KR0183118B1 - Process of producing optical elements - Google Patents

Abstract

Disclosed is a method of manufacturing an optical component suitable for mass production by performing side polishing of an optical waveguide element after forming a plurality of optical waveguide elements in a batch process using a substrate. The present invention provides a method for manufacturing an optical component provided by connecting an optical element with a metal electrode and an optical fiber, wherein the connection is performed after forming the metal electrode and then polishing the side surface of the optical element. According to the present invention, lateral polishing of the optical waveguide device is performed after the formation of various thin films and metal electrodes, thereby simplifying the manufacturing process of the optoelectronic device, and increasing productivity by reducing the time and cost required for complicated optical alignment. Can be written.

Description

Manufacturing method of optical parts

1A is a plan view of a conventional channel type optical waveguide device.

FIG. 1B is a cross-sectional view taken along the line AA ′ of FIG. 1A.

2 is a cross-sectional view showing the connection relationship between the optical waveguide element and the optical fiber of FIG.

FIG. 3A is a plan view showing the side surface of the optical waveguide device immediately after formation of the optical waveguide according to the prior art.

3B is a cross-sectional view taken along the line AA ′ of FIG. 3A.

4A and 4B are diagrams for explaining the change of the transmission efficiency of the optical signal according to the polishing state of the side surface of the optical waveguide element.

5 is a view showing an optical waveguide device in which a metal electrode is formed on a conventional optical waveguide.

6A to 6D are diagrams showing a first embodiment of the manufacturing method of the optical device according to the present invention.

7 is a view for explaining the connection of the optical element and the optical fiber according to the present invention.

8 is a plan view of a wafer showing one example of a batch processing for mass production of an optical waveguide device according to the present invention.

9 is a plan view of a wafer showing a state in which a plurality of surface mounting components are mounted on a surface of an individual device according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an optical component, and more particularly, to a method for manufacturing an optical component suitable for mass production by performing side polishing of an optical waveguide element after forming a plurality of optical waveguide elements in a batch process using a substrate.

In general, an optical element used for optical communication using an optical fiber uses an optical waveguide element having an optical waveguide as a basic. The optical waveguide forms impurities on the optical substrate through thermal diffusion or ion implantation, and has a microstructure in which microscopic identification of the micron unit is very difficult. The optical device needs to receive an optical signal from the outside or transmit the optical signal to another place outside, where the optical fiber is most used. Therefore, in order to transmit the optical signal through the optical fiber, it is necessary to connect the input / output part of the optical element with the optical fiber. Usually, the method of connecting the input / output part of the optical element and the optical fiber is called fiber pigtailing.

First, the structure of the optical waveguide device will be described with reference to FIGS. 1A and 1B.

FIG. 1A is a plan view of a conventional channel type optical waveguide device, and FIG. 1B is a cross-sectional view taken along the line a-a 'in FIG. 1A.

1A and 1B, reference numeral 1 denotes an optical substrate, and reference numeral 2 denotes a channel type optical waveguide formed by selectively injecting or diffusing impurities into the optical substrate 1. Further, reference numeral d denotes the depth of the optical waveguide 2 having a value of about 3 to 10 mu m, and reference character t denotes the thickness of the optical substrate 1 which usually has 0.5 to 2 mu m.

Next, the connection method of an optical element and an optical fiber is demonstrated with reference to FIG.

2 is a cross-sectional view showing the connection relationship between the optical waveguide element and the optical fiber of FIG.

In FIG. 2, part a represents an optical waveguide element and part b represents an optical fiber. Further, reference numeral 3 denotes a cladding layer of the optical fiber, and reference numeral 4 denotes a core layer of the optical fiber.

In particular, the optical waveguide element (a part) and the optical fiber (b part) are connected to each other in a state where the optical waveguide element channel (2) and the optical fiber core (4) are aligned precisely. Sending and receiving is possible. The optical signal transmission efficiency is greatly influenced by the flatness of the side surface 5 of the optical waveguide 2 and the end face 6 of the optical fiber, and an optical polishing process is required to improve the flatness. In order to improve the flatness of the optical fiber, a cutter or an optical fiber cross-section polisher is used, and in the case of an optical waveguide device, the complex side 5 is polished.

FIG. 3A is a plan view showing the side surface of the optical waveguide device immediately after formation of the optical waveguide according to the prior art, and FIG. 3B is a cross-sectional view taken along the line A-A 'of FIG. 3A. 3A and 3B, the same reference numerals as those in FIG. 2 denote the same members.

Specifically, as shown in FIGS. 3A and 3B, the state of the side surface 5 immediately after the formation of the optical waveguide 2 exhibits a fairly irregular and rough surface.

4A and 4B are diagrams for explaining the change of the transmission efficiency of the optical signal according to the polishing state of the side surface of the optical waveguide element. In Figs. 4A and 4B, the same reference numerals and reference numerals denote the same members in Fig. 2. Specifically, FIG. 4A is a view illustrating a state in which the side surfaces 5 and 6 of the optical waveguide device a and the optical fiber b are not polished, and FIG. 4B is the optical waveguide device a and the optical fiber b. The figure which shows the state with which side grinding | polishing 5a, 6b of () was performed well.

In particular, the optical signal 20 in a poor polishing state of the side surface 5 of the optical waveguide element has a signal with the core 4 of the optical fiber due to severe irregular scattering at the edge as shown in FIG. 4A. It becomes difficult to deliver. On the contrary, when the polished state of the side surface 5a of the optical waveguide element is good, as shown in FIG. 4B, efficient optical signal transmission is possible. Therefore, in order to improve the transmission efficiency of the optical signal, the side surface of the optical waveguide device must be polished.

On the other hand, since a general optical device uses a photoelectric effect, a metal electrode should be formed after optical waveguide formation and side polishing, which will be described with reference to FIG. 5.

5 is a view showing an optical waveguide device in which a metal electrode is formed on a conventional optical waveguide.

In FIG. 5, an optical waveguide 2 is formed on the substrate 1, a metal electrode 7 is formed thereon, and the side surface 5a of the optical waveguide element is uniform. However, the conventional optical waveguide device forms the metal electrode 9 after the side polishing.

In the conventional optical waveguide device, since the edge polishing process for the coupling with the optical fiber of the post process is performed immediately after the optical waveguide is formed, the process is performed individually for each individual element after the polishing process. There is a disadvantage that a batch process is not possible.

Accordingly, an object of the present invention is to provide a manufacturing method of an optical component that can be processed in a batch process to improve the productivity and yield of the optical device, and to reduce the time and manufacturing cost required for complex optical alignment. .

In order to achieve the above object, the present invention provides a method for manufacturing an optical component provided by connecting an optical device having a metal electrode and an optical fiber, wherein the connection is performed after forming the metal electrode and then polishing the side surface of the optical device. It provides a method for manufacturing an optical component, characterized in that.

The optical element is any one selected from an optical waveguide element, an optical modulator, an optical coupler, and an optical integrated circuit element, and the connection is performed by using an adhesive on the adhesive surface of the optical fiber and the optical element.

According to an embodiment of the invention, forming an optical waveguide in a portion of the substrate; Forming a first metal layer on the optical waveguide and the substrate; Forming a second metal pattern on a portion of the first metal layer; Manufacturing an optical waveguide device by polishing a substrate having the optical waveguide and side surfaces of the first metal layer; And connecting the optical waveguide device having the polished side surface to an optical fiber.

The method may further include forming a buffer thin film after forming the optical waveguide, and forming a thickness of the first metal layer smaller than a depth of the optical waveguide.

In addition, the substrate is made of any one of the substrate material selected from LiNbO ₃ , LiTaO ₃ , GaAs, InP, and glass, it is also possible to selectively add impurities to the substrate material.

The method may further include sequentially forming a dielectric, a conductor, and a dielectric after the forming of the optical waveguide, and further comprising forming a surface mount component before the manufacturing of the optical waveguide device. It may be.

According to another embodiment of the invention, forming an optical waveguide in a portion of the substrate; Forming a first metal layer on the optical waveguide and the substrate; Forming a second metal pattern and a connection auxiliary block on a portion of the first metal layer, respectively; Manufacturing an optical device by polishing a side surface of the substrate having the optical waveguide, the first metal layer, and the connection auxiliary block; And connecting the optical device with the polished side surface to the optical fiber.

The method may further include forming a buffer thin film after forming the first metal layer, and may further include sequentially forming a dielectric, a conductor, and a dielectric after the forming of the optical waveguide.

The method may further include forming a surface mounting component before manufacturing the optical waveguide device, and the connection auxiliary block is formed on the metal layer using an adhesive.

According to the present invention, lateral polishing of the optical waveguide device is performed after the formation of various thin films and metal electrodes, thereby simplifying the manufacturing process of the optoelectronic device, and increasing productivity by reducing the time and cost required for complicated optical alignment. Can be written.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

First, the manufacturing method of the optical element by this invention is demonstrated.

Example 1

6A to 6D are diagrams showing a first embodiment of the manufacturing method of the optical device according to the present invention.

6A shows the step of forming an optical waveguide on a substrate.

Specifically, the optical waveguide 42 is formed on the substrate 41. The substrate 41 uses any one substrate material selected from LiNbO 3, LiTaO 3, GaAs, InP, and glass, and impurities may be selectively added to the substrate material. In addition, the optical waveguide 42 forms impurities in the substrate through thermal diffusion or ion implantation, and the side surface 45 of the substrate is provided in an uneven rough state.

FIG. 6B shows forming the first metal layer and the second metal pattern on the optical waveguide.

Specifically, the first metal layer 52 thinner than about 1/5 to 1/20 of the depth of the optical waveguide 42 is formed. Subsequently, a second metal pattern 53 is formed on a portion of the first metal layer 52, and the side surface 45 of the substrate continues in an uneven rough state as in FIG. 6A. The second metal pattern 53 is used for metal electrodes or wiring.

6C illustrates a step of forming an auxiliary block on a portion of the first metal layer 52.

Specifically, the polishing auxiliary block 51 for connecting the optical fiber to the localized portion of the first metal layer 52 is fixed with an adhesive 55. At this time, the side surface 45 of the substrate and the side surface 54 of the auxiliary block are cut by the saw to maintain the rough surface state. The auxiliary block 51 is used for polishing the side of the optical element, and also used for connection to the optical fiber in a later process.

FIG. 6D shows the polishing of the side surfaces of the first metal layer and the substrate having the optical waveguide.

Specifically, in the state in which the auxiliary block 54 is bonded, the side surface 45 of the substrate having the optical waveguide and the side surface 54 of the auxiliary block 51 are simultaneously polished to complete the optical device.

Example 2

The second embodiment of the optical device manufacturing method according to the present invention is the same except that the optical device is completed without using the auxiliary block of the first embodiment.

Specifically, the processes of FIGS. 6A and 6B of the first embodiment are performed. Subsequently, the side surface of the substrate having the optical waveguide and the first metal layer is polished to complete the optical device.

Example 3

The third embodiment of the optical device manufacturing method according to the present invention is the same as the first and second embodiments except that the buffer thin film is formed after the step of forming the optical waveguide.

Specifically, the steps of FIG. 6A of the first embodiment are carried out. Subsequently, a buffer thin film, for example, an oxide film, is formed on the optical waveguide in accordance with the optical waveguide device within about 1000 m to 10 m, and then the first metal layer is formed. Next, after the second metal pattern is formed on a part of the first metal layer, the process steps of the first and second embodiments are performed in the same manner to complete the optical device.

Example 4

The fourth embodiment of the optical device manufacturing method according to the present invention is the same as the first to third embodiments except for sequentially forming a dielectric, a conductor and a dielectric after the step of forming the optical waveguide.

Specifically, the steps of FIG. 6A of the first embodiment are carried out. Subsequently, a dielectric, a conductor, and a dielectric are sequentially formed on the optical waveguide. The dielectric is formed of an oxide film, a nitride film, a tantalum oxide film, or the like, and the conductor is formed of a metal or a metal compound. Subsequently, a first metal layer is formed on the dielectric alone. Next, after the second metal pattern is formed on a part of the first metal layer, the process steps of the first and second embodiments are performed in the same manner to complete the optical device.

The manufacturing method of the optical device according to the first to fourth embodiments of the present invention does not need to remove the auxiliary block in order to form the metal electrode or the second metal pattern for wiring. In addition, there is an advantage that can provide a wide contact surface due to the auxiliary block for the connection during the connection (pigtailing) with the optical fiber in the post-process.

Next, the connection relationship between the optical element and the optical fiber according to the first embodiment of the present invention will be described.

7 is a view for explaining the connection of the optical element and the optical fiber according to the present invention. Specifically, part c represents an optical waveguide device and part d represents an optical fiber. Further, reference numeral 43 denotes a cladding layer of the optical fiber, and reference numeral 44 denotes a core layer of the optical fiber.

In FIG. 7, the optical waveguide element c is provided with the optical waveguide 42 on the substrate 41. As shown in FIG. The first metal layer 52 is provided on the optical waveguide 42 much thinner than the optical waveguide depth, and the second metal pattern 53 is formed on a portion of the first metal layer 52. In addition, the auxiliary auxiliary block 51 for connecting the optical fiber is fixed to the localized portion of the upper end of the optical waveguide 52 using the adhesive agent 55. The optical fiber d has a core layer 44 of the optical fiber and a cladding layer 43 surrounding the optical fiber d. The connection between the optical waveguide element c and the optical fiber d is bonded using an adhesive.

In particular, the connection method of the present invention can be used in the connection without removing the auxiliary block to increase the contact surface 50 between the optical fiber and the optical waveguide device to greatly improve the coupling strength, good coupling to vibration or changes in ambient environmental conditions State can be maintained.

On the other hand, since the optical device according to the present invention can attach the auxiliary block for polishing directly on the first metal layer and then cut the desired part for polishing, a plurality of individual devices can be simultaneously formed on one optical substrate (wafer). This will be described with reference to FIG.

8 is a plan view of a wafer showing one example of a batch processing for mass production of an optical waveguide device according to the present invention.

In Fig. 8, reference numeral 56 denotes a wafer which is a substrate, reference numeral 57 denotes an individual optical element, reference numeral 51 denotes an auxiliary block, and reference numeral 58 denotes a cutting line of the substrate.

In the method of manufacturing an optical device of the present invention, as shown in FIG. 8, a large number of auxiliary blocks 51 can be used to batch process a large number of individual devices 57 on one wafer at the same time. The productivity of the child can be greatly improved. The auxiliary block 51 is used as an auxiliary block for polishing or connection.

9 is a plan view of a wafer showing a state in which a plurality of surface mounting components are mounted on a surface of an individual device according to the present invention. In Fig. 9, the same reference numerals as those in Fig. 8 denote the same members.

In FIG. 9, a number of surface mount components 60, such as chip resistors, chip capacitors, chip inductors and chip thermistors, can be mounted on the surfaces of the individual optical elements 57. In FIG. In other words, various surface mount components 60 can be freely mounted in the same manner as the auxiliary auxiliary blocks 51 for polishing, which is suitable for automated production.

In addition, even after fixing a plurality of surface-mounted components 60 on the surface of the individual elements 57 can be polished by the side can be produced by a batch process (batch process) can be improved mass production.

According to the method of manufacturing an optical device according to the present invention, the side polishing of the optical device is performed after the formation of various thin films and metal electrodes, which simplifies the manufacturing process of the optical device, and removes defects generated during polishing, thereby improving the productivity of the product. Improvements can be made and productivity can be increased by reducing the time and cost of complex optical alignment.

Although the present invention has been described with reference to specific embodiments, the present invention is not limited to the above embodiments, and modifications and improvements are possible within the scope of ordinary knowledge of those skilled in the art.

Claims (15)

An optical component manufacturing method provided by connecting an optical element having a metal electrode and an optical fiber, wherein the connection is performed after forming the metal electrode and polishing the side surface of the optical element. Way. The method of claim 1, wherein the optical device is any one selected from an optical waveguide device, an optical modulator, an optical coupler, and an optical integrated circuit device. The method of manufacturing an optical component according to claim 1, wherein the connection is performed by using an adhesive on the adhesive surface of the optical fiber and the optical element. Forming an optical waveguide in a portion of the substrate; Forming a first metal layer on the optical waveguide and the substrate; Forming a second metal pattern on a portion of the first metal layer; Manufacturing an optical waveguide device by polishing a substrate having the optical waveguide and side surfaces of the first metal layer; And connecting the optical waveguide device having the polished side surface to the optical fiber. The method of claim 4, further comprising forming a buffer thin film after the forming of the optical waveguide. The method of claim 4, wherein the thickness of the first metal layer is smaller than the depth of the optical waveguide. The method of claim 4, wherein the substrate is made of any one substrate material selected from LiNbO ₃ , LiTaO ₃ , GaAs, InP, and glass, and impurities are selectively added to the substrate material. . The method of claim 4, further comprising sequentially forming a dielectric, a conductor, and a dielectric after the forming of the optical waveguide. The method of claim 8, wherein the dielectric is formed of any one selected from an oxide film, a nitride film, and a tantalum oxide film. The method of manufacturing an optical component according to claim 4, further comprising the step of further forming a surface mounting component before manufacturing the optical waveguide device. Forming an optical waveguide in a portion of the substrate; Forming a first metal layer on the optical waveguide and the substrate; Forming a second metal pattern and a connection auxiliary block on a portion of the first metal layer, respectively; Manufacturing an optical device by polishing a side surface of the substrate having the optical waveguide, the first metal layer, and the connection auxiliary block; And connecting the optical element with the side polished to the optical fiber. 12. The method of claim 11, further comprising forming a buffer thin film after the forming of the first metal layer. The method of claim 11, further comprising sequentially forming a dielectric, a conductor, and a dielectric after the forming of the optical waveguide. The method of manufacturing an optical component according to claim 11, further comprising forming a surface mounting component before manufacturing the optical waveguide device. 12. The method of claim 11, wherein the connection auxiliary block is formed on the metal layer using an adhesive.