JP5771256B2 - Imprint glass substrate, resist pattern forming method, imprint glass substrate inspection method and inspection apparatus - Google Patents

Description

  The present invention relates to an imprint glass substrate, a resist pattern forming method, an imprint glass substrate inspection method, and an inspection apparatus.

  Conventionally, as a mold for nanoimprinting, the original pattern is evenly transferred to a bent substrate, and damage caused by pressure and contamination by resin do not occur, increasing the accuracy of the pattern and improving durability. Therefore, by laminating effective materials for each role, a substrate, a pattern portion formed on the substrate and having a concavo-convex pattern, a hard layer formed of a material harder than the pattern portion on the surface of the pattern portion, And the mold for nanoimprint containing the mold release layer formed on the surface of the hard layer is known (for example, refer patent document 1).

In such a mold for nanoimprinting, the pattern portion is formed of a flexible material and is configured to be deformable so that it can be applied to a bent substrate, and the hard layer has silicon oxide (SiO ₂ ) or ITO (Indium Tin). An oxide film such as Oxide) is applied to improve durability and transfer pattern accuracy, and an organic molecular film is applied to the release layer to facilitate separation between polymer thin films that are imprinted with nanoscale structures. It is configured as follows.

  On the other hand, when an inspection for detecting a pattern defect of an imprint mold as in Patent Document 1 or a foreign substance existing on the surface of a pattern portion is performed, an inspection using light is generally performed. It was. That is, the surface image of the nanoimprint mold is acquired by the dark field / scattering method to detect the presence of pattern defects and foreign matters.

JP 2008-68612 A

  However, for the nanoimprint mold described in Patent Document 1 described above, there has been a problem that the detection sensitivity is insufficient in the conventional optical method inspection. That is, in the optical inspection, there is a problem that the detection sensitivity is extremely lowered and the application becomes difficult for an ultrafine pattern having a size of 50 to 100 [nm] or less, and adhesion of a foreign substance or an organic substance. It was. This is considered to be caused mainly by the fact that the pattern and the size of foreign matter are smaller than the wavelength of light, and the S / N (Signal / Noise, signal / noise) is reduced.

  As another inspection method, a defect inspection by a scanning electron microscope (SEM) method using an electron beam having higher sensitivity than the optical method is also possible. For example, since the pixel size smaller than the target foreign material can be used by narrowing the beam diameter, the foreign material can be inspected with high resolution, and the nanoimprint mold described in Patent Document 1 is also inspected. Is possible. However, the SEM method has a problem in that since the pixel size is small, the inspection time becomes enormous, the inspection in a realistic time is difficult, and it is not practical. Further, when the above-described nanoimprint mold is irradiated with an electron beam, the nanoimprint mold is entirely composed of an insulating material such as glass, so that charge-up (charging) becomes significant, and a pattern image is appropriately acquired. There was a problem that I could not.

  Accordingly, the present invention provides an imprint glass substrate, a resist pattern forming method, and an imprint glass that can realize high sensitivity, high speed, and high throughput for inspection of patterns and foreign matters having an ultrafine size of 50 to 100 [nm] or less. It is an object of the present invention to provide a substrate inspection method and inspection apparatus.

To achieve the above object, an inspection method for an imprint glass substrate according to the first invention has a pattern surface on which a fine pattern having irregularities for imprint is formed and a back surface of the pattern surface consisting of a flat surface. An imprinting glass substrate inspection method comprising: a glass substrate, and inspecting an imprinting glass substrate in which the entire pattern surface having the unevenness and the back surface of the pattern surface comprising the flat surface are covered with a transparent conductive film. An electron beam irradiation step of irradiating the pattern surface of the glass substrate for imprint placed on the stage with an electron beam having a predetermined irradiation region, and a plurality of patterns generated from the pattern surface by the irradiation of the electron beam An electron detection step for simultaneously detecting the electrons on a detection surface having a plurality of pixels, and the pattern detected from the electrons detected on the detection surface. Acquiring an image of the emission surface, wherein the defect detection step of detecting a defect of the pattern surface, the defect detection step, the two by the brightness and the electron detecting step when encountering a mirror electrons by the electron detecting step It is characterized in that foreign matter existing on the pattern surface is detected based on the difference from the brightness when the next emission electron is detected.

  As a result, the electron beam can be irradiated in a state where the potential of the pattern surface of the glass substrate for imprinting is stabilized by the transparent conductive film. Since an image can be obtained by forming an image on the detection surface, it is possible to perform defect inspection on an appropriate pattern surface at high speed and with high throughput.

  Thereby, the electric potential of a back surface can be stabilized and it can test | inspect with an electron beam in the state which stabilized the electric potential of the glass substrate for imprint.

An inspection method for a glass substrate for imprints according to a second invention comprises a glass substrate having a pattern surface on which a fine pattern having irregularities for imprinting is formed and a back surface of the pattern surface consisting of a flat surface, the irregularities A method for inspecting an imprint glass substrate in which a convex surface of a fine pattern having a flat surface and a back surface of the pattern surface composed of the flat surface are coated with a transparent conductive film, wherein the imprint glass substrate is on a stage. An electron beam irradiation step of irradiating an electron beam having a predetermined irradiation region onto the pattern surface of the placed glass substrate for imprinting, and a plurality of electrons generated from the pattern surface by irradiation of the electron beam, An electron detection process for simultaneously detecting on a detection surface having pixels, and an image of the pattern surface is acquired from electrons detected on the detection surface. Anda defect detection step of detecting a defect of the pattern surface, the defect detection step, in the case of detecting secondary emission electrons by the brightness and the electron detecting step when encountering a mirror electrons by the electron detecting step A foreign object present on the pattern surface is detected based on a difference from luminance .

  As a result, a conductive film is formed on the pattern surface, so that charge-up can be prevented even when an electron beam is irradiated during pattern inspection, and appropriate inspection can be performed, thereby realizing high-precision pattern formation. be able to. Further, since the conductive film is transparent, the function as a mask can be appropriately maintained, and a resist pattern can be formed on a resist film on another substrate with high accuracy.

  According to a third aspect of the present invention, in the method for inspecting an imprint glass substrate according to the first or second aspect of the invention, the electron beam irradiation step includes a step of irradiating the first electron beam, and then the first electron beam. And irradiating a second electron beam having a lower landing energy.

  Thereby, after adjusting the charged state of the pattern surface of the glass substrate for imprint with the first electron beam, the image of the pattern surface can be obtained with the second electron beam, and the pattern surface image can be obtained in a good state. It can be acquired and a highly accurate inspection can be performed.

  According to a fourth invention, in the method for inspecting an imprint glass substrate according to any one of the first to third inventions, the transmittance of the secondary emission electrons is lower than the transmittance of the mirror electrons. Features.

  As a result, it is possible to generate mirror electrons from the pattern surface by irradiating the second electron beam having a low landing energy, and to enlarge the defects on the pattern surface to perform image acquisition, thereby easily and accurately detecting defects. It can be carried out.

An inspection apparatus for a glass substrate for imprints according to a fifth aspect of the invention comprises a glass substrate having a pattern surface on which a fine pattern having imprint irregularities is formed and a back surface of the pattern surface consisting of a flat surface, the irregularities An imprint glass substrate inspection apparatus for inspecting an imprint glass substrate in which the entire pattern surface having a flat surface and the back surface of the pattern surface comprising a flat surface are coated with a transparent conductive film, and placed on a stage An electron gun that irradiates an electron beam having a predetermined irradiation area onto the pattern surface of the imprinted glass substrate, and a plurality of electrons generated from the pattern surface by the irradiation of the electron beam are detected having a plurality of pixels. A detector for detecting simultaneously on the surface, and acquiring an image of the pattern surface from the electrons detected on the detection surface; Includes a defect detection means for detecting that the said defect detection means, based on a difference between the brightness when the brightness and the detector when the detector detects the mirror electrons detected a secondary emission electrons, wherein It is characterized in that foreign matter existing on the pattern surface is detected.

An inspection apparatus for a glass substrate for imprints according to a sixth aspect of the invention comprises a glass substrate having a pattern surface on which a fine pattern having irregularities for imprinting is formed and a back surface of the pattern surface consisting of a flat surface. An imprint glass substrate inspection apparatus for inspecting a glass substrate for imprint in which a convex surface of a fine pattern having a flat surface and a back surface of the pattern surface comprising the flat surface are coated with a transparent conductive film, on a stage An electron gun that irradiates an electron beam having a predetermined irradiation area onto the pattern surface of the placed glass substrate for imprinting, and a plurality of electrons generated from the pattern surface by the irradiation of the electron beam, A detector that simultaneously detects on the detection surface, and obtains an image of the pattern surface from electrons detected on the detection surface; Includes a defect detecting means for detecting Recessed, wherein the defect detection means, based on a difference between the brightness when the brightness and the detector when the detector detects the mirror electrons detected a secondary emission electrons , Detecting foreign matter existing on the pattern surface.

  Thus, an electron beam having a wide area can be obtained without charging up the glass substrate for imprinting using the projection type electron beam defect inspection apparatus in a state where the potential of the pattern surface of the glass substrate for imprinting is stabilized. The pattern surface image can be acquired by performing irradiation and defect inspection can be performed, and the pattern surface can be inspected at high speed, high throughput, and high accuracy.

  According to a seventh invention, in the glass substrate inspection apparatus for imprints according to the fifth or sixth invention, the electron gun comprises a first electron beam and a second electron beam having a landing energy lower than that of the first electron beam. And a landing energy setting means for setting the landing energy of the electron beam so that the electron beam can be continuously irradiated.

  As a result, by setting an appropriate landing energy, first irradiate an electron beam with a landing energy suitable for adjusting the charged state of the glass substrate for imprinting, and then irradiate an electron beam set to a landing energy suitable for inspection. Thus, an image of the pattern surface can be acquired, and a good pattern surface image can be acquired and high-precision inspection can be performed.

  According to an eighth aspect of the present invention, in the imprint glass substrate inspection apparatus according to any one of the fifth to seventh aspects, the transmittance of the secondary emission electrons is lower than the transmittance of the mirror electrons. Features.

  Thereby, it is possible to directly detect the electrons without converting them into light and obtain an image of the pattern surface, and it is possible to perform the inspection simply and easily.

  ADVANTAGE OF THE INVENTION According to this invention, a fine pattern can be test | inspected with high precision about the glass substrate for imprints in which the nano-order fine pattern was formed.

3 is a diagram illustrating a cross-sectional configuration example of an imprint glass substrate 30 according to Example 1. FIG. It is a cross-sectional block diagram of the glass substrate of the glass substrate 30 for imprints. 5 is a diagram showing a manufacturing process for forming a resist pattern on a silicon substrate 40. FIG. FIG. 3A is a diagram illustrating a process of preparing the silicon substrate 40 and the imprint glass substrate 30. FIG. 3B is a diagram showing a process in which the pattern surface 11 is pressed against the resist film 50. FIG. 3C is a diagram showing a process of irradiating light. FIG. 3D is a diagram illustrating a process of separating the imprint glass substrate 30. It is the figure which showed an example of the transmittance | permeability characteristic of the transparent conductive film 20. It is the figure which showed the cross-sectional structural example of the glass substrate 30a for imprinting based on Example 2. FIG. It is the figure which showed the manufacturing process until resist formation of the glass substrate for imprint 30a. FIG. 6A is a view showing a state where the transparent conductive film 20 is covered. FIG. 6B is a diagram showing a process of covering the metal film 21. FIG. 6C is a diagram illustrating a process of covering the resist 60. As a result, the metal film 21 can be etched. FIG. 6D is a diagram showing a process of forming a resist pattern. It is the figure which showed the manufacturing process from resist pattern formation to completion. FIG. 7A is a diagram showing a process of patterning the metal film 21. FIG. 7B is a diagram showing a process in which the fine pattern 15 is formed on the transparent conductive film 20. FIG. 7C is a diagram showing a process of completing the imprint glass substrate 30a. 6 is a view showing another method for manufacturing an imprint glass substrate according to Example 2. FIG. FIG. 8A is a diagram showing a process in which the transparent conductive film 20 is coated. FIG. 8B is a diagram showing a process in which a resist 60 is coated. FIG. 8C is a diagram showing a process of etching the resist 60. FIG. 8D is a diagram illustrating a process in which the glass substrate for imprint 30a is completed. It is the figure which showed the cross-sectional structural example of the glass substrate 30b for imprinting concerning Example 3. FIG. It is the figure which showed the cross-sectional structure of the glass substrate 30c for imprint which concerns on Example 4. FIG. It is the figure which showed an example of the whole structure of the inspection apparatus of the glass substrate 30 for imprints which concerns on Example 5, 30a-30c. It is the figure which showed the foreign material image obtained with the inspection method of a present Example, and a general principle. FIG. 12A is a diagram illustrating an image 280 of the foreign object 250 obtained by the inspection method and inspection apparatus of the present embodiment. FIG. 12B is a view showing an image 280 obtained by a conventional foreign matter inspection apparatus. FIG. 12C is a side view showing a state where the foreign material 250 exists. It is the figure which showed an example of the enlarged image 280 of the foreign material 250, and its cross-sectional gradation. FIG. 13A is a diagram illustrating an example of an enlarged image 280 of the foreign object 250. FIG. 13B is a diagram showing the cross-sectional gradation at the pixel position. FIG. 14 is a diagram showing a foreign material 250 made of a metal material. FIG. 14A shows a foreign material 250 made of a metal material. FIG. 14B is an enlarged view of the foreign material 250. It is the figure which showed the detector 100 which enabled it to use EB-TDI102 and EB-CCD101 interchangeably. It is the figure which showed an example of the defect detection method by die-die comparison. FIG. 16A is a diagram illustrating an example in which a plurality of dies exist. FIG. 16B is a diagram showing an example of a die pattern and an example of a pattern defect portion. It is a figure for demonstrating an example of the method of electron beam irradiation. FIG. 10 is a diagram illustrating an example of the overall configuration of an inspection apparatus according to a sixth embodiment.

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

  FIG. 1 is a diagram illustrating an example of a cross-sectional configuration of an imprint glass substrate 30 according to a first embodiment to which the present invention is applied. The glass substrate 30 for imprinting according to the first embodiment includes the glass substrate 10 and the transparent conductive film 20 covered on the surface of the glass substrate 10.

  The glass substrate 10 is a substrate made of a transparent and transparent glass material. As the glass substrate 10, various types of glass may be used as a material, and for example, quartz glass may be applied. A pattern surface 11 on which a fine pattern 15 is formed is formed on the surface of the glass substrate 10. The fine pattern 15 may be a shape pattern having unevenness, for example. In FIG. 1, the convex part 12 and the recessed part 13 are formed in the surface of the glass substrate 10, and the pattern surface 11 which has the uneven | corrugated shaped fine pattern 15 is comprised. The fine pattern 15 may be formed, for example, as a nano-order pattern having a pattern width of 10 to 20 [nm], 10 to 50 [nm], or 10 to 100 [nm].

  A transparent conductive film 20 is coated on the pattern surface 11 of the glass substrate 10. The transparent conductive film 20 is covered on the entire pattern surface 11 of the glass substrate 10 and covers all the fine patterns 15. The transparent conductive film 20 is a transparent film that transmits light and has conductivity. The coating thickness of the transmissive conductive film 20 is controlled by, for example, 0.1 to 10 [nm]. The resistance value of the transmissive conductive film 20 may be about 100 to 1000 [μΩ-cm], and the UV light transmittance may be about 70%.

  For example, an ITO (Indium Tin Oxide) film is applied to the transparent conductive film 20. The ITO film is generally obtained by adding 5 to 10 wt% tin oxide to indium oxide. In addition, tin oxide or zinc oxide can also be used as the transparent conductive film 20. In the manufacturing process of the glass substrate 30 for imprinting according to the present embodiment, the transparent conductive film 20 is covered after the fine pattern 15 of the glass substrate 10 is formed.

  FIG. 2 is a diagram illustrating a cross-sectional configuration of the glass substrate 10 of the imprint glass substrate 30 according to the first embodiment. As described with reference to FIG. 1, the glass substrate 10 has a pattern surface 11 in which a fine pattern 15 is formed on one surface. Conventionally, the glass substrate 10 is used as it is as an imprint glass substrate. On the other hand, since the glass substrate 30 for imprinting according to Example 1 described with reference to FIG. 1 is covered with the transparent conductive film 20 over the entire pattern surface 11, while maintaining the transparency of the glass substrate 10, The surface of the pattern surface 11 can be a conductor.

  FIG. 3 is a diagram illustrating a manufacturing process for forming a resist pattern on the silicon substrate 40 using the glass substrate for imprint 30 according to the first embodiment.

  FIG. 3A is a diagram illustrating a process of preparing the silicon substrate 40 and the imprint glass substrate 30. A resist film 50 is formed on the entire surface of one side of the silicon substrate 40. By forming a resist pattern on the resist film 50, a desired pattern can be formed on the silicon substrate 40 in the next etching step.

  On the other hand, in FIG. 3A, an imprint glass substrate 30 according to Example 1 is prepared on a silicon substrate 40 on which a resist film 50 is formed, with the pattern surface 11 facing the resist film 50. The By transferring the fine pattern 15 formed on the pattern surface 11 of the imprint glass substrate 30 to the resist film 50 of the silicon substrate 40, a predetermined resist pattern can be formed on the resist film 50.

  FIG. 3B is a diagram illustrating a process in which the pattern surface 11 of the glass substrate 30 for imprinting is pressed against the resist film 50 on the silicon substrate 40. In FIG. 3B, the imprint glass substrate 30 is pressed against the resist film 50 until it reaches the silicon substrate 40. As a result, the resist film 50 is deformed into a pattern shape that matches the pattern surface 11 formed on the glass substrate 30 for imprinting, and the fine pattern 15 is transferred.

  FIG. 3C is a diagram showing a process of irradiating the silicon substrate 40 with light from the imprint glass substrate 30 side. Since the glass substrate 10 constituting the imprint glass substrate 30 is transparent and the transparent conductive film 20 is also transparent, the light irradiated from the back surface (surface opposite to the pattern surface 11) of the imprint glass substrate 30. Passes through the imprint glass substrate 30 and reaches the resist film 50, and the resist film 50 is cured. Various light may be used as light at this time as long as the resist film 50 can be cured. For example, UV light (ultraviolet, ultraviolet light) may be used. The resist film 50 is made of a material that hardens when irradiated with light such as ultraviolet light.

  FIG. 3D is a diagram showing a process of separating the imprint glass substrate 30 from the resist film 50 of the silicon substrate 40. When the irradiation with ultraviolet light is finished and the glass substrate 30 for imprinting is separated, a predetermined resist pattern is formed on the silicon substrate 40 by the resist film 50. By using this resist pattern, it is possible to process into a pattern shape having a desired uneven fine pattern 15 on the silicon substrate 40 by an etching process or the like. In FIG. 3, the silicon substrate 40 is described as an example of the resist pattern forming substrate. However, as long as the resist film 15 is coated on the surface, the same applies to other types of substrates. This resist pattern forming method can be applied.

  As described above, the method for forming a resist pattern according to the present embodiment can be performed using the imprint glass substrate 30 according to the first embodiment in the same manufacturing process as that of a normal imprint glass substrate. Therefore, in order to form the resist pattern having the high-precision fine pattern 15 on the resist film 50 on the silicon substrate 40, it is necessary to form the fine pattern 15 formed on the imprint glass substrate 30 with high precision. I understand that.

  That is, in this process, the inspection of the imprint glass substrate 30 is necessary before the pattern is transferred by being pressed against the resist surface. If there is a pattern defect or foreign matter on the imprint glass substrate 30, the shape of the pattern defect deformed from the regular pattern shape is transferred to the transferred resist pattern. In addition, if there is a foreign substance, the normal pattern is not transferred due to the influence of the foreign substance. Alternatively, the resist is also deformed in the thickness direction of the resist due to the influence of foreign matter, and when the wafer is etched using the formed resist pattern, only the corresponding part is etched deeply, resulting in defects such as pinholes. Thus, if there is a defect or foreign matter in the fine pattern 15 of the glass substrate 30 for imprinting, a normal semiconductor / LSI structure cannot be formed, resulting in a defective semiconductor.

  For this reason, defect inspection of the glass substrate for imprint 30 is important. In the imprint pattern transfer, since the pattern shape is transferred as it is, the pattern size is 100 [nm] or less, for example, the L / S (Line / Space) line and the space width are each 100 [nm] or less. As described above, since a fine pattern cannot be decomposed with light, it is difficult to cope with the optical inspection apparatus, and it is effective to use a defect inspection apparatus using an electron beam. In particular, since the projection type electron beam defect inspection apparatus can continuously capture a two-dimensional image, it is an effective means for inspecting the fine pattern 15 and minute foreign matter at high speed and with high resolution. The projection type electron beam defect inspection apparatus has a problem that an obtained image is not stable when there is a change in surface potential due to charge-up (charging) or the like. Therefore, it has been difficult to image the insulating glass substrate 10 with the projection type electron beam defect inspection apparatus. In order to solve this problem, in the present embodiment, the transparent conductive film 20 is coated on the pattern surface 11 of the glass substrate 10. Thereby, the surface potential of the glass substrate 10 is stabilized, and a stable electronic image can be obtained when the projection electron beam defect inspection apparatus is used. A specific inspection method and apparatus configuration will be described later.

  FIG. 4 is a diagram illustrating an example of transmittance characteristics of the transparent conductive film 20 used in the glass substrate 30 for imprinting according to the present embodiment. Normally, metal reflects light (visible light). However, as shown in FIG. 4, the transparent conductive film 20 has a transmittance of 80% in the visible light region (the region indicated by Visible in FIG. 4). It can be seen that Thus, in the glass substrate 30 for imprint which concerns on a present Example, it turns out that the pattern surface 11 can be made conductive, without reducing the transmittance | permeability. In FIG. 4, the ultraviolet light region having a wavelength slightly shorter than the visible light region also shows high transmittance. Thus, the imprint glass substrate 30 according to the present embodiment can use not only visible light but also ultraviolet light.

  If the pattern surface 11 is made conductive, the pattern surface 11 can be inspected using various electron beams. In general, by irradiating a sample such as a substrate with an electron beam and detecting electrons generated from the sample, an image of the sample surface can be acquired with higher accuracy than light irradiation. Therefore, when the fine pattern 15 is nano-order, it is preferable to perform the inspection using the electron beam rather than the inspection using the light beam. However, in the inspection using the electron beam, the sample is charged up (charged). And an appropriate surface image cannot be acquired. Sample charge-up is likely to occur when the sample is an insulator. Therefore, the transparent conductive film 20 is coated on the pattern surface 11 to be inspected even if the glass substrate 10 is an insulator and is a material that is easily charged up, like the glass substrate 30 for imprinting according to the present embodiment. Therefore, it is possible to make it difficult for charge-up to occur. As a result, the pattern surface 11 can be inspected with high accuracy using an electron beam, and the fine pattern 15 can be formed with high accuracy. Therefore, the glass substrate 30 for imprinting according to the present embodiment enables highly accurate defect inspection using such an electron beam.

  In addition, the manufacturing method of the glass substrate 30 for imprint which concerns on Example 1 is a transparent conductive film by vapor deposition on the whole surface of the pattern surface 11 of the glass substrate 10 in which the fine pattern 15 of the state shown in FIG. 2 was formed, for example. 20 may be produced. For example, the glass substrate 10 may be placed in the processing chamber, and the transparent conductive film 20 may be deposited by CVD (Chemical Vapor Deposition). Thereby, the transparent conductive film 20 can be formed on the entire pattern surface 11 of the glass substrate 10. In addition, the transparent conductive film 20 may be formed by plating. For example, the glass substrate 10 may be dipped in a plating tank filled with a plating solution, and the transparent conductive film 20 may be formed by electroplating or electroless plating.

  According to the glass substrate 30 for imprinting according to Example 1, the entire pattern surface 11 is covered with the transparent conductive film 20, so that the surface potential is reliably stabilized and the high-resolution pattern surface 11 by the electron beam is formed. Inspection can be performed appropriately.

  FIG. 5 is a diagram showing an example of a cross-sectional configuration of an imprint glass substrate 30a according to a second embodiment to which the present invention is applied. In FIG. 5, the transparent conductive film 20 is coated on the pattern surface 11a of the glass substrate 10 in the same manner as the glass substrate 30 for imprinting according to the first embodiment. This is different from the glass substrate for imprinting according to the first embodiment in that it is formed only on the convex portion 12 of the fine pattern 15 instead of the entire surface. In this way, not only the entire pattern surface 11a but a part of the transparent conductive film 20, for example, only the convex portion 12 may be covered. Since the pattern width of the fine pattern 15 is as extremely small as 10 to 20 [nm], even if the transparent conductive film 20 is formed only on the convex portion 12, the pattern surface 11a made of the insulating glass substrate 10 is It is considered that the conductivity is considerably increased, and a great effect is obtained in suppressing the charge-up during the inspection.

  6 and 7 are diagrams illustrating an example of a method for manufacturing the imprint glass substrate 30a according to the second embodiment. FIG. 6 is a diagram showing manufacturing steps up to resist formation of the imprint glass substrate 30a.

  FIG. 6A is a view showing a state where the transparent conductive film 20 is coated on the entire surface of the glass substrate 10. Thus, in the manufacturing method of the glass substrate 30a for imprint which concerns on Example 2, before performing the pattern process of the glass substrate 10, the surface (flat surface before a process) which forms the fine pattern 15 of the glass substrate 10 For example, a transparent conductive film 20 such as an ITO film is coated.

  FIG. 6B is a diagram illustrating a process of further covering the metal film 21 on the transparent conductive film 20. The metal film 21 serves as a hard pattern mask. The metal film 21 may be a Cr film, for example.

  FIG. 6C is a diagram showing a process in which a resist 60 is further coated on the metal film 21. As a result, the metal film 21 can be etched.

  FIG. 6D is a diagram showing a process in which the resist 60 is etched to form a resist pattern. For the etching of the resist 60, for example, a technique suitable for microfabrication may be used, such as reactive ion etching (Reactive Ion Etching). In this way, a resist pattern is formed.

  FIG. 7 is a diagram illustrating manufacturing steps from the formation of the resist pattern to the completion of the imprint glass substrate 30a according to the second embodiment.

  FIG. 7A is a diagram illustrating a process in which the metal film 21 is etched and a pattern is formed using the metal film 21 as a hard pattern mask. As a result, the fine pattern 15 can be formed on the transparent conductive film 20 by using the metal film 21 as a mask.

  FIG. 7B is a diagram illustrating a process in which the transparent conductive film 20 is etched and the fine pattern 15 is formed on the transparent conductive film 20. In FIG. 7B, the transparent conductive film 20 is left in the portion where the convex portion 12 of the fine pattern 15 is to be formed.

  FIG. 7C is a diagram illustrating a process in which the glass substrate 10 is etched and the imprint glass substrate 30a according to the second embodiment is completed. In FIG.7 (c), the fine pattern 15 is formed on the glass substrate 10, and the pattern surface 11a is completed.

  Here, in the steps of FIGS. 7A to 7C, pattern formation is performed by etching. As described above, a method suitable for fine processing such as reactive ion etching may be applied to the etching. According to the etching process, the depth and the like of the concave portion 13 can be controlled with high accuracy in the angle and the like, so that the fine pattern 15 can be formed with high accuracy. In the manufacturing method of the glass substrate 30 for imprinting according to Example 1, since the transparent conductive film 20 was formed by vapor deposition after the fine pattern 15 was formed, the film thickness of the sidewalls of the fine pattern 15 and the corners of the recesses 13 and the like. It was difficult to control, and for example, it was easy to generate a state where the thickness was partially increased or the corners were rounded. However, according to the method for manufacturing the imprint glass substrate 30a according to the second embodiment, since the transparent conductive film 20 exists only in the convex portion 12, the shape of the film is rounded, or there are portions having different thicknesses. There is no variation factor, and pattern transfer and resist curing can be realized. Moreover, the electric potential of the convex part 12 of the pattern surface 11a of the glass substrate 30a for imprint can be stabilized. In the system of the second embodiment, a metal film such as gold, Pt, Al, Ta, Cr, CrN, DLC (Diamond-like Carbon), carbon, a conductive organic film, or the like is used instead of the transparent conductive film 20. Is possible. These have low transmittance of ultraviolet light, but ultraviolet light is propagated from the side walls and bottom of the recess 13 of the fine pattern 15 which is not coated, so that the resist 50 can be cured.

  As described above, when the imprint glass substrate 30a according to the second embodiment is used, a highly accurate resist pattern can be formed on the substrate such as the silicon substrate 40, and the potential of the pattern surface 11a of the glass substrate 10 can be stabilized. . Therefore, it is possible to realize pattern inspection and foreign matter inspection of the glass substrate 30a for imprinting by the projection type electron beam defect device.

  FIG. 8 is a view showing a method for manufacturing the imprint glass substrate 30a according to the second embodiment different from those shown in FIGS.

  FIG. 8A is a view showing a process in which the entire surface of the glass substrate 10 is coated with the transparent conductive film 20. Since this process is the same as the process of FIG. 6A, the same reference numerals are given to the constituent elements and the description thereof will be omitted.

  FIG. 8B is a diagram showing a process in which a resist 60 is coated on the transparent conductive film 20. In this way, the resist 60 may be formed directly without forming the metal film 21 on the transparent conductive film 20.

  FIG. 8C is a diagram showing a process of etching the resist 60. Etching may be performed by an etching method capable of high-precision fine processing such as reactive ion etching.

  FIG. 8D is a diagram illustrating a process in which the transparent conductive film 20 and the glass substrate 10 are etched, and the imprint glass substrate 30a according to the second embodiment is completed. Also in FIG. 8D, since the processing is performed by etching, the side wall and the bottom of the recess 13 are sufficiently controlled, and a highly accurate fine pattern 15 can be formed.

  In this manner, the resist film 60 may be formed directly on the transparent conductive film 20 without performing the metal film 21 and etching may be performed.

  The resist pattern forming method described in FIG. 3 of the first embodiment can be performed using the glass substrate for imprint 30a according to the second embodiment. According to the imprint glass substrate 30a according to the second embodiment, since the fine pattern 15 on the pattern surface 11a can be formed with high accuracy, a highly accurate resist pattern can be formed on the resist film 50 on the silicon substrate 40. it can.

  FIG. 9 is a diagram showing an example of a cross-sectional configuration of an imprint glass substrate 30b according to Example 3 to which the present invention is applied. 9 is the same as the glass substrate 30 for imprinting according to Example 1 in that the entire surface of the pattern surface 11 is covered with the transparent conductive film 20, but the back surface 16 of the glass substrate 10 is also transparent conductively. The glass substrate 30 for imprinting according to the first embodiment is different from the glass substrate 30 for imprinting in Example 1 in that it is covered with the film 20.

  As described above, the back surface 16 of the glass substrate 10 may also be configured to be covered with the transparent conductive film 20. Thereby, since the potential of the back surface 16 of the glass substrate for imprint 30b is also stabilized, the potential of the entire glass substrate for imprint 30b is further stabilized, and the potential of the pattern surface 11 can be further stabilized.

  In addition, the manufacturing method of the glass substrate 30b for imprint which concerns on Example 3 should just coat | cover the transparent conductive film 20 by vapor deposition, plating, etc. also to the back surface 16 of the glass substrate 10, and is the same as having demonstrated in Example 1. It can manufacture with the manufacturing method of.

  Further, the same method can be applied to the resist pattern forming method described in FIG. 3 of the first embodiment, and it can be applied to a substrate other than the silicon substrate 40 as well as the description in FIG. Detailed description thereof will be omitted.

  According to the glass substrate for imprint 30b according to the third embodiment, the potential of the pattern surface 11 can be further stabilized, and more accurate inspection can be performed in the pattern inspection performed using the electron beam.

  FIG. 10 is a diagram showing an example of a cross-sectional configuration of an imprint glass substrate 30c according to a fourth embodiment to which the present invention is applied. In FIG. 10, the transparent conductive film 20 is covered only on the convex portions 12 of the fine pattern 15 on the pattern surface 11a, which is the same as the glass substrate for imprint 30a according to the second embodiment. The back surface 16 is further covered with a transparent conductive film 20, and is different from the glass substrate for imprint 30c according to the second embodiment.

  Thus, similarly to Example 3, the back surface 16 of the glass substrate 10 may be configured to be covered with the transparent conductive film 20. Thereby, the electric potential of the back surface 16 of the glass substrate 30c for imprint can be stabilized, and the electric potential of the whole glass substrate 30c for imprint can be stabilized. The potential of the pattern surface 11a of the imprint glass substrate 30c can be further stabilized, and even when an electron beam is used, charge-up does not occur and the pattern surface 11a can be inspected with high accuracy. Similar to the second embodiment, the fine pattern 15 on the pattern surface 11a can be formed with high accuracy.

  The imprint glass substrate 30c according to the fourth embodiment can be manufactured in substantially the same manner as the imprint glass substrate 30a according to the second embodiment. Specifically, in FIGS. 6A and 8A of Example 2, the glass substrate 10 having the transparent conductive film 20 coated on the back surface of the glass substrate 10 is prepared first, and thereafter 6B to FIG. 7C and FIG. 8B to FIG. 8D, the same manufacturing method as the glass substrate for imprint 30a according to the second embodiment is performed. Can be applied.

  As for the resist pattern forming method, the contents described in FIG. 3 of the first embodiment can be executed as they are using the glass substrate for imprint 30 c according to the fourth embodiment, and can be applied to substrates other than the silicon substrate 40. The point is the same as that of the first embodiment.

  According to the glass substrate for imprint 30c according to the fourth embodiment, the fine pattern 15 formed on the pattern surface 11a can be formed with high accuracy, the potential of the pattern surface 11a is further stabilized, and an electron beam is used. Highly accurate pattern inspection.

  In Example 5, an inspection method and an inspection apparatus for the imprint glass substrates 30 and 30a to 30c to which the present invention is applied will be described. The inspection method and inspection apparatus for the imprint glass substrates 30 and 30a to 30c according to the fifth embodiment can be commonly applied to the imprint glass substrates 30 and 30a to 30c according to the first to fourth embodiments.

  FIG. 11 is a diagram illustrating an example of the overall configuration of the inspection apparatus for the imprint glass substrates 30 and 30a to 30c according to the fifth embodiment. In the inspection apparatus for the imprint glass substrates 30 and 30a to 30c according to the fifth embodiment, a mapping projection method is applied.

  The inspection apparatus for the imprint glass substrates 30 and 30a to 30c according to the fifth embodiment includes a primary optical system 70 that generates an electron beam, a stage 120 on which the imprint glass substrates 30 and 30a to 30c are placed, A secondary optical system 90 for enlarging an image of emitted electrons or mirror electrons from the sample, a detector 100 for detecting these electrons, an image processing apparatus 110 for processing a signal from the detector 100, and an alignment device An optical microscope 140 and a SEM 150 for review are provided.

  The primary optical system 70 is a unit that generates an electron beam and irradiates the glass substrate 30 for imprinting and 30a to 30c. The primary optical system 70 includes an electron gun 71, lenses 72 and 75, apertures 73 and 74, an E × B filter 76, lenses 77, 79 and 80, and an aperture 78. An electron beam is generated by the electron gun 71, and the electron beam is shaped and directed by the lenses 72 and 75 and the apertures 73 and 74. Then, the electron beam is affected by the Lorentz force due to the magnetic field and the electric field by the E × B filter 76, and the electron beam incident from an oblique direction is deflected vertically downward, so that the glass substrate for imprint 30, 30a-30c. Head towards. The lenses 77, 79, and 80 direct the electron beam and adjust the landing energy LE by appropriately decelerating.

  The electron beam that the primary optical system 70 irradiates toward the imprint glass substrates 30 and 30a to 30c is an electron beam having a predetermined region, and an electron beam having regions for a plurality of pixels in the detector 100. . Therefore, it is possible to irradiate a wide area of the pattern surfaces 11 and 11a with a single irradiation. For example, irradiation may be performed with a beam diameter of 300 μm (or an ellipse of about 270 × 80 [μm]).

  The landing energy LE is adjusted by the landing energy setting means 130. The landing energy setting unit 130 includes an acceleration voltage setting unit 131 that sets the cathode potential of the electron gun 71 and a substrate voltage adjusting mechanism 132 that sets the substrate potential on the stage 120 side. The landing energy setting means 130 sets and adjusts the desired landing energy LE by adjusting the potential difference between the electron gun 71 side and the stage 120 side by the acceleration voltage setting means 131 and the substrate voltage adjustment mechanism 132.

  The primary optical system 70 irradiates the glass substrate 30, 30a to 30c with an electron beam with an electron beam, and irradiates both the first electron beam for precharging and the second electron beam for imaging. You may make it perform.

  The stage 120 is means for placing the imprint glass substrates 30 and 30a to 30c, and is movable in the xy horizontal direction and the θ direction. Further, the stage 120 may be movable in the z direction as necessary. A sample fixing mechanism such as an electrostatic chuck may be provided on the surface of the stage 120.

  The stage 120 is provided with a substrate voltage adjusting mechanism 132. The substrate voltage adjusting mechanism 132 adjusts the landing energy LE of the irradiated electron beam by adjusting the potential of the imprint glass substrates 30 and 30a to 30c. A negative voltage is applied to the glass substrate for imprint 30, 30a to 30c, and the potential of the main surface of the first lens 80 of the secondary optical system 90 is positive. Therefore, the glass substrate for imprint 30 , 30a to 30c, a positive electric field is formed. For example, the substrate voltage may be set to 1 to 3 [kV / mm].

  On the stage 120, the glass substrates 30 and 30a-30c for imprint are mounted, and the primary optical system 70 irradiates the pattern surfaces 11 and 11a with landing energy LE-5 to -10 [eV]. . When foreign matter is present on the pattern surface 11 of the glass substrate 30 for imprinting 30, 30 a to 30 c, the foreign matter is charged up, and incident electrons of the primary optical system 40 are rebounded without contacting the foreign matter 10, The mirror electrons are guided to the detector 100 by the secondary optical system 90. On the other hand, secondary emission electrons (a secondary electron, a reflected electron, a backscattered electron, or a mixed state) are guided to the detector 100 by the secondary optical system 90 in a normal part without foreign matter. At this time, the secondary emission electrons are emitted in a direction spreading from the sample surface 21, so that the transmittance is low, for example, about 0.5 to 4.0%. On the other hand, since the direction of mirror electrons is not scattered, a high transmittance of almost 100% can be achieved. Therefore, it is possible to obtain a high brightness (a state in which the number of electrons is large) only with the signal of the foreign matter forming the mirror electrons, and a large difference / ratio with the surrounding secondary emission electrons, and a high contrast can be obtained. Become.

  Further, the image of the mirror electrons has a property of enlarging more than the optical magnification. FIG. 12 is a diagram showing a foreign substance image on the pattern surface 11 and a schematic principle obtained by the method for inspecting the glass substrate for imprint 30, 30a to 30c according to the present embodiment.

  FIG. 12A is a diagram showing an image 280 of the foreign matter 250 having a size of 40 [nm] obtained by the inspection method and the inspection apparatus for the imprint glass substrates 30 and 30a to 30c according to the present example. In FIG. 12A, the foreign material 250 has a size that approximately fills an area of pixel size 2 × 2 [μm]. Here, the pixel size is an actual size on the sample corresponding to one pixel of the detector, and means a minimum unit size seen on the sample. Accordingly, in FIG. 12A, the actual foreign matter size is 40 [nm], but is enlarged to a size close to 2 × 2 [μm] and displayed on the image 80. . This means that, for example, even if the sample surface is inspected with a pixel size of about 1 [μm] or 1.5 [μm], a foreign material 250 of about 40 [nm] can be found. In FIG. 12A, the landing energy LE of the imaging electron beam for detecting the foreign material 250 is 1 [eV], and the pixel size is 100 [nm]. Usually, when the actual size of the foreign matter is 40 [nm], it is necessary to have a pixel size smaller than 40 [nm] in order to image this, but the electron beam inspection according to this embodiment In the method, a magnified image of the foreign material in which the foreign material 10 is magnified more than the optical magnification can be acquired.

  FIG. 12B is a view showing an image 280 of a foreign matter size 40 [nm] obtained by a conventional SEM (Scanning Electron Microscope) type foreign matter inspection apparatus. In FIG. 12B, an image of the foreign object 250 at a pixel size 2 × 2 [μm] similar to that in FIG. 12A is shown, but compared with the image of the foreign object 250 shown in FIG. And it turns out that it is a considerably small size.

  As described above, the electron beam inspection method according to the present embodiment can acquire an image by greatly enlarging the size of the foreign material 250 as compared with the conventional SEM method. In other words, the signal from the foreign object 250 can be detected by enlarging it more than the optical magnification, and not only high sensitivity can be realized even for the ultra-small size foreign object 250, but a pixel size larger than the actual foreign object is used. Can be detected.

  FIG. 12C is a side view showing a state in which the foreign matter 250 exists on the pattern surfaces 11 and 11a of the glass substrates 30 and 30a to 30c for imprinting. In FIG. 12C, the fine pattern 15 is omitted for easy understanding. You may think that the foreign material 250 exists on the convex part 12. FIG. In FIG. 12C, since the surface of the foreign material 250 has a spherical shape, the electronic signal reflected from the surface moves in a trajectory so as to spread instead of being vertical. This is because the foreign matter 250 has a spherical surface shape, so that the potential distribution is different from that of the pattern surfaces 11 and 11a, and when the pattern surfaces 11 and 11a are viewed macroscopically, the portion where the foreign matter 250 exists. This is because the potential distribution is distorted.

  FIG. 13 is a diagram illustrating an example of the magnified image 280 of the foreign material 250 acquired by the foreign material inspection method according to the present embodiment and its cross-sectional gradation. FIG. 13A is a diagram illustrating an example of an enlarged image 280 of the foreign material 250 acquired by the foreign material inspection method according to the present embodiment. In FIG. 13A, the white area at the center is an enlarged image 281 of the foreign substance 250, and the black areas indicate the surface images 282 of the pattern surfaces 11 and 11a of the glass substrates for imprint 30, 30a to 30c. Here, the foreign substance size (diameter) is 40 [nm], and the optical magnification is 300 times. At this time, according to the conventional foreign matter inspection method, the image of the foreign matter 10 is 40 [nm] × optical magnification 300 = 12 [μm], but according to the foreign matter inspection method according to the present embodiment of FIG. For example, the size of the magnified image 281 of the foreign material 250 is 190 [μm]. The pixel size of the detector is 15 [μm].

  FIG. 13B is a diagram showing the cross-sectional gradation at the pixel position, where the horizontal axis indicates the pixel position coordinates and the vertical axis indicates the cross-sectional gradation. In FIG. 13B, a mountain portion Δ is a region where the gradation is high, and is a portion of the enlarged image 281 that is white in FIG. 13A. That is, the horizontal width Δ of the enlarged image 281 on the image 280 is 190 [μm]. Here, since the pixel size of the detector 100 is 15 [μm], according to the conventional method, the foreign object size is displayed as 12 [μm] on the image 280, and thus the image of the foreign object 250 is 1 pixel. The following signals are generated, and the foreign object 10 cannot be accurately expressed by one pixel.

  On the other hand, according to the inspection method and inspection apparatus for the imprint glass substrates 30 and 30a to 30c according to the present embodiment, the enlarged image 281 of the foreign material 250 can be detected with a 12.7 pixel size. Therefore, it is possible to capture an image with a large pixel size at a lower magnification. If imaging with a large pixel size is possible, the entire pattern surfaces 11 and 11a can be inspected at high speed, and high-speed and high-throughput foreign object inspection is possible. For example, when the foreign matter size is 10 to 30 [nm], the pixel size on the object surface can be 100 to 1000 [nm] larger than the foreign matter size, and high-speed foreign matter inspection is possible.

  As described above, the mirror electron image is enlarged more than the optical magnification, and the enlargement ratio is 5 to 50 times. Typical conditions are often 20-30 times. At this time, the pixel size can be detected with a pixel size three times or more the foreign substance size, and can be realized at high speed and high throughput. Therefore, for example, for a foreign object 10 having a diameter of 20 [nm], imaging and inspection are performed using a pixel size more than three times such as 60 [nm] pixel size, 100 [nm] pixel size, and 500 [nm] pixel size. It becomes possible to do. This has a feature that is remarkably superior in increasing the throughput as compared with the SEM method or the like.

  Returning to FIG. The secondary optical system 90 is a means for guiding electrons reflected from the glass substrate for imprint 30, 30 a to 30 c to the detector 100. The secondary optical system 90 includes lenses 91 and 93, an NA aperture 92, and an aligner 94. Electrons reflected from the pattern surfaces 11 and 11a of the glass substrate 30 for imprint 30 and 30a to 30c pass through the objective lens 80, the lens 79, the aperture 78, the lens 77, and the E × B filter 76 again, and the secondary optics. Guided to system 90. The emitted electrons from the pattern surfaces 11 and 11a of the imprint glass substrates 30 and 30a to 30c are imaged on the detector by the mapping optical system at an enlargement magnification of 50 to 500 times. In the secondary optical system 90, electrons are collected through the lens 91, the NA aperture 92, and the lens 93, and are arranged by the aligner 94 and detected by the detector 100.

  Note that the material of the foreign material 250 is not limited to a semiconductor, an insulator, a metal, or the like. FIG. 14 is a diagram showing a foreign material 250 made of a metal material. FIG. 14A is a diagram showing a foreign material 250 made of a metal material on the pattern surface 11. FIG. 14B is an enlarged view of the foreign material 250 made of a metal material. In FIG. 14B, the surface of the foreign material 250 such as a metal / semiconductor or a mixture of them is formed with a natural oxide film 251 and is covered with an insulating material. Therefore, the foreign material 250 of the metal material may be charged up by the oxide film 251 and can be used.

  Returning to FIG. The detector 100 is means for detecting electrons guided by the secondary optical system 90, and the detector 100 having a plurality of pixels (pixels) on its detection surface is applied. Since the detector 100 has a plurality of pixels on the detection surface, a plurality of electrons from an electron beam having a predetermined region can be detected simultaneously two-dimensionally. Various two-dimensional sensors can be applied to the detector 100. For example, the detector 100 may be a charge coupled device (CCD) or a time delay integration (TDI) -CCD. When a TDI-CCD is applied to the detector 10, the detector 100 has a configuration of an MCP (Micro Channel Plate), a fluorescent plate, a relay lens, and a TDI. The amount of detected electrons is multiplied by the MCP and converted to an optical signal by the fluorescent screen. This two-dimensional optical signal is imaged and detected by the relay lens on the TDI sensor. In TDI, since a two-dimensional image signal can be acquired while continuously moving a sample, high-speed image signal acquisition is possible. The signal from the TDI is subjected to electronic image formation, defect detection, and defect classification determination by the image processing apparatus 110. However, CCDs and TDI-CCDs are sensors that detect signals after converting electrons into light, and thus require means such as photoelectric conversion. Therefore, as described above, a conversion process is required in which electrons are converted into light using photoelectric conversion and scintillator, and image information of light is transmitted to and detected by TDI that detects light.

  In the fifth embodiment, an example in which EB-TDI is applied to the detector 100 will be described. EB-TDI does not require a photoelectric conversion mechanism and light transmission mechanism, and electrons directly enter the EB-TDI sensor surface, so there is no degradation in resolution and high MTF (Modulation Transfer Function) and contrast can be obtained. It becomes. When EB-TDI is used, it is possible to increase the S / N of the weak signal of the small foreign material 10 that has been unstable until now, and higher sensitivity can be obtained. The improvement in S / N reaches 1.2 to 2 times.

  In addition to the EB-TDI, it is effective that an EB-CCD is provided and can be arbitrarily switched and used interchangeably. For example, there is a usage method as shown in FIG.

  FIG. 15 is a diagram showing a detector 100 in which the EB-TDI 102 and the EB-CCD 101 can be switched, and both can be used interchangeably depending on the application. In FIG. 15, the detector 100 includes an EB-CCD 101 and an EB-TDI 102. The EB-CCD 101 and the EB-TDI 102 are electronic sensors that receive an electron beam, and the electron beam e is directly incident on the detection surface. In this configuration, the EB-CCD 101 is used for adjusting the optical axis of an electron beam and adjusting and optimizing image capturing conditions. On the other hand, when the EB-TDI 102 is used, the EB-CCD 101 is moved to a position away from the optical axis by the moving mechanism M, and then the condition obtained when the EB-CCD 101 is used is used. Taking an image with the EB-TDI 102 with reference, evaluation or measurement is performed.

  In this detector 100, the defect detection of the glass substrate 30 for imprinting, 30a-30c by EB-TDI102 is performed using or referring to the electro-optical condition obtained when the EB-CCD 101 is used. Can do. After the defect inspection by the EB-TDI 102, it is also possible to perform review imaging using the EB-CCD 101 and perform defect evaluation such as defect type and size. At this time, the EB-CCD 101 can integrate images, thereby reducing noise and review imaging of a defect detection site with high S / N. At this time, it is effective to use a pixel having a smaller pixel of the EB-CCD 71 than that of the EB-TDI 72. In other words, it is possible to image with a large number of pixels for the signal size expanded by the mapping projection optical system, and it is possible to perform imaging for classification and determination of inspection, defect type, etc. with higher resolution. Become.

  Note that the EB-TDI 102 has, for example, a rectangular shape in which pixels are two-dimensionally arranged so that the electron beam e can be directly received and used to form an electronic image. 16 [μm]. On the other hand, the pixel size of the EB-CCD 101 is, for example, 6 to 8 [μm].

  The EB-TDI 102 is formed in the shape of a package 105. The package 105 itself serves as a feedthrough, and the package pins 103 are connected to the camera 104 on the atmosphere side.

  Returning to FIG. The image processing apparatus 110 is a defect detection unit that generates surface images of the pattern surfaces 11 and 11a of the imprint glass substrates 30 and 30a to 30c from electrons detected by the detector 100, and performs defect detection. Since the image processing apparatus 110 performs image generation and arithmetic processing for detecting defects, arithmetic processing means such as a computer may be applied.

  Next, an example of calculation processing for defect detection performed by the image processing apparatus 110 will be described with reference to FIG. FIG. 16 is a diagram showing an example of a defect detection method by die-to-die comparison.

  FIG. 16A is a diagram illustrating an example in which a plurality of regions (die) where the fine pattern 15 is formed exist on the glass substrate for imprint 30, 30a to 30c. In FIG. 16A, although the die 1 and the die 2 are shown, the same pattern is usually formed on each die. At this time, by comparing the same part of the two dies, if a difference occurs in the pattern signal, it can be determined that the part has a defect. In the example of FIG. 16, similar patterns are created on the die 1 and the die 2. Comparing the same pattern area of these two dies, if there is a defect in one of them, the defect image can be detected by detecting the signal of the defective part in the comparison image (compare the difference signal) .

  FIG. 16B is a diagram showing an example of a die pattern and an example of a pattern defect portion. In the pattern example shown in FIG. 16B, the leftmost pattern has a defect, the middle pattern has an extra pattern, and the rightmost pattern has a normal pattern. ing. When this is compared with a die having all normal patterns to obtain a differential signal, the difference between the part that protrudes from the part where the pattern is missing is not zero, and a positive or negative signal is detected, The signal of the defective part is detected. For example, the dies formed on the imprint glass substrates 30 and 30a to 30c may be compared with each other to detect a defect. The defect may include one or both of a pattern defect and foreign matter adhesion.

  It is also possible to compare with CAD data instead of comparing with two dies. Since there is no defect in CAD data, it is compared with an inspection image obtained by irradiating an electron beam, and if there is a difference, it can be determined that there is a defect at that part.

  FIG. 17 is a diagram for explaining an example of an electron beam irradiation method. As shown in the die 1 of FIG. 17, when the die-die or CAD data-die inspection is performed in the pattern defect inspection, the outer 5 to 500 [μm] area outside the die area is selected as the irradiation region, and the electron Irradiation of the beam is very effective when performing particle inspection as the second inspection continuously. When the electron beam irradiation in the pattern defect inspection includes the precharge effect of the next particle inspection, if the particle inspection area (care area) is the die pattern formation area, as described above, the outside of the die When the beam is irradiated in the first first inspection, the portion is also precharged, and the uniformity of the surface potential state where the precharge is performed increases.

  As other effects, there are the following advantages. That is, when performing scanning, it is important to release the blanking of the electronic boom and perform beam irradiation before the care area. If blanking is canceled in the care area at that time, electron beam irradiation unevenness (dose nonuniformity) at the time of cancellation occurs. Therefore, in order to prevent such a dose non-uniformity and obtain a stable care area image, as shown in FIG. 17, when the electron beam blanking is released outside a certain distance and the electron beam irradiation is started, the beam becomes homogeneous. An image can be obtained, and highly accurate pattern inspection can be performed.

  Next, in the inspection apparatus for the imprint glass substrates 30 and 30a to 30c according to the fifth embodiment, the electron beam irradiation step includes a step of irradiating the first electron beam and a step of irradiating the second electron beam. Consider the case where the landing energy LE1 and LE2 of the first electron beam and the second electron beam are different, including two steps.

  For example, the landing energy at the time of pattern defect inspection is set as the first landing energy LE1. Thereafter, foreign matter inspection is performed in the die region, and the landing energy at this time is set as the second landing energy LE2. At this time, if LE1> LE2, it is very effective. This is because, in the detection of the foreign matter 250, the detection sensitivity can be increased by stabilizing the surface potential of the foreign matter 250 by precharging with the first electron beam. When an electron beam is irradiated with the second landing energy LE2 lower than the potential charged up with the first landing energy LE1, the trajectory of secondary electron emission electrons from the foreign material 250 is greatly affected by the charge-up voltage. It changes and it becomes possible to obtain high S / N.

  The difference between the landing energy LE1 of the first electron beam to be precharged and the landing energy LE2 of the second electron beam is preferably about 5 to 20 [eV] in experiments. Moreover, Preferably, 10-15 [eV] is good. This is because the charge-up voltage varies depending on the value of the first landing energy LE1 when the electron beam of the first landing energy LE1 is irradiated in the negative charging region when there is a potential difference between the foreign material 250 and the surroundings. Due to the relative ratio with the second landing energy LE2, when the first landing energy LE1 is large, the charge-up voltage is high, and a reflection point is formed above the foreign object 250 (on the detector 100 side). Depending on this position, the trajectory and transmittance of the mirror electrons change, and the optimum charge-up voltage condition is determined. On the other hand, if the first landing energy LE1 is too low, the efficiency of mirror electron formation decreases. In this case, it is discovered and invented that the difference between the first landing energy LE1 and the second landing energy LE2 is preferably within the above range. The value of the first landing energy LE1 is 0 to 40 [eV], preferably 5 to 20 [eV].

  Next, using the inspection apparatus for the imprint glass substrates 30 and 30a to 30c according to Example 5 described so far, the foreign matter 150 on the pattern surfaces 11 and 11a of the imprint glass substrates 30 and 30a to 30c is measured. An example of inspection will be described. Assume that the energy LE with which the sample is irradiated with the primary electron beam is 3 [eV]. At this time, in the landing energy LE, the difference between the cathode voltage of the primary electron gun 71 and the voltages (applied voltages) of the glass substrates 30 and 30a to 30c for imprinting becomes the energy of the irradiated electron beam. By this beam irradiation, the foreign matter is charged up, and only the beam irradiated to the foreign matter 250 becomes mirror electrons and is guided to the detector 100 by the secondary optical system 90. In the normal part where the foreign material 250 is not present, secondary emission electrons (secondary electrons, reflected electrons, backscattered electrons, or a mixture thereof) due to beam irradiation are guided to the detector 100 by the secondary optical system 90. At this time, the emission rate η of secondary emission electrons decreases as LE = 0 (closes to 0). Furthermore, since the emission direction from the pattern surfaces 11 and 11a has a divergence distribution (for example, according to the cosine immediately if it is a secondary electron), the rate of reaching the detector 100 in the secondary optical system 90 is: In design calculation, it is about several percent. As described above, since the arrival rate of the mirror electrons is high and the arrival rate / emission rate of the surrounding portions is low, a relatively large ratio of the number of electrons, that is, a difference in luminance occurs. Therefore, a large contrast and S / N can be obtained. For example, S / N = 5 to 10 is obtained with the foreign material 250 of 100 [nmPx] and 20 [nm] φ. Usually, since S / N ≧ 3 can be sufficiently detected and inspected, such an inspection of a very small foreign material 250 can be realized with a pixel size larger than the size of the foreign material.

  Next, an example in which precharge is used in the inspection apparatus for imprint glass substrates 30 and 30a to 30c according to the fifth embodiment will be described. With the precharge landing energy LE1 = 16 [eV] and the landing energy LE2 at the time of imaging / inspection = 3 [eV], the foreign object 250 of the insulator can be efficiently inspected. The foreign matter 250 on the surfaces of the transparent conductive films 20 and 20a and the metal film 21 covered with the pattern surfaces 11 and 11a can be inspected. In this step, the entire inspection region is irradiated with an electron beam with the first landing energy LE1. Next, the foreign matter 250 can be imaged and inspected by irradiating the electron beam with the second landing energy LE2. This depends on how long the precharge effect can be maintained, but normally, it can be maintained for about 10 to 30 hours, and in some cases for 150 hours or more unless the charge removal process is performed.

  When such precharge is performed, the effect of mirror electron formation can be increased and the S / N can be improved by about 3 to 10 times compared to the case where precharge is not performed.

  FIG. 18 is a diagram illustrating an example of the overall configuration of an inspection apparatus for glass substrates for imprints 30 and 30a to 30c according to a sixth embodiment to which the present invention is applied. In Example 6, an example of an inspection apparatus for the imprint glass substrates 30 and 30a to 30c including the apparatus system will be described.

  18, the foreign substance inspection apparatus according to the present embodiment includes a load port 190, a mini-environment 180, a load lock 162, a transfer chamber 161, a main chamber 160, an electron beam column system 200, and an image processing apparatus. There is a system 110. The mini-environment 180 includes an atmospheric transfer robot, a substrate alignment device, a clean air supply mechanism, etc. (not shown). The transfer chamber 161 has a vacuum transfer robot (not shown), and the presence of the robot in the always-vacuum transfer chamber 161 makes it possible to minimize the generation of particles due to pressure fluctuations. .

  The main chamber 160 has a stage 120 that moves in the x, y, and θ (rotation) directions, and an electrostatic chuck is installed thereon. The imprint glass substrates 30 and 30a to 30c themselves or the imprint glass substrates 30 and 30a to 30c are installed on an electrostatic chuck in a state where they are installed on a pallet or a jig.

  The main chamber 160 is controlled by the vacuum control system 230 so that a vacuum state is maintained in the chamber. Further, the main chamber 160, the transfer chamber 161, and the load lock 162 are placed on the vibration isolation table 170 so that vibration from the floor is not transmitted.

  An electronic column 200 is installed in the main chamber 160. In this column, a detector 100 for detecting secondary emitted electrons or mirror electrons from the columns of the primary optical system 70 and the secondary optical system 90 and the glass substrates 30 and 30a to 30c for imprinting is installed. Yes. A signal from the detector 100 is sent to the image processing apparatus system 110 for signal processing. Signal processing can be performed both during on-time processing during inspection and offline processing in which only images are acquired and processed later. Data processed by the image processing apparatus is stored in a recording medium such as a hard disk or a memory. Further, it can be displayed on the console monitor as necessary. For example, an inspection area, a foreign matter number map, a foreign matter size distribution / map, a foreign matter classification, a patch image, and the like. In order to perform such signal processing, system software 220 is provided. An electron optical system control power supply 210 is provided to supply power to the electron column system.

  Next, the conveyance mechanism of the glass substrate 30 for imprints and 30a-30c is demonstrated.

  The imprint glass substrates 30 and 30a to 30c are conveyed from the load port into the mini-environment 180, and alignment work is performed therein. It is transferred to the load lock 162 by the atmospheric transfer robot. The load lock 162 is evacuated from the atmosphere to a vacuum state by a vacuum pump (not shown). When the pressure is about 1 [Pa] or less, the imprint glass substrates 30 and 30a to 30c are transferred from the load lock 162 to the main chamber 160 by the vacuum transfer robot in the transfer chamber 161. And it installs on the electrostatic chuck mechanism on the stage 120.

  High-precision alignment is performed by the x, y, z, θ stage 120 and the optical microscope 150. And the foreign substance inspection and pattern defect inspection of the glass substrate 30 for imprints and 30a-30c are performed by the mapping projection optical system using an electron beam. At this time, the surface potential of the pattern surfaces 11 and 11a is important. In order to measure the surface potential, a surface potential device that can be measured in a vacuum is attached to the main chamber 160. The surface potential measuring device measures a two-dimensional surface potential distribution on the sample and performs focus control of the secondary optical system 90 that forms an electron image. A focus map of a two-dimensional position of the glass substrate for imprint 30, 30a to 30c is produced based on this potential distribution, and the inspection is performed while changing and controlling the focus during the inspection. Thereby, blurring and distortion of an image due to a change in surface potential depending on a place can be reduced, and an inspection for obtaining a stable and accurate image can be performed.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

DESCRIPTION OF SYMBOLS 10 Glass substrate 11, 11a Pattern surface 12 Convex part 13 Concave part 15 Fine pattern 16 Back surface 20 Transparent conductive film 30, 30a, 30b, 30c Glass substrate for imprint 40 Silicon substrate 50, 60 Resist 70 Primary optical system 71 Electron gun 72 75, 77, 79, 80, 91, 93 Lens 73, 74, 78, 92 Aperture 76 E × B filter 90 Secondary optical system 94 Aligner 100 Detector 101 EB-CCD
102 EB-TDI
103 pin 104 camera 105 package 110 image processing apparatus 120 stage 130 landing energy setting means 131 acceleration voltage setting means 132 substrate voltage adjustment mechanism 140 optical microscope 150 SEM
160 Main chamber 161 Transfer chamber 162 Load lock chamber 170 Vibration isolation table 180 Mini environment 190 Load port 200 Electro-optical system 210 Electro-optical system controller 220 System software 250 Foreign material 280 Image

Claims (8)

A glass substrate having a pattern surface on which a fine pattern having irregularities for imprinting is formed and a back surface of the pattern surface consisting of a flat surface;
An imprint glass substrate inspection method for inspecting an imprint glass substrate in which the entire pattern surface having the unevenness and the back surface of the pattern surface consisting of the flat surface are covered with a transparent conductive film,
An electron beam irradiation step of irradiating an electron beam having a predetermined irradiation area on the pattern surface of the glass substrate for imprint placed on the stage;
An electron detection step of simultaneously detecting a plurality of electrons generated from the pattern surface by irradiation of the electron beam on a detection surface having a plurality of pixels;
Obtaining an image of the pattern surface from electrons detected on the detection surface, and detecting a defect on the pattern surface,
The defect detection step detects foreign matter present on the pattern surface based on the difference between the luminance when the mirror electron is detected by the electron detection step and the luminance when the secondary emission electron is detected by the electron detection step. A method for inspecting a glass substrate for imprinting, characterized in that: A glass substrate having a pattern surface on which a fine pattern having irregularities for imprinting is formed and a back surface of the pattern surface consisting of a flat surface;
A method for inspecting an imprint glass substrate for inspecting a glass substrate for imprint in which a convex portion of a fine pattern having the unevenness and a back surface of the pattern surface composed of the flat surface are covered with a transparent conductive film,
An electron beam irradiation step of irradiating an electron beam having a predetermined irradiation area on the pattern surface of the glass substrate for imprint placed on the stage;
An electron detection step of simultaneously detecting a plurality of electrons generated from the pattern surface by irradiation of the electron beam on a detection surface having a plurality of pixels;
Obtaining an image of the pattern surface from electrons detected on the detection surface, and detecting a defect on the pattern surface,
The defect detection step detects foreign matter present on the pattern surface based on the difference between the luminance when the mirror electron is detected by the electron detection step and the luminance when the secondary emission electron is detected by the electron detection step. A method for inspecting a glass substrate for imprinting, characterized in that:   The electron beam irradiation step includes a step of irradiating a first electron beam, and then a step of irradiating a second electron beam having a landing energy lower than that of the first electron beam. Item 3. The method for inspecting an imprint glass substrate according to Item 1 or 2.   The method for inspecting an imprint glass substrate according to any one of claims 1 to 3, wherein the transmittance of the secondary emission electrons is lower than the transmittance of the mirror electrons. A glass substrate having a back surface of the pattern surface consisting of a pattern surface and a flat surface on which a fine pattern having unevenness for imprinting is formed, and the back surface of the pattern surface consisting of the entire pattern surface having the unevenness and the flat surface. Is an imprint glass substrate inspection apparatus for inspecting an imprint glass substrate covered with a transparent conductive film,
An electron gun for irradiating an electron beam having a predetermined irradiation area on the pattern surface of the glass substrate for imprint placed on a stage;
A detector for simultaneously detecting a plurality of electrons generated from the pattern surface by irradiation of the electron beam on a detection surface having a plurality of pixels;
A defect detection means for acquiring an image of the pattern surface from electrons detected on the detection surface and detecting a defect of the pattern surface;
The defect detection means detects foreign matter present on the pattern surface based on a difference between luminance when the detector detects mirror electrons and luminance when the detector detects secondary emission electrons, An inspection apparatus for glass substrates for imprints. The pattern surface comprising a glass substrate having a back surface of the pattern surface comprising a pattern surface and a flat surface on which a fine pattern having unevenness for imprinting is formed, and the pattern surface comprising the convex portions of the fine pattern having the unevenness and the flat surface An imprint glass substrate inspection apparatus for inspecting an imprint glass substrate whose back surface is coated with a transparent conductive film,
An electron gun for irradiating an electron beam having a predetermined irradiation area on the pattern surface of the glass substrate for imprint placed on a stage;
A detector for simultaneously detecting a plurality of electrons generated from the pattern surface by irradiation of the electron beam on a detection surface having a plurality of pixels;
A defect detection means for acquiring an image of the pattern surface from electrons detected on the detection surface and detecting a defect of the pattern surface;
The defect detection means detects foreign matter present on the pattern surface based on a difference between luminance when the detector detects mirror electrons and luminance when the detector detects secondary emission electrons, An inspection apparatus for glass substrates for imprints.   Landing energy for setting the landing energy of the electron beam so that the electron gun can continuously irradiate the first electron beam and the second electron beam having a landing energy lower than that of the first electron beam. 7. The apparatus for inspecting an imprint glass substrate according to claim 5, further comprising setting means.   The inspection apparatus for a glass substrate for imprints according to any one of claims 5 to 7, wherein a transmittance of the secondary emission electrons is lower than a transmittance of the mirror electrons.

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