JP2005181417A - Optical component and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical component equipped with a lens having a desired NA and a method for manufacturing the same. <P>SOLUTION: The optical component 100 comprises a 1st optical path adjusting layer 120 formed on a substrate 110 and having a concave surface 10, and a 2nd optical path adjusting layer 40 having a convex surface 12 on the concave surface 10. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical component and a manufacturing method thereof.

  For the purpose of improving the light coupling efficiency, an optical component such as a lens may be installed at the light emitting element emitting part, the light receiving element incident part, or the optical fiber optical coupling part. In this case, as the NA (Numerical Aperture) of the lens increases, the light from the light emitting element having a wide radiation angle is collimated, or the light from the optical fiber is received by a light receiving element such as an imaging element or a photodetector. This is advantageous when it is used.

  The objective of this invention is providing the optical component provided with the lens which has desired NA, and its manufacturing method.

The optical component according to the present invention is
A first optical path adjustment layer having a concave curved surface formed above the substrate;
A second optical path adjustment layer having a convex curved surface above the concave curved surface.

  In the optical component according to the present invention, when another specific component (hereinafter referred to as “B”) is formed above a specific component (hereinafter referred to as “A”), B is formed directly on A. And the case where B is formed via another on A. The same applies to the optical component manufacturing method according to the present invention.

  The optical component according to the present invention has the concave curved surface formed in the first optical path adjustment layer and the convex curved surface formed in the second optical path adjustment layer. That is, in the optical component according to the present invention, the concave curved surface and the convex curved surface function as a lens. The number of surfaces of the lens included in the optical component according to the present invention is two. Therefore, the NA of the lens of the optical component according to the present invention can be increased as compared with the case where the number of lens surfaces is one.

In the optical component according to the present invention,
The refractive index of the second optical path adjustment layer can be greater than the refractive index of the first optical path adjustment layer.

In the optical component according to the present invention,
The curvature of the concave curved surface may be different from the curvature of the convex curved surface.

In the optical component according to the present invention,
The concave curved surface and the convex curved surface are microlenses,
A plurality of the microlenses can be provided.

The method for manufacturing an optical component according to the present invention includes:
Forming a first precursor layer above the substrate;
Forming a mask layer above the first precursor layer;
Patterning the mask layer;
Etching the first precursor layer using the mask layer as a mask to form a concave curved surface in the first precursor layer;
Curing the first precursor layer to form a first optical path adjustment layer;
Forming a second precursor layer having a convex curved surface above the concave curved surface by discharging droplets toward the concave curved surface;
Curing the second precursor layer to form a second optical path adjustment layer.

  According to the method for manufacturing an optical component according to the present invention, in the step of forming the second optical path adjustment layer, the position of the droplet is automatically corrected because it is a liquid. Then, the center of the concave curved surface and the center of the convex curved surface are substantially at the same position in plan view. Therefore, a lens in which the centers of the two lens surfaces substantially coincide in plan view is formed. According to the method of manufacturing the optical component 100 according to the present invention, when a lens having two lens surfaces is formed using a highly accurate positioning technique, for example, a lens having two lens surfaces bonded to each other is bonded. As compared with the case of forming, positioning can be performed easily and accurately.

In the method of manufacturing an optical component according to the present invention,
The mask layer may be a liquid repellent film having liquid repellency with respect to an etchant used in the step of etching the first precursor layer.

In the method of manufacturing an optical component according to the present invention,
The mask layer may be a resist layer.

In the method of manufacturing an optical component according to the present invention,
In the step of etching the first precursor layer, the etchant can be discharged by a droplet discharge method.

In the method of manufacturing an optical component according to the present invention,
In the step of forming the second precursor layer, the droplets can be discharged by a droplet discharge method.

In the method of manufacturing an optical component according to the present invention,
The concave curved surface and the convex curved surface are microlenses,
A plurality of the microlenses can be arranged.

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

1. 1. First embodiment 1-1. Structure of Optical Component FIG. 1 is a cross-sectional view schematically showing an optical component 100 according to an embodiment to which the present invention is applied. FIG. 2 is a plan view schematically showing the optical component 100 shown in FIG. 1 is a view showing a cross section taken along the line AA of FIG.

  The optical component 100 of the present embodiment includes a base 110, a first optical path adjustment layer 120 having a concave curved surface 10, and a second optical path adjustment layer 40 having a convex curved surface 12. Hereinafter, each component of the optical component 100 according to the present embodiment will be described with reference to FIGS. 1 and 2.

  As the substrate 10, for example, a semiconductor substrate such as a silicon substrate or a GaAs substrate, a glass substrate, or a plastic substrate can be used, but is not particularly limited.

  The first optical path adjustment layer 120 is formed on the base 110. The first optical path adjustment layer 120 has a concave curved surface 10.

  The second optical path adjustment layer 40 is formed on the concave curved surface 10 formed in the first optical path adjustment layer 120. The second optical path adjustment layer 40 has a convex curved surface 12. The convex curved surface 12 of the second optical path adjustment layer 40 is formed so that the center thereof substantially coincides with the center of the concave curved surface 10 in plan view.

  The curvature of the convex curved surface 12 can be the same as the curvature of the concave curved surface 10, but can also be different. By adjusting the curvature of the convex curved surface 12 and the curvature of the concave curved surface 10, aberration of the lens of the optical component 100 according to the present embodiment to be described later can be suppressed.

  The refractive index of the second optical path adjustment layer 40 is preferably larger than the refractive index of the first optical path adjustment layer 120. Since the refractive index of the second optical path adjustment layer 40 is larger than the refractive index of the first optical path adjustment layer 120, the NA (Numerical Aperture) of the lens of the optical component 100 according to the present embodiment, which will be described later, is increased. Can be higher. The larger the difference between the refractive index of the first optical path adjustment layer 120 and the refractive index of the second optical path adjustment layer 40, the higher the NA of the lens.

1-2. Method for Manufacturing Optical Component Next, a method for manufacturing the optical component 100 shown in FIGS. 1 and 2 will be described with reference to FIGS. 3 to 8 are cross-sectional views schematically showing one manufacturing process of the optical component 100 shown in FIGS. 1 and 2, and each correspond to the cross section shown in FIG.

  (1) First, as shown in FIG. 3, the first optical path adjustment layer 120 is formed on the base 110. The first optical path adjustment layer 120 is made of a material that transmits light of a predetermined wavelength. The first optical path adjustment layer 120 may be made of a material that absorbs light having a predetermined wavelength. As the 1st optical path adjustment layer 120, what can be hardened | cured by providing energy, such as a heat | fever or light, can be used, for example.

  Therefore, as the first optical path adjustment layer 120, for example, an ultraviolet curable resin or a thermosetting resin can be used. Examples of the ultraviolet curable resin include an ultraviolet curable acrylic resin and an epoxy resin. An example of the thermosetting resin is a thermosetting polyimide resin.

  The case where a polyimide resin is used as the material of the first optical path adjustment layer 120 will be described below. First, as shown in FIG. 3, a polyimide first precursor layer 122 is formed on a substrate 110. As a method for forming the first precursor layer 122, a known technique such as a spin coating method, a dipping method, a spray coating method, or a droplet discharge method can be used.

  Next, as shown in FIG. 4, a mask layer 124 is formed in a region other than the formation region of the concave curved surface 10 (see FIGS. 1 and 2) on the first precursor layer 122. The mask layer 124 has a pattern in which a portion corresponding to the concave curved surface 10 shown in FIGS. 1 and 2 is opened. That is, in this example, the pattern of the mask layer 124 has a circular opening 126 in plan view. The central axis of the opening 126 is formed to coincide with the central axis of the concave curved surface 10 described above.

  Although a resist layer can be used as the mask layer 124, it is not particularly limited as long as it functions as a mask for the etchant 20 described later. When a resist layer is used as the mask layer 124, the patterning of the mask layer 124 can be performed using a known lithography technique.

  Further, as the mask layer 124, for example, a liquid repellent film such as a FAS (fluoroalkylsilane) film can be used. The liquid repellent film refers to a film having liquid repellency with respect to the etchant 20 described later. Since the etchant 20 has liquid repellency, a difference in wettability of the etchant 20 occurs between a region where the mask layer 124 is formed and a region where the mask layer 124 is not formed. Due to the difference in wettability, the etchant 20 can be wetted and spread only in the opening 126 (see FIG. 4) of the mask layer 124 in the step of etching the first precursor layer 122 (see FIG. 5 and FIG. 6) described later. it can.

  When FAS is used for the mask layer 124, examples of the patterning method for the mask layer 124 include the following methods.

  First, a resist layer is formed in the formation region of the opening 126 of the mask layer 124 using a lithography technique. Next, the semiconductor substrate 101 on which the first precursor layer 122 is formed is put in an atmosphere of FAS gas, thereby forming a monomolecular film of FAS on the exposed surface of the first precursor layer 122. Next, the resist layer is removed using isopropyl alcohol (IPA) or the like. As a result, an FAS monomolecular film (mask layer 124) having an opening 126 is formed.

  As another method, first, an FAS monomolecular film is formed on the surface of the first precursor layer 122 by introducing the semiconductor substrate 101 on which the first precursor layer 122 is formed into an atmosphere of FAS gas. . Next, only the region where the opening 126 of the mask layer 124 is formed is irradiated with ultraviolet rays through a glass mask or the like. As a result, the region of the FAS monomolecular film irradiated with ultraviolet rays is decomposed and removed, and the FAS monomolecular film (mask layer 124) having the opening 126 is formed.

  When a layer other than the liquid repellent film such as a resist layer is used for the mask layer 124, the liquid repellent film can be further coated on the exposed surface of this layer. In this case, the mask layer 124 includes a layer other than the liquid repellent film such as a resist layer and the liquid repellent film. As a result, in the step of etching the first precursor layer 122 described later (see FIGS. 5 and 6), the mask layer 124 can more effectively serve as an etching mask. Specifically, it is possible to more reliably prevent the region covered with the mask layer 124 of the first precursor layer 122 from being etched.

  Next, the concave curved surface 10 (see FIGS. 1 and 2) is formed by etching the first precursor layer 122. Specifically, it is as follows.

  First, as shown in FIG. 5, the etchant 20 is dropped onto the opening 126 (see FIG. 4) of the mask layer 124 by a droplet discharge method. As a result, the etchant 20 wets and spreads in the region surrounded by the mask layer 124, that is, in the opening 126 of the mask layer 124. Then, the first precursor layer 122 is isotropically etched by the etchant 20, and the concave curved surface 10 is formed in the first precursor layer 122 as shown in FIG.

  The curvature of the concave curved surface 10 can be controlled by changing the etching rate when the first precursor layer 122 is isotropically etched by the etchant 20.

  Examples of the droplet discharge method include: (i) a method in which pressure is generated by changing the size of bubbles in the liquid (here, the etchant 20) by heat, and the liquid is discharged from the nozzle 112 of the inkjet head 114; (Ii) There is a method of discharging a liquid from the nozzle 112 of the inkjet head 114 by the pressure generated by the piezoelectric element. From the viewpoint of controllability of pressure, the method (ii) is desirable.

  The alignment between the position of the nozzle 112 of the inkjet head 114 and the discharge position of the etchant 20 is performed using a known image recognition technique used in an exposure process and an inspection process in a general semiconductor integrated circuit manufacturing process. For example, as shown in FIG. 5, alignment between the position of the nozzle 112 of the inkjet head 114 and the opening 126 (see FIG. 4) of the mask layer 124 is performed by image recognition. After the alignment, the voltage applied to the inkjet head 114 is controlled, and then the etchant 20 is discharged.

  In this case, the discharge angle of the etchant 20 discharged from the nozzle 112 varies to some extent, but if the position where the etchant 20 landed is inside the opening 126, the etchant 20 is located in a region surrounded by the mask layer 124. Will spread and the position will be automatically corrected.

  The etching method of the first precursor layer 122 is not particularly limited as long as it is a method that can form the concave curved surface 10 in the first precursor layer 122 as well as the droplet discharge method as described above. For example, as shown in FIG. 7, a method of immersing the semiconductor substrate 101 in the etchant 20 and etching the first precursor layer 122 can also be used.

  As the etchant 20, a known etchant that can etch the first precursor layer 122 can be used. For example, when the first precursor layer 122 is a polyimide resin precursor, an alkaline developer or the like can be used.

  Next, the mask layer 124 is removed as necessary. For example, when a resist layer is used as the mask layer 124, the mask layer 124 can be removed by ashing. For example, when a FAS monomolecular film is used as the mask layer 124, it can be decomposed and removed by irradiating with ultraviolet rays.

  Next, after cleaning the surface of the first precursor layer 122, the semiconductor substrate 101 is heated using a hot plate or a furnace to supply heat to the first precursor layer 122 to cure (imidize) it. Then, the first optical path adjustment layer 120 shown in FIGS. 1 and 2 is formed.

  (2) Next, a process of forming the second optical path adjustment layer 40 (see FIGS. 1 and 2) will be described.

  In the present embodiment, the second optical path adjustment layer 40 is made of a material that allows light of a predetermined wavelength to pass therethrough, similar to the first optical path adjustment layer 120 described above. The second optical path adjustment layer 40 may be made of a material that absorbs light having a predetermined wavelength. As the 2nd optical path adjustment layer 40, what can be hardened | cured by providing energy, such as a heat | fever or light, can be used, for example.

  Therefore, as the second optical path adjustment layer 40, for example, an ultraviolet curable resin or a thermosetting resin can be used. Examples of the ultraviolet curable resin include an ultraviolet curable acrylic resin and an epoxy resin. An example of the thermosetting resin is a thermosetting polyimide resin. As described above, the second optical path adjustment layer 40 is desirably formed of a material having a refractive index larger than that of the first optical path adjustment layer 120.

  The case where a polyimide resin is used as the material of the second optical path adjustment layer 40 will be described below. First, as shown in FIG. 8, the droplets 42 are ejected toward the concave curved surface 10 formed in the first optical path adjustment layer 120 by a droplet ejection method. As a result, the liquid droplet 42 spreads on the concave curved surface 10. Then, the second precursor layer 44 having the convex curved surface 12 is formed on the concave curved surface 10.

  The curvature of the convex curved surface 12 can be controlled by changing the number of droplets 42 discharged by the droplet discharge method.

  As the droplet discharge method, for example, (I) a method in which pressure is generated by changing the size of bubbles in a liquid (here, the droplet 42) by heat, and the liquid is discharged from the nozzle 113 of the inkjet head 115. And (II) a method of discharging a liquid from the nozzle 113 of the inkjet head 115 by a pressure generated by the piezoelectric element. From the viewpoint of controllability of pressure, the method (II) is desirable.

  Alignment between the position of the nozzle 113 of the inkjet head 115 and the discharge position of the droplet 42 is performed using a known image recognition technique used in an exposure process or an inspection process in a general semiconductor integrated circuit manufacturing process. For example, as shown in FIG. 8, alignment between the position of the nozzle 113 of the inkjet head 115 and the concave curved surface 10 is performed by image recognition. After alignment, the voltage applied to the inkjet head 115 is controlled, and then the droplets 42 are ejected.

  In this case, the discharge angle of the droplets 42 discharged from the nozzle 113 varies to some extent, but if the position where the droplets 42 land is on the concave curved surface 10, the droplets 42 are wet on the concave curved surface 10. It spreads and the position is automatically corrected. In other words, the correction is automatically performed so that the center of the concave curved surface 10 and the center of the convex curved surface 12 are substantially at the same position in plan view.

  Next, after cleaning the surface of the second precursor layer 44, the base 110 is heated using a hot plate or a furnace to supply heat to the second precursor layer 44 to cure (imidize) it. Then, the second optical path adjustment layer 40 shown in FIGS. 1 and 2 is formed.

  The optical component 100 shown in FIGS. 1 and 2 is obtained by the above process.

1-3. Operational effects The main operational effects of the optical component 100 and the manufacturing method thereof according to the present embodiment will be described below.

  The optical component 100 according to the present embodiment has the concave curved surface 10 formed on the first optical path adjustment layer 120 and the convex curved surface 12 formed on the second optical path adjustment layer 40. That is, in the optical component 100 according to the present embodiment, the concave curved surface 10 and the convex curved surface 12 function as lenses. The number of surfaces of the lens included in the optical component 100 according to the present embodiment is two. Therefore, the NA of the lens included in the optical component 100 according to the present embodiment is higher than when the number of lens surfaces is one. Thereby, according to the optical component 100 concerning this Embodiment, it has the following advantages compared with the case where the number of surfaces of a lens is one surface.

  (1) Since the focal length of the lens is shortened, when the optical component 100 is installed at the emitting portion of a light emitting element such as a surface emitting semiconductor laser, the radiation angle of light emitted from the optical component 100 to the outside is set. It is possible to reduce the size and collimate the emitted light. Also, light incident on the lens can have a wider emission angle.

  In this case, it is possible to reduce the radiation angle of the emitted light as described above. In other words, if the radiation angle of the emitted light is constant, a lens having two lens surfaces can be made thinner than a lens having one lens surface. That is, according to the optical component 100 according to the present embodiment, the device can be miniaturized.

  (2) When the optical component 100 is installed at an incident portion of a light receiving element such as a photodiode, for example, it becomes easy to reduce the radiation angle of the incident light and collimate the incident light.

  (3) When this optical component 100 is coupled to an optical waveguide such as an optical fiber, coupling efficiency can be improved. In addition, light alignment can be easily performed.

  According to the method of manufacturing the optical component 100 according to the present embodiment, in the step of forming the second optical path adjustment layer 40, the position of the droplet 42 (see FIG. 8) is automatically corrected because it is a liquid. The The center of the concave curved surface 10 and the center of the convex curved surface 12 are substantially the same position in plan view. Therefore, a lens in which the centers of the two lens surfaces substantially coincide in plan view is formed. According to the method for manufacturing the optical component 100 according to the present embodiment, when a lens having two lens surfaces is formed using a highly accurate alignment technique, for example, the lenses are bonded to form two lens surfaces. As compared with the case where a certain lens is formed, alignment can be performed easily and accurately.

2. Second embodiment 2-1. FIG. 9 is a cross-sectional view schematically showing an optical component 200 according to the second embodiment of the present invention. FIG. 10 is a plan view schematically showing the optical component 200 shown in FIG. FIG. 9 is a diagram schematically showing a cross section taken along the line AA of FIG.

  The optical component 200 according to the present embodiment shows an example in which a plurality of optical components 100 according to the first embodiment are arranged. The optical component 200 according to the present embodiment can be used as, for example, a microlens substrate in which microlenses are arranged in an array. In the microlens substrate, the concave curved surface 10 and the convex curved surface 12 included in the optical component 100 according to the first embodiment described above can be used as a microlens. The optical component 200 according to the present embodiment is installed in, for example, a pixel portion of a liquid crystal display panel, a light receiving surface of a solid-state imaging device (CCD), and an optical fiber optical coupling portion.

  As illustrated in FIGS. 9 and 10, the optical component 200 includes a base 110 and a plurality of optical components 100 according to the first embodiment installed above the base 110. The plurality of optical components 100 according to the first embodiment are arranged in a predetermined direction. The base 110 is made of, for example, a glass substrate or a plastic substrate.

  Moreover, in this optical component 200, although the case where the optical component 100 concerning several 1st Embodiment was arranged in the grid | lattice form was demonstrated, the arrangement | sequence system of the optical component 100 concerning 1st Embodiment However, the arrangement is not limited to this, and various arrangement methods such as a staggered pattern can be applied.

2-2. Optical Component Manufacturing Method The optical component 200 according to the second embodiment can be formed by substantially the same process as the manufacturing process of the optical component 100 according to the first embodiment described above. Specifically, it is formed by substantially the same process as the manufacturing process of the optical component 100 of the first embodiment, except that a plurality of optical components 100 according to the first embodiment are arranged and formed. The Therefore, detailed description is omitted.

2-3. Action / Effect The optical component 200 and the manufacturing method thereof according to the present embodiment have substantially the same operation and effect as the optical component 100 and the manufacturing method thereof according to the first embodiment.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments and can take various forms. For example, in the above-described embodiment of the present invention, the case where the optical path adjustment layer has two layers of the first optical path adjustment layer and the second optical path adjustment layer has been described, but three or more optical path adjustment layers may be formed. it can. For example, when there are three optical path adjustment layers, the refractive index of the third optical path adjustment layer formed above the second optical path adjustment layer is made smaller than the refractive index of the second optical path adjustment layer. A lens having a high NA can be formed. The third optical path adjustment layer can be formed on the second optical path adjustment layer using a method similar to the method for forming the second optical path adjustment layer described above. The same applies to the case where four or more optical path adjustment layers are formed.

Sectional drawing which shows typically the optical component which concerns on 1st Embodiment. The top view which shows typically the optical component which concerns on 1st Embodiment. Sectional drawing which shows the manufacturing method of the optical component which concerns on 1st Embodiment. Sectional drawing which shows the manufacturing method of the optical component which concerns on 1st Embodiment. Sectional drawing which shows the manufacturing method of the optical component which concerns on 1st Embodiment. Sectional drawing which shows the manufacturing method of the optical component which concerns on 1st Embodiment. Sectional drawing which shows the manufacturing method of the optical component which concerns on 1st Embodiment. Sectional drawing which shows the manufacturing method of the optical component which concerns on 1st Embodiment. Sectional drawing which shows typically the optical component which concerns on 2nd Embodiment. The top view which shows typically the optical component which concerns on 2nd Embodiment.

Explanation of symbols

  10 concave curved surface, 12 convex curved surface, 20 etchant, 40 second optical path adjustment layer, 42 droplet, 44 second precursor layer, 100 optical component, 112 nozzle, 113 nozzle, 114 inkjet head, 115 inkjet head, 120 first 1 optical path adjusting layer, 122 first precursor layer, 124 mask layer, 126 opening, 200 optical component

Claims (10)

A first optical path adjustment layer having a concave curved surface formed above the substrate;
And a second optical path adjustment layer having a convex curved surface above the concave curved surface. In claim 1,
An optical component in which a refractive index of the second optical path adjustment layer is larger than a refractive index of the first optical path adjustment layer. In claim 1 or 2,
An optical component in which the curvature of the concave curved surface is different from the curvature of the convex curved surface. In any one of Claims 1-3,
The concave curved surface and the convex curved surface are microlenses,
An optical component having a plurality of the microlenses. Forming a first precursor layer above the substrate;
Forming a mask layer above the first precursor layer;
Patterning the mask layer;
Etching the first precursor layer using the mask layer as a mask to form a concave curved surface in the first precursor layer;
Curing the first precursor layer to form a first optical path adjustment layer;
Forming a second precursor layer having a convex curved surface above the concave curved surface by discharging droplets toward the concave curved surface;
Curing the second precursor layer to form a second optical path adjustment layer. In claim 5,
The method for manufacturing an optical component, wherein the mask layer is a liquid repellent film having liquid repellency with respect to an etchant used in the step of etching the first precursor layer. In claim 5,
The method for manufacturing an optical component, wherein the mask layer is a resist layer. In any one of Claims 5-7,
In the step of etching the first precursor layer, the etchant is discharged by a droplet discharge method. In any one of Claims 5-8,
In the step of forming the second precursor layer, the droplet is ejected by a droplet ejection method. In any one of Claims 5-9,
The concave curved surface and the convex curved surface are microlenses,
A method for manufacturing an optical component, comprising arranging a plurality of the microlenses.

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