JP4196324B2 - Manufacturing method of mold for molding optical element and manufacturing method of optical element - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a manufacturing method of a mother mold for manufacturing an optical element molding die capable of molding an optical element, a manufacturing method of an optical element molding die, and an optical element manufacturing method.
[0002]
[Prior art]
In recent years, optical elements such as objective lenses with extremely high accuracy are used in the field of optical pickup devices that are rapidly developing. When a material such as plastic or glass is molded into such an optical element using a mold, a product having a uniform shape can be quickly produced. It can be said that it is suitable for mass production. Here, since the mold is a consumable item and is also expected to be damaged due to an unexpected situation, it is necessary to replace the mold regularly or irregularly in order to mold a highly accurate optical element. It can be said. Accordingly, it can be said that it is necessary to prepare a certain amount of molds with a certain accuracy in advance for molding the optical elements.
[0003]
Here, when a die is manufactured by cutting using a single crystal diamond tool or the like, it is time-consuming and it is difficult to cut out a die having the same shape. There is a possibility that the shape of the product may vary, and the cost is high.
[0004]
[Problems to be solved by the invention]
On the other hand, there is an attempt to produce a mold by growing electroforming on a mother mold having a mother optical surface corresponding to the optical surface of the optical element. When such a die manufacturing method by electroforming is used, an optical element molding die with little dimensional variation can be obtained relatively easily only by preparing one accurate mother die.
[0005]
However, since the mother die is completed through a plurality of steps from the cutting of the material, a part serving as a reference for a series of processing is necessary during that time. Since the design standard of the optical element is generally the optical axis, it is preferable to provide a mark that essentially matches the optical axis. However, providing such a mark on the mother optical surface is This is impossible because the shape of the surface is damaged.
[0006]
On the other hand, a certain type of optical element used in the optical pickup device is provided with a concentric diffraction ring zone on the optical axis of the optical surface in order to improve aberration characteristics. Therefore, if an annular zone corresponding to the diffraction annular zone is formed on the mother optical surface of the master die, the position of the optical axis can be accurately estimated by using the annular zone after the electroforming process. However, detecting the optical axis from the annular zone and performing processing based on the detected optical axis requires a device for reading the annular zone and is troublesome. Furthermore, there is a problem that such a method cannot be used when there is no concentric circle configuration with respect to the optical axis, such as an annular zone corresponding to the diffraction annular zone, on the mother optical surface.
[0007]
The present invention has been made in view of such problems of the prior art, and by ensuring a processing standard, a manufacturing method for manufacturing a highly accurate optical element molding die can be more easily produced, as well as such an optical device. It is an object of the present invention to provide a method for manufacturing an optical element molded by an element molding die.
[0008]
[Means for Solving the Problems]
This object is solved by the following configuration.
The manufacturing method of the optical element molding die of the present invention is as follows.
Forming the mother optical surface of the optical element on the mother member by cutting while rotating the mother member;
Forming the outer peripheral surface of the mother die member by cutting so that the optical axis of the mother optical surface coincides with the rotation center of the outer peripheral surface of the mother die member while rotating the mother die member;
Forming an optical surface having a predetermined shape on the mother optical surface of the mother die member;
Forming an electroformed member having an optical transfer surface corresponding to the optical surface of the matrix member by performing an electroforming process on the matrix member;
In order to obtain the optical element molding die, the optical axis of the mother optical surface coincides with the rotation center of the outer peripheral surface of the electroformed member while the electroformed member and the mother die member are rotated together. And a step of cutting the outer peripheral surface of the electroformed member based on the outer peripheral surface of the matrix member.
[0009]
The step of forming an optical surface having a predetermined shape on the mother optical surface of the mother die member further includes
Forming a resist film on the mother optical surface;
Irradiating the resist film with an electron beam and drawing an annular shape;
And performing a development process to form an annular shape on the mother optical surface.
[0010]
Further, the base member and the electroformed member are integrated, and the outer peripheral surface of the electroformed member is cut with reference to the outer peripheral surface of the base member.
[0011]
Further, the electroformed member is cut after attaching the mother die member to the lathe so that the rotation axis of the lathe and the optical axis of the mother die member coincide with each other on the basis of the outer peripheral surface of the mother die member. It is characterized by being.
[0012]
Further, the matrix member includes an electrode member, and an insulating agent is provided on an outer peripheral surface of the electrode member.
[0013]
Furthermore, the mother optical surface on the mother die member and the outer peripheral surface of the mother die member are processed simultaneously.
[0014]
Further, the matrix member is obtained by fixing a matrix material to the electrode member.
[0015]
Further, the mother optical surface is formed by cutting a mother material.
[0016]
Further, the matrix member is obtained by forming a matrix material on the electrode member.
[0017]
The manufacturing method of the optical element molding die of the present invention is as follows.
Attaching the matrix member to the first lathe;
Forming a mother optical surface of an optical element by cutting on the mother member while rotating the mother member on the first lathe;
The outer peripheral surface of the mother die member is cut so that the optical axis of the mother optical surface coincides with the rotation center of the outer peripheral surface of the mother die member while rotating the mother die member on the first lathe. A step of forming by:
Removing the matrix member from the first lathe;
Forming a resist layer on the mother optical surface of the mother die member;
Drawing a predetermined shape on the resist layer;
Developing to form an optical surface having a predetermined shape on the mother optical surface of the mother mold member;
Forming an electroformed member having an optical transfer surface corresponding to the optical surface of the matrix member by performing an electroforming process on the matrix member;
Attaching the matrix member and the electroformed member to a second lathe;
In order to obtain the optical element molding die, the optical axis of the mother optical surface coincides with the rotation center of the outer peripheral surface of the electroformed member while the electroformed member and the mother die member are rotated together. Cutting the outer peripheral surface of the electroformed member based on the outer peripheral surface of the matrix member;
Removing the electroformed member from the matrix member to obtain an optical element having an optical transfer surface.
[0018]
Further, the base member and the electroformed member are integrated, and the outer peripheral surface of the electroformed member is cut with reference to the outer peripheral surface of the base member.
[0019]
A step of integrating the electroformed member and the backing member;
By rotating the electroformed member and the backing member together with the matrix member and cutting the outer circumferential surface of the backing member based on the outer circumferential surface of the matrix member, the optical axis of the mother optical surface and the And a step for making it coincide with the rotational axis of the backing member.
[0020]
Further, the first lathe and the second lathe are the same.
[0021]
Further, the predetermined shape is an annular shape.
[0022]
The manufacturing method of the optical element molding die of the present invention is as follows.
Forming the mother optical surface of the optical element by cutting on the mother member while rotating the mother member;
Forming the outer peripheral surface of the mother die member by cutting so that the optical axis of the mother optical surface coincides with the rotation center of the outer peripheral surface of the mother die member while rotating the mother die member;
Forming an optical surface having a predetermined shape on the mother optical surface of the mother die member;
Forming an electroformed member having an optical transfer surface corresponding to the optical surface of the matrix member by performing an electroforming process on the matrix member;
Integrating the electroformed member and the backing member;
In order to obtain the optical element molding die, the electroforming member and the mother die member are rotated together so that the optical axis of the mother optical surface coincides with the rotation center of the outer peripheral surface of the backing member, Cutting the outer peripheral surface of the backing member based on the outer peripheral surface of the matrix member;
In order to obtain an optical element having an optical transfer surface, the step of demolding the electroformed member from the matrix.
[0023]
Furthermore, the outer peripheral surface of the electroformed member is cut with the mother die member and the electroformed member being integrated, with the outer peripheral surface of the mother die member as a reference.
[0024]
Furthermore, the electroformed member is cut after being attached to the lathe so that the rotation axis of the lathe and the optical axis of the master member coincide with each other on the basis of the outer peripheral surface of the master member. Features.
[0025]
Further, the backing member includes a sliding member, and the outer peripheral surface of the sliding member is cut based on the outer peripheral surface of the matrix member.
[0026]
An optical element manufacturing method for forming an optical element using the optical element molding die manufactured by the above-described method is also the present invention.
[0027]
Furthermore, the optical element is molded by injecting molten resin into the optical element molding die.
[0028]
The manufacturing method of the optical element molding die of the present invention is as follows.
A process of attaching a base material for forming an optical element molding die to an electrode member for electroforming so as not to be relatively rotatable,
A mother optical surface corresponding to an optical surface of an optical element molded from the optical element molding die is formed by cutting while rotating the matrix material and the electrode member, and cutting is performed on the electrode member. Forming a first mark by processing and further forming an outer peripheral surface of the electrode member;
Forming a second mark on the electrode member based on the first mark, and applying a predetermined treatment to the matrix material based on the second mark;
Growing electroforming on a surface including a mother optical surface of the matrix member;
And processing the grown outer peripheral surface of the electroforming based on the outer peripheral surface of the matrix member.
[0029]
The manufacturing method of the optical element molding die of the present invention is as follows.
While rotating the electrode member for electroforming, a mother optical surface corresponding to the optical surface of the optical element molded from the optical element molding die is formed by cutting, and the electrode member is cut by cutting. Forming a first mark and further forming an outer peripheral surface of the electrode member;
Forming a second mark on the electrode member based on the first mark;
A step of forming a matrix material for forming an optical element molding die on the mother optical surface;
Applying a predetermined treatment to the matrix material based on the second mark;
Growing electroforming on a surface including a mother optical surface of the matrix member;
And processing the grown outer peripheral surface of the electroforming based on the outer peripheral surface of the matrix member.
[0030]
The manufacturing method of the optical element molding die of the present invention is as follows.
An optical surface of an optical element molded from the optical element molding die while rotating a matrix member having an electrode member for forming an electroforming material and a matrix material for forming the optical element molding die Forming a mother optical surface corresponding to the cutting process, and forming the outer peripheral surface of the electrode member by cutting process;
Growing electroforming on a surface including a mother optical surface of the matrix member;
And processing the grown outer peripheral surface of the electroforming based on the outer peripheral surface of the matrix member.
[0031]
Further, the film formation is performed by a CVD method.
[0032]
Further, the predetermined process is a process of forming a concentric shape on the mother optical surface.
[0033]
Further, the method includes a step of determining three-dimensional coordinates of the matrix material based on the second mark.
[0034]
Further, the method includes a step of performing drawing processing corresponding to the shape of the optical element by an electron beam based on the determined three-dimensional coordinates.
[0035]
Further, the drawing process is a process of drawing a shape corresponding to the diffraction zone of the optical element.
[0036]
Furthermore, an optical element manufacturing method for forming an optical element using the optical element molding die manufactured by the above-described optical element molding mold manufacturing method is also the present invention.
[0037]
The present invention includes a step of growing electroforming on the surface including the mother optical surface of the mother die member, and a step of processing the grown electroformed member based on the outer peripheral surface of the mother die member. When forming a mother optical surface on the mother die member, for example, a diamond tool is used to perform cutting while rotating the mother die member. In such a case, the rotation axis coincides with the optical axis. Accordingly, when, for example, the outer peripheral surface of the mother die member is rotationally cut in parallel with the cutting, the axis of the outer peripheral surface coincides with the optical axis of the mother optical surface with high accuracy. Therefore, for example, the outer peripheral surface of an electroformed member (which is a base of an optical element molding die) grown from the master member is processed, or the electroformed member is processed based on the processed outer peripheral surface of the master member. If the positioning portion between the lining member and the backing member is processed, a highly accurate optical element can be finally formed.
[0038]
Since the mother die manufactured by the manufacturing method according to the present invention is to transfer and form an optical element molding die by electroforming, it is necessary to attach an electrode member before electroforming. In such a case, before the mother optical surface is formed, if a matrix material is attached to the electrode member (including the case where the matrix material is formed on the electrode member) and integrated, a series of fabrication of the matrix is performed. In the process, there is an advantage that it can be used to derive a processing standard. Based on this assumption, when forming the mother optical surface on the matrix material, for example, using a diamond tool or the like, cutting is performed while rotating the matrix material. In such a case, the rotation axis is the optical axis. Matches. Therefore, when the first mark is cut on the electrode member in parallel with the cutting process, for example, the first mark can be arranged at an equal distance from the optical axis. In other words, the optical axis is shifted from the first mark. I understand. However, since the first mark is formed by cutting, the mark is relatively large and may not be sufficient as a reference in subsequent processing. Therefore, based on the first mark, a finer second mark is formed on the electrode member, and the second mark is used as a reference for processing, thereby performing high-precision processing in the subsequent steps. It can be done.
[0039]
Furthermore, it is preferable that after the second step, a resist film is formed on the mother optical surface, and the predetermined process is performed on the resist film in the third step.
[0040]
The master mold can also be manufactured as follows. That is, while rotating the electrode member for forming the electroforming, a mother optical surface corresponding to the optical surface of the optical element molded from the optical element molding die is formed by cutting, and cutting is performed on the electrode member. A fourth step of forming a first mark by processing and further forming an outer peripheral surface of the electrode member; and a fifth step of forming a second mark on the electrode member based on the first mark. And a sixth step of forming a base material for forming an optical element molding die on the base optical surface formed by the fourth step, and the second mark. The seventh step of subjecting the matrix material to a predetermined treatment includes a seventh step, and this method can also provide high-precision processing by exhibiting the same effect. In addition, although it is clear, the fifth step may be performed after the sixth step.
[0041]
Further, it is preferable that after the sixth step, a resist film is formed on the mother optical surface, and the predetermined process is performed on the resist film in the seventh step.
[0042]
Further, the film formation is preferably performed by a CVD method. The CVD (Chemical Vapor Deposition) method is a method of supplying one or more source gases of a compound containing the constituent elements of the material to be made into thin films and particles to the reaction section, and forming fine particles and thin films by chemical reaction on the gas phase or substrate surface. How to create. In general, the CVD method has advantages such as a high deposition rate and excellent adhesion to a substrate.
[0043]
Further, when the second mark is formed using a focused ion beam, a fine mark having a line width of, for example, 20 nm can be formed, so that the processing accuracy can be increased.
[0044]
Furthermore, when the third or seventh step includes an eighth step of determining a three-dimensional coordinate of the matrix material based on the second mark, the shape of the mother optical surface is three-dimensionally determined. This is preferable because it can be expressed accurately with coordinates.
[0045]
The third or seventh step includes a ninth step of performing a drawing process corresponding to the shape of the optical element by the electron beam based on the determined three-dimensional coordinates. Since the surface to be processed can be positioned within the range, higher-accuracy processing can be performed.
[0046]
The drawing process is preferably a process for drawing a shape corresponding to the diffraction zone of the optical element.
[0047]
Further, it is preferable that the predetermined process is a process of forming a concentric shape on the mother optical surface because, for example, a fine annular zone corresponding to the diffraction annular zone of the optical element can be formed as the concentric shape. . However, the concentric shape is not limited to the annular zone.
[0048]
Furthermore, if the matrix member includes an electrode member for forming an electroforming, it is not necessary to attach the electrode member during the electroforming process, and the work can be saved. It may be.
[0049]
Further, when an optical element is molded using an optical element molding die formed using the above-described mother mold, an optical element with high accuracy can be manufactured.
[0050]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 is a flowchart showing the steps constituting the mold manufacturing method according to the present embodiment. FIG. 2 is a cross-sectional view showing a matrix material and electrode member assembly (this is called a matrix member or member A) to be processed in the main steps shown in FIG. Hereinafter, the mother die member (or member A) will be described as a mother die manufactured here. FIG. 3 is a top view of the member A. FIG. Note that the mother die member manufactured according to the present embodiment is formed with an annular zone corresponding to the diffraction annular zone of the optical element on its mother optical surface.
[0051]
First, in step S101 (first step) of FIG. ₂ Alternatively, a matrix material 10 made of polysilicon having a substantially hemispherical shape is embedded in a central opening 11a of a disk-shaped electrode member 11 made of a conductive material such as metal, and fixed with an adhesive so as not to be relatively rotatable (see FIG. 2 (a)), the member A is obtained. Thereafter, in step S102, the member A is attached to a chuck of a lathe described later (including an ultra-precision lathe (SPDT processing machine)). Further, since the member A is not rotated in step S103 (second step), the upper surface of the base material 10 is cut with a diamond tool as shown in FIG. 10a is formed, and the peripheral groove 11a (first mark) is cut on the upper surface of the electrode member 11, and the electrode member is further cut. 11 outer peripheral surface 11f is cut (tenth step). At this time, the position of the optical axis of the mother optical surface 10a cannot be confirmed from its outer shape, but the mother optical surface 10a and the circumferential groove 11a are formed coaxially with high precision because they are processed simultaneously. Moreover, the outer peripheral surface 11f of the electrode member 11 formed on the cylindrical surface is also formed coaxially with the optical axis with high accuracy. That is, the outer peripheral surface 11f has a rotation axis, which coincides with the optical axis of the mother optical surface.
[0052]
Here, the circumferential groove 11a may be formed of, for example, a plurality of grooves including a dark field portion (corresponding to a concave portion) and a bright field portion (corresponding to a convex portion). It is more preferable to have one (this can be easily formed if the tip of the diamond tool has irregularities). Further, the uneven shape of the circumferential groove 11a can function as a dike for preventing resist scattering applied as will be described later.
[0053]
Further, in step S104, the member A is removed from the ultra-precision lathe, and in step S105, it is set on a stage of a FIB (Focused Ion Beam) processing machine to be described later. In subsequent step S106, the circumferential groove 11a in the member A on the stage of the FIB processing machine is read, for example, the position of the optical axis of the base material 10 is determined from the inner edge thereof, and in step S107, the determined optical axis is determined. The second (or four or more) second marks 11b at a distance are drawn on the electrode member 11 (see FIGS. 2B and 3). Since the circumferential groove 11a formed by processing with a diamond tool is relatively wide, using this as a reference for processing may reduce processing accuracy. However, the FIB processing machine uses a line with a width of 20 nm. For example, if a crosshair is formed, a fine mark of 20 nm × 20 nm can be formed. By using the mark as a processing reference, higher-precision processing can be expected.
[0054]
In step S108, the member A is removed from the stage of the FIB processing machine, and in step S109, the protective tape 13 is attached on the second mark 11b (see FIG. 2C). This protective tape 13 is for preventing the resist L applied on the base material 10 in the post-processing from adhering to the second mark 11b. If the resist L adheres to the second mark 11b, reading may be inappropriate as a processing reference.
[0055]
Further, in step S110, the member A is set on a spin coater (not shown), and in step S111, a press pin is performed while the resist L is allowed to flow onto the base material 10, and then the main spin is performed in step S112. The resist L is coated (see FIG. 2D). The reason for separating the press pin and the main spin is to coat the resist L having a uniform film thickness on the mother optical surface 10a which is a complicated curved surface.
[0056]
Thereafter, in step S113, the member A is removed from the spin coater, and in step S114, baking is performed to stabilize the film of the resist L. In step S115, the protective tape 13 is peeled off. The member A in such a state is shown in FIG.
[0057]
Subsequently, in step S116, the member A is set in a shape measuring instrument (not shown) (having an image recognition means and a storage means), and in step S117, the second mark is set using the image recognition means of the shape measuring instrument. 11b is detected. Further, in step S118, the three-dimensional coordinates of the mother optical surface 10a of the master material 10 used for the ultra-precision lathe are converted into three-dimensional coordinates based on the second mark 11b and stored in the storage means. . As described above, the mother optical surface 10a is re-stored with new three-dimensional coordinates because the focal depth of the narrow electron beam is smaller than the processing surface of the mother optical surface 10a when performing electron beam drawing in a later process. This is because it is necessary to adjust the relative position between the electron gun and the member A in order to match the two. Note that the second mark 11b can be used as a position recognition mark for an operator to visually recognize the reference point of coordinates related to measurement data during measurement. Thereafter, in step S119, the member A is removed from the shape measuring instrument.
[0058]
In step S120, the member A is set on a three-dimensional stage of an electron beam drawing apparatus, which will be described later, and in step S121, the member A is placed via a reading means (scanning electron microscope: preferably attached to the electron beam drawing apparatus). The second mark 11b of A is detected, and the shape of the work surface of the mother optical surface 10a is obtained from the stored three-dimensional coordinates of the mother optical surface 10a. In step S122, the obtained work surface is obtained. The three-dimensional stage is moved so that the electron beam is focused on the shape, the electron beam B (see FIG. 2D) is irradiated, and a desired annular zone shape is drawn as a predetermined process. After drawing, in step S123, the member A is removed from the three-dimensional stage, and development processing is performed in step S124 to obtain a ring-shaped resist. Here, if the irradiation time of the electron beam B at the same point is lengthened, the resist removal amount increases accordingly. Therefore, by adjusting the position and the irradiation time (dose amount), a blazed annular zone is obtained. Resist can be left. It should be noted that, as described above, a brace-shaped ring zone may be formed on the mother optical surface by obtaining a ring-shaped resist as described above with reference to the outer peripheral surface 11f of the electrode member 11 (13th step). .
[0059]
Further, in step S125, the surface of the mother optical surface 10a of the master material 10 is engraved by dry etching using a plasma shower, and a blazed annular zone 10b (predetermined shape / here, exaggerated from the actual drawing). (See FIG. 2E). The member A processed by the steps so far is manufactured as a mother die. That is, as a result of these processes, an optical surface having a limited shape (pattern) is formed on the mother optical surface. In the present embodiment, the third step corresponds to steps S107, S121, and S122, the seventh step corresponds to steps S121 and S122, the eighth step corresponds to step S121, and the ninth step The process corresponds to step S122.
[0060]
Thereafter, in step S126, the matrix member whose surface is activated, that is, the member A, is immersed in a nickel sulfamate bath, and an electric current is passed between the electrode member 11 and the external electrode 14, whereby the electroformed member 20 is formed. Growing (11th step: see FIG. 2F). At this time, by applying an insulating agent to the outer peripheral surface 11f of the electrode member 11 prior to electroforming, it is possible to suppress the electroforming of the portion where the insulating agent is applied. When the following processing is performed with an allowable tilt angle of 1 minute at the time of injection molding, it is desirable that the axial length of the outer peripheral surface 11f on which the electroformed member serving as the reference surface is not formed be 7 mm or more. In the process of growth, the electroformed member 20 forms an optical surface transfer surface 20a corresponding to the mother optical surface 10a with high accuracy and an annular transfer surface 20b corresponding to the annular zone 10b with high accuracy (optical surface transfer surface). 20a and annular transfer surface 20b are collectively referred to as an optical transfer surface).
[0061]
After that, in step S127, the member A and the electroformed member 20 are integrated with the outer peripheral surface 11f of the electrode member 11 as a reference, and the rotation axis of the SPDT processing machine and the optical axis of the member A are aligned with the chuck. Mounting and cutting the outer peripheral surface 20c of the electroformed member 20 (12th step: see FIG. 2 (g)). In this operation, the optical axis of the mother optical surface coincides with the rotation center of the electroformed member. As described above, by setting the axial length of the outer peripheral surface 11f to 7 mm or more, for example, it is necessary to consider the end face parallelism between the support member (not shown) used when attaching the member A to the chuck and the member A, for example. There is no need to set. In step S103, the SPDT processing machine used (first lathe) and the SPDT processing machine used in step S127 (second lathe but the same here) are used. However, it is possible to use a different SPDT machine.
[0062]
In addition, as shown in FIG. 2G, a pin hole 20d (center) and a screw hole 20e as a positioning portion with the backing member are processed in the electroformed member 20 (a twelfth step). A cylindrical shaft may be formed instead of the pin hole 20d.
[0063]
In step S128 (first half), the electroformed member 20 is integrated with the backing member as described below to form the movable core 30.
[0064]
FIG. 4 is a cross-sectional view of the movable core 30. In FIG. 4, the movable core 30 includes an electroformed member 20 disposed at the front end (right side in the figure), a pressing portion 36 disposed at the rear end (left side in the figure), and a sliding member 35 disposed therebetween. Composed. The sliding member 35 and the pressing portion 36 serve as a backing member.
[0065]
The electroformed member 20 is positioned in a predetermined relationship with the sliding member 35 by engaging the pin portion 20a protruding from the center of the end surface of the cylindrical sliding member 35 with the pin hole 20d. The electroformed member 20 is attached to the sliding member 35 by screwing the bolts 37 inserted into the two bolt holes 35b penetrating the moving member 35 in parallel with the axis into the screw holes 20e.
[0066]
The sliding member 35 has a screw shaft 35c formed so as to protrude from the center of an end surface (left end in the drawing) facing the end surface (right end in the drawing) provided with the pin portion 35a. It is attached to the pressing portion 36 in a predetermined positional relationship by being screwed into a screw hole 36a formed in the portion. In FIG. 4, in this embodiment, considering the wear of the electroformed member 20, the outer peripheral surface 35 e of the sliding member 35 has a larger diameter than the outer peripheral surface of the portion other than the electroformed member 20 and the flange portion 36 b of the pressing portion 36. It has become. Here, in step S128 (second half) in FIG. 1, the outer peripheral surfaces of the sliding member 35 and the pressing portion 36 are finished by cutting along with the rotation on the basis of the outer peripheral surface 11f of the electrode member 11, and thus formed in step S103. The standard is consistently used until step S128, and the coaxiality between the center of the concentric pattern (ring zone 10b) of the matrix member and the outer shape center of the mold sliding portion can be kept within 1 μm (that is, the matrix The optical axis of the optical surface coincides with the rotation center of the backing member having the sliding member 35 and the pressing portion 36). In step S128, after the electroformed member 20 is integrated with the backing member, the outer peripheral surface of the backing member is made coaxial with the matrix member by cutting with reference to the outer peripheral surface of the electroformed member 20 after cutting. It is also possible to finish.
[0067]
Thereafter, the electroformed member 20 is removed from the member A by cutting at a position indicated by an arrow X in FIG. 4 (step S129 in FIG. 1). Further, in step S130, after the electroformed member 20 and the matrix member are removed from the mold, the electroformed member 20 at the tip of the movable core 30 is finished to obtain an optical element molding die.
[0068]
FIG. 5 is a diagram showing a state in which an optical element is molded using the movable core 30 formed as described above. In FIG. 5, the holding portion 42 that holds the optical element molding die 41 having the optical surface transfer surface 41 a is fixed to the movable side cavity 43. The movable cavity 43 has a small opening 43a and a large opening 43b coaxial therewith. When the movable core 30 is inserted into the movable side cavity 43, the outer peripheral surface 35e of the sliding member 35 slides with the inner peripheral surface of the small opening 43a, and the outer peripheral surface 36d of the flange portion 36b of the pressing portion 36 is It slides on the inner peripheral surface of the large opening 43b. By being guided by the two sliding portions, the movable core 30 can move in the axial direction without being largely inclined with respect to the movable side cavity 43. The molten resin is injected between the optical element molding die 31 and the electroformed member 20, and the movable core 30 is pressurized in the direction of the arrow, whereby the optical element OE is molded. According to the present embodiment, by using the electroformed member 20 as an optical element molding die that is accurately transferred from the mother mold member, the optical surface of the optical element OE is provided on the optical surface of the electroformed member 20. The surface transfer surface 20a is transferred and the diffraction ring zone corresponding to the zone transfer surface 20b is accurately formed concentrically with the optical axis (that is, the optical surface of the optical element OE is electroformed. The optical transfer surface of the member 20 is accurately formed with respect to the optical axis).
[0069]
When processing the optical element molding die as described above, since the projection 20c corresponding to the second mark 11b is transferred and formed on the electroformed member 20, this should be used as a processing reference. Thus, it is possible to perform processing of the outer peripheral surface and the like with high accuracy.
[0070]
According to the present embodiment, by forming the second mark 11b on the electrode member 11 integrated with the matrix material 10, the matrix of the matrix is formed in the subsequent process based on the second mark 11b. The material 10 has the advantage that it can be processed with high accuracy. Further, by cutting the outer peripheral surface 11f of the electrode member 11 in parallel with the mother optical surface 10a of the base material 10, the outer peripheral surface 11f can be formed so as to be coaxial with the optical axis. By doing, the process precision in subsequent processes (for example, outer peripheral surface process of the electroformed member 20) can be improved.
[0071]
Next, a second embodiment will be described. The difference between the second embodiment and the first embodiment described above is the configuration of the matrix member. More specifically, an electrode member 111 made of a conductive material such as a metal having a shape similar to that of the member A shown in FIG. 1 is prepared, and the convex surface 111c corresponding to the mother optical surface thereof is used as a mother mold material. SiO ₂ Alternatively, a polysilicon film is formed (see FIG. 7). Such film formation is preferably performed by a CVD process. More specifically, the second embodiment will be described.
[0072]
FIG. 6 is a flowchart showing a process (part of the process is omitted with reference to FIG. 1) constituting the manufacturing method of the matrix member according to the second embodiment. In FIG. 6, in step S201, the electrode member 111 is attached to the chuck of an ultra-precision lathe (SPDT processing machine). Further, since the electrode member 111 is not rotated in step S202 (fourth step), the convex surface 111c is cut with a diamond tool, and the mother optical surface (corresponding to the optical surface of the optical element to be finally formed) is obtained. The peripheral groove 111a (first mark) is cut on the peripheral surface 111d of the electrode member 111, and the outer peripheral surface 111f is cut (tenth step). At this time, the position of the optical axis of the mother optical surface cannot be confirmed from its outer shape, but the mother optical surface, the circumferential groove 111a, and the outer circumferential surface 111f are formed coaxially with high precision because they are processed simultaneously. It becomes.
[0073]
Further, in step S203, the electrode member 111 is removed from the ultraprecision lathe, and in step S204, it is set on the stage of the FIB processing machine. In subsequent step S205, the circumferential groove 111a in the electrode member 111 on the stage of the FIB processing machine is read, for example, the position of the optical axis of the optical surface is determined from the inner edge, and determined in step S206 (fifth step). Three (or four or more) second marks 111b at equal distances from the optical axis are drawn on the peripheral surface 111c of the electrode member 111 (see FIG. 7).
[0074]
In step S207, the electrode member 111 is removed from the FIB processing machine, and in step S208, the protective tape 113 (see FIG. 7) is pasted on the second mark 111b. This protective tape 113 is used to prevent film formation up to the second mark 111b when forming the matrix material 110, and on the matrix material 110 formed by post-processing. This is to prevent the resist applied to the second mark 111b from adhering. If the film or resist adheres to the second mark 111b, the reading may become inappropriate as a processing standard. Thereafter, in step S209 (sixth process), the matrix material 110 is formed on the electrode member 111 by CVD, and the formed electrode member 111 is set as the member A on the spin coater, and the step of FIG. By performing the steps from S110, the mold is manufactured.
[0075]
The second marks 11b and 111b used in the present embodiment have a plane substantially cross shape. For example, as shown in FIG. 3, parallel lines formed substantially parallel to the first mark 11a , And an orthogonal line that is substantially orthogonal (if it is not orthogonal, it only needs to intersect). Thereby, the recognition accuracy of the second marks 11b and 111b for position recognition is improved, and the positioning accuracy in the exposure apparatus and the electron beam drawing apparatus in each step described above can be improved. It should be noted that the second marks 11b and 111b are preferably arranged at positions separated from at least approximately three times the effective diameter of the effective curved surface portion. Furthermore, in the above-described example, the second marks 11b and 111b are formed with concave concave portions by engraving. However, the present invention is not limited to this, and the second marks 11b and 111b may be configured with convex convex portions. In such a case, even if the peripheral surface is covered with the resist L, the position of the subsequent process can be recognized by the convex mark, and thus the protective tape 13 becomes unnecessary.
[0076]
Further, the second marks 11b and 111b may have curved lines parallel to the concentric circles of the circumferential grooves 11a and 111a, and are not limited thereto, and may be crosses in which straight lines intersect each other. . This is because it is easily recognized by the human eye. Furthermore, it is not limited to cross shapes that are orthogonal to each other, and may be crosses that cross each other at least, or may be other various shapes such as a circle or a triangle. However, it is preferable that the shape has an edge or a corner because the point can be specified. On the other hand, if the shape is not so, the shape of the second marks 11b and 111b itself is measured to determine the center position thereof. preferable.
[0077]
In addition, the second marks 11b and 111b may have a cross shape in which only one of the second marks 11b and 111b is elongated in addition to making the lengths of the intersecting lines equal. This facilitates mark recognition. Or it is good also as a structure which deposits the thin film which consists of carbon (carbon) vapor-deposited on the member A, and forms a cross. Thus, having an area in a square shape makes it easier to recognize. In addition, as long as it is not only a square shape but a shape having an area or a shape having a contour, any other shape may be used.
[0078]
Further, the second marks 11b and 111b may be formed from carbon, and may be formed by only a point, not a cross. As described above, when carbon is formed by vapor deposition, the boundary line and the point are clearly visually recognized by the edge effect of the boundary line, so that an arbitrary shape can be formed without forming a cross.
[0079]
(Ultra-precision lathe: SPDT processing equipment)
Hereinafter, a schematic configuration of a control system of an ultra-precision lathe used for cutting the member A, for example, SPDT (Single Point Diamond Turning) will be described with reference to FIGS. 8 (a) and 8 (b).
[0080]
As shown in FIG. 8A, the ultra-precision lathe 100 includes a fixed portion 111 that is a rotation holding member for fixing the workpiece 110 such as the member A, and a cutting tool for processing the workpiece 110. A diamond tool 112 that is a cutting edge of the blade, a Z-axis slide table 120 that moves the fixed portion 111 in the Z-axis direction, and an X that moves the X-axis direction (or in addition to the Y-axis direction) while holding the diamond tool 112 An axis slide table 122 and a surface plate 124 that movably holds the Z axis slide table 120 and the X axis slide table 122 are configured. In addition, a rotation drive unit (not shown) for rotating and driving either one or both of the fixed portion 111 and the diamond tool 112 is provided, and is electrically connected to a control unit 138 described later.
[0081]
Further, as shown in FIG. 8A, the ultra-precision lathe 100 is driven (or added) in the X-axis direction by the Z-direction drive means 131 for controlling the drive of the Z-axis slide table 120 and the X-axis slide table 122. X-direction drive means 132 and Y-direction drive means 133 for controlling the drive in the Y-axis direction, feed amount control means 134 for controlling the feed amount by these, and cut amount control means 135 for controlling the cut amount. And a temperature control means 136 for controlling the temperature, a storage means 137 for storing various control conditions and control tables or processing programs, and a control means 138 for controlling these parts.
[0082]
As shown in FIG. 8 (b), the diamond tool 112 includes a diamond tip 113 constituting the main body portion, a rake face 114 composed of the apex angle α formed at the tip portion, and a first relief constituting the side surface portion. It comprises a surface 115 and a second flank 116. On the cutting edge included in the rake face 114, a plurality of uneven portions 114a are formed in advance or due to wear.
[0083]
The ultra-precision lathe 100 having the above-described configuration operates as follows in general. That is, the workpiece 110 is processed by the relative movement of the diamond tool 112 with respect to the workpiece 110 that is the set member A. At this time, since the cutting edge of the diamond tool 112 has an R bite configuration, the point on which the cutting edge strikes sequentially changes and is resistant to wear.
[0084]
In the present embodiment, when machining the member A using the ultra-precision lathe as described above, while controlling the temperature, the feed amount and the cutting amount are controlled to control the curved portion. It will be cut.
[0085]
(About focused ion beam (FIB) processing equipment)
(Configuration explanation)
Next, a schematic configuration of the focused ion beam processing apparatus for forming the second marks 11b and 111b will be described with reference to FIG.
[0086]
A focused ion beam processing apparatus (FIB: Focused Ion Beam apparatus) processes a member A with a focused ion beam using a metal ion source such as Ga and observes a scanned image obtained by scanning the member A with a focused ion beam ( SIM (Scanning Ion Microscope) is performed, and an ion beam generated from an ion source and accelerated is finely focused by an electrostatic condenser lens, an objective lens, or the like, and irradiated onto the member A. The irradiation point of the beam is scanned by a deflector, for example, secondary electrons generated from the member A by this scanning are detected, and a scanned image or the like is displayed based on this detection signal.
[0087]
The focused ion beam processing apparatus 200 is maintained in a high vacuum. As shown in FIG. 9, a liquid metal ion source 201 serving as an ion source, an extraction electrode 202 that extracts ions, and a plurality of ions that accelerate the ion beam to a desired energy. Accelerating tube 203 composed of stages, condenser lens 204 whose aperture can be varied by an aperture 205 for limiting the ion beam, objective lens 206 whose aperture can be variably adjusted by an aperture 207, and which focuses the ion beam and irradiates the sample, deflector 208, E × B mass analyzer 209 with blanking / E × B restriction aperture, emitter alignment 210, alignment set stigmator 211, alignment set 212, alignment set stigmator 213, and member A to be processed are placed The position and inclination of the member A A stage 214 that can be freely adjusted, a detector 215 for detecting a position recognition mark, a laser interferometer 217 including a laser supply source 216 and an optical system, a stage driving means 220 for driving the stage 214, and control of each part thereof A control circuit 230 for performing the operation, an operation input unit 261 for performing the operation input, an image recognition unit 260 for observing and recognizing the member A and the scanned image, a power source (not shown), and the like.
[0088]
The apertures 205 and 207 have openings that can change the diameter of the ion beam, for example, by restricting the path of the ion beam, and have a thickness that allows the ion beam to pass through other than the openings. . The aperture may be formed in N stages.
[0089]
The detector 215 is for detecting, for example, secondary electrons generated based on the irradiation of the ion beam onto the member A.
[0090]
The stage driving means 220 includes an X direction driving mechanism 221 for driving the stage in the X direction, a Y direction driving mechanism for driving in the Y direction, a Z direction driving mechanism for driving in the Z direction, and a θ direction. And a θ-direction drive mechanism for driving the motor.
[0091]
The control circuit 230 includes an ion source control circuit 231 that controls the ion source 201, an acceleration tube control circuit 232 that controls the acceleration tube 203, a first focusing control circuit 233 that controls focusing by the condenser lens 204, and an objective lens. The second focusing control circuit 234 for controlling focusing by the 206, the deflection control circuit 235 for controlling the deflector of the deflector 208, the stage control circuit 236 for controlling the stage driving means 220, and the secondary generated by the member A By controlling a detector control circuit 237 that controls signal processing from the detector 21 that detects ions, a laser interferometer control circuit 238 that controls the laser interferometer 217, and an E × B mass analyzer 209, ions are detected. Ion selection control circuit 239 to be selected, emitter alignment 210, alignment set stigmator 211, 1st to 4th alignment control circuits 240, 241, 242, and 243 for controlling the image set 212 and alignment set stigmator 213, various control tables, a storage unit 250 that stores programs, and various display images are displayed. It includes a display processing unit 251 for processing and a control unit 252 such as a CPU that controls these operations.
[0092]
The storage unit 250 is realized as an area of a storage device such as a semiconductor memory or a disk device, and stores a combination of image data and position data. For example, a combination of position data including cross-section position coordinates and cross-sectional image data in which the pixels constituting each cross-sectional image data are stored in the scanning order can be stored as a pair of data. The storage unit 250 is provided with a plurality of areas for storing the data, and can store the data corresponding to the cross sections formed at specific positions of the member A, for example, in the order of the position data.
[0093]
The display processing unit 251 performs processing to display, for example, an image or the like on the image recognition unit 260 based on each image data and position data stored in the storage unit 250 in order to display a specific location. The display processing unit 251 can read pixel data of arbitrary X, Y, and Z coordinates from the data stored in the storage unit 250 and display a stereoscopic image viewed from a desired viewpoint on the image recognition unit 260. It is good. Various display methods can be considered. For example, a contour is extracted from adjacent pixel data, and the front-rear relationship of the contour is determined so that a hidden portion can be displayed with a broken line or the like. It is preferable. Further, the image data is subjected to image processing such as contour extraction due to a change in luminance, and the size and position of a characteristic part of the surface of the member A such as a hole or a line formed by an ion beam are recognized, The stage 214 may be configured to determine whether or not the member A is disposed at a desired position and whether or not holes and lines having a desired size are formed in the member A by an ion beam.
[0094]
The control unit 252 receives a detection signal from the detector 215 via, for example, the detector control circuit 237, forms image data, and sets each unit based on an instruction from the operation input unit 261 or image data. Set various conditions. Further, the stage 214 and each unit for ion beam irradiation can be controlled in accordance with an operator instruction input from the operation input unit 261 or the like.
[0095]
The control unit 252 receives all detection signals from the detector 215 converted into digital values by the detector control circuit 237. The detection signal changes according to the position where the ion beam is scanned, that is, the deflection direction of the ion beam. Therefore, the surface shape and material of the member A at each scanning position of the ion beam can be detected by synchronizing the deflection direction and the detection signal. The control unit 252 can reconstruct these corresponding to the scanning position and display the image data of the surface of the member A on the image recognition unit 260.
[0096]
(Description of operation)
In the focused ion beam apparatus 200 having the above-described configuration, first, the member A in which the mother optical surface 10 and the first marks 11b and 111b are formed on one surface on the stage 214 provided in the focused ion beam apparatus 200. The focused ion beam apparatus 200 is set up until the surroundings are in a vacuum state and the ion beam can be scanned on the member A.
[0097]
Next, a certain area on the member A is scanned with the ion beam. At this time, ions from the ion source 201 are generated at an extraction voltage of 5 to 10 kV and accelerated by the acceleration tube 203. The accelerated ion beam is focused by the condenser lens 204 and the objective lens 206 and reaches the member A on the stage 214.
[0098]
When an alloy ion source such as Au—Si—Be is used, only necessary ions are moved straight by the E × B mass analyzer 209, and the necessary ions are separated by bending the trajectory of unnecessary ions. You can choose.
[0099]
In addition, when handling an ion having an isotope such as Si, it is preferable that the crossover point of the ion beam by the condenser lens 204 is adjusted and controlled so as to be at the center of the E × B mass analyzer 209. . Thereby, it is possible to effectively use isotopes without separating them. In this way, the ions can be focused at one point on the member A by the objective lens 206 and scanned, for example, in a raster shape.
[0100]
By scanning, secondary electrons and secondary ions emitted from the surface of the member A are detected, and based on the detection result, image processing is performed by the display processing unit 251 to recognize a SIM image indicating the surface shape of the region. Displayed on the unit 260. For example, each time the stage 214 is moved, a SIM image is displayed and the stage 214 is aligned so that a specific location can be displayed.
[0101]
For example, the operator may specify, for example, a processing region, a processing time, and an ion beam current value as a processing condition setting for a SIM image displaying a specific location using the operation input unit 261 or the like. . For example, a SIM image of the surface of the member A is acquired, a processing area is set for a specific location, a processing time of the processing area, and an ion beam diameter and current value of an ion beam used for processing are specified. To do. Note that the state of the member A may be observed using another observation optical system (not shown).
[0102]
Here, in the present embodiment, the image recognition unit 260 recognizes the first marks 11 a and 111 a on the member A based on the detection signal from the detector 215.
[0103]
Then, parallel lines parallel to the lines of the first marks 11a and 111a are formed by an ion beam. At this time, it is preferable to form the parallel lines so as to draw a part of the arc or linearly by the relative movement of the stage 214 and the ion beam.
[0104]
At this time, the focused ion beam processing apparatus 200 scans the processing region. Since the amount of sputtering is determined by the material of member A, the type of ion beam (difference in ion beam current value), energy, dose, etc., the processing region is dug to a substantially constant depth by one scan. It is advanced. Corresponding to scanning, all detection signals of secondary electrons and secondary ions are stored in the storage unit 250, image data at a specific location is acquired, and an image at an arbitrary position is obtained in accordance with an operator's instruction. be able to.
[0105]
Next, an orthogonal line substantially orthogonal to the parallel line is formed by an ion beam. By forming a plurality of these, for example, three places in the direction along the circumference of the concentric circles of the first marks 11a and 111a, a plurality of second marks 11b and 111b can be formed.
[0106]
Note that the formation procedure when forming the second marks 11b and 111b at three locations is not limited to the above, and the parallel lines at the three locations are formed by rotating the stage 214 intermittently in advance. Then, after that, an orthogonal line may be formed for each location.
[0107]
Furthermore, these control procedures are stored in advance as a control program in the storage unit 250 or the like, and when the operation input unit 261 forms, for example, three second marks 11b and 111b, "3" In the case of forming five places, by inputting “5”, the first marks 11a and 111a are automatically detected and the points where the second marks 11b and 111b are to be formed are automatically calculated. It is preferable that the second marks 11b and 111b are automatically formed by pressing an execution start button or the like.
[0108]
In this way, using the focused ion beam device, the observation optical system of the focused ion beam device or the secondary ion image is used for observation, the first mark is recognized, and the coordinates are determined at the stage position of the focused ion beam device. know. The second mark can be formed by scanning the focused ion beam at the coordinate position.
[0109]
Here, the line width (beam focusing) is preferably about 1 nm to about 50 nm, for example. However, this is limited to the case where Ga ions are implanted. More preferably, it is about 20 nm. This is because the positional deviation of the central axis of the optical element needs to be within 1 μm, and the position can be determined by a sufficiently small diameter with respect to this 1 μm.
[0110]
Note that the focused ion beam processing apparatus is not limited to such an example, and processing with an ion beam and surface observation are simultaneously performed, and images of a plane parallel to the surface of the member A are sequentially acquired to obtain three-dimensional image data. You may have the structure which obtains arbitrary cross sections by image conversion while accumulating.
[0111]
(About electron beam lithography system)
(Configuration explanation)
Next, the overall schematic configuration of the electron beam drawing apparatus will be described with reference to FIG. FIG. 10 is an explanatory diagram showing the overall configuration of the electron beam lithography apparatus of this example.
[0112]
As shown in FIG. 10, the electron beam drawing apparatus 401 forms a high-resolution electron beam probe with a large current and scans the member A to be drawn at a high speed, thereby forming a high-resolution electron beam probe. Then, an electron gun 412 which is an electron beam generating means for generating an electron beam and irradiating the target with a beam, a slit 414 for passing the electron beam from the electron gun 412, and an electron beam passing through the slit 414 An electron lens 416 for controlling the focal position with respect to the member A, an aperture 418 disposed on a path through which the electron beam is emitted and configured to have a desired electron beam shape by an opening, and deflecting the electron beam A deflector 420 that controls the scanning position on the target member A and a correction coil 422 that corrects the deflection. It is configured. These parts are arranged in the lens barrel 410 and maintained in a vacuum state when the electron beam is emitted.
[0113]
Further, the electron beam drawing apparatus 411 is an XYZ stage 430 that is a placement table for placing the member A to be drawn, and a transport unit for transporting the member A to a placement position on the XYZ stage 430. A loader 440, a measuring device 480 that is a measuring means for measuring the reference point of the surface of the member A on the XYZ stage 430, a stage driving means 450 that is a driving means for driving the XYZ stage 430, a loader , A vacuum exhaust device 470 that exhausts the interior of the lens barrel 410 and the housing 411 including the XYZ stage 430 to be a vacuum, and an observation system 491 that observes the member A. , And a control circuit 492 which is a control means for controlling these controls.
[0114]
The electronic lens 416 is respectively controlled by generating a plurality of electronic lenses according to the current values of the coils 417a, 417b, and 417c, which are separately provided at a plurality of locations along the height direction. The focal position of the electron beam is controlled.
[0115]
The measuring device 480 includes a first laser length measuring device 482 that measures the member A by irradiating the member A with a laser, and a laser beam emitted from the first laser length measuring device 482 (the first laser length measuring device 482). A first light receiving portion 484 that reflects the member A and receives the reflected light, and a second laser length measuring device 486 that performs irradiation from an irradiation angle different from that of the first laser length measuring device 482. And a second light receiving portion 488 that receives the reflected light when the laser light (second irradiation light) emitted from the second laser length measuring device 486 reflects the member A. Yes.
[0116]
The stage driving unit 450 includes an X direction driving mechanism 452 that drives the XYZ stage 430 in the X direction, a Y direction driving mechanism 454 that drives the XYZ stage 430 in the Y direction, and a Z direction driving that drives the XYZ stage 430 in the Z direction. A mechanism 456 and a θ-direction drive mechanism 458 for driving the XYZ stage 430 in the θ direction are configured. As a result, the XYZ stage 430 can be operated three-dimensionally and alignment can be performed.
[0117]
Although not shown, the control circuit 492 includes an electron gun power supply unit for supplying power to the electron gun 412, an electron gun control unit for adjusting and controlling current, voltage, and the like in the electron gun power supply unit, an electron lens 416 ( A lens power supply unit for operating each of the plurality of electronic lenses, and a lens control unit for adjusting and controlling each current corresponding to each electronic lens in the lens power supply unit.
[0118]
Further, the control circuit 492 includes a coil control unit for controlling the correction coil 422, a shaping deflection unit for deflecting in the molding direction by the deflector 420, and a secondary for performing deflection in the sub-scanning direction by the deflector 420. To generate a deflection unit, a main deflection unit for deflecting in the main scanning direction by the deflector 420, an electric field control circuit which is an electric field control unit for controlling the electric field of the electron beam, a drawing pattern, and the like for the member A Pattern generation circuit, various laser control systems, a stage control circuit for controlling the stage driving means 450, a loader control circuit for controlling the loader driving device 460, a measurement information input unit for inputting measurement information, and input information Memory that is a storage means for storing a plurality of other information, a program memory that stores a control program for performing various controls, and a control system that includes each unit Control unit, which is formed by, for example, CPU controls the these units, is configured to include a.
[0119]
(Description of operation)
In the electron beam lithography apparatus 401 having the above-described configuration, when the member A conveyed by the loader 440 is placed on the XYZ stage 430, the vacuum exhaust device 470 causes air in the lens barrel 410 and the housing 411 to After exhausting dust and the like, an electron beam is irradiated from the electron gun 412.
[0120]
The electron beam irradiated from the electron gun 412 is deflected by the deflector 420 via the electron lens 416, and the deflected electron beam B (hereinafter, only with respect to the deflection-controlled electron beam after passing through the electron lens 416) Drawing may be performed by irradiating the drawing position on the surface of the member A on the XYZ stage 430, for example, the curved surface portion (curved surface) 12.
[0121]
At this time, the measurement device 480 measures the drawing position on the member A (at least the height position among the drawing positions) or the position of a reference point as described later, and the control circuit 492 is based on the measurement result. The position of the focal depth of the electron beam B, that is, the focal position is controlled by adjusting and controlling each current value flowing through the coils 417a, 417b, and 417c of the electron lens 416 so that the focal position becomes the drawing position. Move controlled.
[0122]
Alternatively, based on the measurement result, the control circuit 492 moves the XYZ stage 430 so that the focal position of the electron beam B becomes the drawing position by controlling the stage driving unit 450.
[0123]
In this example, the control may be performed by either the electron beam control or the XYZ stage 430 control, or by using both.
[0124]
Next, the first laser beam length 482 of the measuring device 480 irradiates the member A with the first light beam S1 from the direction intersecting the electron beam, and the first light beam S1 transmitted through the member A is irradiated. The first light intensity distribution is detected by receiving light.
[0125]
At this time, since the first light beam S1 is reflected at the bottom of the member A, the (height) position on the flat portion of the member A is measured and calculated based on the first intensity distribution. Become. However, in this case, the (height) position of the member A on the mother optical surface 10 cannot be measured.
[0126]
Therefore, in this example, a second laser length measuring device 486 is further provided. That is, the second laser length measuring device 486 irradiates the member A with the second light beam S2 from a direction substantially orthogonal to the electron beam different from the first light beam S1, and transmits the second light beam S2 through the member A. Is received by the second light receiving unit 488, the second light intensity distribution is detected, and the position is measured and calculated based on the second light intensity distribution.
[0127]
Then, using the height position of the member A as a drawing position, for example, the focus position of the electron beam is adjusted and drawing is performed.
[0128]
The present invention has been described above with reference to the embodiments. However, the present invention should not be construed as being limited to the above-described embodiments, but may be appropriately changed or improved (including combinations of the embodiments). Of course, it is possible.
[0129]
【The invention's effect】
According to the present invention, a manufacturing method of a mother die that can easily manufacture a highly accurate mother die by securing a processing standard, a manufacturing method of an optical element molding die using such a mother die, and such a method It is possible to provide a method for manufacturing an optical element molded by an optical element molding die.
[Brief description of the drawings]
FIG. 1 is a flowchart showing steps constituting a mold manufacturing method according to a first embodiment;
FIG. 2 is a cross-sectional view showing an assembly of a matrix material and an electrode member to be processed, that is, a member A in the main process shown in FIG.
3 is a top view of member A. FIG.
4 is a cross-sectional view of the movable core 30. FIG.
FIG. 5 is a diagram showing a state in which an optical element is molded using a movable core 30. FIG.
FIG. 6 is a flowchart showing a process (part of the process is omitted with reference to FIG. 1) constituting the manufacturing method of the matrix member according to the second embodiment.
FIG. 7 is a cross-sectional view showing an assembly of a matrix material and an electrode member processed by the matrix member manufacturing method according to the second embodiment;
8A is a schematic configuration diagram showing an example of the configuration of an ultra-precision lathe used for machining the member A, and FIG. 8B is a diagram of the ultra-precision lathe in FIG. 8A. It is a perspective view which shows an example of the blade edge | tip of the diamond tool used.
9 is an explanatory diagram showing an example of the configuration of a focused ion beam processing apparatus used for processing the member A. FIG.
FIG. 10 is an explanatory diagram showing an example of the configuration of an electron beam drawing apparatus.
[Explanation of symbols]
A Matrix material
10 Matrix material
11 Electrode member
11a, 111a First mark (circumferential groove)
11b, 111b Second mark
100 Super-precision lathe (SPDT processing equipment)
200 Focused ion beam processing equipment
301 Coating material coating device
401 Electron beam drawing apparatus

Claims (29)

Forming the mother optical surface of the optical element on the mother member by cutting while rotating the mother member;
Forming the outer peripheral surface of the mother die member by cutting so that the optical axis of the mother optical surface coincides with the rotation center of the outer peripheral surface of the mother die member while rotating the mother die member;
Forming an optical surface having a predetermined shape on the mother optical surface of the mother die member;
Forming an electroformed member having an optical transfer surface corresponding to the optical surface of the matrix member by performing an electroforming process on the matrix member;
In order to obtain the optical element molding die, the optical axis of the mother optical surface coincides with the rotation center of the outer peripheral surface of the electroformed member while the electroformed member and the mother die member are rotated together. And a step of cutting the outer peripheral surface of the electroformed member on the basis of the outer peripheral surface of the mother die member. The step of forming an optical surface having a predetermined shape on the mother optical surface of the mother die member further includes
Forming a resist film on the mother optical surface;
Irradiating the resist film with an electron beam and drawing an annular shape;
The method for producing a mold for forming an optical element according to claim 1, further comprising: performing a development process to form an annular shape on the mother optical surface. 3. The optical element according to claim 1, wherein the base member and the electroformed member are integrated, and the outer peripheral surface of the electroformed member is cut with reference to the outer peripheral surface of the base member. Manufacturing method of mold for molding. The electroformed member is cut after attaching the mother die member to the lathe so that the rotation axis of the lathe and the optical axis of the mother die member coincide with each other on the basis of the outer peripheral surface of the mother die member. The method for producing an optical element molding die according to claim 3. 5. The method for manufacturing an optical element molding die according to claim 1, wherein the matrix member includes an electrode member, and an insulating agent is provided on an outer peripheral surface of the electrode member. . 6. The method of manufacturing an optical element molding die according to claim 1, wherein the mother optical surface on the mother member and the outer peripheral surface of the mother member are processed simultaneously. The method for manufacturing an optical element molding die according to any one of claims 1 to 6, wherein the matrix member is obtained by fixing a matrix material to an electrode member. The method for producing an optical element molding die according to claim 7, wherein the mother optical surface is formed by cutting a material of the mother die. 7. The method for manufacturing an optical element molding die according to claim 1, wherein the matrix member is obtained by forming a matrix material on an electrode member. Attaching the matrix member to the first lathe;
Forming a mother optical surface of an optical element by cutting on the mother member while rotating the mother member on the first lathe;
The outer peripheral surface of the mother die member is cut so that the optical axis of the mother optical surface coincides with the rotation center of the outer peripheral surface of the mother die member while rotating the mother die member on the first lathe. A step of forming by:
Removing the matrix member from the first lathe;
Forming a resist layer on the mother optical surface of the mother die member;
Drawing a predetermined shape on the resist layer;
Developing to form an optical surface having a predetermined shape on the mother optical surface of the mother mold member;
Forming an electroformed member having an optical transfer surface corresponding to the optical surface of the matrix member by performing an electroforming process on the matrix member;
Attaching the matrix member and the electroformed member to a second lathe;
In order to obtain the optical element molding die, the optical axis of the mother optical surface coincides with the rotation center of the outer peripheral surface of the electroformed member while the electroformed member and the mother die member are rotated together. Cutting the outer peripheral surface of the electroformed member based on the outer peripheral surface of the matrix member;
And a step of removing the electroformed member from the matrix member in order to obtain an optical element having an optical transfer surface. 11. The optical element molding according to claim 10, wherein the matrix member and the electroformed member are integrated, and the outer peripheral surface of the electroformed member is cut with reference to the outer peripheral surface of the matrix member. Mold production method. A step of integrating the electroformed member and the backing member;
By rotating the electroformed member and the backing member together with the matrix member and cutting the outer circumferential surface of the backing member based on the outer circumferential surface of the matrix member, the optical axis of the mother optical surface and the The method for manufacturing an optical element molding die according to claim 10, further comprising a step for matching with the rotation axis of the backing member. The method for manufacturing an optical element molding die according to any one of claims 10 to 12, wherein the first lathe and the second lathe are the same. The method for manufacturing an optical element molding die according to any one of claims 10 to 13, wherein the predetermined shape is an annular shape. Forming the mother optical surface of the optical element by cutting on the mother member while rotating the mother member;
Forming the outer peripheral surface of the mother die member by cutting so that the optical axis of the mother optical surface coincides with the rotation center of the outer peripheral surface of the mother die member while rotating the mother die member;
Forming an optical surface having a predetermined shape on the mother optical surface of the mother die member;
Forming an electroformed member having an optical transfer surface corresponding to the optical surface of the matrix member by performing an electroforming process on the matrix member;
Integrating the electroformed member and the backing member;
In order to obtain the optical element molding die, the electroforming member and the mother die member are rotated together so that the optical axis of the mother optical surface coincides with the rotation center of the outer peripheral surface of the backing member, Cutting the outer peripheral surface of the backing member based on the outer peripheral surface of the matrix member;
And a step of removing the electroformed member from the mother die in order to obtain an optical element having an optical transfer surface. 16. The optical element forming device according to claim 15, wherein the outer peripheral surface of the electroformed member is cut with the mother die member and the electroformed member integrally, with the outer peripheral surface of the mother die member as a reference. Mold production method. The electroformed member is cut after being attached to the lathe so that the rotation axis of the lathe and the optical axis of the master member coincide with each other on the basis of the outer peripheral surface of the master member. The method for producing a mold for molding an optical element according to claim 16. The said backing member contains a sliding member, and the outer peripheral surface of the said sliding member is cut based on the outer peripheral surface of the said matrix member, The Claim 15 thru | or 17 characterized by the above-mentioned. Manufacturing method of optical element molding die. An optical element manufacturing method for forming an optical element using the optical element molding die manufactured by the method according to claim 1. The method of manufacturing an optical element according to claim 19, wherein the optical element is molded by injecting molten resin into the optical element molding die. A process of attaching a base material for forming an optical element molding die to an electrode member for electroforming so as not to be relatively rotatable,
A mother optical surface corresponding to an optical surface of an optical element molded from the optical element molding die is formed by cutting while rotating the matrix material and the electrode member, and cutting is performed on the electrode member. Forming a first mark by processing and further forming an outer peripheral surface of the electrode member;
Forming a second mark on the electrode member based on the first mark, and applying a predetermined treatment to the matrix material based on the second mark;
Growing electroforming on a surface including a mother optical surface of the matrix member;
And a step of processing the grown outer peripheral surface of the electroforming based on the outer peripheral surface of the matrix member. While rotating the electrode member for electroforming, a mother optical surface corresponding to the optical surface of the optical element molded from the optical element molding die is formed by cutting, and the electrode member is cut by cutting. Forming a first mark and further forming an outer peripheral surface of the electrode member;
Forming a second mark on the electrode member based on the first mark;
A step of forming a matrix material for forming an optical element molding die on the mother optical surface;
Applying a predetermined treatment to the matrix material based on the second mark;
Growing electroforming on a surface including a mother optical surface of the matrix member;
And a step of processing the grown outer peripheral surface of the electroforming based on the outer peripheral surface of the matrix member. An optical surface of an optical element molded from the optical element molding die while rotating a matrix member having an electrode member for forming an electroforming material and a matrix material for forming the optical element molding die Forming a mother optical surface corresponding to the cutting process, and forming the outer peripheral surface of the electrode member by cutting process;
Growing electroforming on a surface including a mother optical surface of the matrix member;
And a step of processing the grown outer peripheral surface of the electroforming based on the outer peripheral surface of the matrix member. The method of manufacturing an optical element molding die according to claim 22, wherein the film formation is performed by a CVD method. 23. The method for manufacturing an optical element molding die according to claim 21, wherein the predetermined process is a process of forming a concentric shape on the mother optical surface. 23. The method of manufacturing an optical element molding die according to claim 21, further comprising a step of determining three-dimensional coordinates of the matrix material based on the second mark. 27. The method for producing an optical element molding die according to claim 26, further comprising a step of performing drawing processing corresponding to the shape of the optical element by an electron beam based on the determined three-dimensional coordinates. 28. The method for producing an optical element molding die according to claim 27, wherein the drawing process is a process of drawing a shape corresponding to a diffraction zone of the optical element. An optical element manufacturing method, wherein an optical element is molded using the optical element molding mold manufactured by the optical element molding mold manufacturing method according to any one of claims 21 to 28.

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