JP4217551B2 - Fine processing method and fine processing apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present invention provides a master for fine processing such as semiconductor manufacturing.UnevenpatternTheWork pieceSurface ofPress to transferFineProcessing method andFineThe present invention relates to a processing apparatus.
[0002]
[Prior art]
Nanoimprint lithography has been proposed as an alternative to a method for forming a fine pattern on a semiconductor substrate using ultraviolet rays, X-rays, or an electron beam (see Patent Documents 1 and 2).
[0003]
Hereinafter, a conventional technique will be described with reference to FIG.
[0004]
In FIG. 10 (1), a pattern is drawn, and a mold 101 as an original plate is fixed to a mold table 102. On the substrate side, a resist 104 for patterning is applied on the wafer 103.
[0005]
Next, the nanoimprint process will be described. The mold 101 and the wafer 103 are opposed to each other as shown in FIG. 10A, and the mold 101 is pressed against the resist 104 as shown in FIG. 10B, whereby the pattern drawn on the mold 101 is transferred to the resist 104. Then, when the mold 101 is released from the resist 104, irregularities are formed in the resist 104 according to the pattern of the mold 101 as shown in FIG. 10C, and then by reactive ion etching (RIE) as shown in FIG. Patterning is possible.
[0006]
[Patent Document 1]
US Pat. No. 5,772,905
[Patent Document 2]
JP 2000-232095
[0007]
[Problems to be solved by the invention]
However, the above conventional example has the following drawbacks.
[0008]
In nanoimprint processing, very fine uneven pattern transfer is performed by an extremely simple method called pressing. The processing conditions depend on the mechanical characteristics of the mold and target. When applying nanoimprint processing to mass production or practical use, it is necessary to make it adaptable to molds and targets having various characteristics. Even when the same type of mold and target are used, it is necessary to adapt to individual differences between lots and characteristic differences due to changes over time. Furthermore, a fail-safe mechanism for preventing damage to the mold and target due to unexpected troubles of the apparatus is necessary. For example, if the mold is pressed with an excessive force, the mold or the target may be damaged. However, these points are not considered in the conventional method, and it is difficult to apply to mass production and practical use.
[0009]
Accordingly, an object of the present invention is to provide a fine processing apparatus and a fine processing method suitable for mass production and practical use.
[0014]
[Means for Solving the Problems]
  A micromachining method according to one aspect of the present invention is a micromachining method in which an original plate is pressed against the surface of a workpiece, and the pattern of the unevenness of the original plate is inverted and transferred to the workpiece.
  By pressing meansWith a predetermined pressing forcePress the original plate against the standard workpieceDistance between the original plate and the reference workpieceMeasure
  Based on the measurement result, the control parameter of the pressing meansPressing force or distance between the original plate and the workpieceIt is a fine processing method characterized by adjusting.
[0015]
  Further, the micromachining method according to another aspect of the present invention is a micromachining method for inverting and transferring an uneven pattern of the original to the workpiece by pressing the original against the surface of the workpiece.
  By pressing meansWith a predetermined pressing forcePress the reference master against the workpieceDistance between the reference original plate and the workpieceMeasure
  Based on the measurement result, the control parameter of the pressing meansPressing force or distance between the original plate and the workpieceIt is a fine processing method characterized by adjusting.
[0018]
  Further, the micromachining apparatus according to another aspect of the present invention is a micromachining apparatus that reverses and transfers the uneven pattern of the original to the workpiece by pressing the original against the surface of the workpiece.
  Holding means for holding the original plate;
  Has a reference originalAnd
  The pressing is performed by pressing the reference original plate against the workpiece with a predetermined pressing force to measure the distance between the reference original plate and the workpiece, and pressing force as a control parameter or the original plate and the workpiece. Adjust the distance based on the measurement resultThis is a fine processing apparatus characterized by the above.
[0019]
  Further, the micromachining apparatus according to another aspect of the present invention is a micromachining apparatus that reverses and transfers the uneven pattern of the original to the workpiece by pressing the original against the surface of the workpiece.
  Holding means for holding the workpiece;
  With reference workpieceAnd
  The pressing measures the distance between the original plate and the reference workpiece by pressing the original plate against the reference workpiece with a predetermined pressing force, and the pressing force as a control parameter or the original plate and the workpiece. Adjust the distance based on the measurement resultThis is a fine processing apparatus characterized by the above.
[0026]
Further objects or other features of the present invention will become apparent from the preferred embodiments described with reference to the accompanying drawings.
[0027]
DETAILED DESCRIPTION OF THE INVENTION
Details of a preferred embodiment of the present invention will be described below with reference to the accompanying drawings.
[0028]
[First Embodiment]
FIG. 4 shows the configuration of the nanoimprint microfabrication apparatus of this example. In FIG. 4, a mold 1 as an original on which a transfer pattern composed of irregularities is drawn is fixed to a mold table 2 as a mold holding means. The mold table 2 is mounted on the mold stage 3. The pressing stage 5 as a mold pressing means is attached to the frame 10 and performs pressing by driving the mold stage 3 in the + Z and −Z directions in the figure. The pressing force by the pressing stage 5 is measured by force measuring means 4 such as a strain gauge or a spring balance. The pressing stage 5 is driven by a linear motor or air.
[0029]
A resist 7 for patterning is applied to the wafer 6 to be a transfer target. For example, PMMA (polymethylmethacrylate) is used as the resist. The wafer 6 is held by a wafer chuck 8, and the wafer chuck 8 is mounted on a wafer stage 9. The wafer stage has a degree of freedom with respect to the six axes X, Y, Z, ωx, ωy, and ωz in the figure, and the wafer position can be precisely controlled.
[0030]
A mold temperature measuring means 11 and a mold temperature adjusting means 12 are installed in the vicinity of the mold table 2. The mold temperature can be measured by the mold temperature measuring means 11 and adjusted by the mold temperature adjusting means 12.
[0031]
The wafer chuck 8 is provided with a wafer temperature measuring means 13 and a wafer temperature adjusting means 14. The wafer temperature can be measured by the wafer temperature measuring means 13 and adjusted by the wafer temperature adjusting means 14. Here, for example, a thermocouple, a platinum thermometer, or the like may be used as the wafer temperature measuring means 13, and the temperature adjustment using a fluid such as a heater, a Peltier element, or water is used as the wafer temperature adjusting means 14. May be used.
[0032]
Prior to the transfer, a relative displacement between the mold 1 and the wafer 6 is measured and corrected by a displacement measurement means (not shown). A known technique may be used for the positional deviation measuring means for the mold 1 and the wafer 6, and the positional deviation correction is performed by the wafer stage 9.
[0033]
Next, the control block of the present embodiment will be described with reference to FIG.
[0034]
The overall control unit (S0501) controls the entire sequence of the processing apparatus, and provides an interface with the outside of the apparatus and a man-machine interface to the operator.
[0035]
The transfer control unit (S0511) drives and controls the wafer transfer unit (S0512) and the mold transfer unit (S0513) according to a command from the overall control unit (S0501).
[0036]
The wafer stage control unit (S0509) drives and controls the wafer stage drive unit (S0510) according to a command from the overall control unit (S0501).
[0037]
The mold control unit (S0502) controls the mold pressing unit (S0506), the mold temperature adjusting unit (S0507), and the wafer temperature adjusting unit (S0508) according to a command from the overall control unit (S0501).
[0038]
FIG. 5 only shows an example of the control block of this embodiment, and there are many other configurations for achieving the same object.
[0039]
Next, the operation of this embodiment will be described with reference to FIGS.
[0040]
FIG. 1 is an overall processing flow of a fine processing method using the nanoimprint processing apparatus of this embodiment.
[0041]
S0101 is a process of transporting the mold 1 from the outside of the processing apparatus to the mold table 2 using a mold transport system (not shown in FIG. 4).
Steps S0102 and S0107 are steps of transferring the wafer 6 from the outside of the processing apparatus to the wafer chuck 8 using a wafer transfer system (not shown in FIG. 4).
[0042]
The main point of the present invention is to perform the condition setting step of S0102 to S0106 in the nanoimprint processing flow.
[0043]
That is, it is important to obtain the optimum processing conditions by the processes of S0102 to S0106 before performing the processed wafer pressing process S0108.
The condition-taking wafer that has completed the condition setting process of S0102 to S0104 is carried out of the nanoimprint processing apparatus, and the condition setting wafer post-processing process S0105 is performed. The post-processed wafer is observed with an observation apparatus, and the optimum value of the processing conditions is determined (S0106).
[0044]
After setting the optimum processing conditions to the overall control unit (S0501), the main processing wafer is carried in (S0107), the main processing wafer pressing processing (S0108) is performed, and then it is carried out of the processing apparatus (S0109). ). This processing step of S0107 to S0109 is repeated as many times as necessary.
[0045]
The detailed operation of the conditioned wafer pressing process (S0103) of this embodiment will be described with reference to FIG.
[0046]
First, processing parameters for performing the condition setting are set (S0103-01). In this embodiment, three types of pressing force, mold temperature, and wafer temperature and their respective drive transient characteristics are used as processing parameters. The pressing force is the most fundamental parameter in the pressing process. The mold temperature and the wafer temperature are parameters that affect the elasticity of the mold and the target, and there should be a temperature suitable for the material. In the present embodiment, paying attention to the relationship between the pressing force and the elasticity of the material, the above parameters are adopted. Further, when driving the pressing force, mold temperature, and wafer temperature, the transient characteristics are also controlled, so that more precise processing can be performed. In particular, it is desirable to set the transient characteristics of the pressing force in accordance with the elasticity of the material.
[0047]
The processing parameters are set by the operator or loaded in advance with a job file created in the overall control unit (S0501) in FIG.
[0048]
Next, in the processing condition measurement step (S0103-02), the pressing force, mold temperature, and wafer temperature at that time are measured. In the following description with reference to FIG. 5, the mold control unit (S0502) obtains the measured value by the force measurement unit (S0503), the mold temperature measurement unit (S0504), and the wafer temperature measurement unit (S0505), respectively, and the overall control unit Notify (S0501).
[0049]
In the machining condition adjustment step (S0103-03), the overall control unit (S0501) notifies the mold control unit (S0502) of the machining parameter values determined based on the measurement values measured in the machining condition measurement step, and drives the drive. Command. The mold controller (S0502) drives the mold pressing unit (S0506), the mold temperature adjusting unit (S0507), and the wafer temperature adjusting unit (S0508) according to the commanded parameter values.
[0050]
Next, in the processing condition measurement step (S0103-04), the pressing force, mold temperature, and wafer temperature as a result of driving in the processing condition adjustment step (S0103-03) are measured again and notified to the overall control unit (S0501). To do.
[0051]
In the next machining condition comparison (S0103-05) step, the overall control unit (S0501) compares the set drive target value with the measured value after driving. If the difference is within the predetermined allowable range, the process proceeds to the conditional processing end determination (S0103-06) step. When the difference is outside the allowable range, the process returns to the machining condition adjustment step (S0103-03), and the retry operation is performed within the determined number of times. If you do not want to retry, set the maximum number of times to one.
[0052]
In the conditional processing end judgment (S0103-06) step, it is determined whether or not the conditional processing process is to be ended. . At that time, it is possible to move to another shot.
[0053]
FIG. 3 shows a flow of the wafer pressing main processing step (S0108). In this embodiment, as in the condition-conditioning wafer pressing process (S0103), the procedure is measurement → drive → measurement. When the processing time is more important, the measurement can be omitted and only S0108-06 and 07 can be executed.
As another form of the present embodiment, it is also possible to perform pressing by driving the Z axis on the wafer stage side.
[0054]
In addition, the configuration of this embodiment is such that wafer processing and processing condition setting are performed outside the apparatus, but it is naturally possible to configure such that processing can be performed within the same apparatus.
[0055]
[Second Embodiment]
FIG. 8 shows the configuration of the nanoimprint microfabrication apparatus of the second embodiment of the present invention. The difference between this embodiment and the first embodiment is that the wafer surface is divided into a plurality of regions and conditions are applied to each region.
[0056]
The laser interferometer 21 measures the position of the mold table 2 with respect to the reference point of the apparatus. Since the position of each of the three points is measured, information on Z, ωx, and ωy of the mold table 2 can be obtained. The wafer height measuring means 22 is fixed to an immovable part of the mold stage base, and can measure the Z distance of one point on the wafer surface with the mold stage base as a reference. By driving the X and Y axes of the wafer stage and measuring a plurality of points on the wafer surface, Z, ωx, and ωy information on the wafer surface can be obtained. From the above information, the relative Z, ωx, ωy relationship between the mold stage 3 and the wafer stage 9 can be obtained. In the present embodiment, the mold stage 3 has a degree of freedom with respect to the three axes Z, ωx, and ωy by the mold stage driving unit 15. The pressing operation of this embodiment is performed by the Z drive mechanism of the mold stage 3.
[0057]
Next, the control block of the present embodiment will be described with reference to FIG.
[0058]
The wafer stage control unit (S0909) drives and controls the wafer stage drive unit (S0910) according to a command from the overall control unit (S0901). The point that characterizes this embodiment is that the following operation is performed.
[0059]
The wafer stage control unit (S0909) obtains measured values of three or more points determined on the wafer from the wafer height measuring means (S0922), and divides Z, ωx, Obtain ωy. The minimum number of divided surfaces obtained by dividing the wafer is 1. In this case, the entire wafer surface is represented by a set of “Z, ωx, ωy] coordinates.
[0060]
The obtained Z, ωx, ωy information of the wafer surface is converted into a difference value from the virtual reference plane and stored in the overall control unit (S0901).
[0061]
The mold control unit (S0902) is instructed by the overall control unit (S0901) for target values of Z, ωx, and ωy of the mold stage. Accordingly, the Z, ωx, and ωy axis driving of the mold stage is controlled.
[0062]
FIG. 9 only shows an example of the control block of the present embodiment, and there are a number of other configurations for achieving the same object.
[0063]
The overall processing flow of this embodiment is almost the same as that in FIG. 1, but is different in the wafer pressing process.
[0064]
The detailed operation of the conditioned wafer pressing process (S0103) of this embodiment will be described with reference to FIG.
[0065]
First, using the wafer height measuring means, the height of a grid point obtained by dividing the wafer on, for example, 10 mm × 10 mm is measured (S0103-11). The pitch of the grating may be determined from the mold area, wafer flatness, etc., and is not limited to this dimension. The operation of driving the wafer stage in the XY directions and aligning the measurement point of the wafer with the measurement point of the measurement means is repeated as many times as necessary. The measurement result is notified from the wafer stage control unit (S0909) to the overall control unit (S0901). From this information, the overall control unit (S0901) creates Z mapping data on the wafer surface.
[0066]
Next, processing parameters for setting the drive conditions are set (S0103-12). In this embodiment, the Z of the wafer at the center of the area to be pressed is controlled so as to always have a constant value. The wafer area ωx, ωy is set and controlled on the assumption that it is parallel to the mold surface. In this case, assuming that the mold surface is parallel to the bottom surface, ωx and ωy of the wafer area are matched with the virtual mold surface.
[0067]
The ωx and ωy of the mold are parameters for correcting the angle of the mold surface. This is for removing the influence at the time of pressing due to an angle error at the time of creating the mold bottom surface and the surface because the mold bottom surface is attached to the mold table as a reference surface. Further, in many cases, it is desirable that the mold surface and the wafer surface be parallel, but depending on the characteristics of the mold, it may be possible to obtain better results by providing an angle. Even in this case, it is possible to obtain more suitable processing conditions according to the present embodiment.
[0068]
The Z of the mold can be said to be the condition that most affects the processing result in the pressing processing of the present embodiment. In addition, it is considered that the Z drive transient characteristic has an optimum value depending on the mold characteristic.
[0069]
In view of the above, in this embodiment, the mold Z and its transient characteristics, molds ωx and ωy are used as processing parameters.
[0070]
In the next wafer coordinate driving step (S0103-13), the overall control unit (S0901) drives the wafer area to be subjected to the conditional processing to the processing position based on the mapping data.
[0071]
Next, in the mold driving step (S0103-13), the overall control unit (S0901) drives the molds ωx and ωy of the processing conditions first, and then presses and drives the mold in the processing conditions Z and its transient characteristics.
[0072]
In the next mold pressing releasing step (S0103-14), the pressing of the mold Z is released in order to make the wafer stepable.
[0073]
When machining under different conditions, the process returns to the machining parameter setting step (S0103-12) and the necessary conditions are machined.
[0074]
In this embodiment, the servo control of the wafer stage position and the mold stage position is performed based on the measured value. Therefore, the measurement condition confirmation step is omitted.
[0075]
FIG. 7 shows a flow of the wafer pressing main processing step (S0108) of this embodiment. Since the drive order of each axis is the same as that in the above-described condition processing step (S0103), description thereof is omitted.
[0076]
As another form of the present embodiment, it is also possible to perform pressing by driving the Z axis on the wafer stage side.
[0077]
As another form of the present embodiment, a means for measuring the angle of the mold surface may be provided and used as information for setting the angle of the mold surface.
[0078]
[Third Embodiment]
The feature of this embodiment is that the processing control parameter is the pressing force, the processing correction parameter is the pressing force, and the measurement parameter is the distance between the mold and the wafer. The pressing force is corrected based on the distance measurement result during pressing.
[0079]
FIG. 13 shows the configuration of the nanoimprint microfabrication apparatus of this example. In FIG. 13, a mold 1 serving as an original on which a transfer pattern composed of unevenness is drawn is fixed to a mold base 2. The mold table 2 is mounted on the mold stage 3. The pressing stage 5 is attached to the frame 10, and pressing is performed by driving the mold stage 3 in the + Z and -Z directions in the figure. The pressing force by the pressing stage 5 is measured by the force measuring means 4.
[0080]
A resist 7 for patterning is applied to the wafer 6 to be a transfer target. For example, PMMA is used as the resist. The wafer 6 is held by a wafer chuck 8, and the wafer chuck 8 is mounted on a wafer stage 9. The wafer stage has a degree of freedom with respect to the six axes X, Y, Z, ωx, ωy, and ωz in the figure, and the wafer position can be precisely controlled.
[0081]
The laser interferometer 21 measures the position of the mold table 2 with respect to the reference point of the apparatus. Since the positions of three points are measured, information on Z, ωx, and ωy of the mold stage 3 can be obtained. The wafer height measuring means 22 is fixed to an immovable part of the mold stage base, and can measure the Z distance of one point on the wafer surface with the mold stage base as a reference. By driving the X and Y axes of the wafer stage and measuring a plurality of points on the wafer surface, Z, ωx, and ωy information on the wafer surface can be obtained. From the above information, the relative Z, ωx, ωy relationship between the mold stage 3 and the wafer stage 9 can be obtained. In the present embodiment, the mold stage 3 has a degree of freedom with respect to the three axes Z, ωx, and ωy by the mold stage driving unit 15. The pressing operation of this embodiment is performed by the Z drive mechanism of the mold stage 3.
[0082]
Prior to the transfer, relative positional deviations in the XY directions of the mold 1 and the wafer 6 are measured and corrected by a positional deviation measuring means (not shown). A known technique may be used for the positional deviation measuring means for the mold 1 and the wafer 6, and the positional deviation correction is performed by the wafer stage 9.
[0083]
Next, the control block of the present embodiment will be described with reference to FIG.
[0084]
The overall control unit (S1401) controls the sequence of the entire processing apparatus, and provides an interface with the outside of the apparatus and a man-machine interface to the operator.
[0085]
The transfer control unit (S1408) drives and controls the wafer transfer unit (S1409) and the mold transfer unit (S1410) according to a command from the overall control unit (S1401). The wafer stage control unit (S1405) drives and controls the wafer stage drive unit (S1405) according to a command from the overall control unit (S1401). The point that characterizes this embodiment is that the following operation is performed.
[0086]
The wafer stage control unit (S1405) obtains measured values of three or more points determined on the wafer from the wafer height measuring means (S1406), and divides Z, ωx, Obtain ωy. The minimum number for dividing a wafer is 1, in which case the entire wafer surface is represented by a set of “Z, ωx, ωy” coordinates.
[0087]
The obtained Z, ωx, ωy information of the wafer surface is converted into a difference value from the virtual reference plane and stored in the overall control unit (S1401).
[0088]
The mold controller (S1402) is instructed by the overall controller (S1401) for target values of Z, ωx, and ωy of the mold stage. Accordingly, the Z, ωx, and ωy axis driving of the mold stage is controlled.
[0089]
FIG. 14 only shows an example of the control block of this embodiment, and there are many other configurations for achieving the same object.
[0090]
Next, the operation of this embodiment will be described with reference to FIG.
[0091]
FIG. 11 is a processing flow for one wafer of the nanoimprint processing apparatus of this embodiment.
[0092]
S1101 is a process of transporting the mold 1 from the outside of the processing apparatus to the mold table 2 using a mold transport system (not shown in FIG. 13). At this time, if another mold is mounted on the mold table 2 by the previous process, the previous mold is removed and then the mold to be used is mounted.
[0093]
Step S <b> 1102 is a step of transporting the wafer 6 from the outside of the processing apparatus to the wafer chuck 8 using a wafer transport system (not shown in FIG. 13).
[0094]
S1103 is a step of setting an initial value of the pressing force target value at the time of pressing and an initial value of the drive correction amount. Here, it is assumed that the initial value of the pressing force target value is set to F1 and the initial value of the drive correction amount is set to 0.
[0095]
Next, feedback to the drive correction condition in the pressing process, which is the main point of the present embodiment, will be described.
[0096]
In the state where the first shot is pressed (S1104), the pressing force is the initial value F1 set in S1103. In this state, wafer height measurement (S1105) and mold height measurement (S1106) are performed, and the distance between the mold reference surface and the wafer reference surface is calculated. Thereby, it can be seen how much the mold is pushed in with a predetermined driving force. If the wafer side or the mold side is softer than expected, it is pushed deeper, and if it is harder than assumed, it is pushed shallower. With reference to the predetermined relationship between the pressing force and the distance, it is determined whether or not the distance measurement result at this time is within an allowable range (S1107). The correction amount is determined by the distance measurement result for the target value. If the target value is not changed, the allowable range of distance remains unchanged even if the correction amount is changed.
[0097]
For example, conditions as shown in FIG. 12 are set in advance. In FIG. 12, the characteristic of the design value is the curve C, and the area between the curve A and the curve B is within the allowable range. If it is outside the allowable range, the pressing force target value is corrected (S1108). For example, when the result of pressing with the initial pressing force target value F1 is the point Z1, the distance is outside the allowable range. From this state, correction is made so as to be within an allowable range (distance is between D1−Dd and D1 + Du). With reference to the design curve C, the drive correction amount ΔF1 is set so that the distance becomes D1. Next, the process proceeds to step S1104, and the pressing is continued with the force of F1 + ΔF1 = F2. Similarly, wafer height measurement (S1105) and mold height measurement (S1106) are performed. As a result, in this example, the point moved to the point Z2. The distance was slightly different from D1, but was within the allowable range from D1-Dd to D1 + Du. This operation is repeated until the distance measurement result is within the allowable range. However, although not shown in FIG. 11, an upper limit is set for the number of loops.
[0098]
After the pressing of the first shot is completed, a determination is made for the predetermined number of shots (S1109). If there are remaining shots, the pressing is released and the wafer stage is driven to the second shot position (S1110). The second shot is pressed with the total amount of the correction amount determined in the first shot and F1 (S1104). In step S1107 of the second shot, the target value remains F1, so that the allowable range of distance is between D1−Dd and D1 + Du, as in the first shot. Therefore, if the physical factors related to the pressing of the first shot and the second shot are almost the same, the process should proceed without changing the correction amount for the second shot. After the third shot, the same processing steps are performed up to the final shot, and the wafer is carried out of the apparatus (S1111).
[0099]
Since the above is the processing step for one wafer, the steps S1105, S1106, and S1107 may be omitted. If it is not necessary to exchange the mold for processing the second and subsequent wafers, the step of carrying in the mold (S1101) is omitted.
[0100]
The characteristics shown in FIG. 12 are an example for explanation, and may actually be set according to the characteristics of the mold, processing accuracy, and the like.
[0101]
As another form of the present embodiment, it is also possible to perform pressing by driving the Z axis on the wafer stage side. In this case, the wafer stage becomes the pressing means.
It is also conceivable that the target value of the pressing force is specified not only as a static value but also as a characteristic considering time variation. However, since it is difficult to provide feedback for the shot, it is necessary to feed back to the processing conditions after the next shot.
[0102]
[Fourth Embodiment]
The feature of this embodiment is that it has a mold calibration process for pressing the working mold against the reference target, and a wafer calibration process for pressing the reference mold against the workpiece wafer. The control parameter for processing is the pressing force. The processing control parameter is corrected based on the distance information between the mold and the wafer with respect to the driving force obtained in the calibration process.
[0103]
FIG. 16 shows the configuration of the nanoimprint microfabrication apparatus of this example. Description of the same parts as those in the third embodiment is omitted.
[0104]
In FIG. 16, the reference mold 31 is held on a reference mold table 32. The mold table 32 has a mechanism that allows the reference mold 31 to be replaced. The reference mold is made of a material and shape suitable for wafer calibration. For example, the same material as the mold used during processing is used. The reference wafer 33 is held on a reference wafer table 35, and the reference wafer table 35 has a mechanism capable of replacing the reference wafer 33. In this embodiment, since a wafer is used as a target to be processed, a wafer cut out accordingly is used as a reference target. A resist 34 may be applied to the reference wafer, or may not be applied depending on the purpose.
[0105]
The laser interferometer 21 measures the position of the mold table 2 with respect to the reference point of the apparatus. From this measurement result, the height information of the mold 1 and the reference mold 31 can be acquired.
[0106]
The wafer height measuring means 22 is an optical distance measuring sensor. The height of the surface of the wafer 6 and the surface of the reference wafer 35 can be measured.
[0107]
Next, the operation of this embodiment will be described with reference to FIG.
[0108]
FIG. 15 is a processing flow for one wafer of the nanoimprint processing apparatus of this embodiment.
[0109]
S1501 is a process of transporting the mold 1 from the outside of the processing apparatus to the mold table 2 using a mold transport system (not shown in FIG. 16). If another mold is mounted on the mold base 2 by the previous process, the previous mold is removed and then the mold to be used is mounted.
[0110]
S1502 is a step of setting an initial value of the pressing force target value at the time of pressing.
[0111]
  S1503 is a step of pressing the mold 1 against the reference wafer 33 to calibrate the mold pressing characteristics. The wafer stage 9 is driven in the XY directions so that the reference wafer 33 faces the processing mold 1. Next, the processing mold 1 is pressed against the reference wafer 33 with a predetermined pressing force. The height of the reference wafer 33 and the height of the reference surface of the mold 1 at that time are measured, and the distance between the mold 1 reference surface and the wafer is calculated. Thereby, it can be seen how much the mold is pushed in with a predetermined driving force. If the mold side is softer than expected, it is pushed deeper, and if it is harder than expected, it is pushed shallower. With reference to a predetermined relationship between the pressing force and the distance, the pressing force is corrected by the mold factor. The method of correction is3Implementation ofFormIt is the same as that described in.
[0112]
S1504 is a process of transporting the wafer 6 from the outside of the processing apparatus to the wafer chuck 8 using a wafer transport system (not shown in FIG. 16).
[0113]
  In step S1505, the reference mold 31 is pressed against the workpiece wafer 6 to calibrate the mold pressing characteristics. The wafer stage 9 is driven in the XY directions so that the workpiece wafer 6 faces the reference mold 31. At this time, in the configuration of FIG. 16, the wafer height is measured by the wafer height measuring unit 22 by moving the wafer stage to the −X side and causing the reference mold 31 to face the + X side portion on the wafer 6. be able to. Next, the reference mold 31 is pressed against the workpiece wafer 6 with a predetermined pressing force. The height of the wafer 6 to be processed and the height of the reference surface of the reference mold 31 at that time are measured, and the distance between the reference surface of the reference mold 31 and the wafer 6 to be processed is calculated. Thereby, it can be seen how much the mold is pushed in with a predetermined driving force. If the wafer side is softer than expected, it is pushed deeper, and if it is harder than assumed, it is pushed shallower. With reference to the predetermined relationship between the pressing force and the distance, the pressing force due to the wafer factor is corrected. The method of correction is3Implementation ofFormIt is the same as that described in.
  With the above operation, the pressing characteristics due to the mold factor and the wafer factor are calibrated.
[0114]
In the mold pressing step of S1506, processing is performed with the corrected pressing force target value. Thereafter, a predetermined number of shots are processed, and the processed wafer is carried out of the apparatus (S1508).
[0115]
The above is the processing process for one wafer. If it is not necessary to replace the mold for processing the second and subsequent wafers, the steps S1501 to S1503 are omitted.
[0116]
In this embodiment, the processing control parameter is the pressing force, and this pressing force is corrected. However, the processing control parameter may be the distance (interval) between the mold and the wafer.
[0117]
[Fifth Embodiment]
The feature of this embodiment is that the processing control parameter is the pressing force, the processing correction parameter is the pressing force, and the measurement parameter is the mold temperature. The pressing force is corrected by the amount of deviation of the mold temperature from the predetermined temperature.
[0118]
FIG. 18 shows the configuration of the nanoimprint microfabrication apparatus of this example. Description of the same parts as those in the third embodiment is omitted.
[0119]
The mold temperature measuring means 41 can measure the temperature of the mold 1.
Next, the operation of this embodiment will be described with reference to FIG.
[0120]
FIG. 17 is a flow for one wafer of the nanoimprint processing apparatus of this embodiment.
[0121]
S1701 is a process of transporting the mold 1 from the outside of the processing apparatus to the mold table 2 using a mold transport system (not shown in FIG. 18). At this time, if another mold is mounted on the mold table 2 by the previous process, the previous mold is removed and then the mold to be used is mounted.
[0122]
Step S1702 is a process of transporting the wafer 6 from the outside of the processing apparatus to the wafer chuck 8 using a wafer transport system (not shown in FIG. 18).
[0123]
S1703 is a step of setting an initial value of the pressing force target value at the time of pressing and an initial value of the drive correction amount. Here, it is assumed that the initial value of the pressing force target value is set to F3 and the initial value of the drive correction amount is set to 0.
[0124]
S1704 is a step of pressing the mold 1 against the wafer 6 to be processed. In this state, mold temperature measurement (S1705) is performed. This temperature is compared with a predetermined temperature, and it is determined whether or not the temperature measurement result at this time is within an allowable range by referring to a predetermined relationship between the temperature deviation amount and the pressing force correction amount (S1706). The correction amount is determined by the distance measurement result for the target value. If the target value is not changed, the allowable range of distance remains unchanged even if the correction amount is changed.
[0125]
For example, conditions as shown in FIG. 19 are set in advance. In FIG. 19, the characteristic of the pressing force correction amount with respect to the temperature deviation amount is a curve D, and the deviation from the assumed temperature is in a range of −Tu to + Td. If it is outside the allowable range, a correction amount is set (S1707). For example, it is assumed that the temperature deviation amount when pressing with the initial pressing force target value F3 is ΔT3 (point Z3). In this case, the temperature deviation amount is outside the allowable range. When the correction amount of the pressing force is read from the curve D, it is ΔF3, so ΔF3 is set as the correction value of the pressing force. Next, the process proceeds to step S1704, and the pressing is continued with the force of F3 + ΔF3. The mold temperature is measured again (S1705), and it is determined whether it is within the allowable range (S1706). This loop is repeated until the temperature is within an acceptable range. Thus, the pressing process for the first shot is completed. As can be easily imagined, the upper limit of the number of retries is set in this loop, and if the upper limit is exceeded, it is determined that the processing of the shot is abnormal.
[0126]
After the pressing of the first shot is completed, a determination is made for the predetermined number of shots (S1708). If there are remaining shots, the pressing is released and the wafer stage is driven to the second shot position (S1709). The second shot is pressed with the total amount of the correction amount determined in the first shot and F3 (S1704). In the step S1706 of the second shot, the target value remains F3, so that the allowable range of distance is between -Td and + Tu, as in the first shot. Therefore, if the physical factors related to the pressing of the first shot and the second shot are almost the same, the process should proceed without changing the correction amount for the second shot. After the third shot, the same processing steps are performed up to the final shot, and the wafer is unloaded from the apparatus (S1710).
[0127]
In this embodiment, the mold temperature is used as a measurement parameter. However, depending on the purpose, a method that considers the wafer temperature is also conceivable.
[0128]
[Sixth Embodiment]
Other embodiments will be described.
[0129]
In this example, the processing control parameter is the distance between the mold and the wafer, the correction parameter is the distance between the mold and the wafer, and the measurement parameter is the pressing force. This form can be easily understood when the distance and the pressing force in the third embodiment are exchanged.
[0130]
In this example, a distance servo drive system is configured. The target is given as a distance, and the mold is positioned by measuring the distance between the mold and the wafer.
[0131]
As the correction characteristics, for example, conditions as shown in FIG. 20 are set in advance. In FIG. 20, the characteristic of the design value is the curve J, and the area between the curve G and the curve H is within the allowable range. If it is outside the allowable range, the target distance value is corrected. For example, when the result of pressing with the initial distance target value D3 is the point Z3, the distance is outside the allowable range. From this state, correction is made so as to be within an allowable range (the pressing force is between F3−Fd and F3 + Fu). With reference to the design curve J, the distance target value is corrected to D4 so that the pressing force is F3. Next, the pressing is continued with the corrected target value. As a result, in this example, the point moved to the point Z4. The pressing force at this time was slightly deviated from F3, but entered an allowable range between F3-Fd and F3 + Fu. The loop is repeated within a predetermined number of times until the pressing force result falls within the allowable range.
[0132]
[Seventh Embodiment]
Other embodiments will be described.
[0133]
In this example, the processing control parameter is the distance between the mold and the wafer, the correction parameter is the distance between the mold and the wafer, and the measurement parameter is the mold temperature. This form can be easily understood when the distance and the pressing force in the fifth embodiment are replaced.
[0134]
The correction method is almost the same as in the fifth embodiment. If the matter relating to the pressing force in FIG. 19 is replaced with the distance, it can be understood as it is, so that it is replaced with the description.
[0135]
[Eighth Embodiment]
The feature of this embodiment is that the pressing force is measured at the time of machining, the measured value is judged based on a predetermined abnormality judgment condition, and a warning or machining interruption is taken if necessary.
[0136]
FIG. 23 shows the configuration of the nanoimprint microfabrication apparatus of this example. In FIG. 23, a mold 1 serving as an original on which a transfer pattern composed of unevenness is drawn is fixed to a mold base 2. The mold table 2 is mounted on the mold stage 3. The pressing stage 5 is attached to the frame 10, and pressing is performed by driving the mold stage 3 in the + Z and -Z directions in the figure. The pressing force by the pressing stage 5 is measured by the force measuring means 4.
[0137]
A resist 7 for patterning is applied to the wafer 6 to be a transfer target. For example, PMMA is used as the resist. The wafer 6 is held by a wafer chuck 8, and the wafer chuck 8 is mounted on a wafer stage 9. The wafer stage 9 has a degree of freedom with respect to the six axes X, Y, Z, ωx, ωy, and ωz in the figure, and the wafer position can be precisely controlled.
[0138]
Prior to the transfer, relative positional deviations in the XY directions of the mold 1 and the wafer 6 are measured and corrected by a positional deviation measuring means (not shown). A known technique may be used for the positional deviation measuring means for the mold 1 and the wafer 6, and the positional deviation correction is performed by the wafer stage 9.
[0139]
Next, the control block of the present embodiment will be described with reference to FIG.
[0140]
The console (S2401) provides an external interface and a man-machine interface to the operator.
[0141]
The overall control unit (S2402) controls the sequence of the entire processing apparatus.
[0142]
The abnormality detection unit (S2403) receives the measurement value from the pressing force measurement unit (S2407), and determines the state based on a predetermined condition. The determination result can be notified to the overall control unit (S2402) and the mold control unit (S2404). The mold control unit (S2404) controls the mold pressing means (S2408) according to a command from the overall control unit (S2402). The mold pressing means (S2408) is an actuator that generates a pressing force according to a command value of a given force.
[0143]
The wafer stage control unit (S2405) drives and controls the wafer stage drive unit (S2409) according to a command from the overall control unit (S2402).
[0144]
The transfer control unit (S2406) drives and controls a wafer transfer unit (S2410) and a mold transfer unit (S2411) (not shown in FIG. 23) according to a command from the overall control unit (S2402).
[0145]
FIG. 24 only shows an example of the control block of the present embodiment, and there are a number of other configurations for achieving the same object.
[0146]
Next, the operation of this embodiment will be described with reference to FIG.
[0147]
FIG. 21A is a processing flow for one wafer of the nanoimprint processing apparatus of this embodiment.
[0148]
S2101 is a process of transporting the mold 1 to the mold table 2 using the mold transport system. At this time, if another mold is mounted on the mold table 2 by the previous process, the previous mold is removed and then the mold to be used is mounted.
[0149]
Step S2102 is a process of transporting the wafer 6 to the wafer chuck 8 using the wafer transport system.
[0150]
S2103 is a step of setting the command value F1 of the pressing force at the time of pressing, the abnormality determination values F2 to F4, and the delay value.
[0151]
Subsequently, the abnormality determination process is started (S2104), the abnormality monitoring flag is turned ON (S2105), the first shot is pressed (S2106), the abnormality monitoring flag is turned OFF (S2107), and the pressing is released ( S2108).
[0152]
Here, the abnormality determination method in the pressing step, which is the main point of the present embodiment, will be described.
[0153]
The abnormality determination process in FIG. 21 (2) is a process executed in parallel with the one wafer processing process. While the process is activated and the abnormality monitoring flag is ON, the pressing force is monitored, and if it is determined to be an abnormal value, a predetermined action is performed.
[0154]
Check whether the abnormality monitoring flag is ON (start) (S2121). If it is ON, after waiting for the set delay (S2122), the process proceeds to the abnormality monitoring flag end check (S2123). The delay is provided in order not to output a meaningless abnormality determination until the pressing force reaches a predetermined value from the start of pressing. When the flag check in S2123 is ON, abnormality determination (S2125) is performed on the result of the pressing force measurement (S2124). The method of abnormality determination will be described later. If normal, the process returns to S2123 to continue the loop. If a result other than normal is obtained in S2125, an action is performed according to the type of abnormality. If the result is a warning, the warning history is set for the console (S2128) and the warning is displayed on the console display (S2129). Then, returning to (S2123), the loop is continued. If the result of branching due to the abnormal type (S2126) is a processing interruption, a processing interruption interrupt process is immediately performed (S2127).
[0155]
If only normal or warning is issued, it is detected in S2123 that the abnormality monitoring flag is turned off, and the process ends.
[0156]
Here, the abnormality determination method will be described with reference to FIG.
[0157]
The range from F1-F3 to F1 + F2 is set to the normal range (S2201) with respect to the target value F1 of the pressing force. If the measured value is within this range, there will be no problem in processing. On the other hand, the range from 0 to F1-F3 (S2203) and the range from F1 + F2 to F1 + F4 (S2202) are the warning ranges. The warning range is a range in which the processing accuracy deteriorates, but the mold, target, and apparatus are not damaged. A range of F1 + F4 or more (S2204) is a processing interruption range. In this range, the mold, target, and device may be damaged. In this embodiment, since the determination is made based on the pressing force, the machining interruption range is not set on the side that is too small.
[0158]
In this embodiment, abnormality determination is performed by detecting the pressing force that should be controlled according to the target value. Possible causes of abnormalities include equipment failure or transient abnormal pressing force due to differences in mold and target characteristics.
[0159]
Note that the characteristics shown in FIG. 22 are merely examples for explanation, and may actually be set in accordance with the characteristics of the mold, processing accuracy, and the like.
[0160]
Returning to FIG. 21 (1), the description will be continued. After releasing the pressing of the first shot, the number of shots is determined (S2109). If there are remaining shots, movement between shots (S2110) is performed, the process proceeds to step S2103, and processing after the second shot is performed. When the processing of the predetermined shot is completed, the processed wafer is unloaded from the chuck to a predetermined position (S2111). As a processing history of the wafer, a warning history is output to a file (S2112) so that it can be referred to in subsequent processing.
[0161]
The above is the processing process for one wafer. If it is not necessary to replace the mold for processing the second and subsequent wafers, the step of carrying in the mold (S2101) is omitted.
[0162]
As another form of the present embodiment, it is also possible to perform pressing by driving the Z axis on the wafer stage side.
[0163]
In addition, as the abnormality determination method in FIG. 22, it is conceivable to specify not only a static value but also a characteristic that takes into account a time change.
[0164]
[Ninth Embodiment]
The feature of this embodiment is that the distance between the mold and the target is measured at the time of processing, the measured value is determined based on a predetermined abnormality determination condition, and a warning or processing interruption is taken if necessary.
[0165]
Hereinafter, the difference from the first embodiment will be mainly described.
[0166]
FIG. 27 shows the configuration of the nanoimprint microfabrication apparatus of this example. In FIG. 27, the mold stage 3 is fixedly installed. The mold stage driving unit 15 is mounted on the mold stage 3 and presses and drives the mold table 2.
[0167]
The laser interferometer 21 is a means for measuring the mold height, and measures the distance of the mold table 2 reference surface with respect to the apparatus reference.
The wafer height measuring unit 22 measures the distance of the wafer surface with respect to the mold stage 3.
[0168]
If the thickness of the mold 1 is known from the measured values of the laser interferometer 21 and the wafer height measuring means 22, the distance between the mold and the wafer can be known.
[0169]
The mold height measuring means and the wafer height measuring means can use other types of distance measuring means.
[0170]
Next, the control block of the present embodiment will be described with reference to FIG.
[0171]
The abnormality detection unit (S2803) receives measurement values from the wafer height measurement unit (S2812) and the mold height measurement unit (S2813), and determines the state based on a predetermined condition. The determined result can be notified to the overall control unit (S2802) and the mold control unit (S2804).
[0172]
FIG. 28 only shows an example of the control block of this embodiment, and there are many other configurations for achieving the same object.
[0173]
Next, the operation of this embodiment will be described with reference to FIG.
[0174]
FIG. 25A is a processing flow for one wafer of the nanoimprint processing apparatus of this embodiment.
[0175]
S2503 is a step of setting the command value F1 of the pressing force at the time of pressing, the abnormality determination values D1 to D4, and the delay value.
[0176]
Here, the abnormality determination method will be described with reference to FIG. The distance between the mold and the wafer is the distance between the reference surfaces, and may be a relative value. Plotting in the direction in which the mold and the wafer are separated from the upper side of FIG. With respect to the target value D1, the range from D1-D3 to D1 + D2 is set as a normal range (S2601). If the measured value is within this range, there will be no problem in processing. On the other hand, the range of D1-D4 to D1-D3 (S2603) and the range of D1 + D2 or more (S2602) are the warning range. The warning range is a range in which the processing accuracy deteriorates, but the mold, target, and apparatus are not damaged. The range below D1-D4 (S2604) is the processing interruption range. In this range, the mold, target, and device may be damaged. In this embodiment, since the determination is performed based on the distance between the mold and the wafer, the processing interruption range is not set on the excessive side.
[0177]
Note that the characteristics shown in FIG. 26 are merely examples for explanation, and may be actually set according to the characteristics of the mold, processing accuracy, and the like.
[0178]
As another form of the present embodiment, it is also possible to perform pressing by driving the Z axis on the wafer stage side.
[0179]
In this embodiment, the distance between the mold and the target is obtained by measuring the height, but when one of them is fixed, the height of only one is measured. The relative angles thereof may be obtained by
[0180]
In addition, as the abnormality determination method in FIG. 26, it is conceivable to specify not only a static value but also a characteristic considering time change.
[0181]
[Tenth embodiment]
The feature of the present embodiment is that the angle between the mold and the target is measured at the time of processing, the measured value is determined based on a predetermined abnormality determination condition, and a warning or processing interruption is taken if necessary.
[0182]
Hereinafter, the difference from the eighth embodiment will be mainly described.
[0183]
FIG. 31 shows the configuration of the nanoimprint microfabrication apparatus of this example.
[0184]
The laser interferometer 21 is a mold stage distance measuring unit, and measures the distance of the mold table 2 reference surface with respect to the apparatus reference. By measuring three points on the mold reference surface, the ωx and ωy axis angles relative to the apparatus reference can be measured.
[0185]
The wafer height measuring unit 23 measures the distance of the wafer surface with respect to the mold stage 3. Since the configuration is such that three points on the wafer can be measured at the same time, the angle of the wafer relative to the apparatus reference can be measured.
[0186]
It should be noted that other types of distance measuring means may be used for the mold stage distance measuring means and the wafer height measuring means.
[0187]
The control block of this embodiment is the same as that shown in FIG.
[0188]
Next, the operation of this embodiment will be described with reference to FIG.
[0189]
FIG. 29A is a processing flow for one wafer of the nanoimprint processing apparatus of this embodiment.
[0190]
S2903 is a step of setting the command value F1 of the pressing force at the time of pressing, the abnormality determination values A1 to A5, and the delay value.
[0191]
Here, the abnormality determination method will be described with reference to FIG. The wafer-to-mold angle (ωx, ωy) is an angle between the reference surfaces, and may be a relative value. Each of ωx and ωy is determined separately under the same determination condition. With respect to the target value A1, a range from A1-A3 to A1 + A2 is set as a normal range (S3001). If the measured value is within this range, there will be no problem in processing. On the other hand, the range of A1-A5 to A1-A3 (S3003) and the range of A1 + A2 to A1 + A4 (S3002) are set as warning ranges. The warning range is a range in which the processing accuracy deteriorates, but the mold, target, and apparatus are not damaged. The range below A1-A5 (S3005) and the range above A1 + A4 (S3004) are the processing interruption ranges. In this range, the mold, target, and device may be damaged. In this embodiment, since the determination is performed based on the angle between the mold and the wafer, processing interruption ranges are set on both sides of the excess and the excess.
[0192]
Note that the characteristics shown in FIG. 30 are merely examples for explanation, and may be actually set in accordance with the mold characteristics, processing accuracy, and the like.
[0193]
As another form of the present embodiment, it is also possible to perform pressing by driving the Z axis on the wafer stage side.
[0194]
In this embodiment, the relative angles of the mold and target are obtained by measuring the angles of both the mold and the target. However, when one of them is fixed, only one of the angles is measured. The relative angles may be obtained.
[0195]
In addition, as the abnormality determination method of FIG. 30, it is conceivable to specify not only a static value but also a characteristic considering time change. Furthermore, it may be possible to set different abnormality determination values for ωx and ωy.
[0196]
[Eleventh embodiment]
The feature of the present embodiment is that the temperature of the mold and the target is measured during processing, the measured value is determined based on a predetermined abnormality determination condition, and a warning or processing interruption is taken if necessary.
[0197]
Hereinafter, the difference from the eighth embodiment will be mainly described.
[0198]
Temperature measuring means is installed in the vicinity of the mold and the wafer so that the respective temperatures can be measured.
[0199]
FIG. 34 shows the control block of this embodiment.
[0200]
The abnormality detection unit (S3403) receives the measurement values from the wafer temperature measurement unit (S3412) and the mold temperature range measurement unit (S3413), and determines the state based on a predetermined condition. The determined result can be notified to the overall control unit (S3402) and the mold control unit (S3404).
[0201]
Note that FIG. 34 only shows an example of the control block of this embodiment, and there are many other configurations for achieving the same object.
[0202]
Next, the operation of this embodiment will be described with reference to FIG.
[0203]
FIG. 32A is a processing flow for one wafer of the nanoimprint processing apparatus of this embodiment.
[0204]
S3203 is a step of setting the command value F1 of the pressing force at the time of pressing, the abnormality determination values T1 to T5, and the delay value.
[0205]
Here, the abnormality determination method will be described with reference to FIG. The wafer temperature and the mold temperature are separately determined under the same determination conditions. A range from T1-T3 to T1 + T2 is set as a normal range (S3301) with respect to the target value T1. If the measured value is within this range, there will be no problem in processing. On the other hand, the range from T1-T5 to T1-T3 (S3303) and the range from T1 + T2 to T1 + T4 (S3302) are the warning ranges. The warning range is a range in which the processing accuracy deteriorates, but the mold, target, and apparatus are not damaged. A range of T1 to T5 or less (S3305) and a range of T1 + T4 or more (S3304) are set as a machining interruption range. In this range, the mold, target, and device may be damaged. In this embodiment, since the determination is performed based on the mold and wafer temperatures, processing interruption ranges are set on both sides of the excess and the excess.
[0206]
Note that the characteristics shown in FIG. 33 are merely examples for explanation, and may actually be set according to the characteristics of the mold, processing accuracy, and the like.
[0207]
As another form of the present embodiment, it is also possible to perform pressing by driving the Z axis on the wafer stage side.
[0208]
In addition, as the abnormality determination method of FIG. 33, it is conceivable to specify not only a static value but also a characteristic considering time change.
Furthermore, it is conceivable to set different abnormality determination values for the wafer temperature and the mold temperature, and temperature measuring means may be provided for only one of them.
[0209]
[Twelfth embodiment]
A nanoimprint semiconductor wafer microfabrication method for a semiconductor wafer according to a twelfth embodiment of the present invention will be described below.
The feature of the present embodiment is that the following four items of information are obtained before processing, and the pressing force as the processing conditions is determined.
(1) Mold hardness
(2) Total area of convex part of mold convex / concave pattern
(3) Mold irregularity tip shape
(4) Surface hardness of wafer (including surface film)
FIG. 36 shows the configuration of a nanoimprint microfabrication apparatus to which this embodiment method is applied. In FIG. 36, a mold 1 serving as an original on which a transfer pattern composed of irregularities is drawn is fixed to a mold base 2. The mold table 2 is mounted on the mold stage 3. The pressing stage 5 is attached to the frame 10, and pressing is performed by driving the mold stage 3 in the + Z and -Z directions in the figure. The pressing force by the pressing stage 5 is measured by the force measuring means 4.
A resist 7 for patterning is applied to the wafer 6 to be a transfer target. For example, PMMA is used as the resist. The wafer 6 is held by a wafer chuck 8, and the wafer chuck 8 is mounted on a wafer stage 9. The wafer stage 9 has a degree of freedom with respect to the six axes X, Y, Z, ωx, ωy, and ωz in the figure, and the wafer position can be precisely controlled.
[0210]
Prior to the transfer, relative positional deviations in the XY directions of the mold 1 and the wafer 6 are measured and corrected by a positional deviation measuring means (not shown). A known technique may be used for the positional deviation measuring means for the mold 1 and the wafer 6, and the positional deviation correction is performed by the wafer stage 9.
[0211]
Next, the control block of the present embodiment will be described with reference to FIG.
[0212]
The console S3701 provides an interface with the outside of the apparatus and a man-machine interface to the operator.
[0213]
The overall control unit S3702 controls the sequence of the entire processing apparatus.
[0214]
The mold control unit S3703 controls the mold pressing unit S3707 according to a command from the overall control unit S3702. The mold pressing unit S3707 is an actuator that generates a pressing force according to a command value of the applied force.
[0215]
Wafer stage controller S3704 drives and controls wafer stage driver S3708 in response to a command from overall controller S3702.
[0216]
The transfer control unit S3705 drives and controls a wafer transfer unit S3709 and a mold transfer unit S3710 (not shown in FIG. 36) according to a command from the overall control unit S3702.
[0217]
FIG. 37 only shows an example of the control block of this embodiment, and there are a number of other configurations for achieving the same object.
[0218]
Next, the operation of this embodiment will be described with reference to FIG.
[0219]
FIG. 35 is a processing flow for one wafer of the nanoimprint processing apparatus of this embodiment.
[0220]
S3501 is a process of inputting the characteristics of the mold to the console S3701. Specifically, the following items are input.
(1) Mold hardness
(2) Total area of convex part of mold convex / concave pattern
(3) Mold irregularity tip shape
(4) Surface hardness of wafer (including surface film)
Here, as the hardness of the mold (1), a value estimated from the material used for the mold, a processing method of the mold, or the like, or a value obtained by measuring the hardness by any method can be input.
[0221]
The value calculated from the CAD pattern can be input as the total convex area of the mold uneven pattern of (2).
[0222]
A value calculated from a CAD pattern, a value measured by an SEM, or the like can be input as the tip shape value of the mold unevenness in (3).
[0223]
S3502 is a step of inputting the wafer characteristics to the console S3701. Specifically, the following items are input.
[0224]
As the surface hardness value of the wafer (including the surface film) in (4), it is possible to input a delivery specification of the wafer to be used or a value obtained by measuring a sample before processing by some method.
[0225]
S3503 is a process of processing the values input in S3501 and S3502 and determining a processing parameter. There are various ways to determine the parameters. For example, it can be theoretically expressed as a mathematical expression, and the parameters of the numerical expression can be further optimized by experiment.
[0226]
S3504 is a process of transporting the mold 1 to the mold table 2 using the mold transport system. At that time, if another mold is mounted on the mold table 2 by the previous process,
After removing the previous mold, install the mold to be used.
[0227]
S3505 is a step of aligning the mold 1 with respect to the apparatus reference.
[0228]
In step S3506, the wafer 6 is transferred to the wafer chuck 8 using the wafer transfer system.
[0229]
Step S3507 is a step of aligning the wafer 6 with respect to the apparatus reference and the mold 1.
[0230]
S3508 is a process of pressing the mold 1 against the wafer 6. When there are a plurality of processing shots, a predetermined number of shots are processed by step-and-repeat while repeating pressing and releasing.
[0231]
In step S3509, the wafer that has been subjected to the pressing process is carried out of the apparatus.
[0232]
The above is the processing process for one wafer. Regarding the processing of the second and subsequent wafers, if it is not necessary to replace the mold and the characteristics of the wafer 6 can be regarded as equivalent, the steps S3501 to S3504 are omitted.
[0233]
[Thirteenth embodiment]
The twelfth embodiment is an example where the processing condition to be corrected is a pressing force. As another embodiment, the following processing conditions can be corrected. (1) Distance in the pressing direction of the mold against the target
(2) Angle of mold surface with respect to target surface
(3) Target or / and mold temperature
Here, the distance in the pressing direction of the mold against the target of (1) is actually the distance between the measurement standards. This is because it is difficult to measure the distance between the mold and the target when they are pressed. Accordingly, the measurement value has an error due to deformation of the mold or the target. In order to correct this error, as in the twelfth embodiment, it is possible to obtain the correction parameter for the measurement value by inputting the mold and target information in advance and processing the information.
[0234]
The angle correction of the mold surface with respect to the target surface in (2) is to correct the distribution of the pressing force in the shot by the surface shape of the target, the cross-sectional shape due to the multilayer structure, and the like. A force component for rotating the mold is generated around the ωx and ωy axes of the coordinate axes shown in FIG. Since the influence of this force on the pressing process varies depending on the purpose of the process, the correction amount may be determined in accordance with the purpose. As the prior information, the angle correction parameter can be determined by setting the surface shape of the target, the cross-sectional shape by the multilayer structure, and the coefficient for determining the angle correction depending on the processing purpose.
[0235]
The temperature correction of the target and / or the mold (3) is to correct the difference in hardness between the mold and the target by the temperature. In addition to the method of correcting by the pressing force of the twelfth embodiment, it may be used in the case of a combination of a mold and a target that can obtain a preferable result when the temperature is also corrected.
[0236]
Next, an embodiment of a device manufacturing method using the above-described micromachining apparatus and micromachining method will be described.
[0237]
[Fourteenth embodiment]
FIG. 38 shows a manufacturing flow of a semiconductor device (a semiconductor chip such as an IC or LSI, a liquid crystal panel or a CCD). In step 1 (circuit design), a semiconductor device circuit is designed. In step 2 (mask production), a mold on which the designed circuit pattern is formed is produced. On the other hand, 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 the prepared mold and wafer. The next step 5 (assembly) is called a post-process, and is a process of forming a chip using the wafer created in step 5, and includes processes such as an assembly process (dicing and bonding), a packaging process (chip encapsulation), and the like. 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).
[0238]
FIG. 39 shows the detailed flow of the wafer process. In step 11 (oxidation), the wafer surface is oxidized. In step 12, 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. In step 14 (ion implantation), ions are implanted into the wafer. In step 15 (resist process), a resist (sensitive material) is applied to the wafer. In step 16 (transfer), the circuit pattern is transferred by pressing the mold against the resist by the above-described microfabrication apparatus or microfabrication method, and further, anisotropic etching is performed for patterning. In step 17 (etching), the wafer is etched using the patterned resist as a mask. In step 18 (resist stripping), the resist that has become unnecessary after the etching is removed. By repeating these steps, a circuit pattern is formed on the wafer.
[0239]
By using the manufacturing method of this embodiment, it becomes possible to manufacture a highly integrated device, which has been difficult in the past.
[0240]
As mentioned above, although preferable embodiment of this invention was described, this invention is not limited to this, A various deformation | transformation and change are possible within the range of the summary.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating an overall processing flow of a nanoimprint processing apparatus according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a condition setting processing flow of the nanoimprint processing apparatus according to the first embodiment of the present invention.
FIG. 3 is a diagram illustrating a main processing flow of the nanoimprint processing apparatus according to the first embodiment of the present invention.
FIG. 4 is a diagram for explaining the outline of the device configuration of the nanoimprint processing apparatus according to the first embodiment of the present invention.
FIG. 5 is a diagram illustrating an outline of a control block configuration of the nanoimprint processing apparatus according to the first embodiment of the present invention.
FIG. 6 is a diagram illustrating a condition setting processing flow of a nanoimprint processing apparatus according to a second embodiment of the present invention.
FIG. 7 is a diagram for explaining the main processing flow of the nanoimprint processing apparatus according to the second embodiment of the present invention;
FIG. 8 is a diagram for explaining an outline of a device configuration of a nanoimprint processing apparatus according to a second embodiment of the present invention.
FIG. 9 is a diagram illustrating an outline of a control block configuration of a nanoimprint processing apparatus according to a second embodiment of the present invention.
FIG. 10 is a diagram for explaining a conventional technique.
FIG. 11 is a diagram for explaining a flow of one wafer processing of the nanoimprint processing apparatus according to the third embodiment of the present invention.
FIG. 12 is a diagram illustrating processing correction characteristics of the nanoimprint processing apparatus according to the third embodiment of the present invention.
FIG. 13 is a diagram illustrating a device configuration of a nanoimprint processing apparatus according to a third embodiment of the present invention.
FIG. 14 is a diagram illustrating an outline of a control block configuration of a nanoimprint processing apparatus according to a third embodiment of the present invention.
FIG. 15 is a diagram for explaining a one-wafer processing flow of the nanoimprint processing apparatus according to the fourth embodiment of the present invention;
FIG. 16 is a diagram illustrating a device configuration of a nanoimprint processing apparatus according to a fourth embodiment of the present invention.
FIG. 17 is a diagram for explaining a one-wafer processing flow of the nanoimprint processing apparatus according to the fifth embodiment of the present invention;
FIG. 18 is a diagram illustrating a device configuration of a nanoimprint processing apparatus according to a fifth embodiment of the present invention.
FIG. 19 is a diagram illustrating processing correction characteristics of the nanoimprint processing apparatus according to the fifth embodiment of the present invention.
FIG. 20 is a diagram illustrating processing correction characteristics of the nanoimprint processing apparatus according to the sixth embodiment of the present invention.
FIG. 21 is a view for explaining a one-wafer processing flow of the nanoimprint processing apparatus according to the eighth embodiment of the present invention;
FIG. 22 is a diagram for explaining abnormality determination characteristics of the nanoimprint processing apparatus according to the eighth embodiment of the present invention;
FIG. 23 is a diagram illustrating a device configuration of a nanoimprint processing apparatus according to an eighth embodiment of the present invention.
FIG. 24 is a diagram illustrating an outline of a control block configuration of a nanoimprint processing apparatus according to an eighth embodiment of the present invention.
FIG. 25 is a diagram for explaining a one-wafer processing flow of the nanoimprint processing apparatus according to the ninth embodiment of the present invention;
FIG. 26 is a diagram for explaining abnormality determination characteristics of the nanoimprint processing apparatus according to the ninth embodiment of the present invention.
FIG. 27 is a diagram illustrating a device configuration of a nanoimprint processing apparatus according to a ninth embodiment of the present invention.
FIG. 28 is a diagram illustrating an outline of a control block configuration of a nanoimprint processing apparatus according to a ninth embodiment of the present invention.
FIG. 29 is a view for explaining a one-wafer processing flow of the nanoimprint processing apparatus according to the tenth embodiment of the present invention.
FIG. 30 is a diagram for explaining abnormality determination characteristics of the nanoimprint processing apparatus according to the tenth embodiment of the present invention.
FIG. 31 is a diagram illustrating a device configuration of a nanoimprint processing apparatus according to a tenth embodiment of the present invention.
FIG. 32 is a view for explaining a one-wafer processing flow of the nanoimprint processing apparatus according to the eleventh embodiment of the present invention;
FIG. 33 is a diagram for explaining abnormality determination characteristics of the nanoimprint processing apparatus according to the eleventh embodiment of the present invention.
FIG. 34 is a diagram illustrating an outline of a control block configuration of a nanoimprint processing apparatus according to an eleventh embodiment of the present invention.
FIG. 35 is a view for explaining a one-wafer processing flow of the nanoimprint processing apparatus according to the twelfth embodiment of the present invention;
FIG. 36 is a diagram illustrating a device configuration of a nanoimprint processing apparatus according to a twelfth embodiment of the present invention.
FIG. 37 is a diagram illustrating an outline of a control block configuration of a nanoimprint processing apparatus according to a twelfth embodiment of the present invention.
FIG. 38 is a diagram showing a device manufacturing flow;
FIG. 39 is a diagram showing the wafer process of FIG. 38;
[Explanation of symbols]
1 Mold
2 Mold base
3 Mold stage
4 Force measuring means
5 Pressing stage
6 Wafer
7 resist
8 Wafer chuck
9 Wafer stage
10 frames
11 Mold temperature measurement means
12 Mold temperature adjustment means
13 Wafer temperature measuring means
14 Wafer temperature adjusting means
15 Mold stage drive
21 Laser interferometer
22 Wafer height measuring means
31 Standard mold
32 Standard mold base
33 Reference wafer
34 resist
35 Reference wafer stand
41 Mold temperature measuring means

Claims (5)

In a micromachining method of inverting and transferring the pattern of the unevenness of the original plate to the workpiece by pressing the original plate against the surface of the workpiece,
Measuring the distance between the original plate and the reference workpiece by pressing the original plate against the reference workpiece with a predetermined pressing force by the pressing means;
A micromachining method comprising adjusting a pressing force as a control parameter of the pressing means or a distance between the original plate and the workpiece based on the measurement result. In a micromachining method of inverting and transferring the pattern of the unevenness of the original plate to the workpiece by pressing the original plate against the surface of the workpiece,
Measuring the distance between the reference original plate and the workpiece by pressing the reference original plate against the workpiece with a predetermined pressing force by the pressing means;
A micromachining method comprising adjusting a pressing force as a control parameter of the pressing means or a distance between the original plate and the workpiece based on the measurement result. In a micromachining apparatus that reverses and transfers the uneven pattern of the original to the workpiece by pressing the original against the surface of the workpiece,
Holding means for holding the original plate;
It possesses a reference original,
The pressing is performed by pressing the reference original plate against the workpiece with a predetermined pressing force to measure the distance between the reference original plate and the workpiece, and pressing force as a control parameter or the original plate and the workpiece. The fine processing apparatus is characterized in that the distance is adjusted based on the measurement result . In a micromachining apparatus that reverses and transfers the uneven pattern of the original to the workpiece by pressing the original against the surface of the workpiece,
Holding means for holding the workpiece;
Possess a reference workpiece,
The pressing measures the distance between the original plate and the reference workpiece by pressing the original plate against the reference workpiece with a predetermined pressing force, and the pressing force as a control parameter or the original plate and the workpiece. The fine processing apparatus is characterized in that the distance is adjusted based on the measurement result . Preparing a work piece and an original plate; and
5. A device manufacturing method comprising: transferring the pattern of the original plate to the workpiece by the microfabrication apparatus according to claim 3 or 4.

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