JP2008010845A - Hologram recording medium, method of fabricating hologram recording medium, and exposing method using hologram recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hologram recording medium enabling the correct exposure while reducing the influence of the unevenness of an exposed member in an exposing method using holography, to provide a method of fabricating the hologram recording medium, and to provide an exposing method using the hologram recording medium. <P>SOLUTION: The exposing method includes the steps of: forming a hologram recording medium by forming interference fringes on hologram recording means, the interference fringes being formed by irradiating the hologram recording means with a first laser beam through a mask original plate and simultaneously irradiating the hologram recording means with a second laser beam; and irradiating, through the hologram recording medium, a resist formed on a device forming substrate with a third laser beam oscillated from a second laser oscillator. The mask original plate is a light shield film provided on a translucent substrate so as to have a thickness equal to or larger than the maximum difference of the surface of the resist. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a hologram recording medium, a method for producing the hologram recording medium, and an exposure method using the hologram recording medium.
More specifically, the present invention relates to a hologram recording medium, a method for producing the hologram recording medium, and an exposure method using the hologram recording medium, which can reduce the influence of undulation and unevenness on the surface of an object to be exposed.

  In recent years, an exposure technique using holography has attracted attention as a method for forming a pattern in a manufacturing process of a semiconductor device. The exposure technology using holography includes a process of recording a hologram by irradiating a medium for recording a hologram (hereinafter referred to as “hologram recording medium”) with object light and reference light (recording process), and hologram recording. Irradiating the medium with reproduction light to form a reproduction image of the interference fringes formed on the hologram recording medium on the resist (reproduction process).

  In the recording step, the hologram recording medium is irradiated with a first laser beam (object beam) through a mask (mask original plate) on which a desired pattern is formed, and the second laser beam is emitted from a direction different from the first laser beam. Irradiate laser light (reference light). The first laser beam and the second laser beam are simultaneously irradiated onto the hologram recording medium, whereby interference fringes are formed on the hologram recording medium. On the other hand, in the reproduction process, the resist formed on the element formation substrate is irradiated with laser light as reproduction light via a hologram recording medium on which interference fringes are formed, thereby reproducing diffracted light (which reproduces the pattern of the mask original plate). A reconstructed image is formed and the resist is exposed.

Further, the present invention relates to an exposure method (reduced exposure) in which a resist is made finer than an original pattern by using laser light oscillated from different types of laser oscillators in a recording process and a reproducing process of an exposure technique using holography. Research etc. are being conducted (for example, Patent Document 1).
JP 2004-253660 A

  The exposure method using holography does not require an optical lens when exposing the photosensitive material (resist) by irradiating light, so there is no aberration due to the lens, and a higher resolution can be obtained compared to the exposure method in photolithography. However, the depth of focus becomes shallower. Therefore, when exposing the resist formed on the element formation substrate using holography, if the surface of the element formation substrate has waviness, the resist formed thereon has waviness and unevenness, and the resist Exposure may be insufficient. As a result, there arises a problem that an accurate resist pattern cannot be formed.

  In view of the above problems, the present invention provides a hologram recording medium capable of reducing the influence of undulations and irregularities on the surface of an object to be exposed and accurately exposing in an exposure method using holography, and a method for producing the hologram recording medium, and It is an object to provide an exposure method using the hologram recording medium.

  In an exposure method of the present invention, a laser beam oscillated from a first laser oscillator is divided to form a first laser beam and a second laser beam, and the first laser beam is passed through a mask original plate. By irradiating the hologram recording means simultaneously with the second laser beam, the hologram recording means is formed to form an interference fringe on the hologram recording means to form a hologram recording medium, and the second laser is passed through the hologram recording medium. Irradiating a resist formed on the element formation substrate with a third laser light oscillated from an oscillator, and having a mask original plate having a translucent substrate with a difference of at least the maximum height difference of the resist surface. A light-shielding film having a film thickness is used.

Further, an exposure method of the present invention is the above-described exposure method, wherein in the above exposure method, a resist is formed by using autofocusing in which the shape of the third laser beam is linear and the third laser beam is automatically focused on the resist surface. It is characterized by irradiating.
Furthermore, one of the exposure methods of the present invention is characterized in that, in the above exposure method, the thickness of the light-shielding film is from 0.3 μm to 10 μm.

  One of the hologram recording media of the present invention divides a laser beam oscillated from a first laser oscillator to form a first laser beam and a second laser beam, and uses the first laser beam as a mask original plate. By irradiating the hologram recording means via the second laser beam and simultaneously irradiating the hologram recording means, the third laser light is applied to the element forming substrate via the hologram recording means on which interference fringes are formed. A hologram recording medium for irradiating a resist formed on the substrate, wherein the interference fringes comprise a light-shielding film having a thickness greater than or equal to the maximum height difference of the resist surface on a substrate having translucency. It is characterized by being formed.

  Moreover, one of the hologram recording media of the present invention is characterized in that, in the configuration of the hologram recording medium, the thickness of the light shielding film is not less than 0.3 μm and not more than 10 μm.

One of the methods for producing a hologram recording medium of the present invention is to divide a laser beam oscillated from a first laser oscillator to form a first laser beam and a second laser beam,
By irradiating the hologram recording means with the first laser light through the mask original plate, and simultaneously irradiating the hologram recording means with the second laser light, the hologram recording means with the interference fringes formed is used for the first recording. 3 is a method for producing a hologram recording medium in which a resist formed on an element forming substrate is irradiated with the laser beam of No. 3, wherein the interference fringes are formed on a translucent substrate with a film having a maximum height difference of the resist surface. The mask original plate is provided with a light-shielding film having a thickness.

  One of the methods for producing a hologram recording medium of the present invention is characterized in that, in the method for producing a hologram recording medium, the light-shielding film has a thickness of 0.3 to 10 μm.

  Set the thickness of the light-shielding film on the mask original plate in consideration of the waviness and unevenness of the object to be exposed, and irradiate the object to be exposed with laser light through the hologram recording medium using the mask original plate provided with the light-shielding film. By doing this, it is possible to reduce the influence of the undulation and unevenness of the surface of the object to be exposed in the exposure process. By applying the present invention, even when a wiring layer pattern is formed by exposure using holography in a manufacturing process of a semiconductor device, exposure failure of a resist used for etching a wiring is prevented and wiring is performed. It is possible to prevent disconnection or the like.

  Embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following description, and it is easily understood by those skilled in the art that modes and details can be variously changed without departing from the spirit and scope of the present invention. Therefore, the present invention should not be construed as being limited to the description of the embodiments below. Note that in the structures of the present invention described below, the same reference numerals may be used in common in different drawings.

(Embodiment 1)
In this embodiment mode, an example of an exposure method, a hologram recording medium, and a manufacturing method thereof according to the present invention using holography will be described with reference to the drawings.

First, an example of an exposure apparatus and an exposure method used in this embodiment is shown in FIG.
The exposure apparatus shown in FIG. 1 includes a laser oscillator 101, a beam splitter 102 that divides laser light emitted from the laser oscillator 101, mirrors 103 and 106 that reflect laser light in a desired direction, and a beam spot of the laser light. Magnifying optical systems 104 and 105 for enlarging the scale, and stages 112a and 113a.

  The stage 112a and the stage 113a are provided in order to place a sample used for exposure, and the position can be adjusted in the vertical direction and the horizontal direction. Here, an example is shown in which the mask original plate 108 is disposed on the stage 112a and the hologram recording unit 111a is disposed on the stage 113a as a sample.

Next, a process (recording process) of recording the pattern of the mask original plate 108 on the hologram recording unit 111a using the exposure apparatus shown in FIG. 1 will be described.
The laser light oscillated from the laser oscillator 101 is split into laser light having an appropriate intensity ratio by the beam splitter 102. Here, the light is divided into a first laser beam 114a and a second laser beam 114b.

  The first laser beam 114a is then diffracted through the mask original plate 108 after the scale of the beam spot is enlarged by the magnifying optical system 105, and then enters the hologram recording means 111a as the object beam 109. On the other hand, the second laser beam 114b is incident on the hologram recording unit 111a as the reference beam 110 after the scale of the beam spot is enlarged by the magnifying optical system 104.

  Thus, by simultaneously irradiating the hologram recording means 111a with the object beam 109 and the reference light 110, interference fringes derived from the pattern of the mask original plate 108 are formed on the hologram recording means 111a, and a hologram recording medium is obtained. The hologram recording unit 111a in which the pattern of the mask original 108 is formed as interference fringes is referred to as a hologram recording medium 111b (sometimes simply referred to as “hologram” or “hologram mask”).

  Next, the hologram recording means 111a (hologram recording medium 111b) on which the interference fringes are formed is irradiated with laser light, and the resist is exposed by irradiating the laser light diffracted by the hologram recording medium 111b. An example of the process of reproducing the pattern 108 (reproduction process) will be described with reference to FIG.

  The traveling direction of the laser beam 131 oscillated from the laser oscillator 121 is changed by the mirror 123, and then the scale of the beam spot of the laser beam 131 is expanded by the expanding optical system 124. Then, after the traveling direction is changed by the mirrors 125 and 126, the reproduction reference light 127 is incident on the hologram recording medium 111 b. The reproduction reference light 127 incident on the hologram recording medium 111b is diffracted by the interference fringes of the hologram recording medium 111b, and a part of the reproduction reference light 127 enters the resist 130 provided on the element formation substrate 129 as the reproduction light 128. Thereafter, a desired resist pattern can be obtained by developing the resist.

  Here, the element formation substrate 129 is disposed on the stage 112b, and the hologram recording medium 111b is disposed on the stage 113b. The reproduction reference beam 127 is incident on the hologram recording medium 111b from the opposite direction to the reference beam 110 shown in FIG. 1, and the resist 130 is arranged at the position where the mask original plate 108 shown in FIG.

Next, the mask original plate 108 and the hologram recording medium 111b used in the above-described exposure method will be described with reference to FIG.
FIG. 3A shows an example in which interference fringes are formed in the hologram recording means 111a by using a mask original plate 108 in which a light-shielding film 108b having a thickness Hc is selectively provided on a light-transmitting substrate 108a. Yes. FIG. 3B shows an example in which the resist 130 formed on the element formation substrate 129 is exposed using the hologram recording unit 111a (hologram recording medium 111b) on which interference fringes are formed. In FIG. 3, the surface of the element formation substrate 129 has a maximum height difference hb, and a resist 130 having a film thickness Hr is formed on the element formation substrate 129.

  In this embodiment, the mask original plate 108 is used in consideration of waviness and unevenness formed on the surface of the resist 130 to be exposed later. In FIG. 3, the thickness Hc of the light shielding film 108b of the mask original 108 is larger than the maximum height difference hr on the resist 130 surface, and preferably the difference between the highest position on the surface of the element forming substrate 129 and the maximum position on the resist 130 surface. larger than hbr. For example, the thickness Hc of the light shielding film 108b is set to 0.3 μm or more and 10 μm or less.

  Therefore, as the hologram recording medium 111b, a pattern (light-shielding film) having a film thickness larger than the maximum height difference hr on the resist 130 surface (or the difference hbr between the lowest position on the surface of the element forming substrate 129 and the highest position on the resist 130 surface). 108b pattern) interference fringes are used. The maximum height difference hb on the surface of the element formation substrate 129, the maximum height difference on the surface of the resist 130, and the like are preferably measured in advance before forming the interference fringes on the hologram recording unit 111a.

  Here, the maximum height difference of the surface of the element formation substrate means that the reproduction light 128 is irradiated at an instant on the object to be exposed (here, the resist 130 provided on the element formation substrate 129) via the hologram recording medium 111b. In this range, the difference between the highest part and the lowest part of the surface of the element formation substrate 129 in the direction perpendicular to the surface of the element formation substrate 129 is meant. The maximum height difference of the surface can be measured using a laser interferometer, an atomic force microscope (AFM (Atomic Force Microscope)), or the like.

  For example, in the reproducing process, when the entire surface of the resist 130 formed on the element formation substrate 129 is irradiated with the reproduction light 128 at one time, the undulations and unevenness in the entire element formation substrate 129 or the film thickness of the resist 130 is set. Considering this, the film thickness of the light shielding film 108b of the mask original 108 may be determined. Further, in the reproduction process, when the reproduction light 128 is irradiated onto a partial region of the resist 130 formed on the element formation substrate 129, the partial light region (the range where the reproduction light 128 is irradiated) is applied. The thickness of the light shielding film 108b in the mask original plate 108 may be determined in consideration of the undulations and unevenness of the element formation substrate or the thickness of the resist in the range.

  Further, in the reproduction process, when the resist 130 formed on the element formation substrate 129 is irradiated with the linear laser beam as the reproduction light 128 while scanning in one direction, the linear laser beam is emitted at a certain moment. In consideration of the undulations and unevenness of the element formation substrate 129 in the irradiated range (the area of the shaped linear laser beam), or the thickness of the resist in the range, the thickness of the light shielding film 108b in the mask original plate 108 is determined. Just decide.

  Further, the maximum height difference of the resist surface is within a range in which the reproduction light 128 is irradiated at an instant on the object to be exposed (here, the resist 130 provided on the element formation substrate 129) via the hologram recording medium 111b. The difference between the highest part and the lowest part of the surface of the resist 130 in the direction perpendicular to the surface of the element formation substrate 129 is said.

  Further, the difference between the lowest position on the surface of the element formation substrate and the maximum position on the resist surface is in an object to be exposed (here, the resist 130 provided on the element formation substrate 129) via the hologram recording medium 111b. This is the difference between the lowest part of the surface of the element formation substrate 129 and the highest part of the surface of the resist 130 in the direction perpendicular to the surface of the element formation substrate 129 within the range where the reproduction light 128 is irradiated instantaneously.

  When the resist 130 is formed on the element formation substrate 129 so that the film thickness is uniform, the maximum height difference hb on the surface of the element formation substrate 129 and the maximum height difference hr on the surface of the resist 130 are the same. (Hb = hr). When the maximum height difference hb on the surface of the element formation substrate 129 is sufficiently large (Hr << hb) as compared with the film thickness Hr of the resist 130, the lowest position on the surface of the element formation substrate 129 and the highest height on the surface of the resist 130. The position difference hbr and the maximum height difference hr on the resist 130 surface are close to each other (hbr≈hr).

Next, the mask original plate and laser oscillator used in the above-described exposure method will be specifically described.
As the substrate 108a, a glass substrate including a quartz substrate can be used.
As the material of the light shielding film 108b, a metal thin film material such as chromium (Cr) or an emulsion (photographic emulsion) can be used. Further, when chromium is used as the material of the light shielding film, a two-layer structure in which a chromium oxide interference film is formed on the surface of the chromium film may be used in order to reduce the reflectance of the surface. The emulsion is obtained by dispersing fine particles of silver halide as a photosensitive component in gelatin, and silver bromide can be used as the silver halide.

  In addition, silicon, iron oxide, molybdenum silicide, or the like may be used as a material for the light shielding film, or a material in which a pigment or a dye is dispersed in a transparent inorganic or organic material may be used. The light-shielding film 108b is preferably provided so as to have an optical density value of 2 or more, preferably 3 or more, more preferably 5 or more. The optical density (OD) is expressed by OD = −log (I ′ / I) (I is the intensity of incident light, I ′ is the intensity of transmitted light), and indicates the degree of opacity of the translucent medium.

  When the light shielding film 108b is provided thick, if a metal thin film material such as chromium is used, it may take time and cost to manufacture the mask original plate. However, since the mask original provided with the light shielding film 108b is used for forming interference fringes in the hologram recording means, it is used less frequently than the mask used in the photolithographic process, and if it is prepared once, it can be used for a long time. It has the advantage that it can be used repeatedly. In addition, it is preferable that the light shielding films 108b formed over the substrate 108a have the same thickness. In this case, the mask original plate can be easily manufactured as compared with the case where the thickness of the light shielding film 108b is provided separately according to the undulation or unevenness of the object to be exposed.

  The hologram recording medium 111b may be a computer generated hologram in which interference fringes obtained by calculation are formed in addition to those in which interference fringes are formed using the mask original plate. The computer generated hologram is obtained by calculating an interference fringe pattern instead of using the mask original plate 108 and directly drawing on the hologram recording means using an electron beam drawing apparatus or the like to form the interference fringe. In the case of using a computer generated hologram, there is an advantage that it is not necessary to actually produce a mask original.

As the laser oscillator 101 and the laser oscillator 121, a solid-state laser such as YAG laser, YVO ₄ laser, YLF laser, YAlO ₃ laser, GdVO ₄ laser, or the like can be used. Specifically, a solid laser using a crystal in which Cr, Nd, Er, Ho, Ce, Co, Ti, or Tm is doped into a crystal such as YAG, YVO ₄ , YLF, YAlO ₃ , GdVO ₄ or the like is used. In the present invention, the fundamental wave to the fifth harmonic of these solid-state laser oscillators are applied according to use. Harmonics with respect to the fundamental wave can be obtained by using a nonlinear optical element.

  As the laser oscillator 101 and the laser oscillator 121, the same laser oscillator may be used, or different laser oscillators may be used. Further, the laser beams 114 a and 114 b oscillated from the laser oscillator 101 and the laser beam 131 oscillated from the laser oscillator 121 may be laser beams having the same wavelength or laser beams having different wavelengths.

  For example, in the reproducing step shown in FIG. 2, the first laser beam 131 used in the recording step shown in FIG. 1 is used as the laser beam 131 used when the resist 130 is irradiated with the laser beam 131 through the hologram recording medium 111b for exposure. Laser light having a shorter wavelength than the laser light 114a and the second laser light 114b can be used.

  In addition, as the laser beam 131 used in the reproduction process, harmonics of the first laser beam 114a and the second laser beam 114b used in the recording process can be used. For example, using the same type or the same laser oscillator as the laser oscillator 101 used in the recording process as the laser oscillator 121 used in the reproduction process, the laser light oscillated from the laser oscillator 121 via a nonlinear optical element is modulated into a harmonic. can do. Note that the stage 112b and the stage 113b shown in FIG. 2 may be the same stage as the stage 112a and the stage 113a used in the recording process shown in FIG.

  Specifically, in the recording process shown in FIG. 1, a YAG laser is used as the laser oscillator 101, and a fundamental wave (wavelength: 1064 nm) of the YAG laser is used as the first laser beam 114a and the second laser beam 114b. On the other hand, in the reproduction step shown in FIG. 2, a YAG laser is used as the laser oscillator 121, and the laser light oscillated from the laser oscillator 121 is modulated into a harmonic by a non-linear optical element to be a laser light 131.

  As the laser beam 131, for example, a third harmonic (wavelength 355 nm) of a YAG laser is used. In this case, the wavelengths of the first laser beam 114a and the second laser beam 114b used in the recording process with respect to the laser beam 131 used in the reproducing process are tripled, and the pattern formed on the mask original plate 108 is reduced to 1/3 times. The patterned pattern 130 can be exposed to the resist 130. Note that the laser oscillator is not limited to the YAG laser, and the same kind of laser oscillator may be used as the laser oscillator 101 and the laser oscillator 121, and any of the solid lasers described above can be used.

  Alternatively, the second harmonic (wavelength 532 nm) of the YAG laser may be used as the first laser beam 114a and the second laser beam 114b, and the third harmonic (wavelength 355 nm) of the YAG laser may be used as the laser beam 131. . In this case, the wavelengths of the first laser beam 114a and the second laser beam 114b used in the recording process with respect to the laser beam 131 used in the reproducing process are 1.5 times, and the pattern formed on the mask original plate 108 is 1/1. The resist 130 can be exposed to a pattern reduced by a factor of five. When harmonics are used as the first laser beam 114a and the second laser beam 114b, the laser beam oscillated from the laser oscillator 101 is divided into the first laser beam 114a and the second laser beam 114b. What is necessary is just to modulate to a harmonic using a nonlinear optical element.

  In this way, in the exposure method using holography, by making the wavelength of the laser beam used in the recording process shorter than the wavelength of the laser beam used in the reproduction process, it is possible to reduce the mask pattern and expose the resist to the resist. It becomes.

  Note that although the case where a resist is formed over an element formation substrate has been described in this embodiment mode, the element formation substrate includes a substrate, a conductive film that forms a wiring layer, an insulating film, a semiconductor element such as a transistor, and the like. The layer is not particularly limited. For example, a transistor, an insulating film, and a conductive film that are sequentially stacked on a substrate also serve as an element formation substrate, and in this case, the maximum height difference of the element formation substrate is within a range irradiated with reproduction light. The difference between the highest part and the lowest part of the layer (in this case, the conductive film) formed on the outermost surface.

  In this embodiment, an example in which a transmission hologram is used has been described. However, a reflection hologram may be used. In the case of using a reflection type hologram, for example, the incident directions of the reference light 110 in the recording process shown in FIG. 1 and the reproduction reference light 127 in the reproduction process shown in FIG. 2 may be reversed. Specifically, in the recording step, the reference beam 110 is incident in a direction different from the direction in which the object beam 109 is irradiated with the hologram recording unit 111a as a boundary (incident from the upper surface side of the hologram recording unit 111a in FIG. 1) for reproduction. In the process, the reproduction reference beam 127 is incident from the opposite direction of the reference beam 110 (incident from the lower surface side of the hologram recording medium 111b in FIG. 2).

  In this way, the thickness of the light shielding film of the mask original is determined in consideration of the undulation and unevenness of the object to be exposed, and through the hologram recording means in which interference fringes are formed using the mask original having the light shielding film. By irradiating the object to be exposed with laser light, the influence of the undulation or unevenness of the object to be exposed can be reduced during exposure. Therefore, for example, even in the case of forming a wiring layer pattern by exposure using holography in a semiconductor device manufacturing process, the resist formed on the wiring layer is accurately exposed to form a pattern. Therefore, it is possible to prevent disconnection of the wiring.

In addition, even in the case of using an exposure method (reduced exposure) in which the original pattern is made finer by irradiating laser light of different wavelengths in the recording process and the reproducing process, the resist pattern is accurately used. Can be formed.
Note that this embodiment can be freely combined with any of the other embodiments in this specification.

(Embodiment 2)
In the reproduction process shown in the above embodiment mode, auto-focusing is used when the resist 130 formed on the element formation substrate 129 is irradiated with linear laser light as the reproduction light 128 while scanning in one direction. You may do it. Hereinafter, a case where autofocus is used will be described with reference to FIG. Here, a description will be given of a rectangular shape in which the surface of the element formation substrate 129 is parallel to the X-axis direction and the Y-axis direction. 4A is a top view of an object to be exposed (here, a resist 130 formed on the element formation substrate 129), and FIG. 4B is a diagram of the object to be exposed in FIG. 4A. A cross-sectional view is shown.

In this embodiment mode, the resist 130 is irradiated with a linear laser beam 140 having a major axis and a minor axis in the X-axis direction (FIG. 4A). Note that by irradiating the laser beam 140 so that the minor axis direction of the linear laser beam 140 and the X-axis direction are parallel to each other, the laser beam can be efficiently irradiated. In the present embodiment, autofocus is used when the laser beam 140 is scanned in parallel with the X-axis direction.
The auto-focusing means that the laser beam focused on the object to be exposed is automatically focused on the object to be exposed. When the laser beam 140 is irradiated, the surface of the element formation substrate 129, the hologram recording medium 111b, Can be kept constant.

  By irradiating the object to be exposed with the linear laser beam 140 using autofocus, in the rectangular element formation substrate 129, the undulation or unevenness of the element formation substrate 129 in one direction (here, the X-axis direction), etc. Can be reduced. Therefore, when exposing the exposure object using the hologram recording medium 111b, the range of the element formation substrate 129 irradiated with the laser beam 140 in the other direction (here, the Y-axis direction) (a in FIG. 4B). -B)) may be considered.

  In the case of using autofocus, hologram recording is performed by setting the direction in which the undulation and the unevenness are large in the X-axis direction or the Y-axis direction of the element formation substrate 129 as the traveling direction of the laser beam (here, the X-axis direction). It is possible to further reduce the influence of undulation, unevenness, and the like of the element formation substrate 129 when the object to be exposed is exposed using the medium 111b.

  For example, when a glass substrate having a thickness of 0.7 mm and “X” × “Y” = 600 mm × 720 mm is placed on a stage, the undulation of the glass substrate is measured. 7.4 μm / 10 cm in the X direction and 4.8 μm / 10 cm in the Y direction. Moreover, the maximum height difference only with the glass substrate was confirmed to be 3.5 μm / 10 cm in the X direction and 1.6 μm / 10 cm in the Y direction.

  Therefore, in the glass substrate having the above-described undulation, the irradiation of the laser beam as the reproduction light may be scanned in a direction parallel to the X-axis direction, and the glass substrate in the Y-axis direction parallel to the long-axis direction of the laser light. Waviness should be considered. For example, when a linear laser beam 140 having a major axis direction of 10 cm is scanned in the X axis direction, the glass substrate undulations or irregularities in the range of 10 cm in the Y axis direction (here 1.6 μm (disposed on the stage) In this case, in consideration of 4.8 μm)), the thickness of the light shielding film of the mask original plate may be determined as shown in the first embodiment. On the other hand, the influence of the substrate waviness or unevenness in the X-axis direction can be reduced by autofocus.

In this way, when the exposure object is irradiated while scanning the linear laser beam in one direction as the reproduction light in the reproduction process, element formation in the traveling direction of the linear laser beam is performed by using autofocus. It is possible to reduce the influence of the substrate undulations and unevenness. In addition, since the influence of the undulation or unevenness of the element formation substrate in the traveling direction can be reduced by using autofocus, it is possible to perform exposure using a light-shielding film having a smaller film thickness in the mask original plate.
Note that this embodiment can be freely combined with any of the other embodiments in this specification.

(Embodiment 3)
In this embodiment mode, an exposure method different from that of the above embodiment mode is described with reference to drawings. Specifically, an exposure method using total reflection holography using a prism will be described.
First, FIG. 5 shows an example of an exposure apparatus used in a process (recording process) of recording a mask original pattern on a hologram recording means.

  The exposure apparatus shown in FIG. 5 includes a laser oscillator 101, a beam splitter 102 that divides the laser light oscillated from the laser oscillator 101, mirrors 103, 125a, and 126a that reflect the laser light in a desired direction, Magnifying optical systems 104 and 105 for expanding the scale of the beam spot and stages 112a and 113a are provided.

  The stage 112a and the stage 113a are provided in order to place a sample used for exposure, and the position can be adjusted in the vertical direction and the horizontal direction. Here, as an example, a mask original plate 108 is arranged on the stage 112a, and an example in which the hologram recording means 111a mounted on the prism 132 is arranged on the stage 113a is shown.

Next, a process (recording process) of recording the pattern of the mask original 108 on the hologram recording unit 111a mounted on the prism 132 using the exposure apparatus shown in FIG.
The laser light oscillated from the laser oscillator 101 is split into laser light having an appropriate intensity ratio by the beam splitter 102. Here, the light is divided into a first laser beam 114a and a second laser beam 114b.

  The first laser beam 114a is then diffracted by the mask original plate 108 and then incident on the hologram recording means 111a as the object beam 109 after the scale of the beam spot is expanded by the magnifying optical system 105. On the other hand, the scale of the beam spot is enlarged by the magnifying optical system 104 and the traveling direction of the second laser beam 114b is changed by the mirrors 125a and 126a, and then enters the hologram recording unit 111a as the reference light 110. Here, the reference light 110 is totally reflected at the boundary surface between the hologram recording unit 111 a and the air via the prism 132.

In this way, the object light 109 and the reference light 110 are simultaneously irradiated onto the hologram recording unit 111a, whereby interference fringes depending on the pattern of the mask original plate 108 are formed on the hologram recording unit 111a.
As the laser oscillator 101, a solid-state laser such as YAG laser, YVO ₄ laser, YLF laser, YAlO ₃ laser, GdVO ₄ laser, or the like can be used. Specifically, a solid laser using a crystal in which Cr, Nd, Er, Ho, Ce, Co, Ti, or Tm is doped into a crystal such as YAG, YVO ₄ , YLF, YAlO ₃ , GdVO ₄ or the like is used. In the present invention, the fundamental wave to the fifth harmonic of these solid-state laser oscillators are applied depending on the use. The harmonic with respect to the fundamental wave can be obtained by using a nonlinear optical element.

Next, FIG. 6 shows an example of a process (reproduction process) in which the hologram recorded in the hologram recording means 111a formed in FIG.
The traveling direction of the laser beam 131 oscillated from the laser oscillator 121 is changed by the mirror 123, and then the scale of the beam spot of the laser beam 131 is expanded by the expanding optical system 124. Then, after the traveling direction is changed by the mirrors 125 b and 126 b, the reproduction reference light 127 enters the hologram recording medium 111 b through the prism 132.

  The reproduction reference light 127 incident on the hologram recording medium 111b is diffracted by the interference fringes of the hologram recording medium 111b, and a part of the reproduction reference light 127 enters the resist 130 provided on the element formation substrate 129 as the reproduction light 128. Note that the magnifying optical system 124 and the mirrors 125b and 126b shown in FIG. 6 can be the same as the magnifying optical system 104 and the mirrors 125a and 126a shown in FIG. 5, respectively.

Here, the element formation substrate 129 is disposed on the stage 112b, and the hologram recording medium 111b is disposed on the stage 113b. The reproduction reference beam 127 is incident on the hologram recording medium 111b from the opposite direction to the reference beam 110 shown in FIG. 5 via the prism 132, and the resist 130 is located at the position where the mask original plate 108 shown in FIG. Has been placed.
Further, the mask original plate 108 used in this embodiment can be the same as that shown in the first embodiment.

  In this way, the thickness of the light shielding film of the mask original is determined in consideration of the undulation and unevenness of the object to be exposed, and through the hologram recording medium on which interference fringes are formed using the mask original having the light shielding film. By irradiating the object to be exposed with laser light, the influence of the undulation or unevenness of the object to be exposed can be reduced during exposure. Therefore, for example, even in the case of forming a wiring layer pattern by exposure using holography in a semiconductor device manufacturing process, the resist formed on the wiring layer is accurately exposed to form a pattern. Therefore, it is possible to prevent disconnection of the wiring. In addition, even in the case of using an exposure method (reduced exposure) in which the original pattern is made finer by irradiating laser light of different wavelengths in the recording process and the reproducing process, the resist pattern is accurately used. Can be formed.

In the present embodiment, the same apparatus can be used in the recording process and the reproducing process. In this case, it can be realized in the reproduction process by rotating the hologram recording medium 111b by 180 degrees or by rotating the prism 132 used in the recording process by 180 degrees (see FIG. 17).
Further, this embodiment can be freely combined with any of the other embodiments in this specification. For example, the autofocus shown in the second embodiment may be used in the reproduction process.

(Embodiment 4)
In this embodiment mode, an exposure method different from that of the above embodiment mode will be described with reference to drawings. Specifically, in the exposure method using holography, a case where a recording process and a reproduction process are performed using the same laser oscillator and exposure apparatus will be described.
First, an example of an exposure apparatus used in the present embodiment is shown in FIG.

  The exposure apparatus shown in FIG. 15 includes a laser oscillator 101, a non-linear optical element 122a that modulates laser light oscillated from the laser oscillator 101 into harmonics, beam splitters 102 and 133 that divide the laser light, and a desired laser light. Mirrors 103, 106, 126, 134, 135 that reflect in the direction of, magnification optical systems 104, 105 that expand the scale of the laser beam spot, stages 112, 113, and shutters 141 a-141 c that block the laser light have.

The stage 112 and the stage 113 are provided in order to place a sample used for exposure, and the position can be adjusted in the vertical direction and the horizontal direction. Here, an example is shown in which a mask original plate 108 is disposed on the stage 112 and a hologram recording unit 111a is disposed on the stage 113 as a sample.
The shutters 141a to 141c are provided with a material that blocks laser light, and the laser light can be selectively blocked by opening and closing the shutters 141a to 141c.

Next, a process (recording process) for recording the pattern of the mask original plate 108 on the hologram recording unit 111a will be described.
The laser light oscillated from the laser oscillator 101 is modulated into a harmonic by the nonlinear optical element 122a to become a laser light 142. Next, the laser beam 142 is split by the beam splitter 102 into a laser beam having an appropriate intensity ratio. Here, it is divided into a first laser beam 142a and a second laser beam 142b. In the case where a fundamental wave is used in the recording process, laser light is incident on the beam splitter 102 without passing through the nonlinear optical element 122a.

  Then, after the scale of the beam spot is enlarged by the magnifying optical system 105, the first laser beam 142a is diffracted by the mask original plate 108 and then enters the hologram recording means 111a as the object light 109. On the other hand, the second laser beam 142b is split into a third laser beam 142c and a fourth laser beam 142d by the beam splitter 133 after the scale of the beam spot is expanded by the magnifying optical system 104.

  The third laser beam 142c is incident on the hologram recording unit 111a as the reference beam 110 after the traveling direction is changed by the mirror 106. The fourth laser beam 142d is blocked by the shutter 141c after the traveling direction is changed by the mirrors 126 and 134. In the present embodiment, the beam splitter 133 may be a mirror, and can be configured to move during the recording process so as not to obstruct the optical path.

As described above, the hologram recording unit 111a is simultaneously irradiated with the object beam 109 and the reference beam 110, whereby interference fringes between the object beam 109 and the reference beam 110 are formed on the hologram recording unit 111a. That is, the hologram of the pattern of the mask original plate 108 is recorded on the hologram recording unit 111a.
In the recording process, the shutters 141a and 141b are in an open state (a state in which laser light is not blocked), and a shutter 141c is in a closed state (a state in which laser light is blocked).

Next, FIG. 16 shows an example of a process of reproducing the hologram recorded in the hologram recording unit 111a formed in FIG.
The laser light oscillated from the laser oscillator 101 used in the recording process shown in FIG. 15 is modulated into a harmonic by the nonlinear optical element 122b to become a laser light 143. The laser beam 143 is modulated into a harmonic so that the wavelength is shorter than that of the laser beam 142 used in the recording process. Next, the laser beam 143 is divided into laser beams having an appropriate intensity ratio by the beam splitter 102. Here, it is divided into a fifth laser beam 143a and a sixth laser beam 143b. The wavelength of the laser beam 143 is the same as the wavelength of the laser beam 142 or shorter than the wavelength of the laser beam 142.

  Then, the fifth laser beam 143a is blocked by the shutter 141a. The sixth laser beam 143b is expanded into the seventh laser beam 143c and the eighth laser beam 143d by the beam splitter 133 after the scale of the beam spot of the sixth laser beam 143b is expanded by the expansion optical system 104. Divided. The seventh laser beam 143c is blocked by the shutter 141b. The eighth laser beam 143d is incident on the hologram recording medium 111b as the reproduction reference beam 127 after the traveling direction is changed by the mirrors 134, 126, and 135.

  The reproduction reference light 127 incident on the hologram recording medium 111b is diffracted by the interference fringes formed on the hologram recording medium 111b, and a part of the reproduction reference light 127 becomes reproduction light 128 on the resist 130 provided on the element formation substrate 129. Incident. Here, a resist 130 is arranged on the stage 112, and a hologram recording medium 111b on which interference fringes are formed is arranged on the stage 113.

The reproduction reference beam 127 is incident on the hologram recording medium 111b from the opposite direction to the reference beam 110 shown in FIG. 15, and the resist 130 is disposed at the position where the mask original plate 108 shown in FIG.
In the recording process, the shutters 141a and 141b are in an open state (a state in which laser light is not blocked), and a shutter 141c is in a closed state (a state in which laser light is blocked).

As described above, by providing the shutters 141a to 141c, in the exposure method using holography, the recording process and the reproduction process can be performed using the same laser oscillator and exposure apparatus. In this embodiment, in the recording process and the reproducing process, the mask original and the resist are arranged on the same stage, and the position where the hologram recording medium 111b is arranged does not change. It becomes possible to reduce the influence of undulation and unevenness on the exposed object.
Note that this embodiment can be freely combined with any of the other embodiments in this specification.

(Embodiment 5)
In this embodiment, a method for manufacturing a semiconductor device using the exposure method described in the above embodiment will be described with reference to drawings. Note that in this embodiment, a static random access memory (SRAM) cell having six transistors is described as an example, but the present invention is not limited to this.

  The SRAM shown in this embodiment includes inverters 301 and 302, and inputs of the inverters 301 and 302 are connected to bit lines BL1 and BL2 via switches S1 and S2, respectively (FIG. 7). ). The switches S1 and S2 are controlled by a row selection signal transmitted through the word line WL. Each inverter 301, 302 is powered by a high voltage VDD and a low voltage GND which is generally grounded. In order to write information in the memory cell, the voltage VDD is applied to one of the bit lines BL1 and BL2, and the voltage GND is applied to the other of the bit lines BL1 and BL2.

  Inverter 301 includes an n-channel transistor N1 and a p-channel transistor P1 connected in series. The source of the p-channel transistor P1 is connected to the voltage VDD, and the source of the n-channel transistor N1 is connected to the voltage GND. The drain of the p-channel transistor P1 and the drain of the n-channel transistor N1 are connected, and the gate of the p-channel transistor P1 and the gate of the n-channel transistor N1 are connected.

  Similarly, the inverter 302 includes a p-channel transistor P2 and an n-channel transistor N2 connected like a p-channel transistor P1 and an n-channel transistor N1, and the p-channel transistor P2 and the n-channel transistor N2 are connected to each other. The drain is connected, and the gate of the p-channel transistor P2 and the gate of the n-channel N2 are connected.

  In the operation of the SRAM shown in FIG. 7, the switches S1 and S2 are turned on, and the input and output states of the inverters 301 and 302 are set. Next, the switches S1 and S2 are turned off, and the signal states in the inverters 301 and 302 are maintained. In order to read information from the memory cell, each bit line BL1, BL2 is precharged to a voltage range between the voltages VDD and GND. The switches S1 and S2 are turned on, and the voltage on the bit line changes based on the signal state of the inverters 301 and 302. Data stored in the memory cell is read by the sense amplifier connected to the bit line.

  An example of the circuit arrangement of the SRAM shown in FIG. 7 is shown in FIG. FIG. 8 shows an SRAM formed of a semiconductor film and two wiring layers including a gate wiring layer. When the semiconductor film 408b in which the n-channel transistor is formed and the semiconductor film 408a in which the p-channel transistor is formed are disposed in the lower layer, the first wiring layers 456 and 458 are disposed on the upper layer via an insulating film. 460 is arranged.

  The first wiring layer 456 is a layer for forming a gate electrode, and an n-channel transistor N1 and a p-channel transistor P1 are formed crossing the semiconductor films 408b and 408a. The first wiring layer 458 is a layer for forming a gate electrode, and an n-channel transistor N2 and a p-channel transistor P2 are formed crossing the semiconductor films 408b and 408a. The first wiring layer 460 is a word line (WL), and switches S1 and S2 are formed crossing the semiconductor film 408b. The first wiring layers 456, 458, and 460 have such a relationship with the semiconductor films 408b and 408a, and form gate electrodes.

  The second wiring layers 462, 432b, 432c, and 464 are formed with the first wiring layers 456, 458, and 460 through an insulating layer. The second wiring layer 462 forms a bit line (BL1), the second wiring layer 464 forms a bit line (BL2), the second wiring layer 432b forms a power supply line (VDD), and the second wiring layer 432c forms a ground potential line (GND). is doing.

  The contact hole C1 is an opening formed in the insulating layer and connects the second wiring layer 462 and the semiconductor film 408b. The contact hole C2 is an opening formed in the insulating layer, and connects the second wiring layer 464 and the semiconductor film 408b. The contact hole C3 is an opening formed in the insulating layer and connects the conductive film 431a forming the second wiring layer and the semiconductor film 408b. The contact hole C4 is an opening formed in the insulating layer, and connects the conductive film 431a forming the second wiring layer and the semiconductor film 408a. The contact hole C5 is an opening formed in the insulating layer, and connects the second wiring layer 432d and the semiconductor film 408b. The contact hole C6 is an opening formed in the insulating layer, and connects the second wiring layer 432d and the semiconductor film 408a.

  Further, the contact hole C7 is an opening formed in the insulating layer, and connects the second wiring layer 432b and the semiconductor film 408a. The contact hole C8 is an opening formed in the insulating layer and connects the second wiring layer 432c and the semiconductor film 408b. The contact hole C9 is an opening formed in the insulating layer, and connects the conductive film 431a forming the second wiring layer and the first wiring layer 458. The contact hole C10 is an opening formed in the insulating layer, and connects the second wiring layer 432d and the first wiring layer 456. In this way, the SRAM shown in FIG. 8 is formed by the contact holes C1 to C10 connecting the semiconductor film and the first wiring layer and the second wiring layer.

Next, a manufacturing process of such an SRAM will be described with reference to FIG. 9, which is a cross-sectional view corresponding to line AB (p-channel transistor P1 and n-channel transistor N2) shown in FIG.
First, the semiconductor film 403 is formed over the substrate 401 with the insulating film 402 functioning as a base film, and the resist 404 is formed over the semiconductor film 403 (FIG. 9A).

  The substrate 401 is selected from a glass substrate, a quartz substrate, a metal substrate (for example, a ceramic substrate or a stainless steel substrate), and a semiconductor substrate such as a Si substrate. In addition, a substrate such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyethersulfone (PES), or acrylic can be selected as the plastic substrate.

The insulating film 402 is formed using silicon oxide, silicon nitride, silicon oxynitride (SiO _x N _y ) (x>y> 0), silicon nitride oxide (SiN _x O _y ) (x>) by a CVD method, a sputtering method, or the like. It is formed using an insulating material such as y> 0). For example, in the case where the insulating film 402 has a two-layer structure, a silicon nitride oxide film may be formed as the first insulating film and a silicon oxynitride film may be formed as the second insulating film. Alternatively, a silicon nitride film may be formed as the first insulating film, and a silicon oxide film may be formed as the second insulating film.

  In this manner, by forming the insulating film 402 functioning as a blocking layer, alkali metal such as Na or alkaline earth metal from the substrate 401 can be prevented from adversely affecting the element formed thereon. Note that the insulating film 402 may be omitted when quartz is used for the substrate 401.

  The semiconductor film 403 is preferably formed using a crystalline semiconductor film. The crystalline semiconductor film is obtained by crystallizing an amorphous semiconductor film formed over the insulating film 402 by heat treatment or laser light irradiation, or after amorphizing the crystalline semiconductor film formed over the insulating film 402. , Recrystallized materials, and the like.

When crystallization or recrystallization is performed by laser light irradiation, an LD-excited continuous wave (CW) laser (YVO ₄ , second harmonic (wavelength 532 nm)) can be used as a laser light source. The second harmonic is not particularly limited to the second harmonic, but the second harmonic is superior to higher harmonics in terms of energy efficiency. When the semiconductor film is irradiated with the CW laser, energy is continuously given to the semiconductor film. Therefore, once the semiconductor film is in a molten state, the molten state can be continued. Furthermore, the solid-liquid interface of the semiconductor film can be moved by scanning with a CW laser, and crystal grains that are long in one direction can be formed along the direction of this movement.

  The solid laser is used because the output stability is higher than that of a gas laser or the like, and stable processing is expected. Note that not only the CW laser but also a pulse laser having a repetition frequency of 10 MHz or more can be used. If a pulse laser with a high repetition frequency is used, the semiconductor film can always remain in a molten state if the laser pulse interval is shorter than the time from when the semiconductor film melts until it solidifies. A semiconductor film including crystal grains that are long in one direction can be formed.

Other CW lasers and pulse lasers with a repetition frequency of 10 MHz or more can also be used. For example, examples of the gas laser include an Ar laser, a Kr laser, and a CO ₂ laser. Examples of the solid-state laser include a YAG laser, a YLF laser, a YAlO ₃ laser, a GdVO ₄ laser, a KGW laser, a KYW laser, an alexandrite laser, a Ti: sapphire laser, a Y ₂ O ₃ laser, and a YVO ₄ laser.

In addition, there are ceramic lasers such as YAG laser, Y ₂ O ₃ laser, GdVO ₄ laser, and YVO ₄ laser. Examples of the metal vapor laser include a helium cadmium laser. In the laser oscillator, it is preferable to emit laser light in TEM ₀₀ (single transverse mode) because the energy uniformity of the linear beam spot obtained on the irradiated surface can be increased. In addition, a pulsed excimer laser may be used.

  As the resist 404, a composition containing a photosensitive agent may be used. Both a negative type (a photoresist in which an exposed portion remains as a pattern after development) and a positive type (a photoresist in which an unexposed portion remains as a pattern after development) are used. Is possible. In the present embodiment, a case where a negative resist is used is shown.

  Next, the resist 404 is selectively removed by exposing and etching the resist 404 through a mask in which a light-shielding metal 406 is selectively provided over the light-transmitting film 405. A resist pattern is formed. Then, the semiconductor film 403 not covered with the resist pattern is selectively removed, so that an island-shaped semiconductor film is formed (FIG. 9B). Here, resists 407a and 407b are formed by selectively removing the resist 404, and island-shaped semiconductor films 408a and 408b are formed by selectively removing the semiconductor film 403 not covered with the resists 407a and 407b. The example which formed is shown. Here, the resist 404 is exposed using an exposure method such as a stepper or MPA.

Next, a conductive film 410 is formed through the gate insulating film 409 so as to cover the island-shaped semiconductor films 408a and 408b, and a resist 411 is formed over the conductive film 410 (FIG. 9C).
For the gate insulating film 409, silicon oxide, silicon nitride, silicon oxynitride (SiO _x N _y ) (x>y> 0), silicon nitride oxide (SiN _x O _y ) (x>y> 0), or the like is used. Such an insulating layer is formed by a vapor deposition method or a sputtering method.

Further, the semiconductor films 408a and 408b are formed in an oxygen atmosphere (eg, oxygen (O ₂ ) and a rare gas (including at least one of He, Ne, Ar, Kr, and Xe) atmosphere, or oxygen and hydrogen (H ₂ ). And a rare gas atmosphere) or a nitrogen atmosphere (for example, a nitrogen (N ₂ ) and rare gas (including at least one of He, Ne, Ar, Kr, and Xe) atmosphere, or a nitrogen, hydrogen, and rare gas atmosphere Alternatively, the gate insulating film 409 can be formed by subjecting the surfaces of the semiconductor films 408a and 408b to oxidation treatment or nitridation treatment with high-density plasma treatment in an atmosphere of NH ₃ and a rare gas. By forming the gate insulating film 409 by performing oxidation treatment or nitridation treatment on the surfaces of the semiconductor films 408a and 408b by high-density plasma treatment, the density of defect states serving as traps for electrons and holes can be reduced.

  The conductive film 410 is formed using other refractory metal such as tungsten, molybdenum, titanium, tantalum, chromium, niobium, or the like. Alternatively, an alloy of the above metals such as an alloy of molybdenum and tungsten, titanium nitride, or tungsten nitride, or a conductive metal nitride or conductive oxide may be used. And it can form with the laminated structure of a tantalum nitride and tungsten. Alternatively, polysilicon doped with an impurity element such as phosphorus may be used.

  Next, after selectively exposing the resist 411 using the hologram recording medium 412, the resist 411 is etched and selectively removed to form a resist pattern. Then, the conductive film 410 which is not covered with the resist pattern is selectively removed, so that a conductive film to be a gate electrode is formed (FIG. 10A). Here, resists 413a and 413b are formed by selectively removing the resist 411, and gate electrodes 414a and 414b are formed by selectively removing the conductive film 410 not covered with the resists 413a and 413b. An example is shown.

  The resists 413a and 413b used in forming the conductive films to be the gate electrodes 414a and 414b in FIG. 10A are formed by using an exposure method using holography for the resist 411. Specifically, an interference fringe is formed on the hologram recording means using any one of the recording steps shown in the above embodiment, and the hologram recording means (hologram recording medium 412) on which the interference fringe is formed is used. Exposure is performed by irradiating the resist 411 with laser light. Note that the laser beam applied to the resist 411 obtains a pattern having a finer structure than the pattern formed on the mask original plate by using the harmonics of the laser beam used in the recording process for forming the interference fringes on the hologram recording medium 412. It is also possible.

  Next, using the gate electrodes 414a and 414b and the resists 413a and 413b or the gate electrodes 414a and 414b as masks, an impurity element imparting N-type conductivity is added to the semiconductor films 408a and 408b at a low concentration, and the low-concentration impurity regions 415 are added. Form. After that, a resist 416 is selectively formed over the semiconductor film 408b and the gate electrode 414b, and a high-concentration impurity element imparting p-type conductivity is selectively added to the semiconductor film 408a using the gate electrode 414a as a mask (FIG. 10). (B)). Through this step, a channel region is formed in the region of the semiconductor film 408a located below the gate electrode 414a, and a P-type high-concentration impurity region 417 serving as a source region or a drain region is formed in other regions.

  Next, after the resist 416 is removed, an insulating film is formed so as to cover the gate insulating film 409, the gate electrode 414a, and the gate electrode 414b. The insulating film is formed by a single layer or a stack of layers including an inorganic material of silicon, silicon oxide, or silicon nitride, or a layer including an organic material such as an organic resin, by a CVD method, a sputtering method, or the like. . After the formation, the insulating layer is selectively etched by anisotropic etching mainly in the vertical direction to form an insulating film 418 (also referred to as a sidewall) in contact with the side surfaces of the gate electrode 414a and the gate electrode 414b.

  After that, a resist 419 is selectively formed above the semiconductor film 408a and the gate electrode 414a, and a high concentration that imparts N-type to the semiconductor film 408b using the insulating film 418 in contact with the side surfaces of the gate electrode 414b and the gate electrode 414b as a mask. An impurity element is selectively added (FIG. 10C). Through this step, a channel region is formed in the region of the semiconductor film 408b located below the gate electrode 414b, and a low-concentration impurity region (also referred to as an LDD region) indicating N-type is formed in the region of the semiconductor film 408b located below the insulating film 418. N-type high concentration impurity region 420 to be a source region or a drain region is formed in other regions.

  Next, an insulating film is formed so as to cover the semiconductor films 408a and 408b and the gate electrodes 414a and 414b, and then a resist is formed over the insulating film (FIG. 11A). Here, a case is shown in which a resist 423 is formed over the insulating film 422 after the insulating film 421 and the insulating film 422 are stacked as the insulating film.

The insulating films 421 and 422 are formed by a CVD method, a sputtering method, or the like, and include silicon oxide, silicon oxynitride (SiO _x N _y ) (x>y> 0), and silicon nitride oxide (SiN _x O _y ) (x> y > 0) and the like can be used. Alternatively, a single layer or a stacked structure including an organic material such as polyimide, polyamide, polyvinylphenol, benzocyclobutene, acrylic, or epoxy, a siloxane material such as a siloxane resin, or an oxazole resin can be used.

  Note that the siloxane material corresponds to a material including a Si—O—Si bond. Siloxane has a skeleton structure formed of a bond of silicon (Si) and oxygen (O). As a substituent, an organic group containing at least hydrogen (for example, an alkyl group or an aromatic hydrocarbon) is used. A fluoro group can also be used as a substituent. Alternatively, an organic group containing at least hydrogen and a fluoro group may be used as a substituent.

  The oxazole resin is, for example, photosensitive polybenzoxazole. Photosensitive polybenzoxazole has a low dielectric constant (dielectric constant 2.9 at room temperature of 1 MHz) and high heat resistance (TG / DTA: Thermogravimetry-Differential Thermal Analysis) and heat at a temperature of 5 ° C./min. Decomposition temperature 550 ° C.) and low water absorption (0.3% at normal temperature 24 hours). Oxazole resin has a low relative dielectric constant (about 2.9) compared to the relative dielectric constant (about 3.2 to 3.4) of polyimide, etc., so that the generation of parasitic capacitance is suppressed and high speed operation is performed. Can do.

Here, as the insulating film 421, silicon oxide, silicon oxynitride (SiO _x N _y ) (x>y> 0), or silicon nitride oxide (SiN _x O _y ) (x>y> 0) is used by a CVD method. The insulating film 422 is formed using an organic material such as polyimide, polyamide, polyvinylphenol, benzocyclobutene, acrylic, or epoxy, a siloxane material such as a siloxane resin, or an oxazole resin.

  Next, the resist 423 is selectively irradiated with laser light through the hologram recording medium 424. Thereafter, the resist 423 is etched and selectively removed to form a resist pattern. Then, the insulating films 421 and 422 not covered with the resist pattern are selectively removed to expose the semiconductor films 408a and 408b (FIG. 11B). Here, resists 425a to 425e are formed by selectively removing the resist 423, and the insulating films 421 and 422 that are not covered with the resists 425a to 425e are selectively removed to form contact holes 426a to 425a. An example in which 426d is formed is shown.

  A contact hole having a smaller diameter than the mask original plate can be formed by reduced exposure using holography. As a result, the distance between the contact holes 426a to 426d can be reduced, and the degree of integration can be improved.

  In the manufacturing process, the swell of the substrate may differ depending on the process (for example, before and after the formation of the conductive film). In this case, since the maximum height difference on the surface of the object to be exposed differs, it is preferable to change the thickness of the light shielding film of the mask original used for forming the interference fringes on the hologram recording means according to the process.

Next, after removing the resists 425a to 425e, a conductive film 427 is formed over the insulating film 422 and the contact holes 426a to 426d, and a resist 428 is formed over the conductive film 427 (FIG. 11C). .
The conductive film 427 can have a single-layer structure or a stacked structure formed using one kind of element selected from aluminum, tungsten, titanium, tantalum, molybdenum, nickel, and neodymium, or an alloy containing a plurality of such elements.

  For example, the conductive film formed using an alloy containing a plurality of the elements can be formed using an aluminum alloy containing titanium, an aluminum alloy containing neodymium, or the like. Further, in the case of providing a stacked structure, for example, an aluminum layer or an aluminum alloy layer as described above may be stacked between titanium layers. Here, the conductive film 431b forms a power supply line (VDD), and the conductive film 431c forms a ground potential line (GND).

  Next, the resist 428 is irradiated with laser light through the hologram recording medium 429, and then the resist 428 is etched and selectively removed to form a resist pattern. Then, the conductive film 427 that is not covered with the resist pattern is selectively removed, so that a conductive film to be a source electrode or a drain electrode is formed (FIG. 12A). Here, the resist 428 is selectively removed to form resists 430a to 430d, and the conductive film 427 that is not covered with the resists 430a to 430d is selectively removed to be a conductive film that becomes a source electrode or a drain electrode. An example in which films 431a to 431d are formed is shown.

  Then, by removing the resists 430a to 430d, a transistor can be formed. As described above, in the manufacturing process of the semiconductor device, by applying the exposure method using the holography described in the first to fourth embodiments, even when combining with different exposure methods, a fine pattern is formed. In addition, alignment can be performed with high accuracy.

In this embodiment mode, an exposure method using holography is applied when forming a gate electrode, a contact hole, or a source electrode or a drain electrode. However, the present invention is not limited to this, and an island-shaped semiconductor is used. An exposure method using holography may be applied in all steps such as a film formation step, or an exposure method using holography may be applied only to the step of forming a gate electrode. That is, in the manufacturing process of a semiconductor device, an exposure method using holography may be applied in at least one step.
Note that this embodiment can be freely combined with any of the other embodiments in this specification. For example, instead of the exposure method shown in the present embodiment, total reflection holography may be used.

(Embodiment 6)
In this embodiment, an example of usage of a semiconductor device obtained using the manufacturing method described in Embodiment 5 will be described. Specifically, application examples of a semiconductor device capable of inputting and outputting data without contact will be described below with reference to the drawings. A semiconductor device in which data can be input / output without contact is also referred to as an RFID tag, an ID tag, an IC tag, an IC chip, an RF tag, a wireless tag, an electronic tag, or a wireless chip depending on the application.

  The semiconductor device 80 has a function of communicating data without contact, and controls the high frequency circuit 81, the power supply circuit 82, the reset circuit 83, the clock generation circuit 84, the data demodulation circuit 85, the data modulation circuit 86, and other circuits. A control circuit 87, a memory circuit 88, and an antenna 89 are provided (FIG. 13A). The high frequency circuit 81 is a circuit that receives a signal from the antenna 89 and outputs the signal received from the data modulation circuit 86 from the antenna 89, and the power supply circuit 82 is a circuit that generates a power supply potential from the received signal, and a reset circuit 83. Is a circuit that generates a reset signal, a clock generation circuit 84 is a circuit that generates various clock signals based on the reception signal input from the antenna 89, and a data demodulation circuit 85 demodulates the reception signal to control the control circuit 87. The data modulation circuit 86 is a circuit that modulates the signal received from the control circuit 87.

  Further, as the control circuit 87, for example, a code extraction circuit 91, a code determination circuit 92, a CRC determination circuit 93, and an output unit circuit 94 are provided. The code extraction circuit 91 is a circuit that extracts a plurality of codes included in an instruction sent to the control circuit 87, and the code determination circuit 92 compares the extracted code with a code corresponding to a reference. The CRC determination circuit 93 is a circuit that detects the presence or absence of a transmission error or the like based on the determined code.

  In FIG. 13A, in addition to the control circuit 87, a high frequency circuit 81 and a power supply circuit 82 which are analog circuits are included. Even in such a circuit, as described in the above embodiment, an exposure method using holography can be used. By using such an exposure method, the size of the transistor can be reduced, so that the chip size can be reduced even when a glass substrate or the like with low flatness is used.

  Next, an example of operation of the above-described semiconductor device will be described. First, a radio signal is received by the antenna 89. The radio signal is sent to the power supply circuit 82 via the high frequency circuit 81, and a high power supply potential (hereinafter referred to as VDD) is generated. VDD is supplied to each circuit included in the semiconductor device 80. The signal sent to the data demodulation circuit 85 via the high frequency circuit 81 is demodulated (hereinafter, demodulated signal). Further, the signal and the demodulated signal that have passed through the reset circuit 83 and the clock generation circuit 84 via the high frequency circuit 81 are sent to the control circuit 87. The signal sent to the control circuit 87 is analyzed by the code extraction circuit 91, the code determination circuit 92, the CRC determination circuit 93, and the like.

  Then, information on the semiconductor device stored in the memory circuit 88 is output in accordance with the analyzed signal. The output semiconductor device information is encoded through the output unit circuit 94. Further, the encoded information of the semiconductor device 80 passes through the data modulation circuit 86 and is transmitted on the radio signal by the antenna 89. Note that in a plurality of circuits included in the semiconductor device 80, a low power supply potential (hereinafter referred to as VSS) is common and VSS can be GND.

As described above, by transmitting a signal from the reader / writer to the semiconductor device 80 and receiving the signal transmitted from the semiconductor device 80 by the reader / writer, the data of the semiconductor device can be read.
The semiconductor device 80 may be of a type in which supply of power supply voltage to each circuit is performed by electromagnetic waves without mounting a power supply (battery), or each circuit is mounted by using electromagnetic waves and a power supply (battery). It is good also as a type which supplies a power supply voltage to.

  Next, an example of a usage pattern of a semiconductor device capable of inputting and outputting data without contact will be described. A reader / writer 3200 is provided on a side surface of the portable terminal including the display portion 3210, and a semiconductor device 3230 is provided on a side surface of the article 3220 (FIG. 13B). When the reader / writer 3200 is held over the semiconductor device 3230 included in the product 3220, information about the product such as the description of the product, such as the raw material and origin of the product, the inspection result for each production process and the history of the distribution process, is displayed on the display unit 3210. Is done.

  Further, when the product 3260 is conveyed by a belt conveyor, the product 3260 can be inspected using the reader / writer 3240 and the semiconductor device 3250 provided in the product 3260 (FIG. 13C). In this manner, by using a semiconductor device in the system, information can be easily acquired, and high functionality and high added value are realized.

  In addition to the above, the semiconductor device manufactured by using the exposure method of the present invention has a wide range of uses, and any product that can be used for production, management, etc. without clarification of information such as the history of an object without contact. It can also be applied to such things. For example, banknotes, coins, securities, certificate documents, bearer bonds, packaging containers, books, recording media, personal belongings, vehicles, foods, clothing, health supplies, daily necessities, medicines, etc. It can be provided and used in an electronic device or the like. These examples will be described with reference to FIG.

  Banknotes and coins are money that circulates in the market, and include those that are used in the same way as money in a specific area (cash vouchers), commemorative coins, and the like. Securities refer to checks, securities, promissory notes, etc. (FIG. 14A). The certificate refers to a driver's license, resident's card, etc. (FIG. 14B). Bearer bonds refer to stamps, gift tickets, various gift certificates, etc. (FIG. 14C). Packaging containers refer to wrapping paper for lunch boxes, plastic bottles, and the like (FIG. 14D). Books refer to books, books, and the like (FIG. 14E).

  Further, the recording medium refers to DVD software, video tape, and the like (FIG. 14F). Vehicles refer to vehicles such as bicycles, ships, and the like (FIG. 14G). Personal belongings refer to bags, glasses, and the like (FIG. 14H). Food refers to food, beverages, and the like. Clothing refers to clothing, footwear, and the like. Health supplies refer to medical equipment, health equipment, and the like. Livingware refers to furniture, lighting equipment, and the like. Chemicals refer to pharmaceuticals, agricultural chemicals, etc. Electronic devices refer to liquid crystal display devices, EL display devices, television devices (television receivers, flat-screen television receivers), cellular phones, and the like.

  Forgery can be prevented by providing the semiconductor device 80 on bills, coins, securities, certificates, bearer bonds, and the like. In addition, by providing semiconductor devices 80 for personal items such as packaging containers, books, recording media, personal items, foods, daily necessities, electronic devices, etc., the efficiency of inspection systems and rental store systems will be improved. Can do. By providing the semiconductor device 80 in vehicles, health supplies, medicines, etc., it is possible to prevent forgery and theft, and in the case of medicines, it is possible to prevent mistakes in taking medicine.

  The semiconductor device 80 is provided by being attached to the surface of the article or embedded in the article. For example, a book may be embedded in paper, and a package made of an organic resin may be embedded in the organic resin. In addition, even when a semiconductor device is provided on paper or the like, damage to an element included in the semiconductor device can be prevented by providing the semiconductor device by miniaturization using the exposure method described in the above embodiment mode. can do.

In this way, by providing semiconductor devices in packaging containers, recording media, personal items, foods, clothing, daily necessities, electronic devices, etc., it is possible to improve the efficiency of inspection systems and rental store systems. it can. Further, forgery or theft can be prevented by providing a semiconductor device in the vehicles. Moreover, by embedding it in creatures such as animals, it is possible to easily identify individual creatures. For example, by embedding a semiconductor device equipped with a sensor in a living creature such as livestock, it is possible to easily manage health conditions such as body temperature as well as the year of birth, gender or type.
Note that this embodiment can be freely combined with any of the other embodiments in this specification.

The figure which shows an example of the exposure method of this invention. The figure which shows an example of the exposure method of this invention. The figure which shows an example of the exposure method of this invention. The figure which shows an example of the exposure method of this invention. The figure which shows an example of the exposure method of this invention. The figure which shows an example of the exposure method of this invention. 8A and 8B illustrate an example of a method for manufacturing a semiconductor device using the exposure method of the present invention. 8A and 8B illustrate an example of a method for manufacturing a semiconductor device using the exposure method of the present invention. 8A and 8B illustrate an example of a method for manufacturing a semiconductor device using the exposure method of the present invention. 8A and 8B illustrate an example of a method for manufacturing a semiconductor device using the exposure method of the present invention. 8A and 8B illustrate an example of a method for manufacturing a semiconductor device using the exposure method of the present invention. 8A and 8B illustrate an example of a method for manufacturing a semiconductor device using the exposure method of the present invention. FIG. 6 shows an example of a usage pattern of a semiconductor device manufactured by using the exposure method of the present invention. FIG. 6 shows an example of a usage pattern of a semiconductor device manufactured by using the exposure method of the present invention. The figure which shows an example of the exposure method of this invention. The figure which shows an example of the exposure method of this invention. The figure which shows an example of the exposure method of this invention.

Explanation of symbols

80 Semiconductor Device 81 High Frequency Circuit 82 Power Supply Circuit 83 Reset Circuit 84 Clock Generation Circuit 85 Data Demodulation Circuit 86 Data Modulation Circuit 87 Control Circuit 88 Memory Circuit 89 Antenna 91 Code Extraction Circuit 92 Code Determination Circuit 93 CRC Determination Circuit 94 Output Unit Circuit 101 Laser Oscillator 102 Beam splitter 103 Mirror 104 Magnifying optical system 105 Magnifying optical system 106 Mirror 108 Mask original plate 109 Object light 110 Reference light 111a Hologram recording means 111b Hologram recording medium 112 Stage 113 Stage 121 Laser oscillator 122 Non-linear optical element 123 Mirror 124 Enlarging optical system 125 mirror 126 mirror 127 reproduction reference beam 128 reproduction beam 129 element forming substrate 130 resist 131 laser beam 132 prism 133 beam spring Mirror 134 Mirror 140 Laser beam 142 Laser beam 143 Laser beam 301 Inverter 302 Inverter 401 Substrate 402 Insulating film 403 Semiconductor film 404 Resist 405 Film 406 Metal 409 Gate insulating film 410 Conductive film 411 Resist 412 Hologram recording medium 415 Impurity region 416 Resist 417 High concentration impurity region 418 Insulating film 419 Resist 420 High concentration impurity region 421 Insulating film 422 Insulating film 423 Resist 424 Hologram recording medium 427 Conductive film 428 Resist 429 Hologram recording medium 456 Wiring layer 458 Wiring layer 460 Wiring layer 462 Wiring layer 464 Wiring layer 108a Substrate 108b Light shielding film 112a Stage 112b Stage 113a Stage 113b Stage 114a Laser light 114b Laser light 1 2a Nonlinear Optical Element 122b Nonlinear Optical Element 125a Mirror 125b Mirror 141a Shutter 141b Shutter 141c Shutter 142a Laser Light 142b Laser Light 142c Laser Light 142d Laser Light 143a Laser Light 143b Laser Light 143c Laser Light 143d Laser Light 3200 Reader / Writer 3210 Display Unit 3220 Product 3230 Semiconductor device 3240 Reader / writer 3250 Semiconductor device 3260 Product 407a Resist 408a Semiconductor film 408b Semiconductor film 413a Resist 414a Gate electrode 414b Gate electrode 425a Resist 426a Contact hole 426b Contact hole 426c Contact hole 426d Contact hole 430a Resist 431a Conductive film 431b Conductive film 431b film 31c conductive film 432b wiring layer 432c wiring layer 432d wiring layer

Claims (15)

Splitting the laser beam oscillated from the first laser oscillator to form a first laser beam and a second laser beam;
A hologram recording medium is formed by irradiating the hologram recording means with the first laser light through a mask original plate and simultaneously irradiating the hologram recording means with the second laser light to form interference fringes on the hologram recording means. Form the
Irradiating a resist formed on the element formation substrate with a third laser beam oscillated from a second laser oscillator via the hologram recording medium,
An exposure method comprising using as the mask original plate a light-transmitting substrate provided with a light-shielding film having a film thickness equal to or greater than the maximum height difference of the resist surface on a translucent substrate. In claim 1,
An exposure method using an organic substance containing a metal material, emulsion, silicon, iron oxide, molybdenum silicide, pigment or dye as the light shielding film. In claim 2,
An exposure method using chromium as the metal material. In any one of Claims 1 thru | or 3,
Irradiation of the third laser beam to the resist is
An exposure method comprising irradiating the resist using an autofocus that automatically adjusts the focus of the third laser light on the resist surface by making the shape of the third laser light linear. In any one of Claims 1 thru | or 4,
An exposure method, wherein a wavelength of the third laser light is shorter than wavelengths of the first laser light and the second laser light. In any one of Claims 1 thru | or 5,
An exposure method using a solid laser oscillator as the first laser oscillator and the second laser oscillator. In any one of Claims 1 thru | or 6,
An exposure method, wherein a thickness of the light shielding film is 0.3 μm or more and 10 μm or less. Splitting the laser beam oscillated from the first laser oscillator to form a first laser beam and a second laser beam;
By irradiating the hologram recording means with the first laser light through the mask original plate and simultaneously irradiating the hologram recording means with the second laser light, through the hologram recording means in which interference fringes are formed, A hologram recording medium that irradiates a resist formed on an element forming substrate with a third laser beam,
The hologram recording medium, wherein the interference fringes are formed using the mask original plate provided with a light-shielding film having a film thickness equal to or greater than a maximum height difference of the resist surface on a translucent substrate. . In claim 8,
The hologram recording medium according to claim 1, wherein the light shielding film is an organic material containing a metal material, an emulsion, silicon, iron oxide, molybdenum silicide, or a pigment or dye. In claim 9,
A hologram recording medium, wherein the metal material is chromium. In any one of Claims 8 to 10,
A hologram recording medium, wherein the light-shielding film has a thickness of 0.3 to 10 μm. Splitting the laser beam oscillated from the first laser oscillator to form a first laser beam and a second laser beam;
By irradiating the hologram recording means with the first laser light through the mask original plate and simultaneously irradiating the hologram recording means with the second laser light, through the hologram recording means in which interference fringes are formed, A method of manufacturing a hologram recording medium in which a third laser beam is irradiated onto a resist formed on an element forming substrate, wherein the interference fringes are formed on a substrate having translucency and have a difference in height of a maximum height of the resist surface or more. A method for producing a hologram recording medium, comprising forming the mask original plate including a light-shielding film having a film thickness. In claim 12,
A method for producing a hologram recording medium, wherein a metal material, emulsion, silicon, iron oxide, molybdenum silicide, or an organic substance containing a pigment or dye is used as the light-shielding film. In claim 13,
A method for manufacturing a hologram recording medium, wherein chromium is used as the metal material. 15. In any one of claims 12 to 14,
A method for manufacturing a hologram recording medium, wherein the thickness of the light-shielding film is 0.3 μm or more and 10 μm or less.

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