JP2007296783A - Working device/method and device manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a working device which can realize a more rapid stamping process than a conventional type of the device and having excellent throughput. <P>SOLUTION: This working device transfers a pattern to an object to which an image is transferred by pressing a mold with a formed pattern to a resist applied to the object. In addition, the working device has a control means to control the distribution of the coating weight of the resist to be applied to the object, based on the three-dimensional surface shape and/or the thickness distribution of the mold and the three-dimensional surface shape and/or the thickness distribution of the object. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention generally relates to a processing apparatus and method, and more particularly, to a processing apparatus and method for transferring a pattern of a mold as an original to a substrate such as a wafer. The present invention is suitable for a processing apparatus and a method using a nanoimprint technology for fine processing for manufacturing, for example, a semiconductor, MEMS (Micro Electro-Mechanical Systems), and the like.

  2. Description of the Related Art When a fine structure (device such as an electronic circuit, a MEMS, or a grating lens) is manufactured using a lithography technique, a projection exposure apparatus has been conventionally used. The projection exposure apparatus transfers a pattern by reducing and projecting a pattern drawn on a reticle (mask) onto a substrate (silicon or glass) coated with a resist (photosensitive agent). A projection exposure apparatus can form a very fine structure, but is very expensive and cannot be easily used.

  On the other hand, nanoimprint, which can form a very fine structure and is a low-cost patterning method, has attracted attention. Nanoimprint is a method of copying a pattern on a resist by pressing (imprinting) a mold (template) on which a fine pattern is formed by electron beam exposure or the like onto a wafer coated with a resin material as a resist. . In the nanoimprint, if a mold is prepared, it is only necessary to have a stamping mechanism that presses the mold against a resin material, so that fine processing can be realized at low cost. Currently, nanoimprints can transfer a fine shape of about 10 nm and have sufficient performance for miniaturization. Nanoimprints are expected to be applied to new devices that were not manufactured because they were not profitable with projection exposure apparatuses. In particular, they are expected to be a means for forming a fine periodic structure of a magnetic recording medium.

  For nanoimprinting, a thermal cycle method, a photocuring method (also referred to as “UV curing type”), and the like have been proposed as a transfer method. The thermal cycle method is a method in which a resin (thermoplastic material) to be processed is heated to a glass transition temperature or higher (that is, the fluidity of the resin is increased), a mold is impressed, and the mold is released after being cooled. The photocuring method is a method in which an ultraviolet curable resin (UV curable resin) is used, and the mold is peeled after being exposed to light and cured in a state of being stamped with a transparent mold (for example, see Patent Document 1).

  The photocuring method is suitable for manufacturing a semiconductor element because the temperature can be controlled relatively easily. In addition, high precision overlay accuracy (accuracy when overlaying several patterns on a substrate) is essential for the manufacture of semiconductor elements. The photocuring method can observe an alignment mark on a substrate through a transparent mold, and is suitable for manufacturing a semiconductor element from the viewpoint of alignment. On the other hand, since the thermal cycle method includes a heating step, the substrate and the mold are thermally expanded due to a temperature rise, and it is very difficult to maintain the overlay accuracy.

  FIG. 21 is a diagram for explaining nanoimprinting by a photocuring method, in which FIG. 21A shows a stamping process, FIG. 21B shows a curing process, and FIG. 21C shows a mold releasing process. . First, as shown in FIG. 21A, a mold MP made of a material that transmits ultraviolet rays (for example, quartz) is pressed against a substrate (wafer) ST coated with a UV curable resin UCR. Thereby, the UV curable resin UCR flows along the pattern formed on the mold MP.

  Next, in a state where the mold MP is pressed against the substrate ST, as shown in FIG. As a result, the UV curable resin UCR is cured into the shape (pattern) of the mold MP. Then, as shown in FIG. 21C, the mold MP is pulled away from the substrate ST. As a result, the UV curable resin UCR maintaining the shape of the mold MP remains on the substrate ST, and the pattern is transferred to the substrate ST. For large substrates, the substrate is moved each time the pattern is transferred, and the above-described steps are repeated to sequentially transfer the pattern to the entire substrate. The transferred resin (resist) pattern is equivalent to the resist pattern transferred by the projection exposure apparatus when the base of the pattern is removed.

In the photocuring method, it is important to make the thickness of the resin constant (uniform) during photosensitizing and curing so that the pattern transferred onto the substrate is not affected by the subsequent etching process. In addition, when pressing the mold, it is important not to cause thickness unevenness in the resin. Therefore, it is necessary to press the mold in a state where the pattern surface of the mold (surface on which the pattern is formed) and the substrate (transfer surface) are maintained in parallel.
JP 2000-194142 A

  However, since the actual mold and substrate have undulation and thickness distribution that cannot be removed, the distance (gap) between the mold and the substrate becomes non-uniform. In such a case, if the resin is uniformly applied to the substrate, for example, it takes a long time until the resin wraps around a region where the substrate is thick. In other words, the time required for the stamping process becomes long, and the throughput of the apparatus decreases.

  Accordingly, an object of the present invention is to provide a processing apparatus that realizes a faster stamping process and has an excellent throughput.

  In order to achieve the above object, a processing apparatus according to one aspect of the present invention is a processing apparatus that presses a mold on which a pattern is formed to a transfer target to which a resist is applied, and transfers the pattern to the transfer target. And based on the three-dimensional surface shape and / or thickness distribution of the mold and the three-dimensional surface shape and / or thickness distribution of the transferred body, it is applied to the transferred body. It has a control means which controls the application amount distribution of the resist.

  A processing method according to another aspect of the present invention is a processing method in which a pattern-formed mold is pressed against a transferred object to which a resist is applied, and the pattern is transferred to the transferred object. Before the contact with the resist, the step of measuring the three-dimensional surface shape and / or thickness distribution of the transferred object, and the application to the transferred object based on the measurement result measured in the measuring step And determining the resist coating amount distribution, and applying the resist to the transfer object according to the coating amount distribution determined in the determining step.

  A device manufacturing method as still another aspect of the present invention includes a step of transferring a pattern to a transfer object using the above-described processing apparatus, and a step of etching the transfer object to which the pattern is transferred. It is characterized by that.

  Further objects and other features of the present invention will become apparent from the preferred embodiments described below with reference to the accompanying drawings.

  According to the present invention, it is possible to provide a processing apparatus that realizes a faster stamping process and has an excellent throughput.

  Hereinafter, a processing apparatus according to one aspect of the present invention will be described with reference to the accompanying drawings. In addition, in each figure, the same reference number is attached | subjected about the same member and the overlapping description is abbreviate | omitted. Here, FIG. 1 is a schematic sectional view showing the configuration of the processing apparatus 1 of the present invention. FIG. 2 is an enlarged cross-sectional view showing the vicinity of the mold chuck 19.

  The processing apparatus 1 presses the mold on which the pattern is formed against the transfer target to which the resist is applied, and transfers the pattern to the transfer target. In this embodiment, the processing apparatus 1 is a nanoimprint apparatus using a photocuring method.

  As shown in FIG. 1, the processing apparatus 1 includes a wafer chuck 10, a fine movement stage 11, an XY stage 12, a base surface plate 13, a reference mirror 14, laser interferometers 15a and 15b, a support column 16, And a top plate 17. Further, the processing apparatus 1 includes a mold 18, a mold chuck 19, a mold chuck stage 20, an ultraviolet light source 21, a collimator lens 22, a guide plate 23, a guide bar 24, and an actuator 25. Further, the processing apparatus 1 includes a coating device 26, an alignment scope 27, a mold control unit 32, a wafer control unit 34, a resist control unit 36, and a main control unit 38.

  Wafer chuck 10 holds wafer WF. The fine movement stage 11 has a function of correcting (adjusting) the position, z position, and tilt of the wafer WF in the θ (rotation around the z axis) direction. Fine movement stage 11 is arranged on XY stage 12 for positioning wafer WF at a predetermined position.

  The base surface plate 13 places the XY stage 12 thereon. The reference mirror 14 reflects light from the laser interferometer 15a in order to measure the position of the fine movement stage 11. The reference mirror 14 is arranged in the x direction and the y direction on the fine movement stage 11. The support column 16 stands on the base surface plate 13 and supports the top plate 17.

  As shown in FIG. 2, the mold 18 has a surface (mold surface) on which a concavo-convex pattern PT transferred to the wafer WF is formed, and is fixed to the mold chuck 19 by a mechanical holding means (not shown). Similarly, the mold chuck 19 is placed on the mold chuck stage 20 by a mechanical holding means (not shown).

  The mold chuck 19 has a plurality of positioning pins AP that regulate the position of the mold 18 on the mold chuck 19 when the mold 18 is fixed. Further, the mold chuck 19 has a reflection surface that reflects light from the laser interferometer 15b in order to measure the positions in the x direction and the y direction.

The mold chuck stage 20 has a function of correcting (adjusting) the position and inclination of the mold 18 (mold chuck 19) in the θ (rotation around the z axis) direction. The mold chuck 19 and the mold chuck stage 20 have openings 19 a and 20 a for guiding ultraviolet light irradiated from the ultraviolet light source 21 through the collimator lens 22 to the mold 18, respectively.

  The guide plate 23 fixes the guide bar 24. The guide bar 24 penetrates the top plate 17, one end is fixed to the mold chuck stage 20, and the other end is fixed to the guide plate 23.

  The actuator 25 is a linear actuator composed of an air cylinder or a linear motor, and drives the guide bar 24 in the z direction. As a result, the mold 18 held by the mold chuck 19 can be pressed against the wafer WF (imprint), or the mold 18 can be separated from the wafer WF (release).

The coating device 26 is configured by coating a liquid resist RT on the surface of the wafer WF and, for example, a nozzle that discharges the resist RT and a two-dimensional drive mechanism that drives the nozzle. Moreover, the coating device 26 may be configured by a one-dimensional nozzle array or a two-dimensional nozzle array and a one-dimensional drive mechanism that drives the nozzle. Of course, the one-dimensional nozzle array or the two-dimensional nozzle array may have a fine movement mechanism that allows fine movement in all or a part of the x direction, the y direction, the z direction, and the θ direction.
Furthermore, the coating device 26 has a retracting mechanism (not shown) so that the nozzle or nozzle array and the mold 18 do not come into contact with each other in the stamping process (that is, when the mold 18 is pressed against the wafer WF).

  FIG. 3 is a schematic block diagram illustrating an example of a specific configuration of the coating apparatus 26. First, with reference to FIG. 3, a pump system (three types in the present embodiment) for discharging the resist RT from the nozzle will be described. However, the pump system is not limited to these, and it goes without saying that any of these pumps may be used.

  FIG. 3A shows a coating apparatus 26 having a pump that instantaneously applies heat and uses generation of bubbles due to boiling as a power source. The coating device 26 shown in FIG. 3A has a photo-curing resin tank 26a, a nozzle 26b, and a heater 26c. The photo-curing resin (resist RT) is received from the nozzle 26b by a current pulse applied to the heater 26c. Discharge.

  FIG. 3B shows a coating apparatus 26 having a pump that applies a voltage to the piezo element and uses the deformation force of the piezo element as a power source. 3B includes a photocurable resin tank 26a, a nozzle 26b, and a piezo element 26d, and the photocurable resin (resist RT) is applied from the nozzle 26b by a voltage pulse applied to the piezo element 26d. ) Is discharged.

  FIG. 3C shows a coating device 26 having a pump using air pressure as a power source. The coating device 26 shown in FIG. 3C includes a photocurable resin tank 26a, a nozzle 26b, a syringe 26e, a valve 26f, and a pump 26g. The coating device 26 shown in FIG. 3C discharges the photo-curing resin (resist RT) from the nozzle 26b by instantaneously opening the valve 26f and introducing the gas compressed by the pump 26g into the syringe 26e.

  A combination of a pump and a nozzle as shown in FIG. 3 is called a nozzle head. An example of the configuration of the nozzle head array used in the processing apparatus 1 is shown in FIG. As shown in FIG. 4, when nozzle heads 262 are arranged vertically and horizontally, for example, if a 35 mm square head array is formed at 1 mm intervals, 1296 nozzle head arrays 260 are obtained. Each nozzle head 262 has a power source (the above-described heater, piezo element, gas pump, etc.).

  Another configuration of another nozzle head array used in the processing apparatus 1 is shown in FIG. As shown in FIG. 5, the nozzle head array 260A has 36 nozzle heads 262A arranged in a line at 1 mm intervals. The nozzle head array 260A has an array head drive mechanism (not shown), and can drive the nozzle head array 260A over a length of 35 mm at intervals of 1 mm, for example. Each nozzle head 262A has a power source (the above-described heater, piezo element, gas pump, etc.).

  Although the nozzle head array 260A shown in FIG. 5 has only one line of nozzle heads 262A, a plurality of lines of nozzle heads 262A may be scanned.

  Further, as shown in FIG. 6, nozzle head arrays 260 </ b> B and 260 </ b> C in which nozzle heads having different opening sizes (that is, different opening sizes) are arranged may be used in the processing apparatus 1. A nozzle head array 260B shown in FIG. 6A is a modification of the nozzle head array 260, and includes a nozzle head 262B having a large opening and a nozzle head 264B having a small opening. A nozzle head array 260C shown in FIG. 6B is a modification of the nozzle head array 260A, and includes a large-opening nozzle head 262C and a small-opening nozzle head 264C.

  The nozzle heads 262B and 262C with large openings discharge (apply) a coarse amount of photocurable resin (resist RT), and the nozzle heads 264B and 264C with small openings discharge (apply) a small amount of photocurable resin (resist RT). ) Thereby, the nozzle head arrays 260B and 260C can more accurately control the discharge amount (application amount) of the resist RT. Further, the nozzle head arrays 260B and 260C can increase the discharge amount of the resist RT by using two types of nozzle heads, which contributes to the improvement of the throughput of the apparatus.

  The alignment scope 27 includes an optical system and an imaging system for observing the alignment marks arranged on the wafer WF and the mold 18 and measures the positional deviation between the wafer WF and the mold 18 in the x direction and the y direction.

  The mold control unit 32 is connected to the mold chuck stage 20 and controls the posture of the mold 18 through a function of correcting the position and inclination of the mold 18 in the mold 18.

  The wafer control unit 34 is connected to the fine movement stage 11 and controls the posture of the wafer WF through a function of correcting the position, z position, and tilt of the wafer WF in the fine movement stage 11.

  The resist control unit 36 is connected to the coating device 26 and controls the coating amount of the resist RT applied (dropped) onto the wafer WF. As will be described later, the resist control unit 36 depends on the surface shape and thickness distribution of the wafer WF or the surface shape and thickness distribution of the mold 18 (based on the calculation result of the main control unit 38 described later). The application amount of the resist RT is controlled. In other words, the resist control unit 36 controls the resist RT coating amount distribution by varying the resist RT coating amount in accordance with the position (region) of the wafer WF.

  For example, when the coating device 26 is the nozzle head array 260 shown in FIG. 4, the resist control unit 36 controls the drive (discharge amount and movement position of the resist RT) of each nozzle head 262. Further, when the coating device 26 is the nozzle head array 260A shown in FIG. 5, the resist control unit 38, after completing the application (discharge) of the resist RT by the nozzle head 262A for one line, via a drive mechanism (not shown). The nozzle head 262A is scanned for 1 mm. Further, the resist control unit 38 controls the driving (discharge amount of the resist RT) of each nozzle head 262A. By repeating this, the resist RT is applied to the entire surface of the transfer region on the wafer WF.

  The main control unit 38 controls the posture of the mold 18 and the wafer WF and the application amount (application amount distribution) of the resist RT applied to the wafer WF via the mold control unit 32, the wafer control unit 34, and the resist control unit 36. To do.

  The main control unit 38 includes a three-dimensional surface shape (flatness) of the wafer chuck 10, a thickness distribution of the wafer WF (thickness variation), a three-dimensional surface shape (flatness) of the mold chuck 19, and a mold. 18 information such as thickness distribution (thickness variation) is acquired. Based on such information, the main control unit 38 calculates the optimum posture of the mold 18 and the wafer WF, and controls the mold 18 and the wafer WF to the optimum posture via the mold control unit 32 and the wafer control unit 34. .

  In the present embodiment, the main control unit 38 controls each of the wafers WF based on the surface shape and / or thickness distribution of the wafer WF, the surface shape and / or thickness distribution of the mold 18, and the density of the pattern PT of the mold 18. The coating amount of the resist RT at the position (region) is calculated. In other words, the main control unit 38 calculates the coating amount distribution formed on the wafer WF, and controls the registration control unit 36 based on the calculation result.

  Hereinafter, the operation of the processing apparatus 1, particularly the control method (processing method) of the main control unit 38 will be described. FIG. 7 is a flowchart for explaining the operation of the machining apparatus 1. The operation of the processing apparatus 1 includes a stamping process, a curing process, and a release process. However, since the curing step and the release step are the same as the curing step and the release step described with reference to FIG. 21, detailed description thereof will be omitted, and the stamping step will be described.

  Referring to FIG. 7, first, a three-dimensional surface shape (flatness) of wafer chuck 10 measured in advance is acquired (step 102). Similarly, the thickness distribution of the wafer WF measured before placing the wafer WF on the wafer chuck 10 is acquired (step 104). At this time, the thickness distribution of the wafer WF is acquired as information for each shot of the wafer WF. Based on the acquired three-dimensional surface shape of the wafer chuck 10 and the thickness distribution of the wafer WF, the three-dimensional surface shape (flatness of the wafer WF when the wafer WF is placed on the wafer chuck 10). ) Is calculated (step 106).

  Next, the three-dimensional surface shape (flatness) of the mold chuck 19 measured in advance is acquired (step 108). Similarly, the thickness distribution of the mold 18 measured before placing the mold 18 on the mold chuck 19 is acquired (step 110). Based on the acquired three-dimensional surface shape of the mold chuck 19 and the thickness distribution of the mold 18, the three-dimensional surface shape (flatness of the mold 18 when the mold 18 is placed on the mold chuck 19. ) Is calculated (step 112).

  If the flatness of the mold 18 is good, steps 108 to 112 may be omitted. Similarly, when the flatness of the wafer chuck 10 and the mold chuck 19 is good, steps 102 and 108 may be omitted. In this embodiment, for convenience of explanation, after calculating the three-dimensional flatness of the wafer WF, the three-dimensional flatness of the mold 18 is calculated. After calculating the flatness, the three-dimensional flatness of the wafer WF may be calculated. Of course, the three-dimensional flatness of the mold 18 and the three-dimensional flatness of the wafer WF may be calculated simultaneously.

  Next, based on the three-dimensional surface shape of the wafer WF and the mold 18 calculated in steps 106 and 112, the distribution of the distance (gap) between the mold 18 and the wafer WF when the mold 18 is imprinted on the wafer WF. (Inter-distance distribution) is calculated (step 114).

  On the other hand, the spatial density of the pattern PT is calculated based on the pattern information (the shape of the pattern PT) of the mold 18, and the average per unit area is calculated based on the spatial density and the depth of the pattern PT. A depth distribution is calculated (step 116).

  Next, based on the gap distance distribution calculated in step 114 and the depth distribution calculated in step 116, the application amount distribution of the resist RT applied to the wafer WF is calculated (step 118). Specifically, the distance between the mold 18 and the wafer WF (that is, the resist RT applied to the mold 18 and the wafer WF) according to the surface shape and thickness distribution of the wafer WF and the surface shape and thickness distribution of the mold 18. The distribution of the coating amount is calculated so that the distance is uniform. Accordingly, the thickness of the resist RT applied to the wafer WF varies depending on the position of the wafer WF. Further, in order to form the calculated application amount distribution, the discharge amount of the resist RT discharged (applied) from the application device 26 (for example, each nozzle head 262) is calculated.

  Next, a resist RT is applied to the wafer WF according to the calculated discharge amount (primary step 120). Thereby, the resist RT having the coating amount distribution calculated in step 118 is applied to the wafer WF, and the distance between the mold 18 and the resist RT when the mold 18 is pressed against the wafer WF becomes uniform. Then, the mold 18 is imprinted on the wafer WF coated with the resist RT (step 122).

  Here, steps 114 to 118 will be described in more detail.

  For example, the gap distance distribution calculated in step 114 is shown in FIG. In FIG. 8A, the curve shows contour lines. However, in actuality, it may be information as a function such as a high-order polynomial for the position. Further, instead of the detailed gap distance distribution as shown in FIG. 8A, a simplified gap distance distribution as shown in FIG. 8B may be used. In the inter-gap distance distribution shown in FIG. 8B, the region is divided into four (regions e1, e2, e3, e4), and the inter-gap distance of each region e1, e2, e3, e4 is 150 nm, 200 nm, 250 nm. , 300 nm. Hereinafter, in order to admire the explanation, the gap distance distribution shown in FIG. 8B will be described as an example.

  Next, a mold 18 as shown in FIG. 9 is considered. The pattern PT of the mold 18 is formed only in the region e1 as shown in FIG. 9A, and the depth of the pattern PT is 200 nm as shown in FIG. 9B. Further, the density of the pattern PT (area ratio between the concave portion and the convex portion) is 1: 1. In this case, the average mold depth of the region e1 is 100 nm (100 × 0.5). Further, the average mold depth of the other regions e2, e3, and e4 is 0 nm. Therefore, the average depth density per unit area calculated in step 116 has a distribution as shown in FIG.

Referring to FIG. 9 (c), in the region e1, since the substantial average gap distance is the same as that of 100 nm, the gap distance considering the average depth of the pattern PT of the mold 18 is considered. Is calculated as shown in FIG. In other words, the distances between the gaps considering steps 114 and 116 are 250 nm, 200 nm, 250 nm, and 300 nm in the regions e1, e2, e3, and e4, respectively. Based on such information, for example, as shown in FIG. 10B, it is converted into a target application amount per 1 mm ² (that is, an application amount that makes the distance between the mold 18 and the resist RT uniform in the stamping process). To do. Specifically, one shot is divided in accordance with the unit interval in the xy direction where the resist RT is applied, and converted into the application amount in each region.

  In the present embodiment, the example in which the region is divided into four parts has been described. Of course, the gap distance distribution shown in FIG. 8A may be expressed by a high-order polynomial, and the subsequent steps may be processed in the same manner. Further, the gap distance distribution shown in FIG. 8A is divided into a mesh shape as shown in FIG. 10C and processed as a digital data array of positions and parameters (gap distance, coating amount distribution, etc.). It doesn't matter. In addition, when dividing into meshes, it is also possible to make the dimensions according to the interval between the nozzles of the coating device 26 and the step width of the nozzle.

  In this way, the processing apparatus 1 can apply the resist RT so that the distance between the mold 18 and the resist RT in the stamping process is uniform according to the surface shape and thickness distribution of the mold 18 and the wafer WF. . Thereby, the processing apparatus 1 can shorten the time which a stamping process requires, and can improve a through-put. Further, it is possible to prevent the resist RT from coming around at the time of stamping, to reduce defects in the pattern PT to be transferred, and to improve the yield.

  FIG. 11 is a schematic cross-sectional view illustrating a configuration of a processing apparatus 1A that is a modification of the processing apparatus 1. 1 A of processing apparatuses have the transfer stage 40 arrange | positioned in the position which transfers the pattern PT of the mold 18, and the measurement station 50 which measures the three-dimensional surface shape (flatness) of the wafer WF. In this embodiment, the measurement station 50 includes a measurement device 52 and a measurement stage 54.

  The wafer WF is transported between the two stages of the measurement stage 54 and the transfer stage 40 while being placed (adsorbed) on the chuck 10A. In the transfer stage 40, the mold 18 is imprinted on the wafer WF coated with the resist RT.

  A chuck mark CM for measuring the position of the wafer WF is disposed on the chuck 10A. In the measurement stage 54, the three-dimensional positional relationship between the chuck mark CM and the wafer WF is measured by the alignment detection system 42a. Further, the measured wafer WF moves to the transfer stage 40 while being attracted to the chuck 10A.

  In the transfer stage 40, the three-dimensional position of the chuck mark CM is measured by the alignment detection system 42b. Based on the measurement result and the positional relationship between the wafer WF and the chuck mark CM, the three-dimensional position (position in the xyz direction) of the wafer WF on the transfer stage 40 is detected.

  As shown in FIG. 12, a plurality of cantilevers 60 are arranged on the measurement stage 54 as a measurement device 52 that measures the surface shape of the wafer WF. FIG. 12 is a schematic plan view illustrating an arrangement example of the cantilever 60 as the measuring device 52. In the present embodiment, 36 cantilevers 60 are arranged vertically and horizontally at intervals of 1 mm (total of 1296) in a square region having a side of 35 mm. A structure in which a plurality of cantilevers 60 are arranged in this way is called a multi-cantilever.

  The cantilever 60 is used in a commercially available atomic force microscope (AFM) or the like, and utilizes the atomic force (Van der Waals force) acting between the measurement object and the cantilever 60 in the Z direction ( Measure the position (perpendicular to the page).

  FIG. 13 is a diagram for explaining the principle of measuring the surface shape of the wafer WF by the cantilever 60. If the position of the cantilever 60 in the Z direction with respect to an arbitrary position as a reference (for example, the position of the back surface 60b of the cantilever 60) is the position C, and the surface position of the measurement point of the wafer WF as the measurement target is the position d, the relationship between the two Is as shown in FIG. FIG. 14 is a graph (force curve) showing the relationship between the position C of the cantilever 60 and the surface position d of the wafer WF when the wafer WF is gradually brought close to the cantilever 60 held at the position C. The Z direction (upward direction in the figure) shown in FIG. 13 is the positive direction.

  When the cantilever 60 is sufficiently away from the wafer WF, the position C of the cantilever 60 does not change even if the wafer WF is brought close to the cantilever 60. However, when the surface position of the wafer WF is close to a certain point and becomes the position d1 (that is, when the distance between the probe 60a of the cantilever 60 and the surface of the wafer WF becomes a predetermined distance), an atomic force acts on both. First attract each other. When the wafer WF further approaches the cantilever 60, the cantilever 60 is attracted to the surface of the wafer WF by attractive force, and the position C of the cantilever 60 gradually decreases (attractive force region). Further, when the wafer WF approaches the cantilever 60 and the surface position of the wafer WF reaches the position d2, the two repel each other due to the atomic force. When the wafer WF further approaches the cantilever 28, the cantilever 60 tries to move away from the surface of the wafer WF by repulsive force, and the position C of the cantilever 60 increases rapidly (repulsive force region).

  In the present embodiment, in order to use the repulsion characteristics in the repulsive force region, the cantilever 60 and the wafer WF are arranged such that the distance between them is Cd2 or less. Of course, it is possible to use the attractive characteristics in the attractive region, but there may be a plurality of positions of the wafer WF with respect to the position C of one cantilever 60 in the attractive region. Therefore, it should be noted that the position of the wafer WF may not be uniquely determined from the position C of the cantilever 60.

  When setting the distance between the cantilever 60 and the wafer WF, it is necessary to consider the height variation of the surface shape of the wafer WF. This is because if the distance between the cantilever 60 and the wafer WF is made smaller than the height variation of the surface shape of the wafer WF, the probe 60a of the cantilever 60 may come into contact with the surface of the wafer WF.

  For example, when a multi-cantilever is configured by arranging 1000 or more cantilevers 60, a height variation in the nanometer order occurs. Therefore, before measuring the surface of the wafer WF, a calibration operation for calibrating the height variation of each of the plurality of cantilevers 60 using a sample tool (so-called jig) whose flatness is known in advance is required. Become.

  Hereinafter, a calibration procedure for calibrating the height variation of the cantilever 60 to an accuracy of 3 nm or less will be described. The surface measurement range of the sample wafer as a jig whose flatness is known in advance is set to be located 500 nm below the tip of the probe 60a of the cantilever 60 (multi-cantilever). Then, the Z-direction position of each cantilever 60 of the multi-cantilever is optically measured each time the sample wafer is moved by 5 nm while moving the sample wafer in the + Z direction (that is, the direction close to the multi-cantilever).

  This is repeated until the moving distance reaches 600 nm, and measurement data at a total of 120 locations is acquired. Based on each measurement data, a force curve of each cantilever 60 is created, and the position of the transition point of each cantilever 60 from the attractive region to the repulsive region (that is, position d2 in FIG. 14) is grasped. Based on the information on the position d2 of the transition point of each cantilever 60 and the information on the flatness of the sample wafer, the height variation of each cantilever 60 is calculated. By applying the calculated height variation of each cantilever 28 to the actual surface shape measurement of the wafer WF, it is possible to minimize the influence of the height variation of the cantilever 60 on the nanometer order. Further, the influence of the flatness of the sample wafer can be further reduced by rotating the sample wafer by 90 ° in the XY plane and performing calibration a total of four times and using the average value.

  FIG. 15 is a side view of a multi-cantilever having a plurality of cantilevers 60 measuring the surface of the wafer WF. The measurement method of the cantilever 60 shown in FIG. 15 is called an optical lever method. As described above, the cantilever 60 moves up and down according to the height position of the surface of the wafer WF by the atomic force acting between the measurement probe 60a and the surface of the wafer WF. The oblique incident light GIL is incident on the back surface 60b of the cantilever 60, and the reflected light from the back surface 60b is detected by the photodetector 56 such as a CCD, thereby measuring the height of the cantilever 60, that is, the surface shape of the wafer WF. be able to.

  FIG. 16 is a schematic side view showing a configuration of an optical lever type focus detection system 58 that performs height measurement by a plurality of cantilevers 60 using one optical system. The measurement light ML emitted from the laser light source 58a is divided by the multi-spot generator 58b, and enters the back surface 60b of each of the plurality of cantilevers 60 as the oblique incident light GIL via the light projecting optical system 58c. The reflected light from the plurality of back surfaces 60b is guided to the light receiving surface of the photodetector 58e through the light receiving optical system 58d. A commercially available AFM uses a quadrant sensor as a photodetector, but in this embodiment, a two-dimensional imaging device (for example, an area CCD or the like) is used as the photodetector 58e. Since the light receiving position of the photodetector 58e changes according to the height (Z direction) position of the back surface 60b of the cantilever 60, the light received by the photodetector 58e is photoelectrically converted to change the position of the cantilever 60 in the Z direction. It can be measured.

  The surface measurement of the wafer WF in the measurement stage 54 is performed before the transfer of the pattern PT to the wafer WF in the transfer stage 40. Specifically, first, the surface shape of the shot area where the pattern PT is first transferred on the wafer WF is measured by a plurality of cantilevers 60.

  Next, the wafer WF is moved, and the surface shape of each other shot area is measured by a plurality of cantilevers 60. When the surface shapes of all shot regions are measured, alignment is performed by an alignment detection system (off-axis scope) 42a in order to obtain the position in the XY direction of the wafer WF. In such alignment, in many cases, alignment is performed by global alignment, and the XYZ position of the chuck mark CM provided on the chuck 10A is measured using the alignment detection system 42a.

  The wafer WF whose surface shape has been measured on the measurement stage 54 moves to the transfer stage 40 while being placed on the chuck 10A, and the resist RT is applied to transfer the pattern PT. Note that the transfer of the pattern PT to the wafer WF is started, and a wafer WF whose surface shape is to be measured (that is, a new one) is carried into the measurement stage 54. Thus, by simultaneously performing the transfer of the pattern PT to the wafer WF and the measurement of the surface shape of the wafer to which the pattern PT is transferred next, it is possible to prevent the throughput of the processing apparatus 1A from being lowered. Further, the resist RT applied to the wafer WF uses the surface shape of the wafer WF measured by the measuring device 52 (which may include the surface shape of the mold 18 as will be described later). The coating amount distribution is such that the distance is uniform.

  Hereinafter, the operation of the processing apparatus 1A, that is, the measurement of the surface shape of the wafer WF and the transfer of the pattern PT to the wafer WF will be described.

  First, the three-dimensional surface shapes (flatness) of the measurement stage 54 and the transfer stage 40 are measured. Based on the measurement result, an offset (difference) in the surface shape (flatness) of the chuck 10A when the chuck 10A is placed on the measurement stage 54 or the transfer stage 40 is calculated. The calculation result is stored in a memory (not shown), for example. However, you may store in the main control part 38 shown with the processing apparatus 1. FIG.

  Next, the wafer WF is carried into the measurement stage 54, the surface shape of the wafer WF is measured by the measuring device 52, and the surface shape of the wafer WF is stored in a memory (not shown) for each shot. Then, the wafer WF whose surface shape is measured is moved to the transfer stage 40 while being placed on the chuck 10A.

  Next, based on the offset (difference) in the surface shape (flatness) of the chuck 10 </ b> A and the surface shape of the wafer WF measured by the measuring device 52, the surface shape of the wafer WF placed on the transfer stage 40 is calculated. . The calculation result is stored in a memory (not shown).

  Next, based on the surface shape of the wafer WF placed on the transfer stage 40 and the surface shape of the mold 18 held by the mold chuck 19, a gap distance distribution when the mold 18 is pressed against the wafer WF is calculated. The surface shape of the mold 18 held by the mold chuck 19 is preferably calculated based on the thickness distribution of the mold 18 and the surface shape of the mold chuck 19 which are measured in advance.

  Next, the spatial density of the pattern PT is calculated based on the pattern information of the mold 18 (shape of the pattern PT), and the average per unit area is calculated based on the spatial density and the depth of the pattern PT. A typical depth distribution.

  Next, based on the calculated inter-gap distance distribution and depth distribution, the application amount distribution of the resist RT applied to the wafer WF (application such that the distance between the mold 18 and the resist RT applied to the wafer WF is uniform). (Quantity distribution) is calculated. Further, in order to form the calculated application amount distribution, the discharge amount of the resist RT discharged (applied) from the application device 26 (for example, each nozzle head 262) is calculated.

  Next, a resist RT is applied to the wafer WF according to the calculated discharge amount. Thereby, the resist RT having the calculated application amount distribution is applied to the wafer WF, and the distance between the mold 18 and the resist RT when the mold 18 is pressed against the wafer WF becomes uniform. Then, the mold 18 is impressed on the wafer WF coated with the resist RT, and the resist RT is cured by irradiating ultraviolet rays, and then the mold 18 is released. The stamping of the mold 18, the curing of the resist RT and the release of the mold 18 are repeated until the pattern PT is transferred to all shots on the wafer WF, and the wafer WF having the pattern PT transferred to all shots is carried out. To do.

  On the other hand, after the wafer WF whose surface shape has been measured is moved to the transfer stage 40, the wafer WF to which the pattern PT is transferred next is conveyed and measured on the measurement stage 54. The measurement of the surface shape of the wafer WF to which the pattern PT is next transferred is performed while the pattern PT is transferred to the wafer WF whose surface shape has been measured. In other words, the measurement of the surface shape of the wafer WF is performed so that at least part of it overlaps with the transfer of the pattern PT onto the wafer WF as shown in FIG. FIG. 17 is a diagram illustrating the relationship between the stage position (that is, the measurement stage 54 and the transfer stage 40) for each wafer and time in the operation of the processing apparatus 1A. Referring to FIG. 17, the processing apparatus 1A measures the surface shape of the wafer WF and transfers the pattern PT onto the wafer WF at the same time, despite measuring the surface shape of the wafer WF. It can be seen that the decrease in the thickness can be prevented. Of course, the processing apparatus 1A, like the processing apparatus 1, applies the resist RT so that the distance between the mold 18 and the resist RT in the stamping process is uniform according to the surface shape and thickness distribution of the mold 18 and the wafer WF. Can be applied. Thereby, the processing apparatus 1A can shorten the time required for the stamping process, and can improve the throughput. Further, it is possible to prevent the resist RT from coming around at the time of stamping, to reduce defects in the pattern PT to be transferred, and to improve the yield.

  In the present embodiment, the processing apparatus 1A is configured such that the chuck 10A on which the wafer WF is placed can move between the measurement stage 54 and the transfer stage 40. However, as shown in FIG. 18, the measurement stage 54 or the transfer stage 40 may be configured to reciprocate between the measurement position and the transfer position together with the chuck 10A on which the wafer WF is placed. Here, FIG. 18 is a schematic plan view showing an example of the configuration of the measurement stage 54 and the transfer stage 40 of the processing apparatus 1A.

  In the processing apparatus 1A of this embodiment, the coating apparatus 26 is disposed on the stamping mechanism side that transfers the pattern PT to the wafer WF, but may be disposed on the measurement side that measures the surface shape of the wafer WF. In this case, after measuring the surface shape of all shots of the wafer WF, the resist RT is applied to the wafer WF and conveyed to the transfer stage 40.

  Further, the surface shape of the mold 18 (a state where the mold 18 is mounted on the mold chuck 19) can be measured using, for example, a multican lever. Specifically, a reference wafer is carried in advance to the measurement stage 54 and the surface shape is measured. Then, the wafer is moved to the transfer stage 40, and a stamping process (coating, stamping, and curing) is performed under the same conditions as when the pattern PT is actually transferred. At this time, only one shot is required for transfer. The wafer is conveyed again to the measurement stage 54, and the surface shape after the transfer is measured by a multi-cantilever. Based on the surface shape of the chuck 10A on the measurement stage 54, the surface shape of the chuck 10A on the transfer stage 40, the surface shape of the reference wafer, and the surface shape after transfer of the reference wafer, the mold 18 is used. What is necessary is just to calculate the surface shape. The surface shape of the mold 18 may be measured only once when the mold 18 is replaced.

  Next, with reference to FIGS. 19 and 20, an embodiment of a device manufacturing method using the processing apparatus 1 or 1A will be described. FIG. 19 is a flowchart for explaining how to fabricate devices (ie, semiconductor chips such as IC and LSI, LCDs, CCDs, and the like). Here, the manufacture of a semiconductor chip will be described as an example. In step 1 (circuit design), a device circuit is designed. In step 2 (mold production), a mold on which the designed circuit pattern is formed is produced. In step 3 (wafer manufacture), a wafer is manufactured using a material such as silicon. Step 4 (wafer process) is called a pre-process, and an actual circuit is formed on the wafer using a mold and a wafer. Step 5 (assembly) is called a post-process, and is a process for forming a semiconductor chip using the wafer created in step 4. The assembly process (dicing, bonding), packaging process (chip encapsulation), and the like are performed. Including. In step 6 (inspection), inspections such as an operation confirmation test and a durability test of the semiconductor device created in step 5 are performed. Through these steps, the semiconductor device is completed and shipped (step 7).

  FIG. 20 is a detailed flowchart of the wafer process in Step 4. In step 11 (oxidation), the surface of the wafer is oxidized. In step 12 (CVD), an insulating film is formed on the surface of the wafer. In step 13 (electrode formation), an electrode is formed on the wafer by vapor deposition or the like. Step 14 (ion implantation) implants ions into the wafer. In step 15 (resist process), a resist (resin) is applied to the wafer. In step 16 (transfer), the circuit pattern is transferred by pressing the mold against the resist by the processing apparatus 1 or 1A. In step 17 (etching), portions other than the transferred circuit pattern are removed. In step 18 (resist stripping), the resist that has become unnecessary after the etching is removed. By repeating these steps, multiple circuit patterns are formed on the wafer. According to such a device manufacturing method, a device can be manufactured with higher productivity than in the past. Thus, the device manufacturing method using the processing apparatus 1 or 1A and the resulting device also constitute one aspect of the present invention.

  The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist.

It is a schematic sectional drawing which shows the structure of the processing apparatus as one side surface of this invention. It is an expanded sectional view which shows the vicinity of the mold chuck of the processing apparatus shown in FIG. It is a schematic block diagram which shows an example of the specific structure of the coating device of the processing apparatus shown in FIG. It is a schematic plan view which shows an example of a structure of the nozzle head array used with the processing apparatus shown in FIG. It is a schematic plan view which shows another structure of the nozzle head array used with the processing apparatus shown in FIG. It is a schematic plan view which shows another structure of the nozzle head array used with the processing apparatus shown in FIG. It is a flowchart for demonstrating operation | movement of the processing apparatus shown in FIG. It is a figure which shows an example of the distance distribution between gaps calculated by step 114 shown in FIG. It is a figure which shows an example of a structure of the mold of the processing apparatus shown in FIG. It is a figure which shows the distance between gaps which considered the average depth of the pattern of the mold shown in FIG. 9, and the application quantity distribution of a resist. It is a schematic sectional drawing which shows the structure of the processing apparatus as one side of this invention. It is a schematic plan view which shows the example of arrangement | positioning of the cantilever as a measuring device of the processing apparatus shown in FIG. It is a figure for demonstrating the principle of the surface shape measurement of the wafer by a cantilever. It is a figure for demonstrating the principle of the surface shape measurement of the wafer by a cantilever. It is a schematic side view which shows an example of the specific structure of the measuring device of the processing apparatus shown in FIG. It is a schematic side view which shows an example of the specific structure of the measuring device of the processing apparatus shown in FIG. FIG. 12 is a diagram showing the relationship between the stage position (measurement stage and transfer stage) for each wafer and time in the operation of the processing apparatus shown in FIG. 11. It is a schematic plan view which shows an example of a structure of the measurement stage and transfer stage of the processing apparatus shown in FIG. It is a flowchart for demonstrating manufacture of devices (semiconductor chips, such as IC and LSI, LCD, CCD, etc.). FIG. 20 is a detailed flowchart of the wafer process in Step 4 shown in FIG. 19. FIG. It is a figure for demonstrating the nanoimprint by a photocuring method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing apparatus 10 Wafer chuck 11 Fine movement stage 12 XY stage 13 Base surface plate 14 Reference mirrors 15a and 15b Laser interferometer 16 Support column 17 Top plate 18 Mold 19 Mold chuck 20 Mold chuck stage 21 Ultraviolet light source 22 Collimator lens 23 Guide bar plate 24 Guide bar 25 Actuator 26 Coating device 26a Light curable resin tank 26b Nozzle 26b
26c heater 26d piezo element 26e syringe 26f valve 26g pump 260 to 260C nozzle head arrays 262 and 262A nozzle head 262B and 262C nozzle head (large opening)
264B and 264C nozzle head (small opening)
27 Alignment scope 32 Mold control unit 34 Wafer control unit 36 Resist control unit 38 Main control unit 1A Processing device 10A Chuck 40 Transfer stage 42a and 42b Alignment detection system 50 Measurement station 52 Measurement device 54 Measurement stage 56 Photo detector 60 Cantilever 58a Laser Light source 58b Multi-spot generator 58c Light projecting optical system 58d Light receiving optical system 58e Photo detector 80 Cleaning device PT Pattern WF Wafer RT Resist

Claims (10)

A processing apparatus for transferring the pattern to the transferred body by pressing the mold on which the pattern is formed against a resist applied to the transferred body,
Control means for controlling the coating amount distribution of the resist to be applied to the transferred body based on the surface shape and / or thickness distribution of the mold and the surface shape and / or thickness distribution of the transferred body. A processing apparatus comprising:   The processing apparatus according to claim 1, wherein the surface shape of the mold and the surface shape of the transferred object are surface shapes in a state where the mold and the transferred object are held by holding means.   The processing apparatus according to claim 1, further comprising a measuring unit that measures a surface shape of the mold and / or a surface shape of the transferred body.   The processing apparatus according to claim 1, wherein the measuring unit is a multi-cantilever. A chuck for holding the transfer object;
A first stage that is disposed at a transfer position for transferring the pattern to the transfer target, and on which the chuck is placed;
A second stage that is disposed at a measurement position for measuring the surface shape of the transfer object and on which the chuck is placed;
The processing apparatus according to claim 1, wherein the chuck is configured to be movable between the first stage and the second stage.   The processing apparatus according to claim 1, further comprising a coating unit that includes a plurality of nozzles that discharge the resist and that applies the resist to the transfer target.   The processing apparatus according to claim 1, wherein the control unit controls an application amount distribution of the resist applied to the transfer target based on the density of the pattern. A processing method of transferring the pattern to the transferred body by pressing a mold on which a pattern is formed against a resist applied to the transferred body,
Measuring the surface shape and / or thickness distribution of the transferred body before bringing the mold into contact with the resist;
Determining a coating amount distribution of the resist to be applied to the transfer object based on the measurement result measured in the measurement step;
And a step of applying the resist to the transfer object according to the application amount distribution determined in the determining step. Contacting the mold and the resist applied to the transfer object in the application step;
And repeating the measurement step, the determination step, the application step, and the contact step,
The processing method according to claim 8, wherein at least a part of the measurement step and the contact step overlap in time. Using the processing device according to claim 1 to transfer a pattern to a transfer target;
Etching the transferred object to which the pattern has been transferred.