JP4810496B2 - Pattern forming apparatus, pattern forming method, and template - Google Patents

Description

  The present invention relates to a pattern forming apparatus, a pattern forming method, and a template.

  With the miniaturization and high integration of semiconductor integrated circuits, there has been a drawback that high precision of a photolithography apparatus is required as a pattern transfer technique for realizing fine processing, resulting in high apparatus cost.

  On the other hand, an optical nanoimprint method (SFIL: step and flash imprint lithography) has been proposed as a technique for performing fine pattern formation at low cost (see, for example, Patent Document 1). This is to press a stamper (template) having the same unevenness as the pattern to be formed on the substrate against the liquid photocurable organic material layer applied to the surface of the substrate to be transferred, and hold it until the organic material is spread in the uneven pattern. Thereafter, the pattern is transferred to the resist layer by irradiating light to cure the organic material layer and separating (releasing) the template from the organic material layer.

  If the holding time from when the template is pressed against the substrate surface until light irradiation is short, the organic material is insufficiently filled in the concavo-convex pattern, and the shape accuracy of the transferred pattern is lowered. When a process such as etching is performed using such a pattern as a resist, problems such as abnormalities in the processing shape occur.

As the holding time is increased, the organic material is sufficiently filled in the concavo-convex pattern, but there is a problem that the throughput is reduced accordingly.
JP 2001-68411 A

  An object of the present invention is to provide a pattern forming method and a pattern forming apparatus that optimize the filling time of an organic material into a template, have no defective filling of the organic material, and have a high throughput.

  A pattern forming apparatus according to an aspect of the present invention includes a wafer substrate support that holds a wafer substrate coated with an organic material on a surface, a predetermined uneven pattern formed on one surface, and information on the uneven pattern is described. A template holding unit that holds the light-transmitting template, a sensor that reads and outputs information on the concavo-convex pattern, and the template holding unit is driven based on a drive control signal, and the template holding unit holds the template holding unit. Based on the light irradiation control signal, the driving unit that contacts the organic material applied to the wafer substrate surface with the template, and the template held by the template holding unit is irradiated with light from the other surface side of the template. Information on the concavo-convex pattern output from the sensor that outputs the drive control signal and the light source Based, in which and a control unit that the template outputs said light irradiation control signal to the light source after contacting the organic material after a predetermined period of time is irradiated with light.

  In addition, a pattern forming apparatus according to an aspect of the present invention includes a wafer substrate support that holds a wafer substrate coated with an organic material on a surface, and a template having a predetermined uneven pattern formed on one surface and having light transmittance. A template holding unit for holding, driving the template holding unit based on a drive control signal, and a drive unit for bringing the template held in the template holding unit into contact with the organic material applied to the wafer substrate surface; Irradiating the template with light that does not cure the organic material, receiving reflected light, and outputting a received light intensity, and based on a light irradiation control signal, the template held in the template holding unit, A light source that emits light for curing the organic material from the other side of the template, and the drive control signal is output. Control that determines whether the received light intensity output from the filling detector is equal to or higher than a predetermined level, and outputs the light irradiation control signal so that the light source emits light when it is determined to be higher than a predetermined level A section.

  A pattern forming method according to an aspect of the present invention is a pattern forming method using a pattern forming apparatus having a wafer substrate support, a template holding unit, a sensor, a drive unit, a light source, and a control unit, and the wafer substrate support A step of holding the wafer substrate by the step, a step of reading the information of the concavo-convex pattern of the template in which a predetermined concavo-convex pattern is formed on one surface by the sensor and the light-transmitting information describes the information of the concavo-convex pattern; A step of holding the template by the template holding unit, a step of applying an organic material to the surface of the wafer substrate, a step of driving the template holding unit by the driving unit, and bringing the template into contact with the organic material; , Holding based on information of the concavo-convex pattern read by the sensor by the control unit A step of outputting a light control signal after elapse of the calculated holding time after the template contacts the organic material, and the organic material via the template based on the light control signal by the light source Irradiating with light.

  A pattern forming method according to an aspect of the present invention is a pattern forming method using a pattern forming apparatus having a wafer substrate support, a template holding unit, a driving unit, a filling detector, a light source, and a control unit, A step of holding a wafer substrate by a wafer substrate support, a step of holding a template having a predetermined concavo-convex pattern formed on one surface thereof by the template holding unit, and a light transmissive template; and an organic material on the surface of the wafer substrate A step of applying, a step of driving the template holding unit by the driving unit to bring the template into contact with the organic material, a light from which the organic material is not cured is irradiated from the filling detector to the template, and reflected light Receiving the light and outputting the received light intensity, and whether the received light intensity is a predetermined value or more by the control unit. A step of outputting a light control signal when it is determined to be equal to or greater than a predetermined value, and a step of irradiating the organic material with light that cures the organic material based on the light control signal by the light source through the template. , Are provided.

  The template according to one aspect of the present invention is a template having a first concavo-convex pattern formed on a central portion of one surface and having light transmittance, and the first concavo-convex pattern is formed on a peripheral portion of the one surface. Are provided with a second concavo-convex pattern having the same pattern width as the minimum pattern width and the maximum pattern width.

  According to the present invention, the filling time of the organic material into the template can be optimized, the filling of the organic material can be prevented, and the throughput can be increased.

  Hereinafter, a pattern forming apparatus and a pattern forming method according to embodiments of the present invention will be described with reference to the drawings.

  (First Embodiment) FIG. 1 shows a schematic configuration of a pattern forming apparatus according to a first embodiment of the present invention. The pattern forming apparatus includes a light irradiation unit 1, a barcode sensor 2, a wafer substrate support 3 that holds a wafer substrate 7, a template transport unit 4, and a control unit 5. The light irradiation unit 1 includes a chuck 1a, a lens 1b, a telescopic unit 1c, and a light source 1d.

  The chuck 1 a grips the template 6 conveyed by the template conveyance unit 4. Light emitted from the light source 1d is applied to the template 6 held by the chuck 1a through the lens 1b.

  FIG. 2 shows the upper surface of the template 6. In the central portion 6a on one surface side (wafer substrate side) of the template 6, the same uneven pattern as the pattern to be formed on the wafer substrate 7 is formed. A template ID 6c and a barcode 6d are described on the peripheral portion 6b of the template 6 on the other surface side (light irradiation portion side).

  The template ID 6c includes template information such as a template name, a maximum pattern size included in the template, a minimum pattern size, a pattern density, and a groove depth (pattern height). The bar code 6d is a bar code of this template information. The template 6 is formed of a material that transmits light emitted from the light source 1d, such as quartz glass.

  The bar code sensor 2 reads the bar code 6 d and outputs the read template information to the control unit 5.

  The control part 5 controls the expansion-contraction part 1c and the light source 1d. A photocurable organic material is applied to the surface of the wafer substrate 7 supported by the wafer substrate support 3 by an ink jet apparatus (not shown), and the expansion / contraction part 1c extends to contact the template 6 with the photocurable organic material. The

  While this contact state is maintained for a predetermined time, the concavo-convex pattern of the template 6 is filled with the photocurable organic material. Thereafter, light is irradiated from the light source 1d to cure the photocurable organic material. After the photocurable organic material is cured, the stretchable portion 1 is contracted to separate (release) the template 6 from the photocurable organic material.

  The control unit 5 stores template holding time information acquired in advance. The template holding time information is information indicating the relationship between each item of the template information (maximum pattern size and the like) and the optimum time until the concavo-convex pattern of the template 6 is filled with the photocurable organic material.

  For example, as shown in FIG. 3, as the maximum pattern (groove) size in the concavo-convex pattern increases, the time until the photocurable organic material is filled increases. The control unit 5 acquires and stores such information in advance. Then, based on the template information read by the barcode sensor 2 and the template holding time information, the time for holding the template 6, that is, filling the liquid photocurable organic material into the concavo-convex pattern is calculated.

  For example, when the read template information includes information that the maximum pattern size is 1000 nm, the holding (filling) time is 40 sec.

  After the calculated holding time has elapsed, the light source 1d is controlled to emit light.

  A cross section of a pattern forming process using this pattern forming apparatus will be described with reference to FIG.

  As shown in FIG. 4A, a liquid photocurable organic material 8 is applied onto the surface of the wafer substrate 7 supported by the wafer substrate support 3 by an ink jet apparatus (not shown). It is assumed that the template 6 whose template information has been read by the barcode sensor 2 is attached to the chuck 1a.

  As shown in FIG. 4B, the template 6 having the stretchable part 1c stretched and held by the chuck 1a is brought into contact with the photocurable organic material 8 on the surface of the wafer substrate 7.

  As shown in FIG. 4 (c), the photocurable organic material 8 is filled in the concavo-convex pattern of the template 6 while being held for a predetermined time. The holding time is calculated by the control unit 5 based on the template information read by the barcode sensor 2 and the holding time information stored in the control unit 5.

  As shown in FIG. 4 (d), after the calculated holding time has elapsed, the light curable organic material 8 is irradiated with light emitted from the light source 1d via the lens 1b and the template 6 to cause the photocurable organic material 8 to Harden.

  As shown in FIG. 4 (e), the stretchable portion 1 c is shrunk and the template 6 is separated (released) from the photocurable organic material 8. Since the photocurable organic material 8 is cured, the state (shape) when the template 6 is in contact is maintained.

  Since the holding time of the template (filling time of the photocurable organic material) is determined based on the concave / convex pattern shape of the template, poor filling of the photocurable organic material can be suppressed. Further, since the template holding time is an optimum time, it is possible to prevent a decrease in throughput.

  As described above, the pattern forming apparatus according to the present embodiment can optimize the filling time of the organic material into the template, and can increase the throughput without defective filling of the organic material.

  In the above embodiment, the relationship with the maximum pattern size is shown as an example of the template holding time information (FIG. 3). However, the relationship between the minimum pattern size, the pattern density, and the groove depth (pattern height) is acquired in advance and controlled. It may be stored in the unit 5 and the holding time may be calculated using it.

  (Second Embodiment) FIG. 5 shows a schematic configuration of a pattern forming apparatus according to a second embodiment of the present invention. The pattern forming apparatus includes a light irradiation unit 51, a wafer substrate support 52 that holds the wafer substrate 55, and a control unit 53. The light irradiation unit 51 includes a chuck 51a, a lens 51b, a telescopic unit 51c, a light source 51d, and a filling detector 51e.

  The chuck 51a grips the template 54. Light emitted from the light source 51d is applied to the template 54 held by the chuck 51a through the lens 51b.

  FIG. 6 shows the upper surface of the template 54. In the central portion 54a on one surface side (wafer substrate side) of the template 54, the same uneven pattern as the pattern to be formed on the wafer substrate 55 is formed. Further, a filling monitor pattern 54c is formed in the peripheral portion 54b of the template 54 on the same surface side (wafer substrate side) as the uneven pattern.

  The filling monitor pattern 54c is a periodic pattern (L & S, C / H, etc.) in which a plurality of pattern sizes are changed. The groove pattern size and the groove depth of the filling monitor pattern 54c are matched with the periodic pattern (L & S, C / H, etc.) included in the concave / convex pattern (main pattern) formed in the central portion 54a. For example, lines & spaces and contact holes having a minimum pattern width and a maximum pattern width included in the main pattern are formed.

  The filling detector 51e has a light emitting unit 71 and a light receiving unit 72 as shown in FIG. The light emitted from the light emitting unit 71 is reflected by the photocurable organic material 73 in the filling monitor pattern of the template 54, and the light receiving unit 72 receives the reflected light. The light emitting portion 71 emits light having a wavelength that does not cure the photocurable organic material 73.

  As shown in FIG. 7 (a), when the filling monitor pattern of the template 54 is not sufficiently filled with the photocurable organic material 73, the light scattering is large and the light receiving level at the light receiving portion 72 is low.

  On the contrary, as shown in FIG. 7B, if the filling monitor pattern of the template 54 is sufficiently filled with the photocurable organic material 73, the light scattering is small and the light receiving level at the light receiving portion 72 is high. Become.

  FIG. 8 shows an example of the relationship between the elapsed time from the contact of the template with the photocurable organic material and the light reception level (signal intensity) at the light receiving unit 72. FIG. 8 shows a case where the filling monitor pattern size is large (solid line) and a case where the filling monitor pattern size is small (broken line). It can be seen that the signal intensity increases with time. The level at which the signal intensity is saturated is set as the filling end level. This filling end level is acquired in advance and stored in the control unit 53 as filling end level information.

  The control part 53 controls the expansion / contraction part 51c, the light source 51d, and the filling detector 51e.

  A cross section of a pattern forming process using this pattern forming apparatus will be described with reference to FIG.

  As shown in FIG. 9A, a liquid photocurable organic material 90 is applied onto the surface of the wafer substrate 55 supported by the wafer substrate support 52 by an ink jet apparatus (not shown).

  As shown in FIG. 9 (b), the stretchable part 51 c extends and the template 54 held by the chuck 51 a is brought into contact with the liquid photocurable organic material 90 on the surface of the wafer substrate 55.

  As shown in FIG. 9C, light is emitted from the light emitting unit 71 of the filling detector 51 e to the filling monitor pattern 54 c of the template 54, the reflected light is received by the light receiving unit 72, and the received light level is transmitted to the control unit 53. To do. At this time, the light irradiated to the filling monitor pattern 54c is light having a wavelength that does not cure the photocurable organic material. The filling monitor pattern 54c includes a plurality of patterns (L & S, C / H, etc.) having different pattern sizes, and sequentially detects the received light level of the reflected light from each pattern and transmits it to the control unit 53.

  As shown in FIG. 9D, the control unit 53 performs control to emit light from the light source 51d when it is determined that the light reception level of the reflected light from each pattern of the filling monitor pattern 54c has reached the filling end level. Do. The light emitted from the light source 51d is applied to the photocurable organic material 90 through the lens 51b and the template 54, and the photocurable organic material 90 is cured.

  As shown in FIG. 9 (e), the stretchable part 1 c contracts and the template 54 is separated (released) from the photocurable organic material 90. Since the photocurable organic material 90 is cured, the state (shape) when the template 54 is in contact is maintained.

  The filling state of the filling monitor pattern formed according to the size of the uneven pattern of the template is monitored, and light is irradiated after the light receiving level at the light receiving unit 72 reaches the filling end level to cure the photocurable organic material 90. Therefore, it is possible to suppress the filling failure of the uneven pattern of the template. Further, since the template holding time is an optimum time, it is possible to prevent a decrease in throughput.

  As described above, the pattern forming apparatus according to the present embodiment can optimize the filling time of the organic material into the template, and can increase the throughput without defective filling of the organic material.

  In the above embodiment, the filling monitor pattern is formed on the template. However, the filling detector 51e may directly monitor the filling state of the uneven pattern on the central portion 54a of the template 54 without forming the filling monitor pattern. good.

  (Third Embodiment) FIG. 10 shows a schematic sectional structure of a pattern forming apparatus according to a third embodiment of the present invention. The pattern forming apparatus includes an original stage 102 that holds a template 101, an alignment sensor 103, an alignment stage 104 that fixes the alignment sensor 103, a base 105 that fixes the original stage 102 and the alignment stage 104, a light source 106, and a wafer that holds a wafer substrate 107. A chuck 108, a wafer stage 109 for fixing the wafer chuck 108, a bearing 110, and a stage surface plate 111 are provided.

  The light source 106 emits ultraviolet light. The template 101 is provided with the same concave / convex pattern (main pattern) as the pattern to be formed on the wafer substrate 107, and is made of a material that transmits ultraviolet rays, such as quartz or fluorite. FIG. 11A shows the upper surface of the template 101.

  In the central portion 101a on one surface side (wafer substrate side) of the template 101, the same uneven pattern as the pattern to be formed on the wafer substrate 107 is formed. Alignment marks 101b to 101e are formed at four locations in the center portion 101a of the template 101 in the upper right, lower right, upper left, and lower left in the figure.

  FIG. 11B shows an enlarged view of the alignment mark 101b. The alignment mark is composed of the same line and space as the design node of the main pattern. For example, it has the same width as the minimum width pattern included in the main pattern.

  Here, four alignment marks 101b to 101e are formed as alignment marks, but it is sufficient that three or more alignment marks are formed.

  The original stage 102 has a drive shaft around the Z axis (θ) and positions the template 101. The original stage 102 preferably further has drive shafts around the X axis (ωy) and around the Y axis (ωx). The original stage 102 further includes a positioning sensor (not shown) that measures the position of each drive shaft.

  The base 105 is fixed by an apparatus main body surface plate (not shown).

  The alignment sensor 103 uses the alignment marks 101b to 101e formed on the template 101 and the alignment marks (already formed lower layer alignment marks) drawn on the wafer substrate 107 to establish a connection between the template 101 and the wafer substrate 107. Measure the relative displacement. The alignment sensor 103 is measured using, for example, an optical inspection device or SEM (electron microscope).

  The amount of misalignment can be measured from the intensity distribution of the light that is irradiated from the alignment sensor 103 to the alignment mark, diffracted and reflected, and returned to the alignment sensor 103. The original stage 102 moves so as to correct the measured displacement amount.

  The wafer stage 109 can be moved by a bearing 110 and is preferably driven by six axes of X, Y, Z, ωx, ωy, and θ. The wafer stage 109 may be driven in the X and Y directions by a linear motor while being floated from the stage surface plate 111 by compressed air or the like. The wafer stage 109 has a positioning sensor (not shown) such as a laser interferometer that measures the position of each drive shaft.

  After correcting the positional deviation of the template 101, the template 101 is brought into contact with the liquid photocurable organic material applied to the wafer substrate 107. After holding for a predetermined time so that the photocurable organic material spreads in the uneven pattern of the template 101, the back surface of the template 101 is irradiated with ultraviolet rays from the light source 106. The photocurable organic material is cured by being irradiated with ultraviolet rays through the template 101. After the photocurable organic material is cured, the template 101 is separated.

  Thereby, a desired resist pattern is formed on the wafer substrate 107. In addition, patterns by the alignment marks 101b to 101e are also transferred.

  As shown in FIG. 3, the time required for the photocurable organic material to spread (fill) into the concave / convex pattern of the template 101 becomes longer as the size of the pattern increases. In general, misalignment inspection used for alignment mark measurement is performed using an optical inspection apparatus. Therefore, the pattern size of the alignment mark is very large, reaching a size of several μm to several tens of μm. Therefore, the holding time when the organic material is filled becomes long, and the throughput is lowered.

  In the present embodiment, the alignment marks 101b to 101e are configured by lines and spaces equivalent to the design node of the concave / convex pattern in the template central portion 101a, so that the time until the concave / convex pattern and the alignment mark are filled with the photocurable organic material is increased. Can be matched.

  As described above, the pattern forming apparatus according to the present embodiment can increase the throughput by setting the organic material filling time in the template to an appropriate state.

  You may make it provide the alignment marks 101b-e like this embodiment in the templates 6 and 54 in the said 1st, 2nd embodiment. Thereby, the organic material filling time in the template can be optimized, the filling of the organic material into the main pattern and the alignment mark can be prevented, and the throughput can be increased.

  Each of the above-described embodiments is an example and should be considered not restrictive. The technical scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 is a schematic configuration diagram of a pattern forming apparatus according to a first embodiment of the present invention. It is a top view of a template. It is a graph which shows the relationship between pattern size and organic material filling time. It is process sectional drawing which shows the pattern formation method by the 1st Embodiment. It is a schematic block diagram of the pattern formation apparatus by the 2nd Embodiment of this invention. It is a top view of a template. It is a figure which shows an example of a filling detector. It is a graph which shows the change of the received light intensity in a filling detector. It is process sectional drawing which shows the pattern formation method by the 2nd Embodiment. It is a schematic block diagram of the pattern formation apparatus by the 3rd Embodiment of this invention. It is a top view of a template.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light irradiation part 2 Barcode sensor 3 Wafer substrate support body 4 Template conveyance part 5 Control part 6 Template 7 Wafer substrate

Claims (5)

A wafer substrate support for holding a wafer substrate coated with an organic material on the surface;
A predetermined holding pattern is formed on one surface, and a template holding unit that holds a light-transmitting template in which information on the uneven pattern is described;
A sensor that reads and outputs information of the uneven pattern;
A drive unit that drives the template holding unit based on a drive control signal, and contacts the organic material applied to the wafer substrate surface with the template held in the template holding unit;
Based on a light irradiation control signal, a light source that irradiates light from the other surface side of the template to the template held by the template holding unit;
The light irradiation is performed so that the light source emits light after a predetermined time has elapsed since the template contacts the organic material based on the information of the concave / convex pattern output from the sensor. A control unit for outputting a control signal;
A pattern forming apparatus comprising: A wafer substrate support for holding a wafer substrate coated with an organic material on the surface;
A template holding part for holding a template having a predetermined concavo-convex pattern formed on one surface and having light transmittance;
A drive unit that drives the template holding unit based on a drive control signal, and contacts the organic material applied to the wafer substrate surface with the template held in the template holding unit;
A filling detector that irradiates the template with light that does not cure the organic material, receives reflected light, and outputs received light intensity;
Based on a light irradiation control signal, a light source for irradiating the template held by the template holding unit with light for curing the organic material from the other surface side of the template;
The drive control signal is output, and it is determined whether or not the received light intensity output from the filling detector is equal to or higher than a predetermined level. If it is determined to be higher than a predetermined level, the light source emits light. A control unit for outputting a light irradiation control signal;
A pattern forming apparatus comprising: A pattern forming method using a pattern forming apparatus having a wafer substrate support, a template holding unit, a sensor, a driving unit, a light source, and a control unit,
Holding the wafer substrate by the wafer substrate support;
A step of reading information on the concavo-convex pattern of a template in which a predetermined concavo-convex pattern is formed on one surface by the sensor and has light transmission and information on the concavo-convex pattern is described;
Holding the template by the template holding unit;
Applying an organic material to the surface of the wafer substrate;
Driving the template holding unit by the driving unit to bring the template into contact with the organic material;
Calculating a holding time based on information of the uneven pattern read by the sensor by the control unit, and outputting a light control signal after the calculated holding time has elapsed since the template has contacted the organic material;
Irradiating the organic material with light through the template based on the light control signal by the light source;
A pattern forming method comprising: A pattern forming method using a pattern forming apparatus having a wafer substrate support, a template holding unit, a driving unit, a filling detector, a light source, and a control unit,
Holding the wafer substrate by the wafer substrate support;
A step of holding a template having a predetermined concavo-convex pattern formed on one surface by the template holding unit and having light transmittance;
Applying an organic material to the surface of the wafer substrate;
Driving the template holding unit by the driving unit to bring the template into contact with the organic material;
Irradiating the template with the organic material not cured from the filling detector, receiving reflected light, and outputting the received light intensity;
Determining whether or not the received light intensity is greater than or equal to a predetermined value by the control unit, and outputting a light control signal if determined to be greater than or equal to a predetermined value;
Irradiating the organic material through the template with light that cures the organic material based on the light control signal by the light source;
A pattern forming method comprising: A first concavo-convex pattern is formed at the center of one surface, and the light-transmitting template comprises:
A template comprising a second concavo-convex pattern having the same pattern width as a minimum pattern width and a maximum pattern width included in the first concavo-convex pattern at a peripheral portion of the one surface.

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