JP5376103B2 - Microstructure structure estimation method, structure estimation apparatus, and mold manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and device which enables the estimation of a microstructure of a structure having the microstructure in a non-destructive manner in a short time and capable of further recognizing the distribution of the microstructure, and to provide a mold manufacturing method which enables the efficient manufacture of a mold for molding the structure having the fine structure. <P>SOLUTION: In the method of, the double refraction of the measuring target having the microstructure is measured by a measuring system, a phase difference is operated by using the measuring results and the microstructure is estimated on the basis of the operated phase difference data. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a structure estimation method, a structure estimation apparatus, and a molding die manufacturing method for nondestructively estimating the structure of a fine structure.

  Many proposals have been made regarding the design, manufacturing method, application, etc. of the wave plate using the principle of structural birefringence. For example, Patent Document 1 below discloses that a wavelength plate having a shallow grating depth and resistant to contamination can be obtained by filling a substrate grating with a dielectric medium having a refractive index larger than that of the substrate so as to have a flat surface. The following Patent Document 2 states that even if each of the two sheets has a structure with a period longer than the wavelength, the structure is opposed and engaged to make the period less than ½ of the wavelength and to function the structural birefringence. Disclose. Patent Document 3 below discloses a wave plate having structural birefringence that functions as a quarter wave plate for two different wavelengths.

  FIG. 8 shows a manufacturing process of a conventional molding die for molding a structural birefringent element having a fine concavo-convex structure. A resist mask 100 is formed on a mold base 200 made of silicon as shown in FIG. 8A (S91), and a fine pattern is drawn and developed on the resist mask 100 as shown in FIG. 8B (S92). . Next, a recess 201 corresponding to a fine pattern is formed in the mold base 200 by a dry etching method as shown in FIG. 8C (S93), and then the mold base 200 as shown in FIG. 8D. The upper resist mask 100 is removed (S94). Then, as shown in FIG. 8E, imprint molding is performed by using a mold base 200 having a recess 201 as a molding die and relatively approaching the molding material 300 made of resin (S95).

Next, by releasing the mold, a structural birefringent element 301 made of a resin having a fine concavo-convex structure 302 as shown in FIG. 8F is obtained. Is this structural birefringent element 301 having a desired performance? If it has a desired performance, the molding die is made a finished product (S97), and if it does not have the desired performance, the process returns to step S91 to remanufacture the molding die.
JP 62-269103 A Japanese Patent Laid-Open No. 05-107412 JP 2003-207636 A

  However, in any of the above-mentioned patent documents, no proposal of an appropriate method has been made as a means for confirming whether the shape is actually obtained as designed. In the case of a structural birefringent element having a fine wavelength structure, it is very difficult to measure the structure in a non-destructive manner when a desired phase difference amount cannot be obtained.

  For example, if the structural birefringent element produced as shown in FIG. 8 is broken and the fractured surface is observed using an SEM (scanning electron microscope) or the like, the shape can be measured. It is very difficult to obtain an accurate fracture surface, “observe without deformation”, “remove the influence of pretreatment (coating with conductive material) at the time of observation”, and accurate measurement is difficult.

  Moreover, even if accurate measurement can be performed, it takes a lot of time to know the distribution of the entire structure, which is not easy. In particular, when the direction of the structure is not constant, it takes an enormous amount of time, so it is not practical to measure directly.

  In addition, when manufacturing a molding die for molding the structural birefringent element, when the manufacturing die is manufactured as shown in FIG. 8, the finishing check of the molding die is performed by a molded product actually imprinted. However, if this molded product is not good, it will be necessary to re-create the molding die from the beginning, which is inefficient, and as mentioned above, checking the molded product is very difficult and accurate. Measurement is difficult and takes a lot of time. There is also a method of making a dummy molding die together by etching, etc., and destroying the dummy molding die to check the finish. In this case, however, the dummy molding die is not good. Sometimes it is inefficient to re-create the mold.

  In view of the above-described problems of the prior art, the present invention is capable of estimating the microstructure of a structure having a microstructure in a non-destructive manner in a short time and further knowing the distribution of the microstructure. An object is to provide a structure estimation method and a structure estimation apparatus for an object.

  Another object of the present invention is to provide a method for producing a molding die capable of efficiently producing a molding die for molding a structure having a fine structure.

In order to achieve the above object, a method for estimating a structure of a fine structure according to the present invention includes a step of measuring a transmitted light amount of a measurement object having a fine structure with an unknown fine structure distribution by a measurement system via an analyzer, A phase difference calculation step for calculating a phase difference using the measurement result, and a structure estimation step for estimating the fine structure based on a comparison value between the calculated phase difference data and simulation data of a simulation result calculated in advance. And measuring the two-dimensional distribution of the fine structure of the object to be measured, and nondestructively estimating the fine structure and the two-dimensional distribution thereof based on the structure estimation and the two-dimensional distribution measurement. characterized in that it.

  According to this fine structure estimation method, the amount of transmitted light of a measurement object having a fine structure is measured, and the fine structure is estimated based on the phase difference data calculated using the measurement result. In addition, the fine structure of the fine structure (object to be measured) can be estimated in a short time.

Further comprising a transmittance calculating step of calculating the transmittance of the TE wave and TM wave in the structure estimation method of the microstructures, it is preferable to use a transmission data the calculated in the estimation of the microstructure.

  Further, by measuring the two-dimensional distribution of the fine structure by relatively moving the object to be measured and the measurement system, and / or using the image sensor such as a CCD in the light receiving part of the measurement system By measuring the two-dimensional distribution of the structure, the distribution of the fine structure can be known. The fine structure may be a binary structure.

  Further, it is preferable that the structure estimation step estimates the microstructure using a simulation data of a simulation result calculated in advance and a comparison value between the phase difference data or the phase difference data and the transmittance data. .

  The measurement system preferably includes a visible light source as a light source, and can switch at least two types of wavelengths, and can efficiently perform measurement at a plurality of wavelengths. In this case, the two types of wavelengths are preferably any two of wavelengths λ1, λ2, and λ3 that satisfy the following expressions (1), (2), and (3).

350 nm <λ1 <550 nm (1)
600 nm <λ2 <700 nm (2)
700 nm <λ3 <850 nm (3)

Λ3 is a wavelength corresponding to a light source used for CD recording and / or reproduction, λ2 is a wavelength corresponding to a light source used for DVD recording and / or reproduction, and λ3 is higher than DVD. It is a wavelength corresponding to a light source used for recording and / or reproduction of an optical disk having a recording density.
The light source of the measurement system may be an infrared light source. In this case, the infrared light source is preferably capable of switching at least two types of wavelengths.

The structure estimation apparatus for a fine structure according to the present invention uses a measurement system capable of measuring the amount of light transmitted through an object having a fine structure whose fine structure distribution is unknown through an analyzer, and a measurement result obtained by the measurement system. A phase difference calculating means for calculating a phase difference, a structure estimating means for estimating the fine structure based on a comparison value between the calculated phase difference data and simulation data of a simulation result calculated in advance, and the device under test And measuring means for measuring the two-dimensional distribution of the microstructure of the non-destructively estimating the microstructure and the two-dimensional distribution thereof based on the structure estimation and the two-dimensional distribution measurement. Features.

  According to this fine structure structure estimation apparatus, the above-described fine structure structure estimation method can be executed, the amount of transmitted light of a measurement object having a fine structure is measured, and the phase difference data calculated using the measurement result By estimating the fine structure based on the above, the fine structure of the fine structure (object to be measured) can be estimated in a non-destructive manner in a short time.

With the transmittance calculating means for calculating a transmittance of TE wave and TM wave in the structure estimating device of the microstructures, it is preferable to use a transmission data the calculated in the estimation of the microstructure.

  In addition, an xy stage that moves the object to be measured and the measurement system relative to each other to measure the two-dimensional distribution of the fine structure is provided, and / or an image sensor such as a CCD in a light receiving unit of the measurement system It is possible to know the distribution of the fine structure. The fine structure may be a binary structure.

  Further, it is preferable that the structure estimation unit estimates the fine structure using a simulation data of a simulation result calculated in advance and a comparison value between the phase difference data or the phase difference data and the transmittance data. .

  The measurement system preferably includes a visible light source as a light source, and can switch at least two types of wavelengths, and can efficiently perform measurement at a plurality of wavelengths. In this case, the two types of wavelengths are preferably any two of the wavelengths λ1, λ2, and λ3 that satisfy the following expressions (1), (2), and (3).

350 nm <λ1 <550 nm (1)
600 nm <λ2 <700 nm (2)
700 nm <λ3 <850 nm (3)

Λ3 is a wavelength corresponding to a light source used for CD recording and / or reproduction, λ2 is a wavelength corresponding to a light source used for DVD recording and / or reproduction, and λ3 is higher than DVD. It is a wavelength corresponding to a light source used for recording and / or reproduction of an optical disk having a recording density.
The light source of the measurement system may be an infrared light source. In this case, the infrared light source is preferably capable of switching at least two types of wavelengths.

  The method for producing a molding die according to the present invention includes, for example, forming a mask on the surface of a mold base, forming a fine pattern on the mask, and then etching the surface of the mold base. A method of manufacturing a forming mold having a structure, wherein the microstructure is estimated by the above-described microstructure estimation method or the microstructure estimation apparatus for the mold base material during the etching. Further, the mold base is further etched based on the estimation result.

  According to this method of manufacturing a mold, the microstructure can be estimated by using a mold base material being processed by etching, and the subsequent etching can be performed based on the estimation result. It can be processed as designed, and it is not necessary to remanufacture a molding die, and a molding die for molding a structure having a fine structure can be manufactured accurately and efficiently.

  In the manufacturing method of the molding die, an etching rate is obtained based on the estimation result of the microstructure, and the molding die can be processed as designed by further etching the die base material based on the etching rate. .

  In another method of manufacturing a molding die according to the present invention, for example, a mask is formed on the surface of a mold base, a fine pattern is formed on the mask, and then the surface of the mold base is etched. A method of manufacturing a molding die having a fine structure by estimating the fine structure of the etched die base material by the fine structure structure estimation method or the fine structure structure estimation device described above. And the quality as a molding die of the said mold base material is determined based on the estimation result, It is characterized by the above-mentioned.

  According to this method of manufacturing a mold, the microstructure of the etched mold base is estimated, and the quality of the mold base as a mold is determined based on the estimation result. It is not necessary to make a pass / fail judgment with a molded product molded with a molding die or a dummy molding die, so there is no need to manufacture a molded product or a dummy molding die, and there is no need to remanufacture the molding die, making the molding die more efficient. Can be produced.

  In each of the above manufacturing methods, the mold base is preferably made of a material such as glass that transmits visible light.

  The mold base is preferably made of silicon (Si). In this case, the light source of the measurement system is an infrared light source, so that light from the light source can pass through the silicon. The infrared light source is preferably capable of switching at least two types of wavelengths.

  According to the fine structure structure estimation method and structure estimation apparatus of the present invention, a fine structure can be estimated in a short time in a non-destructive manner, and the distribution of the fine structure can be known. It is.

  Moreover, according to the manufacturing method of the shaping die of this invention, the shaping die for shape | molding the structure which has a fine structure can be manufactured efficiently.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  <First Embodiment>

  FIG. 1 is a perspective view schematically showing a structural birefringent element having a fine structure as an object to be measured (fine structure) in the first embodiment. FIG. 2 is a diagram schematically showing a main part of the structure estimation apparatus for a fine structure according to the first embodiment. FIG. 3 is a diagram schematically showing a measurement state using a polarizer, an object to be measured, and an analyzer in the structure estimation apparatus 50 for a fine structure shown in FIG.

  As shown in FIG. 2, the structure estimation apparatus 50 for a fine structure includes a phase difference measurement apparatus capable of measuring a phase difference and measuring birefringence, and includes laser light sources 2a and 2b each including a laser diode (LD). A laser diode (LD) controller 1 that controls driving of the laser light sources 2a and 2b, a dichroic mirror 3 having wavelength selectivity, a folding mirror 4, a polarizer 6, and a polarizer 6 are rotated about an optical axis a. A rotating stage 5a, a measuring object 7 to be measured, a rotating stage 5b including a motor that rotates the measuring object 7 about the optical axis a, and an analyzer on which transmitted light of the measuring object 7 enters. 8, a rotation stage 5 c including a motor that rotates the analyzer 8 about the optical axis a, and a stage controller 9 that controls the rotation drive of each motor of the rotation stages 5 a to 5 c.

  The structure estimation apparatus 50 for a fine structure further includes a light receiving element 10 on which light from the analyzer 8 is incident, a light receiving circuit 11 that converts a light amount value received by the light receiving element 10 into a voltage, and outputs it as a light intensity signal. A personal computer (PC) 12 that receives a light intensity signal from the circuit 11 and performs various calculations, and a monitor unit 13 that displays calculation results and the like are provided.

  The PC 12 includes a memory that stores various data in a rewritable and readable manner, and controls the entire apparatus including the LD controller 1 and the stage controller 9. Further, the PC 12 performs a simulation on the measurement object 7 to be measured, performs a simulation using, for example, a rigorous coupled wave analysis that is a vector analysis, and constructs a database of the simulation results.

  As shown in FIG. 1, the object to be measured 7 is a structural compound having a binary structure in which fine irregularities having a structural width L, a structural period W, and a structural height H are periodically formed as a fine irregular periodic structure. It is a refracting element and is made of a material that transmits laser light from the laser light sources 2a and 2b.

  Further, regarding the TE wave (P-polarized light) and the TM wave (S-polarized light), in FIG. 1, the TE wave has a polarization direction parallel to the main axis 7a of the fine uneven periodic structure, and the TM wave is incident light on the structural birefringent element. With a polarization direction orthogonal to For example, in a birefringent element such as a wave plate, the direction in which light travels fast (the phase advances) is called the fast axis of the element, and the slow direction (the phase is delayed) is the slow axis. Good, fast axis and slow axis are collectively called the main axis.

  In the optical system of FIG. 2, the laser light from the laser light source 2a passes through the dichroic mirror 3 and passes on the optical axis a, and the laser light from the laser light source 2b is reflected by the folding mirror 4 and the dichroic mirror 3 to be reflected on the optical axis. a passes through the rotating polarizer 6 to become a linearly polarized state, passes through the object 7 to be measured, changes the polarization state, passes through the analyzer 8 rotating around the optical axis a, and receives the light receiving element 10. The transmittance and phase difference can be obtained based on the change in the amount of light detected by the light receiving element 10.

  For example, as shown in FIG. 3, the polarization direction of the linearly polarized light of the incident light that is incident on the measured object 7 from the polarizer 6 is 45 °. The phase axis azimuth is rotated about the optical axis a so that it is 90 °.

While changing the rotation speed of the analyzer 8 to change the transmission axis azimuth θ (FIG. 3) of the analyzer 8, the light intensity of the detection light transmitted through the analyzer 8 and incident on the light receiving element 10 at each rotation position is changed. To detect. That is, the x-component light intensity I _x is measured with the transmission axis direction θ = 0 ° of the analyzer 8, the 45 ° component light intensity I ₄₅ is measured with θ = ₄₅ °, and the y-component light intensity I with θ = 90 °. Measure _y .

  In addition, the rotary stage 5b on which the measurement object 7 is set includes an xy stage controlled by the stage controller 9, so that the measurement position of the measurement object 7 can be changed in the vertical direction and the vertical direction in FIG. it can. Thereby, the two-dimensional distribution of the fine concavo-convex structure of the DUT 7 can be easily measured.

The measurement of each of the light intensities I _x , I ₄₅ , and I _y as described above can be automatically executed in a short time under the control of the personal computer 12 including their distribution measurement.

  In FIG. 2, the laser light sources 2a and 2b can be configured to emit visible light having different wavelengths, and the LD controller 1 can switch the laser light sources 2a and 2b to switch the wavelengths. Further, the number of laser light sources may be further increased. By making it possible to switch a plurality of light sources having different wavelengths, measurement data can be easily obtained in a plurality of wavelength regions.

  The calculation principle of the phase difference δ in the structure estimation method by the microstructure estimation apparatus in FIG. 2 will be described with reference to FIGS.

  The Stokes parameters of incident light (laser light incident on the measured object 7 from the polarizer 6) and detection light (laser light incident on the light receiving element 10) are S and S ′, respectively, as in the following equation (Equation 1). Express.

  In the optical system of FIG. 2, assuming that the DUT 7 is composed of a partial polarizer XP and a phase shifter XR, if the analyzer is P, the conversion matrix can be expressed as the following equation (Equation 2).

  Here, in this optical system, when the fast axis direction of the DUT 7 is 90 ° and the incident light is 45 ° linearly polarized as shown in FIG. 3, each component of the Stokes parameter is expressed by the following equation (Equation 3). It can be expressed as

Here, when replaced with measurable parameters, the above S ′ ₀ , S ′ ₁ , and S ′ ₂ can be expressed by the following equations (Equation 4), respectively.

That is, the phase difference δ is given by the following equation (Formula 5). However, A _x , A _y , I _x , and I _y in Expression 5 are related to the following expression (Expression 6).

The case where the actual measurement system of FIG. 2 is considered will be described with reference to FIG. 3. When the transmission axis direction θ of the analyzer 8 is set to 0 °, I _x is measured. Similarly, I ₄₅ can be measured at θ = 45 °, and I _y can be measured at θ = 90 °. Therefore, the phase difference δ can be calculated from these three measured values I _x , I ₄₅ and I _y .

  Next, a structure estimation method using the microstructure estimation apparatus of FIGS. 1 to 3 will be described with reference to FIGS. 4, 5, and 6. FIG. 4 is a flowchart for explaining the flow of the structure estimation method according to the first embodiment. FIG. 5 is a diagram for explaining the transmittance / phase difference calculation step of FIG. FIG. 6 is a diagram for explaining the structure estimation step of FIG.

In the following, the structural period W, the structural height H, and the filling factor f (= L / P, where L is the structural width) are estimated nondestructively as structural parameters in the fine unevenness of the DUT 7 of FIG.

As shown in FIG. 4, first, by measuring the reference light amount with the light receiving element 10 without setting the object 7 to be measured on the rotary stage 5 b in the microstructure estimation apparatus 50 of FIG. 2, I ′ _x (x (Component reference light intensity), I ′ _y (y component reference light intensity), I ′ ₄₅ (45 ° component reference light intensity) are obtained (S01).

Next, the object to be measured 7 is set on the rotary stage 5b (S02), the amount of transmitted light is measured, and I _x (x component light intensity), I _y (y component light intensity), I ₄₅ (45 ° component light intensity). ) Is obtained (S03).

  Next, the transmittance / phase difference is calculated (S04). That is, as shown in FIG. 5, the transmittances Te and Tm are calculated from the following equations (1) and (2) (S41), and the phase difference is calculated from the above equations (Equations 5 and 6) (S42).

Te = (I _x / I ′ _x ) × 100 (1)
Tm = (I _y / I ′ _y ) × 100 (2)
However, measured transmittance (%) of Te: TE wave (see FIG. 1)
Tm: Measured transmittance of TM wave (see Fig. 1) (%)

  Next, the structure of the DUT 7 is estimated from the calculation result (S05). This structure estimation is performed based on a comparison value between simulation data from a simulation result database and phase difference data (or phase difference data and transmittance data).

  That is, when the comparison value is C, the measured transmittance of the TE wave is Te, the measured transmittance of the TM wave is Tm, the calculation result of the phase difference is δ, and the simulated TE wave transmittance, TM wave transmittance, When the phase differences are STe, STm, and Sδ, the comparison value C is a value calculated from the following equation (3), for example.

C (n) = Sqrt ((Te-Ste (n)) ² + (Te-ST (n)) ² + (k · (δ-Sδ (n))) ² ) (3)
Here, n is a simulation number, and k is a weighting coefficient.

As shown in FIG. 6, the simulation number n is set to 0 (S51), the first comparison value C (n = 0) is calculated by the above equation (3) (S52), and this comparison value C (0) is set to the minimum value. C _min is set (S53).

Next, n → n + 1 is set (S54), and the comparison value C (n) is calculated by the above equation (3) (S55). The comparison value C (n) is compared with the minimum value C _min (S56), if the comparison value C (n) is smaller than the minimum value C _min, then the comparison value C (n) and the minimum value C _min Then, the structure parameter of the simulation number n is stored (S57).

Until all the comparisons are completed (S58), steps S54 to S57 are repeated. Comparison value C in step S56 (n) is larger than the minimum value C _min is whether all of the comparison in the step S58 is completed is determined.

The structural parameters (the structural period W, the structural height H, and the filling factor f (= L / P) in FIG. 1) of the comparison value C (n) that is the minimum value C _min obtained as described above are measured. 7 as a structural parameter in the binary structure (S06), and the result is output (S06) and displayed, for example, on the monitor unit 13 in FIG.

  Further, after the measurement, the xy stage of the rotary stage 5b is driven by the control of the stage controller 9, and the measurement object 7 is moved in the vertical direction and / or the vertical direction in FIG. 2 to change the measurement position of the measurement object 7. 4 is repeated, the two-dimensional distribution of the structural parameters of the DUT 7 can be measured.

  As described above, according to the first embodiment, the fine uneven periodic structure and its two-dimensional distribution of the structural birefringent element as shown in FIG. An estimation result can be obtained in time.

  <Second Embodiment>

  2nd Embodiment is related with the method of manufacturing a shaping die using the structure estimation method of the said fine structure. FIG. 7 is a diagram showing a manufacturing process of a molding die for molding a structural birefringent element having a fine concavo-convex structure according to the second embodiment.

  In the present embodiment, a molding die for molding a structural birefringent element having a fine uneven periodic structure in which fine unevenness having a structure width L, a structure period W, and a structure height H as shown in FIG. 1 is periodically formed. Is manufactured as follows.

  That is, after a resist is uniformly coated on a mold base 20 made of glass as shown in FIG. 7A to form a resist mask 30 (S61), a resist mask as shown in FIG. A predetermined fine pattern is drawn on the surface of 30 by an electron beam and developed with a predetermined developing material (S62).

  Electron beam drawing can be performed by the present inventors using an electron beam drawing apparatus proposed in, for example, Japanese Patent Application Laid-Open Nos. 2004-107793 and 2004-54218. Thereby, a desired drawing pattern can be formed on the resist film with high accuracy on the order of submicrons by three-dimensional drawing with an electron beam.

  Next, a first dry etching using plasma or the like is performed on the mold base 20 having a fine pattern formed on the resist mask 30 (S63). Thereby, as shown in FIG. 7C, the recess 21 corresponding to the fine pattern of the resist mask 30 is formed in the mold base 20.

  Next, the same measurement as that in the first embodiment is performed using the mold base 20 in FIG. 7C as the object 7 to be measured in the fine structure structure estimation apparatus 50 in FIG. The structure parameters (structure period W, structure height H and filling factor f (= L / P) in FIG. 1) of the mold base 20 in FIG. When the periodic structure is not obtained (S64), the second dry etching using plasma or the like is performed as shown in FIG. 7D (S65).

  Next, the structural parameters of the mold base 20 are estimated in the same manner as described above (S64). The steps S64 and S65 are repeated until a desired fine uneven periodic structure is obtained in this way. In this case, the mold base 20 can be accurately etched by calculating the etching rate based on the structural parameter estimated as described above and performing the next dry etching based on the etching rate.

  When the desired fine concavo-convex periodic structure is obtained in step S64, the resist mask 30 on the mold base 20 is removed as shown in FIG. 7E (S66). The mold base 20 is used as a mold, and the mold is completed (S67).

  Although a molding die can be manufactured as described above, according to the present embodiment, the structural parameters of the mold base 20 are estimated and etched in the middle of dry etching on the mold base 20. Since the rate can be accurately known, it is possible to easily manufacture a molding die having a desired fine uneven periodic structure and high accuracy.

  In particular, until now, as shown in FIG. 8, imprint molding was performed with the manufactured molding die, and the molded product was broken to measure the structural parameters. However, such measurement was inaccurate, Although it is difficult and takes a long time, according to the present embodiment, measurement of such a molded product is unnecessary.

  In addition, even if the measurement of the molded product is accurately performed by the conventional method, if the molded product is not good, the molding die must be recreated from the beginning, which is inefficient, and dummy molding is performed. In the conventional method in which the mold is manufactured by etching together and the dummy mold is destroyed and the finish is checked. If the dummy mold is not good, the mold is recreated from the beginning. In other words, it was inefficient, but according to the present embodiment, when each step as shown in FIG. 7 for manufacturing the molding die is completed, the molding die is completed. There is no possibility of remanufacturing the mold, and it is efficient and can reduce the manufacturing cost of the mold.

  When producing a structural birefringent element having a microstructure close to the wavelength of light using a molding die, in order to obtain the desired performance for both transmittance and phase difference, the molding die must be as designed. Although it is necessary to make it into a very strict shape, the etching rate in the dry etching process when producing the molding die is very sensitive to the environment (temperature, vacuum degree, gas density, etc.) in the etching equipment. It is difficult to reproduce it precisely. Therefore, when the shape of the molding die is driven to the design value, it is required to know the etching rate accurately in the middle of the etching, but the manufacturing method of the molding die of the present embodiment is required. Accordingly, since the etching rate can be accurately known, the shape of the molding die can be etched as designed.

  In FIG. 7, the material of the mold base 20 may be, for example, silicon (Si). In this case, the wavelength of the light sources 2a and 2b in FIG. It can permeate | transmit to a measured object (mold base material 20).

  Further, the structure estimation step (S64) is performed on the molding die obtained by the steps of mask formation (S61), drawing / development (S62), dry etching (S63), and mask removal (S66) in FIG. Then, the quality of the final molding die may be determined. This allows non-destructive determination of the quality of a molding die, imprint molding with a molding die manufactured as in the past, and judgment of quality with that molded product, or production of a dummy molding die Thus, it is not necessary to determine whether the dummy product is good or bad.

  As described above, the best mode for carrying out the present invention has been described. However, the present invention is not limited to these, and various modifications are possible within the scope of the technical idea of the present invention. For example, the fine structure structure estimation apparatus of FIG. 2 is configured to use the polarization element rotation method for phase difference measurement, but the present invention is not limited to this, and the phase difference can be measured, and Any other measurement method such as a polarization compensation method or an optical heterodyne method may be used as long as it is an optical system capable of independently measuring the TE wave / TM wave transmittance.

  In the first embodiment, the xy stage is provided in the rotary stage 5b on which the measurement object 7 is set in order to measure the two-dimensional distribution of the fine uneven structure of the measurement object 7. The invention is not limited to this, and an image sensor such as a CCD may be used as the light receiving element 10 instead of the xy stage or together with the xy stage.

It is a perspective view which shows typically the structural birefringence element which has a fine structure as a to-be-measured object (fine structure) in 1st Embodiment. It is a figure which shows roughly the principal part of the structure estimation apparatus of the fine structure by 1st Embodiment. It is a figure which shows typically the measurement state by the polarizer, to-be-measured object, and analyzer in the structure estimation apparatus of the fine structure of FIG. It is a flowchart for demonstrating the flow of the structure estimation method by 1st Embodiment. It is a figure for demonstrating the transmittance | permeability and phase difference calculation step of FIG. It is a figure for demonstrating the structure estimation step of FIG. It is a figure which shows the manufacturing process of the shaping die for shape | molding the structural birefringent element which has a fine concavo-convex structure by 2nd Embodiment. It is a figure which shows the conventional manufacturing process of the shaping die for shape | molding the structural birefringent element which has a fine uneven structure.

Explanation of symbols

2a, 2b Laser light sources 5a to 5c Rotating stage 6 Polarizer 7 Measured object 8 Analyzer 9 Stage controller 10 Light receiving element 12 Personal computer (PC)
20 Mold base 21 Recess 30 Resist mask 50 Fine structure estimation apparatus H Structure height L Structure width W Structure period a Optical axis

Claims (23)

Measuring the amount of light transmitted through the measurement object having a fine structure with an unknown fine structure distribution by a measurement system via an analyzer;
A phase difference calculating step of calculating a phase difference using the measurement result;
A structure estimation step for estimating the fine structure based on a comparison value between the calculated phase difference data and simulation data of a simulation result calculated in advance;
Measuring a two-dimensional distribution of the microstructure of the object to be measured ,
A structure estimation method for a fine structure, wherein the fine structure and its two-dimensional distribution are estimated nondestructively based on the structure estimation and the two-dimensional distribution measurement . The method for estimating a structure of a fine structure according to claim 1, further comprising a transmittance calculating step for calculating the transmittance of the TE wave and the TM wave, wherein the calculated transmittance data is used for estimating the fine structure.   The structure estimation method for a fine structure according to claim 1 or 2, wherein the two-dimensional distribution of the fine structure is measured by relatively moving the object to be measured and the measurement system.   The structure estimation method for a fine structure according to claim 1, 2 or 3, wherein a two-dimensional distribution of the fine structure is measured using an image sensor in a light receiving part of the measurement system.   The structure estimation method for a fine structure according to any one of claims 1 to 4, wherein the fine structure is a binary structure.   6. The structure estimation method for a fine structure according to claim 1, wherein the measurement system includes a visible light source as a light source and is capable of switching at least two types of wavelengths. The structure estimation method for a fine structure according to claim 6, wherein the two types of wavelengths are any two of wavelengths λ1, λ2, and λ3 that satisfy the following expression.
350 nm <λ1 <550 nm
600 nm <λ2 <700 nm
700nm <λ3 <850nm   The structure estimation method for a fine structure according to any one of claims 1 to 5, wherein the light source of the measurement system is an infrared light source.   The structure estimation method for a fine structure according to claim 8, wherein the infrared light source is capable of switching at least two types of wavelengths. A measurement system capable of measuring the amount of light transmitted through an object having a fine structure with an unknown fine structure distribution through an analyzer;
A phase difference calculating means for calculating a phase difference using a measurement result by the measurement system;
A structure estimation means for estimating the microstructure based on a comparison value between the calculated phase difference data and simulation data of a simulation result calculated in advance;
Measuring means for measuring the two-dimensional distribution of the microstructure of the object to be measured ,
An apparatus for estimating a structure of a fine structure, wherein the fine structure and its two-dimensional distribution are estimated nondestructively based on the structure estimation and the two-dimensional distribution measurement . With the transmittance calculating means for calculating a transmittance of TE wave and TM wave, the structure estimating device of a fine structure according transmittance data the calculated to claim 10 for use in the estimation of the microstructure.   The structure estimation apparatus for a fine structure according to claim 10 or 11, further comprising an xy stage for relatively moving the object to be measured and the measurement system in order to measure a two-dimensional distribution of the fine structure.   The structure estimation apparatus for a fine structure according to claim 10, 11 or 12, wherein an image sensor is provided in a light receiving part of the measurement system in order to measure a two-dimensional distribution of the fine structure.   The structure estimation apparatus for a fine structure according to any one of claims 10 to 13, wherein the fine structure is a binary structure.   The structure estimation apparatus for a fine structure according to any one of claims 10 to 14, wherein the measurement system includes a visible light source as a light source and is capable of switching at least two types of wavelengths. The structure estimation apparatus for a fine structure according to claim 15, wherein the two types of wavelengths are any two of wavelengths λ1, λ2, and λ3 that satisfy the following expression.
350 nm <λ1 <550 nm
600 nm <λ2 <700 nm
700nm <λ3 <850nm   The structure estimation apparatus for a fine structure according to any one of claims 10 to 14, wherein the light source of the measurement system is an infrared light source.   The structure estimation device for a fine structure according to claim 17, wherein the infrared light source is capable of switching at least two types of wavelengths. A method for producing a mold having a fine structure by etching the surface of a mold base,
The structure estimation method for a fine structure according to any one of claims 1 to 9 or the fine structure according to any one of claims 10 to 18 for the mold base material during the etching. A manufacturing method of a molding die, wherein the microstructure is estimated by a structure estimation device, and the die base material is further etched based on the estimation result.   The method for producing a molding die according to claim 19, wherein an etching rate is obtained based on the estimation result of the fine structure, and the die base material is further etched based on the etching rate. A method for producing a mold having a fine structure by etching the surface of a mold base,
The structure estimation method for a fine structure according to any one of claims 1 to 9 or the structure estimation apparatus for a fine structure according to any one of claims 10 to 18 for the etched mold base material. Thus, the fine structure is estimated, and the quality of the mold base as a molding die is determined based on the estimation result.   The method of manufacturing a molding die according to claim 19, 20 or 21, wherein the mold base is made of a material that transmits visible light.   The method for manufacturing a mold according to claim 19, 20 or 21, wherein the mold base is made of silicon (Si).

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