 1 exposed from the opening 21 a of the auxiliary film 21. Wash.

After the substrate 1 is washed and dried, the substrate 1 is inserted into a reaction furnace (not shown), and as shown in FIG. 5B, the substrate 1 is removed in the same manner as in the first embodiment. Metal (for example, gold) serving as a catalyst in the growth of the fine wire 10 on the surface
Is deposited (deposition step). Thus, the catalyst layer 2 having a thickness of, for example, 3 nm is formed on the auxiliary film 21 and on the substrate 1 exposed from the opening 21a of the auxiliary film 21.

After the catalyst layer 2 is formed, the substrate 1 is appropriately heated in a reaction furnace (not shown) (for example, at 700 ° C.).
The substrate 1 is slightly tilted for an appropriate time (for example, 30 minutes)
Hold (heating step). As a result, the catalyst layer 2 on the substrate 1 exposed from the opening 21a of the auxiliary film 21
As shown in (c), the silicon on the surface of the substrate 1 is partially dissolved and aggregated to form a molten alloy droplet 2a. In addition,
Here, since the substrate 1 is inclined, the molten alloy droplet 2a, which is a liquid, is formed at the lowest position in the opening 21a by the attraction, that is, near the end of the opening 21a.

On the auxiliary film 21, since the silicon dioxide constituting the auxiliary film 21 is stable, no molten alloy droplet is formed by the catalyst layer 2. That is, the size of the molten alloy droplet 2 a is controlled by the size of the opening 21 a of the auxiliary film 21. This heating step is performed sufficiently until the number of the molten alloy drops 2a becomes one at the opening 21a.

After the formation of the molten alloy droplet 2a, for example, silane gas is introduced in the same manner as in the first embodiment, and FIG.
As shown in (a), a thin silicon wire portion 11 having a thickness corresponding to the size of the molten alloy 2a is selectively grown under the molten alloy droplet 2a. At this time, also in the catalyst layer 2 on the auxiliary film 21, the silane gas is decomposed by the catalytic action of gold. However, since the molten alloy of gold and silicon has good wettability with respect to the surface of the auxiliary film 21 made of silicon dioxide, it hardly aggregates and epitaxial growth of silicon does not occur.

As a result, the silicon thin wire portion 11 is
After being grown longer than the thickness of 1 (for example, longer than 1 μm), it is heated in an oxygen gas atmosphere in the same manner as in the first embodiment, and as shown in FIG. 11 is oxidized to form a silicon dioxide thin wire portion 1
2 (oxidation step). At this time, the ratio of the lengths of the silicon dioxide thin wire portion 12 and the silicon thin wire portion 11 is controlled by the time of the oxidation step. Here, as shown in FIG. 6B, the oxidation is performed until the molten alloy droplet 2a is almost at the same position as the surface of the auxiliary film 21. The molten alloy droplet 2a
When cooled, the dissolved silicon precipitates and solidifies to form the metal part 13. Therefore, in the following description, the metal part 13 will be described.

After the silicon dioxide fine wire portion 12 is formed in this manner, as shown in FIG. 6C, the silicon dioxide fine wire portion 12 is obliquely above the substrate 1 (here, the side where the fine wire 10 approaches the opening 21a). An appropriate metal such as gold or aluminum is deposited from above (from above) to form a deposited layer 32. This vapor deposition layer 32
It becomes the coating layer 22 and the wiring 23. The angle at the time of vapor deposition is set so that metal does not reach the surface of the substrate 1. In this manner, the metal is deposited obliquely from above because a large amount of metal can be deposited on the side surface of the silicon dioxide fine wire portion 12, and the side surface of the silicon dioxide fine wire portion 12 is surely covered and the metal portion 13 is surely deposited. This is because it can be electrically connected to

Next, as shown in FIG. 7A, the tip of the silicon dioxide fine wire portion 12 is exposed by slightly etching back the deposited layer 32 or the like. As the etchant, for example, aqua regia (HNO ₃ : HCl = 1: 3) is used when the deposition layer 32 is made of gold, and hydrochloric acid (H) is used when the deposition layer 32 is made of aluminum.
Cl).

Subsequently, as shown in FIG. 7B, an appropriate metal such as gold or aluminum is vapor-deposited from the upper side on the side opposite to the side where the metal layer 32 was vapor-deposited first. The covering film 22 is formed (the above-mentioned covering step). After that, the vapor deposition layer 32 is etched as necessary,
To form Thereby, the photoelectric conversion element 2 shown in FIG.
It becomes 0.

The photoelectric conversion element 2 according to the present embodiment
0 can also be manufactured as follows.

FIGS. 8 to 10 show this photoelectric conversion element 20.
FIG. 7 shows each manufacturing process in the second manufacturing method. In this manufacturing method, similar to the first manufacturing method,
An auxiliary film 21 is formed (auxiliary film forming step; FIGS. 4 and 5).
(See (a)) and then a catalyst is deposited (deposition step; FIG. 5).
Next, a molten alloy droplet 2a is formed (heating step; see FIG. 5C). After that, in the same manner as in the first manufacturing method, the silicon fine wire portion 11 is grown (growth step; see FIG. 6A) and oxidized (oxidation step; FIG. 6).
(B)).

After that, as shown in FIG. 8A, an appropriate metal such as gold or aluminum is evaporated from a plurality of directions obliquely above the substrate 1 so as to cover the entire silicon dioxide fine wire portion 12. A layer 32 is formed. The angle at the time of vapor deposition is set so that metal does not reach the surface of the substrate 1. Next, as shown in FIG. 8B, a photoresist film 33 is formed on the deposition layer 32 and the auxiliary film 21 by coating.

Subsequently, as shown in FIG. 9A, the photoresist film 33 is exposed using evanescent light. That is, for example, a thin plate 34 to which two silica glass layers 34a and 34b having different refractive indices are joined is brought into contact with the substrate 1, and the thin plate 34 is irradiated with light obliquely from the opposite side of the substrate 1, Two silica glass layers 34a, 34
The light is totally reflected at the joint surface b. As a result, the evanescent light is transmitted to the photoresist film 33 through the silica glass layer 34b, and a portion located in the evanescent light field (that is, a portion covering the tip of the silicon dioxide fine wire portion 12) is exposed.

After exposing the photoresist film 33, as shown in FIG. 9B, development is performed to remove the exposed portion. After the development, as shown in FIG. 10A, the vapor deposition layer 32 is selectively etched using the photoresist film 33 as a mask to expose the tip of the silicon dioxide fine wire portion 12. Thereby, the coating film 22 is formed. After that, as shown in FIG. 10B, the photoresist film 33 is removed using, for example, acetone. After removing the photoresist film 33, the vapor deposition layer 32 is etched as necessary to form the wiring 23. Thus, the photoelectric conversion element 20 shown in FIG. 3 is obtained.

The photoelectric conversion element 2 manufactured as described above
0 is used as follows.

FIG. 11 shows an example in which the photoelectric conversion element 20 is used for observing the surface of the object M to be observed. here,
A case where the surface of the observation target M is observed using evanescent light will be described.

When observing the object M, an ammeter 34 is connected between the wiring 23 and the wiring on the substrate 1 (not shown), and the tip of the silicon dioxide thin wire portion 12 is brought closer to the object M. The object to be observed M is irradiated with light from the opposite side of the photoelectric conversion element 20. Thereby, the silicon dioxide fine wire portion 12 has
Evanescent light transmitted slightly to the photoelectric conversion element 20 side of the observation target M is incident from the tip. The light incident on the silicon dioxide thin wire portion 12 travels inside and reaches the metal portion 13, and a part of the light passes through the metal portion 13 and is transmitted to the silicon thin wire portion 11. In the silicon thin wire portion 11, when light is transmitted, carriers corresponding to the amount of light are generated. As a result, the optical signal is converted into an electric signal, and the electric signal is converted to an ammeter 34.
Is detected by

At this time, since the silicon dioxide fine wire portion 12 as the light input / output portion is sufficiently thin, the photoelectric conversion device 20 can accurately detect even weak light evanescent light. Therefore, the surface of the observation target M can be observed with high accuracy.

Although the case where the surface of the object M is observed using the evanescent light has been described here, the case where the surface of the object M is irradiated with light and the reflected light thereof is observed. It can be used similarly. Also in this case, according to the photoelectric conversion element 20, the silicon dioxide fine wire portion 12 as the light input / output portion is sufficiently thin, so that a fine region can be observed and accurate observation can be performed.

In addition to the observation of the surface of the object M,
The same can be used for reading and writing to an optical memory. Also in this case, according to the photoelectric conversion element 20, since the silicon dioxide thin line portion 12 as the light input / output portion is sufficiently thin, it is possible to read and write a fine region. In addition, in the case of writing, a power source is inserted between the wiring 23 and the wiring on the substrate 1 side (not shown), and the operation is reverse to that in the case of reading. That is, the silicon thin wire portion 11
When a voltage is applied to the substrate, light is generated by the coupling of carriers, transmitted through the metal portion 13, transmitted through the inside of the silicon dioxide thin wire portion 12, and emitted from the tip.

As described above, according to the photoelectric conversion element 20 according to the present embodiment, the silicon thin wire portion 1 as a photoelectric conversion portion
1 and the thin wire 10 including the silicon dioxide thin wire portion 12 as the light input / output portion, the thickness of the light input / output portion can be reduced, and the accuracy of the fine region can be improved. That is, it is possible to observe a fine region with high accuracy, and it is also possible to miniaturize the reading and writing of the optical memory.

Further, according to the photoelectric conversion element 20, the thickness of the fine wire 10 is controlled by the auxiliary film 21, so that
The thickness of the fine line 10 can be made sufficiently thin, and the accuracy with respect to a fine region can be further improved.

Further, according to the photoelectric conversion element 20, the metal portion 1 is attached to the tip of the silicon fine wire portion 11 grown on the substrate 1.
Since the silicon dioxide thin wire portion 12 is formed with the intermediary 3, the light input / output portion and the photoelectric conversion portion can be integrated, and also the substrate 1 can be integrated. Therefore, the size of the entire device is reduced, and the device can be applied as a more practical element.

According to the method for manufacturing the photoelectric conversion element 20 according to the present embodiment, the silicon thin wire portion 11 is
After the growth by the LS method, the tip of the silicon fine wire portion 11 is oxidized using the molten alloy droplet 2a as a catalyst, so that the photoelectric conversion element 20 according to the present embodiment can be easily manufactured. Therefore, the photoelectric conversion element 20 according to the present invention can be realized.

Further, according to the method of manufacturing the photoelectric conversion element 20, the catalyst is deposited on the substrate 1 through the opening 21a of the auxiliary film 21, so that the thin wire 10 is formed according to the size of the opening 21a. Can be controlled. Therefore, the thickness of the thin wire 10 can be reduced with high accuracy, and the accuracy of the photoelectric conversion element 20 can be improved.

(Third Embodiment) FIG. 12 shows a configuration of a photoelectric conversion element 40 according to a third embodiment of the present invention. This photoelectric conversion element 40 has the same structure as the photoelectric conversion element 2 of the second embodiment except that the photoelectric conversion element 40 further includes an insulating layer 41.
It has the same configuration and action as 0. Therefore, the same reference numerals are given to the same components as those in the first embodiment and the second embodiment, and the detailed description thereof will be omitted.

The photoelectric conversion element 40 is provided between the auxiliary film 21 and the silicon thin line portion 11 (that is, the opening 2 of the auxiliary film 21).
1a), an insulating layer 41 filling the space therebetween is provided. This insulating layer 41 is made of polymethyl methacrylate (P
MMA) or a suitable resin having an insulating property such as a photoresist. In the photoelectric conversion element 40, the wiring 23 also has a role as the coating film 22.

The photoelectric conversion element 40 having such a configuration
Can be manufactured as follows.

FIG. 13 shows each manufacturing step in the method for manufacturing the photoelectric conversion element 40. In this manufacturing method, first, the auxiliary film 21 is formed in the same manner as in the second embodiment (auxiliary film forming step; see FIGS. 4 and 5A).
Next, the surface of the substrate 1 exposed by the opening 21a is anisotropically etched, and the opening 2
The center of 1a is made lowest. This allows
As shown in FIG. 13A, the bottom surface of the opening 21a (that is, the surface of the substrate 1 exposed by the opening 21a) is concave.

Subsequently, in the same manner as in the second embodiment,
The catalyst is vapor-deposited (vapor-deposition step; see FIG. 5 (b)) to form a molten alloy droplet 2a (heating step; see FIG. 5 (c)). However, in the heating step, the substrate 1 is made horizontal without tilting.
Thus, in the present embodiment, since the bottom surface of the opening 21a is concave, the molten alloy droplet 2 is located at the center of the opening 21a.
1 aggregates. After that, in the same manner as in the second embodiment, the silicon fine line portion 11 is grown (growing step; FIG. 6).
(See FIG. 6A) and oxidation (oxidation step; see FIG. 6B).

After the oxidation, as shown in FIG. 13B, for example, PMMA is applied to the entire surface and cured by heating or the like to form an insulating layer 41 (insulating step). Insulating layer 4
1 is formed, an appropriate metal such as gold or aluminum is vapor-deposited on the entire surface, and the tip of the silicon dioxide fine wire portion 12 is exposed by etchback or the like to form a coating film 22 and a wiring 2.
Form 3 Thereby, the photoelectric conversion element 40 shown in FIG. 12 is obtained.

As described above, according to the photoelectric conversion element 40 of the present embodiment, since the insulating layer 41 is provided between the auxiliary film 21 and the thin silicon wire portion 11, the metal portion 13 and the substrate 1
Can be improved, and the reliability can be improved.

According to the method of manufacturing the photoelectric conversion element 40 according to the present embodiment, since the insulating layer 41 is formed using a suitable resin after forming the thin wire 10, the photoelectric conversion element 40 according to the present embodiment is formed. The conversion element 40 can be easily manufactured. Therefore, the photoelectric conversion element 40 according to the present invention can be realized.

(Fourth Embodiment) FIG. 14 shows the overall structure of a photoelectric conversion device 50 according to a fourth embodiment of the present invention, and FIG. It represents. This photoelectric conversion element 50 includes a plurality of photoelectric conversion elements 20 and 30 according to the second embodiment or the third embodiment on the substrate 1. Therefore, the same reference numerals are given to the same components as those in the second embodiment and the third embodiment, and the detailed description thereof will be omitted.

In this photoelectric conversion element 50, a plurality of fine wires 10 are formed on a substrate 1 in a matrix. Substrate 1
A plurality of wirings 51 are provided on the surface of
Are formed. Each of the wirings 51 is made of n-type or p-type silicon into which an appropriate impurity is implanted. Further, a plurality of wirings 23 are formed corresponding to the rows of the thin wires 10. Thereby, in this photoelectric conversion element 50, each thin wire 10 is individually connected. Here, the case where each fine wire 10 is formed in a matrix shape has been described, but it may be formed in a linear shape.

As described above, according to the photoelectric conversion element 50 according to the present embodiment, since a plurality of fine wires 10 are formed in a matrix on the substrate 1, it is possible to quickly obtain information in a wide range of fine regions. Can be.

As described above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to the above embodiments, and can be variously modified. For example, in the second embodiment, the coating step is performed after the oxidation step. However, the coating step may be performed after the growth step and before the oxidation step. In the third embodiment, the insulating step is performed after the oxidizing step.
An insulating step may be performed after the growth step and before the oxidation step.

Further, in the second embodiment,
The auxiliary film 21 has been described as being formed of silicon dioxide. However, the auxiliary film 21 may be formed of any other material such as silicon nitride (SiN ₄ ) or an appropriate resin, as long as it does not form a molten alloy droplet with a metal to be deposited in a deposition step. You may make it.

In addition, in the first embodiment described above, silane gas is used as a silicon source gas in the thin wire growth step, but disilane (Si ₂ H ₆ ) gas or trisilane (Si ₃ H ₈ ) gas or a mixture thereof, or silicon chloride (SiC)
l ₄ ) Gas or the like may be used.

In addition, in the second to fourth embodiments, the case where the photoelectric conversion unit is constituted by the silicon thin wire portion 11 has been described. However, in the present invention, the photoelectric conversion unit has the photoelectric conversion function. The present invention can be widely applied to the case where a thin line is used. Also, the case where the light input / output unit is constituted by the silicon dioxide thin line unit 12 has been described, but the present invention can be widely applied to the case where the light input / output unit is constituted by a thin line having a light transmission function.

[0078]

As described above, according to the thin wire according to the present invention, since the silicon thin wire portion formed on one side and the silicon dioxide thin wire portion formed on the other side are provided, light is emitted by the silicon dioxide thin wire portion. And an optical signal and an electric signal can be mutually converted by the silicon thin wire portion. Therefore, there is an effect that it can be used as a photoelectric conversion element or the like corresponding to a fine region.

Further, according to the photoelectric conversion element of the present invention, since the photoelectric conversion section is formed on one side and the thin line on which the light input / output section is formed is provided on the other side, the thickness of the light input / output section is reduced. And the accuracy of the fine region can be improved. That is, there is an effect that the observation of the fine region can be performed with high accuracy, and the reading and writing of the optical memory can be miniaturized.

Further, according to the method for manufacturing a thin wire and the method for manufacturing a photoelectric conversion element according to the present invention, after a silicon thin wire portion or a photoelectric conversion portion is grown on a substrate by the action of a catalyst, the silicon thin wire portion or the photoelectric conversion portion is grown. Since a part of the leading end side of the conversion unit is oxidized by the action of the catalyst, the thin wire and the photoelectric conversion element according to the present invention can be easily manufactured. Therefore, there is an effect that the thin wire and the photoelectric conversion element according to the present invention can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a thin line according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating each manufacturing process in the method for manufacturing the thin wire illustrated in FIG.

FIG. 3 is a sectional view illustrating a configuration of a photoelectric conversion element according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating each manufacturing step in a first manufacturing method of the photoelectric conversion element illustrated in FIG.

FIG. 5 is a sectional view illustrating each step following FIG. 4;

FIG. 6 is a sectional view illustrating each step following FIG. 5;

FIG. 7 is a sectional view illustrating each step following FIG. 6;

FIG. 8 is a cross-sectional view illustrating each manufacturing step in a second manufacturing method of the photoelectric conversion element illustrated in FIG.

FIG. 9 is a sectional view illustrating each step following FIG. 8;

FIG. 10 is a sectional view illustrating each step following FIG. 9;

FIG. 11 is a cross-sectional view for explaining an operation of the photoelectric conversion element shown in FIG.

FIG. 12 is a sectional view illustrating a configuration of a photoelectric conversion element according to a third embodiment of the present invention.

13 is a cross-sectional view illustrating each manufacturing step in the method for manufacturing the photoelectric conversion element illustrated in FIG.

FIG. 14 is a perspective view illustrating a configuration of a photoelectric conversion element according to a fourth embodiment of the present invention.

15 is a cross-sectional view illustrating a configuration of the photoelectric conversion element illustrated in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... board | substrate, 2 ... catalyst layer, 2a ... molten alloy droplet, 10 ... fine wire, 11 ... silicon fine wire part (photoelectric conversion part), 12 ... silicon dioxide fine wire part (light input / output part), 13 ... metal part (electrode part) ), 20, 40, 50: photoelectric conversion element, 21: auxiliary film, 21a: opening, 22: coating film, 23, 51: wiring,
31, 33 ... photoresist film, 31a ... opening, 32 ...
Deposition layer, 34: ammeter, 41: insulating layer, M: object to be observed

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Setsuo Usui 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (72) Inventor Hitoshi Tamada 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation

Claims (19)

[Claims] 1. A silicon thin wire portion made of silicon formed on one side in a length direction, and a silicon dioxide thin wire portion made of silicon dioxide formed on the other side opposite to the silicon thin wire portion in the length direction. A thin wire comprising: 2. The thin wire according to claim 1, further comprising a metal portion made of a metal between the silicon thin wire portion and the silicon dioxide thin wire portion. 3. The thin line according to claim 1, wherein the thickness is 50 nm or less. 4. A photoelectric conversion element for mutually converting an optical signal and an electric signal, wherein an optical input / output part is formed on one side in a length direction and is opposite to the optical input / output part in the length direction. A photoelectric conversion element comprising, on the other hand, a thin wire on which a photoelectric conversion portion is formed. 5. The photoelectric conversion element according to claim 4, wherein said thin wire has an optical input / output unit made of silicon dioxide and a photoelectric conversion unit made of silicon. 6. The thin line structure according to claim 4, wherein a thickness of the thin line is controlled. 7. The photoelectric conversion element according to claim 4, wherein the thin wire has an electrode portion between the light input / output unit and the photoelectric conversion unit. 8. The photoelectric conversion element according to claim 7, wherein the electrode portion of the thin wire is made of a metal. 9. The photoelectric conversion element according to claim 4, wherein at least a part of the side surface of the light input / output unit is covered with a coating film. 10. The photoelectric conversion element according to claim 9, wherein said thin-film coating film is made of metal. 11. The photoelectric conversion element according to claim 4, wherein at least a part of the side surface of the photoelectric conversion unit is covered with an insulating layer. 12. The photoelectric conversion element according to claim 4, wherein a plurality of the thin wires are provided, and each of the thin wires is formed on the substrate with the photoelectric conversion unit serving as the substrate side. 13. The thin line structure according to claim 12, wherein the position of each of the thin lines with respect to the substrate is controlled. 14. The element having a thin line according to claim 12, wherein each of the thin lines is periodically located. 15. A method for producing a thin wire including a silicon thin wire portion made of silicon and a silicon dioxide thin wire portion made of silicon dioxide, the method comprising: evaporating a catalyst for growing the silicon thin wire portion on a substrate. A step of heating the substrate on which the catalyst is deposited in a silicon source gas-containing atmosphere, and selectively growing a silicon fine wire portion on the surface of the substrate by the action of the catalyst; and An oxidation step of selectively oxidizing a part thereof by the action of a catalyst to form a silicon dioxide thin wire portion. 16. A method for manufacturing a photoelectric conversion element provided with a thin wire on which an optical input / output unit and a photoelectric conversion unit are formed, comprising: depositing a catalyst on a substrate; A heating step in an atmosphere containing a raw material gas, and a growth step of selectively growing a thin-line photoelectric conversion portion on the surface of the substrate by the action of a catalyst; An oxidation step of oxidizing to form an optical input / output unit. 17. The method according to claim 16, further comprising, before the growing step, an auxiliary film forming step of forming an auxiliary film having a hole corresponding to a position where the fine line is formed on the substrate.
The manufacturing method of the photoelectric conversion element of Claim. 18. The method according to claim 16, further comprising, after the growing step, a covering step of forming a covering film covering at least a part of a side surface of the light input / output unit. Method. 19. The method according to claim 16, further comprising, after said growing step, an insulating step of forming an insulating film covering at least a part of a side surface of the photoelectric conversion.