KR20060096542A - Apparatus for use in spin coating and method for photo-resistor coating thereof - Google Patents

Abstract

Disclosed is a spin coating apparatus of a spinner installation having a photoresist ejection nozzle for ejecting a photoresist liquid onto a semiconductor wafer and surrounded by a bowl. Such a spin coating apparatus has a rotation chuck for fixing the wafer to an upper surface so that the photoresist liquid injected from the photoresist injection nozzle is coated on the entire surface of the wafer, and the rotation speed of the rotation chuck when the photoresist liquid is coated. And a rotation control unit for sensing the rotational speed so that the rotational speed of the rotary chuck is a reference speed such that the thickness of the photoresist liquid coated on the wafer becomes a predetermined thickness. Thus, the present invention has the effect of reducing the photoresist coating defects by providing an improved spin coating apparatus, thereby sensing the rotational speed of the rotating chuck to provide clear spin data.

Photoresist, Spinner, Spin Coating Equipment, Optical Sensor

Description

Spin coating apparatus and photoresist coating method according thereto {Apparatus for use in spin coating and method for photo-resistor coating

1 is a schematic view showing a conventional spin coating apparatus.

Figure 2 is a schematic view showing a spin coating apparatus according to an embodiment of the present invention.

3 is a flow chart illustrating a method for coating a photoresist liquid on a wafer by a spin coating apparatus in accordance with one embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

8: rotating chuck support 10: rotating chuck

20: bowl W: wafer

30: photoresist injection nozzle 40: rotational speed detection unit

41: support

The present invention relates to a semiconductor manufacturing facility, and more particularly, to a spin coating apparatus for coating a photoresist liquid on a semiconductor wafer.

A semiconductor device (e.g., a semiconductor memory device) is a device which is usually formed of an electric or electronic element through a process such as patterning while forming a film of a conductor and a semiconductor non-conductor on a wafer, and joins them by circuit wiring. . Such semiconductor devices are highly precise and complex devices with a high degree of integration, and a number of rigorous and precise processes are required for manufacturing.

Recently, as the high integration of semiconductor integrated circuits is advanced, the formation of fine patterns becomes more difficult. Accordingly, it is recognized that the photolithography process is more important than other processes such as an oxidation process, a diffusion process, a deposition process, and an etching process in forming a fine pattern.

There are many methods for processing the film quality forming the semiconductor device, but the most common of them is patterning. This patterning operation is performed through photolithography and etching of the formed thin film. Therefore, the most frequently performed and required precision in the manufacture of semiconductor devices can be said to be a photolithography process.

In the photolithography process, a photoresist solution is coated on a corresponding film, exposed using a photomask, and then developed using a developer to transfer a predetermined pattern of the photomask to the photoresist film. to be. Therefore, the process of coating the photoresist on the semiconductor wafer in this process must be required. The coating method of the photoresist film is a method of dipping a wafer in a container containing a liquid photoresist film, dispersing the photoresist film on a wafer, or rolling a photoresist coated roller onto the wafer, using a rotating motor. The semiconductor wafer is classified into a spin coating method in which a semiconductor wafer is fixed and coated on a spin chuck fixed to a rotating motor. The dipping method is not suitable for use in the semiconductor manufacturing process because the photoresist film is deposited on both the upper and lower surfaces of the wafer. The scattering method is also unsuitable because a photoresist film may be deposited on the lower surface of the wafer. The rolling method is used to coat a photoresist film on a printed circuit board. This method is also difficult to control the thickness of the photoresist film is not suitable for use in the semiconductor manufacturing process. Thus, in general, photoresist coating operations typically use a spin coater, which is a spin coating apparatus of a spinner facility. This is because spin coating is the best technique for strict thickness control of the photoresist film.

However, even when the photoresist film is coated by such spin coating, the thickness of the photosensitive film to be coated generally has a predetermined error.

1 is a schematic view showing such a conventional spin coating apparatus.

Referring to FIG. 1, the spin coating apparatus includes a bowl 20, a rotary chuck 10, and a photoresist spray nozzle 30.

The rotary chuck 10 is fixed to the wafer (W) on the upper surface and rotates at a predetermined rotational speed (RPM). Then, the rotary chuck 10 is rotated by the rotational force of the rotary motor is transmitted to the rotary chuck support (8).

The bowl 20 accommodates the rotary chuck 10 and is open at the top thereof to surround the outside, and the photoresist liquid sprayed onto the wafer W is splashed out while the rotary chuck 10 rotates. Serves to prevent this from happening.

The photoresist spray nozzle 30 is positioned above the rotating chuck 10 to which the wafer W is fixed, and is a portion for spraying the photoresist liquid onto the wafer W. The photoresist spray nozzle 30 is typically adapted to move to the position of the air position and the dispense position. The atmospheric position is a position when the spin coating apparatus is not operated, and the dispensing position is such that the photoresist liquid is injected onto the upper surface of the wafer W that rotates according to the rotation of the rotary chuck 10. Position. Therefore, when the photoresist liquid is injected, the nozzle 30 is positioned at the dispense position. In this case, the photoresist includes a photosensitive material, and is a liquid substance diluted by thinner, and the thinner is a kind of solvent, and volatile acetone is used. As shown in FIG. 1, the photoresist injection nozzle 30 has a nozzle shape 31 having a pipe shape bent in an L shape, a nozzle tip 32 connected to one end of the nozzle arm 31, and the nozzle arm 31. The holder block 33 to cover the other end of the).

The photoresist injection nozzle 30 is moved up and down with respect to the bowl 20 at a predetermined height and rotates horizontally at a predetermined angle. That is, in order to move the photoresist injection nozzle 30 from the air position to the dispensing position, the photoresist injection nozzle 30 is first rotated at a predetermined angle so as to be positioned at the wafer W seated on the rotary chuck 10, and in this state. After descending to a predetermined height at finally the photoresist liquid is injected to the wafer (W) through the nozzle tip (32).

The liquid photoresist spreads out to the outer circumferential surface of the wafer by the centrifugal force on the rotating wafer W, and is distributed in the wafer W by the viscosity of the photoresist itself in almost even thickness. Thereafter, the photoresist liquid is introduced into an exposure apparatus in which a subsequent exposure process is performed after solidifying in a state where the thinner is removed through a series of curing processes such as baking.

Meanwhile, in a spin coating apparatus, a plurality of photoresist supply nozzles 30 are usually provided at one facility, and various types of photoresists may be selectively sprayed through the plurality of photoresist supply nozzles 30. To make it possible.

However, even when the photoresist film is coated by the spin coating apparatus, the thickness of the photosensitive film to be coated has a predetermined error. That is, in the spin coating apparatus, the thickness of the photoresist coated on the entire surface of the wafer varies according to the rotational speed per minute (RPM) of the spin chuck. Spin data including the rotational speed per minute of the rotary chuck is directly input by the operator through the keyboard of the main panel of the spin coating apparatus, and is transmitted to the motor through the motor driving unit of the spin coating apparatus. Thus, when coating defects occur on the wafer, the thickness of the photoresist on the front surface of the wafer is measured, and when the predetermined thickness is not reached or exceeds the reference thickness, the spin data is input again into the main panel to adjust the thickness of the photoresist. Will be adjusted. Here, the reference thickness is determined by the rotational speed per minute of the chuck, there is a problem that can not determine the exact spin data because the rotational speed check standards and rotational test method is different for each operator.

In addition, as the spin coating apparatus is used for a long time, rotational instability and rotational force of the rotating motor are generated, and the rotating motor rotates differently from the spin data input by the operator, so that the thickness of the photoresist on the front surface of the wafer does not meet the reference thickness. There is this.

Thus, a large number of coating defects, defects in subsequent processes after the photoresist coating, and quality defects of the finally produced semiconductor device occur.

Accordingly, an object of the present invention is to provide a spin coating apparatus for reducing the photoresist coating defects by detecting the rotation speed in order to solve the above problem.

Another object of the present invention is to provide a spin coating apparatus for improving a problem in which coating defects occur because a standard is not clear because an operator inputs spin data arbitrarily in the conventional spin coating apparatus.

Still another object of the present invention is to provide a spin coating apparatus for reducing quality defects of semiconductor devices produced by reducing coating defects.

Thus, a large number of coating defects, defects in subsequent processes after the photoresist coating, and quality defects of the finally produced semiconductor device occur.

In order to achieve the above objects, according to an aspect of the present invention, a spin coating apparatus having a photoresist ejection nozzle for spraying a photoresist liquid onto a semiconductor wafer and surrounded by a bowl is surrounded by a bowl. A rotating chuck to fix the photoresist liquid sprayed from the photoresist spraying nozzle onto the entire surface of the wafer; And a rotation control unit for sensing the rotational speed of the rotational chuck when the photoresist liquid is coated so that the rotational speed of the rotational chuck becomes a reference speed such that the thickness of the photoresist liquid coated on the wafer becomes a predetermined thickness. It is characterized by.

The rotation control unit may include a rotation detection unit for detecting the rotation speed of the rotation chuck, a support for fixing the rotation detection unit, and a display unit for displaying the rotation speed of the rotation chuck detected by the rotation detection unit. .

The rotation detecting unit may include a light emitting unit for irradiating light onto the rotating chuck or the wafer, and a light receiving unit detecting light reflected by the rotating chuck or the wafer.

In addition, the support is preferably installed spaced apart from the rotary chuck on the inner surface of the bowl.

The rotation control unit may further include an input unit for inputting a rotation speed corresponding to the reference speed when the rotation speed output from the display unit does not match the reference speed.

According to an aspect of the present invention, a method for coating a photoresist liquid on a semiconductor wafer using a spin coating device equipped with a rotary chuck according to an aspect of the present invention provides a rotational speed of the rotary chuck when operation of the rotary chuck is started. Measuring and displaying; Comparing the measured rotational speed with a reference speed and adjusting the rotational speed of the rotary chuck to match the reference speed in different cases; And coating the photoresist liquid on the wafer after the adjustment.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Descriptions in the following embodiments are only shown and limited by way of example and without intention other than the intention to help those of ordinary skill in the art a more thorough understanding of the present invention, It should not be used to limit the scope.

2 is a schematic view showing a spin coating apparatus according to an embodiment of the present invention.

Referring to FIG. 2, a spin coating apparatus of a spinner installation including a photoresist spray nozzle and a bowl surrounded by a bowl for spraying a photoresist liquid on a semiconductor wafer includes a rotary chuck 10 and a rotation controller.

The rotary chuck 10 fixes the wafer to an upper surface so that the photoresist liquid sprayed from the photoresist spray nozzle is coated on the entire surface of the wafer.

The rotation controller detects the rotational speed of the rotary chuck 10 when coating the photoresist liquid so that the rotational speed of the rotary chuck 10 is a predetermined thickness of the photoresist liquid coated on the wafer. To the reference speed. Here, the rotational speed is preferably a rotational speed per minute (RPM). The rotation controller may include a rotation detecting unit 40 for detecting a rotational speed of the rotary chuck 10, a support 42 for fixing the rotation detecting unit, and the rotation chuck 10 detected by the rotation detecting unit. And a display unit for displaying the rotational speed.

The rotation detecting unit 40 includes a light emitting unit for irradiating light to the rotary chuck 10 or the wafer W, and a light receiving unit for detecting light reflected by the rotary chuck 10 or the wafer W. Equipped. As light emitted from the light emitting unit, various types of light such as infrared rays and laser beams may be used.

The support 42 is installed spaced apart from the rotary chuck 10 on the inner surface of the bowl 20. That is, since the support 42 is a portion for mounting and fixing the rotation detecting unit 40 for measuring the rotational speed of the rotary chuck 10 (or the rotational speed of the wafer W), the bowl ( It is preferable that one side or both sides are fixed to the inner surface of 20).

The rotation control unit may further include an input unit for inputting a rotational speed corresponding to the reference speed when the rotational speed output from the display unit does not match the reference speed. When a system for automatically comparing and matching the rotational speed output from the display unit with the reference speed is provided, the input unit is not required separately, but the operator needs to check and input the rotational speed output from the display unit. The input unit is required.

Looking at the process of coating the photoresist on the wafer by the spin coating apparatus, as follows.

First, the washed wafer W is transferred from the wafer carrier (not shown) to the rotary chuck 10 by a wafer transfer device (not shown) of the spin coating apparatus and vacuum-adsorbed. In this state, power is supplied to a motor (not shown) connected to the rotary chuck support 8, and the motor starts to rotate, and the rotation of the motor is transmitted to the rotary chuck support 8 so that the rotary chuck 10 is rotated. Start to rotate In addition, the wafer W vacuum-adsorbed to the rotary chuck 10 also starts to rotate.

Then, when the rotational speed of the wafer W increases and becomes constant, the photoresist liquid jet nozzle 30 is horizontally moved from the outside of the bowl 20 to the inside of the bowl 20 by a transfer device (not shown). It is conveyed, reaches the upper part of the center part of the wafer W, and conveys it vertically downward, and stops at a predetermined distance upwards from the surface of the wafer W. As shown in FIG.

Subsequently, when the photoresist liquid is injected from the photoresist liquid injection nozzle 30 to the surface center portion of the wafer W by a predetermined amount, the photoresist is spread to the edge from the surface center portion of the wafer W by a centrifugal force and has a constant thickness. A resist film is formed. At this time, the photoresist liquid splashing outward from the edge of the wafer W is blocked by the bowl 20 to prevent contamination of the components of the spin coating apparatus due to the photoresist liquid. Thereafter, the photoresist liquid injection nozzle 30 returns to the outside of the bowl 20 through the path opposite to the transfer path and stops.

When the photoresist film is coated by such a spin coating apparatus, the thickness of the photosensitive film to be coated has a predetermined error. The thickness of the photoresist film is analyzed through spin data including the rotational speed of the rotary chuck. That is, when the thickness of the photoresist coated on the front surface of the wafer is different according to the rotational speed (eg, rotational speed per minute (RPM)) of the spin chuck in the spin coating apparatus, that is, the spin data including the rotational speed of the rotational chuck is different. In this case, the spin data measured by the rotation detector 40 is different from the reference data. When the measurement data is displayed by the display unit, the operator inputs the measured spin data to the input unit in consideration of the reference speed. In this case, the spin data is data for indicating that the thickness of the photoresist film is larger or smaller than the reference thickness.

3 is a flowchart illustrating a method for coating a photoresist liquid on a wafer by a spin coating apparatus according to an embodiment of the present invention.

Referring to FIG. 3, a method for coating a photoresist liquid on a semiconductor wafer using a spin coating apparatus equipped with a rotary chuck according to an embodiment of the present invention may be performed when the operation of the rotary chuck is started (S10). Checking (S13) and displaying the rotational speed, and comparing the measured rotational speed with the reference speed (for example, reference RPM) (S14) to adjust the rotational speed of the rotational chuck to match the reference speed when different. And (S15) and coating the photoresist liquid on the wafer after the adjustment.

2 and 3, the method of coating the photoresist liquid may include a wafer carrier for feeding the wafer W, which has been cleaned first, by a wafer transfer device (not shown) of the spin coating apparatus. ) Is transferred to the rotary chuck 10 and sucked under vacuum, and the rotary chuck 10 starts to rotate (S10).

Then, after the rotary chuck is operated (does not matter before the operation), the rotation control unit is turned on (S11). Then, the rotational speed of the rotary chuck 20 is rotated by the input reference speed, and the rotation detection unit 40 (for example, an optical sensor having a light emitting unit and a light receiving unit) of the rotation control unit operates. In step S12, the rotation speed of the rotary chuck 20 is checked (S13). In this case, the checked rotation speed may be output through the display unit of the rotation controller. In addition, the rotation speed measured by the rotation detecting unit 40 is compared with the reference speed (S14). If there is a match, the photoresist liquid is injected by the nozzle 30 (S16). Otherwise, the photoresist liquid is injected after adjusting the rotational speed of the rotary chuck 10 (S16). Thus, by detecting the rotational speed of the rotary chuck 10 to provide clear spin data, photoresist coating defects are reduced.

Although many parts have been described in detail in the above description, these specific descriptions should be construed as illustrative of preferred embodiments of the present invention rather than to limit the scope thereof. Therefore, the scope of the present invention should not be determined by the above embodiments, but by the technical spirit described in the claims.

As described above, the present invention provides an improved spin coating apparatus, thereby detecting the rotational speed of the rotating chuck to provide clear spin data, thereby reducing photoresist coating defects.

In addition, the present invention provides an improved spin coating apparatus, which has the effect of providing spin data with a definite criterion that prevents an operator from arbitrarily inputting spin data.

In addition, the present invention has the effect of improving the quality of the semiconductor device produced by reducing the coating defect by providing an improved spin coating apparatus.

Claims (6)

In a spin coating apparatus of a spinner apparatus having a photoresist spray nozzle for spraying a photoresist liquid onto a semiconductor wafer and surrounded by a bowl: A rotary chuck for fixing the wafer to an upper surface so that the photoresist liquid sprayed from the photoresist spray nozzle is coated on the entire surface of the wafer; And And a rotation control unit for sensing the rotational speed of the rotational chuck when the photoresist liquid is coated so that the rotational speed of the rotational chuck becomes a reference speed such that the thickness of the photoresist liquid coated on the wafer becomes a predetermined thickness. Spin coating device characterized in that. The method of claim 1, The rotation control unit includes a rotation sensing unit for sensing the rotational speed of the rotation chuck, a support for fixing the rotation detection unit, and a display unit for displaying the rotational speed of the rotation chuck detected by the rotation detection unit. Spin coating equipment. The method of claim 2, And the rotation detecting unit comprises a light emitting unit for irradiating light onto the rotating chuck or wafer, and a light receiving unit detecting light reflected by the rotating chuck or wafer. The method of claim 2, The support is spin coating apparatus, characterized in that spaced apart from the rotary chuck on the inner surface of the bowl. The method of claim 2, The rotation control unit further comprises an input unit for inputting a rotational speed corresponding to the reference speed when the rotational speed output from the display unit does not match the reference speed. A method for coating a photoresist liquid on a semiconductor wafer using a spin coating device equipped with a spin chuck: Measuring and displaying a rotation speed of the rotation chuck when the rotation chuck is started; Comparing the measured rotational speed with a reference speed and adjusting the rotational speed of the rotary chuck to match the reference speed in different cases; And And coating the photoresist liquid on the wafer after the adjustment.

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