JP2011077071A - Substrate processing method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a substrate processing method and a substrate processing apparatus which are capable of improving the uniformity of pattern sizes independent of a position within the surface of a substrate to be processed and inhibiting variations in pattern sizes due to a pattern drawing density. <P>SOLUTION: A nozzle guide 2 holds a plurality of nozzles 1 in a two-dimensional alignment, the respective nozzles 1 being at the same distance from the substrate 3 to be processed. The nozzles 1 are respectively mounted with a flow rate control device 4. The flow rate control devices 4 are connected in parallel to an arithmetic processing unit 5. Arbitrary pattern drawing design data is transferred from a data server 6 to the arithmetic processing unit 5. The calculation results of a processing liquid flow rate output from the arithmetic processing unit 5 are reflected to the flow rate control devices 4 mounted to the respective nozzles 1. A developer whose flow rate is controlled by the flow rate control device 4 depending on a pattern drawing density is discharged through the respective nozzles 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a substrate processing method and a substrate processing apparatus for developing a resist using a processing solution such as a developing solution or a rinsing solution (pure or the like) in a resist developing process in a photomask.

  With the recent high integration of semiconductor integrated circuits, photomasks used for manufacturing semiconductor integrated circuits are required to have even finer patterns and higher precision. Therefore, in the photomask manufacturing process, that is, in the pattern drawing process using an electron beam or laser light, the developing process, and the etching process, further miniaturization of the pattern and higher precision are required.

  Conventional development methods for photomasks mainly include spray development and paddle development. In spray development, since a fresh processing solution is always supplied, variation in pattern dimensions due to pattern drawing density is small. However, the development processing capability differs between the central portion and the peripheral portion of the photomask, so that there is a problem that variation in pattern dimensions due to the in-plane position becomes large.

  In paddle development, since the developer is supplied uniformly, there is little variation in pattern dimensions depending on the in-plane position. However, since the processing liquid stays in the photomask during the development process, there is a problem that variation in pattern dimensions due to pattern drawing density increases.

  Variations in pattern dimensions due to in-plane positions can be attributed to a photomask blank, a fogging phenomenon in a pattern drawing process, and a loading effect in a chrome etching process.

  In the development process, there is a countermeasure to control the variation in pattern dimensions due to the in-plane position due to these causes. By changing the opening shape with respect to the width direction of the processing liquid outlet, the processing liquid outlet There has been proposed a treatment liquid nozzle shape that can change the discharge amount depending on the position (see Patent Document 1).

  On the other hand, variations in pattern dimensions due to pattern drawing density include a fogging phenomenon and a development loading.

  In the photomask drawing process, pattern drawing by an electron beam drawing machine is mainly used due to its high accuracy and high resolution, and there may be a mixture of dense and sparse pattern areas. .

  In the case of exposure with an electron beam, it is known that a fogging phenomenon occurs in a dense pattern region, and it is known that the pattern dimension width affected by the fogging phenomenon increases after development.

  In the photomask development process, it is known that a phenomenon (development loading) in which a pattern dimension width decreases due to a local shortage of developer in a dense pattern region.

  There has been proposed a development loading measurement method capable of preventing the influence of the fogging phenomenon during electron beam exposure and optimizing development conditions (see Patent Document 2).

  Only by changing the nozzle shape for which the flow rate can be controlled, the replacement of the nozzle itself must be taken into account depending on the drawing density distribution in the plane of the pattern, which takes time.

  In addition, even with nozzles that can control the flow rate, as compared with conventional substrate processing methods such as spray development and paddle development, the smaller the pattern, the more uneven development due to in-plane position, development time difference, and pattern drawing density dependent processing Variations in pattern dimensions due to the difference in liquid concentration become remarkable, and it is difficult to control the development process.

JP 2007-256884 A JP 2008-78553 A

  An object of the present invention is to provide a substrate processing method and a substrate processing apparatus capable of improving the uniformity of pattern dimensions depending on the in-plane position of the substrate to be processed and suppressing variations in pattern dimensions due to pattern drawing density.

  The substrate processing method according to the invention of claim 1 is characterized in that, in the resist developing process in the photomask, the resist is developed by controlling the flow rate of the developer according to the pattern drawing density.

  The substrate processing method according to a second aspect of the present invention is the substrate processing method according to the first aspect, wherein the pattern drawing design data is fetched into the data server and the drawing density is calculated before the development of the resist. The flow rate of the developer is controlled according to the pattern drawing density based on the result.

  The substrate processing method according to a third aspect of the present invention is the substrate processing method according to any one of the first and second aspects, wherein the processing liquid discharge ports are arranged in a lattice pattern, and the flow rate of the developing solution is set according to the pattern drawing density. It can be controlled.

  According to a fourth aspect of the present invention, there is provided a substrate processing apparatus including processing liquid discharge ports arranged in a lattice pattern, and independently controlling a flow rate of the developing solution at the processing liquid discharge port for each pattern drawing density. And

  A substrate processing apparatus according to a fifth aspect of the present invention is the substrate processing apparatus according to the fourth aspect, further comprising a flow rate control device that independently controls a flow rate of the developer at the processing liquid discharge port, and the flow rate control device. Is characterized by proportionally opening or closing the pneumatic load of the proportional fluid control valve with respect to the digital input.

  A substrate processing apparatus according to a sixth aspect of the present invention is the substrate processing apparatus according to the fifth aspect, characterized in that the flow rate control device can be adjusted in response to changes in temperature and viscosity of the fluid.

  According to the present invention, since the resist is developed by controlling the flow rate of the developing solution in accordance with the pattern drawing density in the resist developing process in the photomask, the uniformity of the pattern dimension is improved by the in-plane position of the substrate to be processed. In addition, variations in pattern dimensions due to pattern drawing density can be suppressed.

  Further, in the present invention, when the processing liquid discharge ports are arranged in a lattice pattern, it is possible to always simultaneously supply a fresh developer and a uniform developer simultaneously. The uniformity of pattern dimensions can be improved.

  Further, in the present invention, when the flow rate can be controlled by the density difference of the pattern drawing density, the variation of the pattern size due to the pattern drawing density can be suppressed, and the pattern size can be controlled by the flow rate.

1 is a schematic side view of a substrate processing apparatus according to Embodiment 1 of the present invention. It is a figure for demonstrating operation | movement of the arithmetic processing unit of the substrate processing apparatus which concerns on Embodiment 1 of this invention. It is a figure which shows the image of the division | segmentation of the drawing design data in the substrate processing apparatus which concerns on Embodiment 1 of this invention. It is a schematic plan view which shows the nozzle guide of the substrate processing apparatus which concerns on Embodiment 1 of this invention. It is a block diagram which shows the flow control apparatus of the substrate processing apparatus which concerns on Embodiment 1 of this invention.

  Hereinafter, embodiments of the present invention will be described in detail.

(Embodiment 1)
FIG. 1 is a schematic side view of a substrate processing apparatus according to Embodiment 1 of the present invention. The substrate processing apparatus according to the first embodiment of the present invention includes a plurality of nozzles 1, a nozzle guide 2, a flow rate control device 4, an arithmetic processing unit 5, a data server 6, a substrate holding unit 7, and a cup 8. The substrate holder 7 holds the substrate 3 to be processed.

  The nozzle guide 2 holds a plurality of nozzles 1 in a two-dimensional arrangement. Further, the nozzle guide 2 keeps each nozzle 1 at the same distance from the substrate 3 to be processed. The nozzle 1 is provided with a flow rate control device 4. Each flow control device 4 is connected to the arithmetic processing unit 5 in parallel. The arithmetic processing unit 5 is connected to the data server 6. The substrate holding unit 7 is provided with a mechanism that holds the substrate 3 to be processed by vacuum suction and can be driven to rotate and move up and down while holding the substrate 3 to be processed. A cup 8 is provided around the substrate holding unit 7 in order to prevent the processing liquid from being scattered in the course of supplying a processing liquid such as a developing liquid and a rinsing liquid (pure water, etc.) or in the developing process. Yes.

  The operation of the substrate processing apparatus according to the first embodiment of the present invention will be described. First, arbitrary pattern drawing design data is transferred from the data server 6 to the arithmetic processing unit 5. Data processing in the arithmetic processing unit 5 will be described in detail in the next section. The calculation result of the processing liquid flow rate output from the arithmetic processing unit 5 is reflected on the flow rate control device 4 provided in each nozzle 1. The developer whose flow rate is controlled according to the pattern drawing density by the flow rate control device 4 is discharged from each nozzle 1. Further, the substrate holding unit 7 can be operated, and the uniformity of the pattern dimension can be improved depending on the in-plane position of the development processing.

  Next, the arithmetic processing unit 5 will be described with reference to FIG. The drawing design data M1 stored in the data server 6 is transferred to the arithmetic processing unit 5. In the arithmetic processing unit 5, pattern registration is performed (step P1), and the area of the registered pattern is divided into areas in a grid pattern as shown in FIG. 3 (step P2). Next, the drawing density is calculated for each divided area (step P3). Next, from the result of this calculation, the flow rate is weighted for each nozzle, and the flow rate is calculated (step P4). The result reflected in the calculation of step P4 is returned to each flow control device 4. A developer is discharged from the flow rate control device 4 onto the substrate 3 to be processed.

  FIG. 4 is a schematic plan view showing the nozzle guide 2. As shown in FIG. 3, the nozzle discharge ports 1 are arranged in a lattice pattern, and the array corresponds to the divided area of the drawing design data of the pattern divided in the lattice pattern.

  Since the nozzle discharge ports 1 are arranged in a grid pattern, a state in which fresh developer is always supplied evenly in the plane is maintained. Therefore, the uniformity of the pattern dimension according to the in-plane position can be achieved.

  The nozzle discharge ports 1 are respectively connected to the flow rate control device 4, and the flow rate of processing development is discharged in a one-to-one correspondence with the divided patterns. The flow rate of the developing solution at this time is controlled at a flow rate corresponding to the pattern drawing density.

  By controlling each nozzle discharge port 1 independently, control corresponding to the pattern density can be performed, and variation in pattern dimensions due to pattern drawing density caused by fogging phenomenon and development loading can be reduced. In addition, by arbitrarily controlling the flow rate of the developing solution, it is possible to intentionally control the pattern dimension variation.

  Next, the flow control device 4 will be described with reference to FIG. The flow control device 4 opens or closes the pneumatic load of the proportional fluid control valve in proportion to the digital input. Specifically, a liquid control device such as a pneumatically operated fluid control valve 9 can be a wafer (not shown), a liquid for final dispensing of liquid to a point of use such as a substrate. It has an inlet pipe 10 and a liquid outlet pipe 11.

  The liquid outlet line 13 is in fluid communication with the friction flow element 12 so that all of the liquid flowing out of the fluid control valve 9 enters the friction flow element 12. A primary pressure sensor 13 such as a pressure transducer that can be integral with the housing of the fluid control valve 9 is a friction flow (such as at or near the outlet of the fluid control valve 9) to sense the first pressure. It is placed at or near the entrance of the element 12. A secondary pressure sensor 14, such as a pressure transducer, is positioned at or near the outlet of the friction flow element 12 to sense the second pressure.

  The valve that generates the valve drive signal for opening or closing the pneumatic proportional control valve 15 is substantially linear, and as the pressure on the actuating diaphragm increases, the fluid flow increases accordingly.

  A pneumatic proportional control valve 15 such as a solenoid is pneumatically connected to the fluid control valve 9. Each pressure sensor 13, 14 (or a single differential pressure sensing device) communicates with a computer processor or control circuit 16, such as a controller, having a proportional integral derivative (PID) feedback component. As each sensor 13, 14 samples the pressure and temperature in the respective fluid piping, each sensor 13, 14 sends the sampled data to the controller 16. The controller 16 compares the values and calculates the pressure drop across the friction flow element 12. A signal from the controller 16 based on this pressure drop is sent to a pneumatic proportional control valve 15, which in accordance with that signal causes the fluid control valve 9 to preferably act on temperature and / or viscosity or density. Adjust after compensation.

DESCRIPTION OF SYMBOLS 1 Nozzle 2 Nozzle guide 3 Substrate to be processed 4 Flow control device 5 Arithmetic processing unit 6 Data server 7 Substrate holding part 8 Cup 9 Flow control valve 10 Liquid inlet piping 11 Liquid outlet piping 12 Friction flow element 13 Primary pressure sensor 14 Secondary Side pressure sensor 15 Pneumatic proportional control valve 16 Controller

Claims (6)

  A substrate processing method comprising: developing a resist by controlling a flow rate of a developing solution in accordance with a pattern drawing density in a resist developing process in a photomask.   The pattern drawing design data is taken into a data server and the drawing density is calculated before developing the resist, and the flow rate of the developer is controlled according to the pattern drawing density based on the result of the calculation. 2. The substrate processing method according to 1.   3. The substrate processing method according to claim 1, wherein the flow rate of the developer can be controlled according to the pattern drawing density by arranging processing liquid discharge ports in a grid pattern.   A substrate processing apparatus comprising processing liquid discharge ports arranged in a lattice pattern and independently controlling a flow rate of a developing solution at the processing liquid discharge port for each pattern drawing density.   A flow control device for independently controlling the flow rate of the developer at the processing liquid discharge port, and the flow control device proportionally opens or closes the pneumatic load of the proportional fluid control valve with respect to the digital input; The substrate processing apparatus according to claim 4.   The substrate processing apparatus according to claim 5, wherein the flow rate control device can be adjusted in accordance with changes in temperature and viscosity of the fluid.

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