JP2008026384A - Photomask and exposure method of photoreceptor using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photomask with which it is possible to three-dimensionally expose a photoreceptor and which has little restriction to the face capable of exposing, and to provide an exposure method of the photoreceptor using the same. <P>SOLUTION: The photomask has a structure including: a mask main body 2 having a transmitting region 5a and a non-transmitting region 5b of an exposure beam B; and a reflection structure 3 provided on one surface of the mask main body 2. The exposure method comprises introducing the exposure beam B reflected by the reflection structure 3 to a face forming an angle with respect to the surface of a substrate 21. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a photomask and a method for exposing a photoconductor using the photomask, and more particularly, to a photomask configuration capable of three-dimensionally exposing the photoconductor and a method for three-dimensionally exposing the photoconductor using the photomask. And about.

Conventionally, for example, as a technique for forming a fine wiring pattern on the outer surface of an insulating substrate, a technique using a photolithography technique is known. Further, as this photolithography technique, a photomask is arranged on the surface side of the substrate, which is a workpiece, and an exposure beam is irradiated vertically from the surface side of the photomask to the surface of the substrate, so that the side surface portion of the substrate A technique for exposing a formed photoresist layer with a desired pattern is known, and as a photomask applied to the exposure method, one having a diffractive structure in a transmission region of an exposure beam has been proposed. (For example, refer to Patent Document 1).
When the photomask described in Japanese Patent Application Laid-Open No. 2006-500632 is used, a diffraction structure among the exposure beams transmitted through the transmission region of the photomask when the exposure beam is vertically irradiated from the surface side of the photomask. The exposure beam incident on the part is diffracted by the diffractive structure part to generate a secondary beam such as ± 1st order light or ± 2nd order light, so that the transmission formed on the photomask using the photoresist layer formed on the side surface part of the substrate Exposure can be performed with a desired pattern specified by the shape and size of the region, and the substrate can be three-dimensionally exposed.

  However, since the technique described in Patent Document 1 uses diffracted light, it is difficult to direct the exposure beam in an arbitrary direction, resulting in a portion that cannot be exposed depending on the size and inclination angle of the surface to be irradiated with the exposure beam. There is a problem that it is easy. In addition, since the influence of the exposure beam that is transmitted through the zero-order light, that is, the diffraction structure portion and irradiated perpendicularly to the surface of the substrate cannot be ignored, an unnecessary exposure pattern is likely to be irradiated onto the surface portion of the substrate. There is also.

  The present invention has been made in order to solve such problems of the prior art, and an object of the present invention is to provide a photomask capable of three-dimensionally exposing a photoconductor and having few exposure surface restrictions, Another object of the present invention is to provide a method for exposing a photoconductor using this photomask.

  In order to solve the above problems, the present invention relates to a photomask firstly, a mask body having a transmission region and a non-transmission region of an exposure beam, and the mask body provided on one side of the mask body and transmitted through the transmission region. It is configured to include a reflective structure having a reflective surface disposed on the optical path of the exposure beam.

  Thus, when a reflective structure is provided on one side of the mask main body, the exposure beam transmitted through the mask main body is reflected by the reflective structure, and its optical path can be changed in a direction according to the shape of the reflective structure. The side surface portion of the substrate, which is the workpiece, the wall surface of the concave stepped portion formed on the surface of the substrate, and the like can also be exposed in a desired pattern. Further, since the optical path of the exposure beam can be changed as appropriate by changing the shape of the reflecting structure, it is less restricted by the size of the exposure surface and the tilt angle, and can be applied to exposure of various shapes of substrates.

  The present invention also relates to a photomask. Secondly, in the photomask of the first configuration, the mask main body has a light shielding film patterned on one surface of a glass substrate, and the light shielding film allows the exposure beam to be A non-transmissive region is formed, and the reflective structure is formed by anisotropic etching of single crystal silicon, and the reflective structure is exposed in the transmissive region. It was configured to be joined to.

  Single crystal silicon which is anisotropically etched so that a specific lattice plane, for example, (111) plane is exposed has high light reflectivity and can be used as a reflective structure. Further, the processing by etching itself is very easy.

  According to the present invention, thirdly, in the photomask of the second configuration, the glass is alkali glass, and the bonding is anodic bonding.

  When alkali glass is used as the glass constituting the mask main body, the anodic bonding of the reflective structure made of single crystal silicon is possible, so that the reflective structure can be easily and reliably bonded to the mask main body.

  Further, the present invention relates to a photomask, fourthly, in the photomask of the second configuration, the light shielding film has a metal layer capable of eutectic bonding with silicon as a surface layer, and the reflective structure is the metal layer. And eutectic bonding.

  In this way, when a metal layer capable of eutectic bonding with silicon is formed on the surface layer of the light-shielding film and a reflective structure made of single crystal silicon is eutectic bonded to the metal layer, even glass other than alkali glass can be bonded firmly. The choice of glass materials will be very wide.

  Further, the present invention relates to a photomask, fourthly, in the photomask having the first to third configurations, a concave step portion is formed on a surface of the mask main body, and the reflection structure is formed on a bottom surface of the step portion. It was configured to arrange.

  As described above, when the reflecting structure is arranged on the bottom surface of the concave step portion formed on the surface of the mask body, the exposure beam transmission region formed on the mask body and the reflecting surface of the reflecting structure are connected to the optical path of the exposure beam. Since the optical path of the reflected light can be changed to the direction approaching the back surface of the mask body without changing the shape of the reflecting structure, the concave shape formed on the side surface portion of the substrate or the surface of the substrate can be changed. When exposing the wall surface of the stepped portion or the like, the exposure beam can be guided to the upper portion of the side surface of the substrate or the upper portion of the wall surface of the stepped portion, and the portions that cannot be exposed can be reduced.

  On the other hand, the present invention relates to a method for exposing a photoconductor using a photomask, the mask body having an exposure beam transmission region and a non-transmission region, and the mask body provided on one side of the mask body and transmitting the transmission region. A step of preparing a photomask comprising a reflecting structure having a reflecting surface disposed on the optical path of the exposure beam; a step of preparing a substrate having a photoresist layer formed on a required surface; and a back surface of the mask body; A step of disposing the surface of the substrate opposite to the substrate; irradiating the exposure beam from the surface side of the mask main body; and transmitting the exposure beam transmitted through the transmission region and the transmission region, and then reflecting on the reflection structure And a step of exposing the photoresist layer with the exposed exposure beam.

  According to such a configuration, since a photomask having a reflective structure is used, the back surface of the mask body and the surface of the substrate are arranged opposite to each other, and an angle with respect to the surface of the substrate such as a side surface portion of the substrate is provided. The surface can be exposed, and the three-dimensional exposure to the substrate can be performed in one operation.

  In addition, the present invention relates to a method for exposing a photosensitive member. Second, in the first method for exposing a photosensitive member, a concave step portion is formed on the surface as the substrate, and at least a photoresist is formed on a wall surface of the step portion. A substrate on which a layer is formed is prepared, the reflective structure is inserted into a stepped portion of the substrate, and the back surface of the mask body is disposed opposite to the surface of the substrate, and then the exposure is performed from the surface side of the mask body. The photoresist layer formed on the wall surface of the stepped portion is exposed by the exposure beam reflected by the reflective structure. Thereby, the exposure with respect to the wall surface of the concave level | step-difference part formed in the surface of a board | substrate can be performed.

  According to another aspect of the present invention, there is provided a substrate having a photoresist layer formed on at least a side surface as the substrate in the first method of exposing the photosensitive member. Is disposed on the side of the substrate and the back surface of the mask body is disposed opposite the front surface of the substrate, and then the exposure beam is irradiated from the surface side of the mask body and reflected by the reflective structure. The photoresist layer formed on the side surface of the substrate was exposed by an exposure beam. Thereby, exposure with respect to the side part of a board | substrate can be performed.

  Since the photomask of the present invention has a reflective structure on one side of the mask main body, the substrate as a workpiece can be three-dimensionally exposed and the surface that can be exposed depending on the size and inclination angle of the exposure surface can be obtained. Restrictions can be reduced.

  Since the photoconductor exposure method of the present invention uses a photomask provided with a reflective structure, it is possible to perform three-dimensional exposure on the substrate with the back surface of the mask body and the surface of the substrate arranged opposite to each other. .

  Hereinafter, embodiments of a photomask according to the present invention will be described with reference to FIGS. 1 is a cross-sectional view of main parts of a photomask according to the first embodiment, FIG. 2 is a manufacturing process diagram of the photomask according to the first embodiment, and FIG. 3 is a cross-sectional view of main parts of the photomask according to the second embodiment. FIG. 4 is a sectional view of an essential part of a photomask according to the third embodiment.

  As shown in FIG. 1, a photomask 1A according to the first embodiment includes a mask main body 2 formed in a parallel plate shape, and a reflective structure provided on the back surface (exposing surface of the exposure beam) of the mask main body 2. It consists of three.

  The mask body 2 is formed by forming a light-shielding film 5 such as chromium on one surface of an alkali glass substrate 4 and forming an exposure beam transmission region 5 a and a non-transmission region 5 b on the light-shielding film 5. The transmissive region 5a and the non-transmissive region 5b are formed in a desired pattern, for example, by applying a photolithography technique.

  As the reflective structure 3, for example, a single crystal silicon is anisotropically etched to form a (111) plane of a crystal lattice with excellent reflectivity, a metal is processed into a desired shape, and molded into a desired shape It is possible to use a plastic surface on which a metal reflective film is formed. When using a metal-processed or plastic surface with a metal reflective film, the shape and angle of the reflective surface can be adjusted arbitrarily, so that the desired exposure can be achieved regardless of the shape and tilt angle of the exposure surface. It becomes possible.

  Hereinafter, the manufacturing method of the photomask 1A according to the first embodiment will be described by taking as an example the case of using anisotropically etched single crystal silicon as the reflective structure 3.

  First, a single crystal silicon substrate 11 shown in FIG. Next, after the single crystal silicon substrate 11 is thermally oxidized to form an oxide film 14 on one surface thereof, the oxide film 14 is patterned as shown in FIG. Next, as shown in FIG. 2C, boron is diffused in the single crystal silicon substrate 11 by vapor phase diffusion to form a layer in which boron is diffused at a high concentration, that is, a boron diffusion layer 15. As shown in FIG. 2D, the oxide film 14 is peeled off. Next, anisotropic etching of the single crystal silicon substrate 11 is performed using the boron diffusion layer 15 as an etching mask to form the reflective structure 3 having a (111) plane as shown in FIG. Next, as shown in FIG. 2 (f), the reflective structure 3 is bonded to the mask body 2. As a bonding method, a low temperature bonding technique using activation of the substrate surface by plasma discharge or an anodic bonding technique can be applied. Finally, as shown in FIG. 2G, the base portion of the single crystal silicon substrate 11 is removed by anisotropic etching to obtain a product photomask 1A. In this case, if the base portion of the single crystal silicon substrate 11 is thinned by polishing, pattern collapse due to the corner undercut phenomenon of alkali etching can be suppressed.

  As shown in FIG. 3, the photomask 1 </ b> B according to the second embodiment is characterized in that a concave step portion 6 is formed on the back surface of the mask body 2 and the reflecting structure 3 is disposed on the bottom surface of the step portion 6. And Except for having the concave step portion 6, the configuration of each portion is the same as that of the photomask 1A according to the first embodiment.

  As shown in FIG. 4, the photomask 1 </ b> C according to the third embodiment is characterized in that a metal capable of eutectic bonding with silicon, such as gold, is used for at least the surface layer portion of the metal layer forming the light shielding portion. The reflective structure is the same as the photomasks 1A and 1B according to the first and second embodiments. For the photomask 1C of this example, the reflective structure 3 made of single crystal silicon can be bonded to the metal layer of the mask body 2 by plasma activated bonding or eutectic bonding.

  Next, an exposure method for a substrate having a concave stepped portion formed on the surface using the photomask 1A according to the first embodiment will be described.

  As shown in FIG. 5, a concave stepped portion 22 is formed on the surface of the substrate 21 that is a workpiece, and a photoresist layer 23 is formed on the surface of the substrate 21 including the inner surface of the stepped portion 22, for example. It is formed to a uniform thickness by spray coating or the like. At the time of exposure, as shown in FIG. 5, the reflective structure 3 is inserted into the stepped portion 22, and the back surface of the photomask 1A is brought into close contact with the photoresist layer 23 on the substrate surface. In this state, an exposure beam B, which is parallel light, is incident on the photomask 1A perpendicularly from the surface side of the photomask 1A. As a result, the surface portion of the substrate 21 and the bottom surface portion of the step portion 22 are exposed with light that passes through the photomask 1A and is not reflected by the reflecting structure 3. Further, the wall surface portion of the stepped portion 22 is exposed with the light transmitted through the photomask 1A and reflected by the reflecting structure 3. Therefore, three-dimensional exposure of the substrate 21 becomes possible.

  If the photomask 1A according to the first embodiment is used, not only the wall surface of the stepped portion 22 formed on the surface of the substrate 21, but also the reflection structure on the outside of the side surface of the substrate 21, as shown in FIG. By positioning 3, the side surface of the substrate 21 can also be exposed.

  In addition, when the photomask 1B according to the second embodiment is used, even when a single crystal silicon that is anisotropically etched is used as the reflective structure 3, as shown in FIG. Since it can be guided to the upper portion or the upper portion of the stepped portion wall surface, it is possible to precisely perform the exposure of the portion that is difficult when the photomask 1A according to the first embodiment is used.

In the case of using a photomask 1C according to the third embodiment, the same effect as the case of using the photomask 1A according to the first embodiment is obtained.

It is principal part sectional drawing of the photomask which concerns on 1st Embodiment. It is a manufacturing process figure of the photomask concerning a 1st embodiment. It is principal part sectional drawing of the photomask which concerns on 2nd Embodiment. It is principal part sectional drawing of the photomask which concerns on 3rd Embodiment. It is a figure which shows the exposure method of the board | substrate using the photomask which concerns on 1st Embodiment. It is a figure which shows the other exposure method of the board | substrate using the photomask which concerns on 1st Embodiment. It is a figure which shows the exposure method of the board | substrate using the photomask which concerns on 2nd Embodiment.

Explanation of symbols

1A, 1B, 1C Photomask 2 Mask body 3 Reflective structure 4 Alkali glass substrate 5 Light-shielding film 5a Exposure beam transmission region 5b Exposure beam non-transmission region 6 Reflection structure setting step 21 Substrate (workpiece)
22 Stepped portion of substrate surface 23 Photoresist layer (photoconductor)

Claims (8)

  A mask main body having a transmission region and a non-transmission region of the exposure beam, and a reflection structure provided on one side of the mask main body and having a reflection surface disposed on the optical path of the exposure beam transmitted through the transmission region. A photomask characterized by The mask body has a light shielding film patterned on one surface of a glass substrate, and the light shielding film forms a non-transmission region of the exposure beam,
The reflective structure is formed by anisotropic etching of single crystal silicon, and the reflective structure is bonded to the exposed glass substrate in the transmissive region. The photomask according to 1.   The photomask according to claim 2, wherein the glass is alkali glass and the bonding is anodic bonding.   3. The photomask according to claim 2, wherein the light shielding film has a metal layer capable of eutectic bonding with silicon in a surface layer, and the reflective structure is eutectic bonded to the metal layer.   4. The photomask according to claim 1, wherein a concave stepped portion is formed on a surface of the mask main body, and the reflective structure is disposed on a bottom surface of the stepped portion. A photo comprising a mask main body having a transmission region and a non-transmission region of the exposure beam, and a reflection structure provided on one side of the mask main body and having a reflection surface disposed on the optical path of the exposure beam transmitted through the transmission region. A step of preparing a mask;
Preparing a substrate having a photoresist layer formed on a required surface;
Arranging the back surface of the mask body and the surface of the substrate opposite to each other;
Irradiating the exposure beam from the surface side of the mask main body, exposing the photoresist layer with an exposure beam transmitted through the transmission region and an exposure beam transmitted through the transmission region and then reflected by the reflective structure When,
A method for exposing a photoconductor using a photomask, comprising:   As the substrate, a substrate having a concave stepped portion formed on the surface and a photoresist layer formed on at least the wall surface of the stepped portion is prepared, and the reflective structure is inserted into the stepped portion of the substrate to form the mask body The back surface of the photomask is disposed opposite to the front surface of the substrate, and then the exposure beam is irradiated from the front surface side of the mask body, and the photo formed on the wall surface of the stepped portion by the exposure beam reflected by the reflective structure. 6. The method of exposing a photoconductor using a photomask according to claim 5, wherein the resist layer is exposed.   As the substrate, a substrate having a photoresist layer formed on at least a side surface is prepared, the reflective structure is disposed on the side of the substrate, and the back surface of the mask body is disposed opposite to the surface of the substrate. 6. The photoresist layer formed on the side surface of the substrate is exposed by irradiating the exposure beam from the surface side of the mask main body, and the exposure beam reflected by the reflective structure. Of exposing a photoconductor using a photomask.

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