JP4374204B2 - Photomask and exposure apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a proximity exposure type exposure apparatus and a photomask.
[0002]
[Prior art]
In a manufacturing process of a semiconductor or a liquid crystal display, there is a step of exposing a pattern to a substrate. As an exposure method in this step, for example, a contact exposure method in which a photomask and a substrate are brought into close contact with each other to expose a pattern on the substrate, and a pattern is formed on the substrate by holding the substrate and the photomask in parallel via a proximity gap. Proximity exposure methods for exposure are known.
[0003]
Conventionally, as a problem in the contact exposure method, it is known that the substrate and the photomask are excessively adhered, and the photomask after the exposure cannot be removed smoothly. Therefore, for example, a technique is disclosed in which a dummy pattern is provided on a photomask to secure a space, and air is introduced between the photomask and the substrate to prevent excessive adhesion (see Patent Document 1). .
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 5-45860
[Problems to be solved by the invention]
However, even in the proximity exposure method in which the substrate and the photomask do not contact each other, if the substrate and the photomask are suddenly separated, the inflow of air to the proximity gap is not in time, and the mask is mounted on the mask holder. Misalignment or dropout may occur in the photomask. This is an obstacle to improving the throughput of the exposure process.
[0006]
SUMMARY OF THE INVENTION An object of the present invention is to provide a photomask and an exposure apparatus that prevent a photomask from being displaced or dropped in a proximity exposure apparatus and improve throughput.
[0007]
[Means for Solving the Problems]
The present invention will be described below. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiment.
[0008]
The photomasks (5, 20) of the present invention are opposed to the substrate in the negative resist photomask which is opposed to the substrate (2) to be exposed through the proximity gap (P) during exposure. A groove (8) for supplying and exhausting gas between the proximity gap and the outside on the surface, and an opening in a surface facing the substrate provided in the groove and communicating with the outside on the back side of the surface An exhaust hole (11), a transparent substrate (5a), and a light shielding film (5b) which is provided on the surface of the transparent substrate facing the substrate and is etched in the transmission portion (5c) to form a device pattern. ) and wherein the supply and exhaust holes, so as not to transmit light beams while passing the gas, is formed by drilling holes at an angle with respect to the light shielding film, by the this, the above problems Solution To.
[0009]
According to the photomask of the present invention, when the substrate is separated from the photomask, the gas is introduced from the outside to the proximity gap through the groove, so that the proxy can be quickly performed as compared with the case where the groove is not provided. Mitty gap pressure recovers from negative pressure to normal pressure. In addition, the proximity gap pressure increases when the substrate and the photomask are brought close to each other. However, the proximity gap pressure quickly becomes the same as the outside because the gas in the proximity gap is exhausted to the outside through the groove. Recover to moderate pressure. For this reason, the substrate and the photomask can be separated or brought close to each other at a relatively high speed without causing the photomask to shift or drop off, thereby improving the throughput of the exposure apparatus. In addition, gas is supplied / exhausted between the outside of the back side of the photomask facing the substrate and the groove by the air supply / exhaust hole penetrating the photomask, so that air supply / exhaust through the groove is effectively performed. It is .
[0010]
In addition, as long as a groove part can supply / exhaust between a proximity gap and its exterior, you may provide an appropriate magnitude | size and a shape. For example, in a photomask including a transparent substrate (5a) and a light shielding film (5b) provided on the transparent substrate and forming a pattern, the groove portion may be formed deeper than the thickness of the light shielding film . The groove may communicate with an edge (5f) of the photomask. The groove may extend from one edge of the photomask to another edge.
[0015]
The photomask of the present invention, the said surface of the substrate opposite to the side of the front Symbol transparent substrate, the groove in the transmissive portion in the pattern of the device (5d) may be provided. In this case, air supply / exhaust between the inside of the pattern and its periphery is quickly performed by the groove portion in the pattern, and air supply / exhaust between the proximity gap and the outside is more efficiently performed. The groove part in the pattern may be a part of the groove part for supplying and exhausting air to / from the outside of the proximity gap described above, or provided separately from the groove part and not connected to the groove part. May be.
[0016]
The exposure apparatus of the present invention, an exposure apparatus for performing exposure to the substrate and the photomask is opposed via a proximity gap, by providing a photo mask of the present invention, for solving the above problems.
[0017]
According to the exposure apparatus of the present invention, when brought into proximity or separating the substrate and the photomask, and more photomasks of the present invention, since the supply and exhaust of the proximity gap is rapidly performed, the throughput is improved.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a schematic view of an exposure apparatus 1 of the present invention. The exposure apparatus 1 is configured as an apparatus that performs proximity-type exposure on the CF substrate 2.
[0019]
The CF substrate 2 is made of, for example, a glass substrate and has a thickness of 1 mm and an area of 4 m ² . A plurality of layers such as a black matrix layer, an R layer, a G layer, and a B layer are formed on the surface of the CF substrate 2 to form, for example, a stripe arrangement pattern (see FIG. 5B). The CF substrate 2 is bonded to a TFT substrate (not shown) after pattern formation, and 24 liquid crystal display devices are manufactured from one set of the CF substrate 2 and the TFT substrate. Therefore, as shown in FIG. 5A, the exposure apparatus 1 exposes the 24 exposure regions 2b... 2b on the CF substrate 2.
[0020]
The exposure apparatus 1 irradiates the photomask 5 with a light beam, a stage 3 on which the CF substrate 2 is placed, a photomask 5 disposed above the CF substrate 2, a mask holder 6 that holds the photomask 5, and the photomask 5. The light source 7, the drive device 9 which drives the stage 3 in a horizontal direction and a vertical direction, and the control apparatus 10 which controls operation | movement of various apparatuses, such as the light source 7 and the drive device 9, are provided. In addition, the exposure apparatus 1 includes various apparatuses such as a laser length measurement system for measuring the stage position, but the description is omitted because it is not the gist of the present invention.
[0021]
The mask holder 6 is configured as a frame-like member extending along the outer periphery of the photomask 5, for example, and has a suction groove 6 a that opens to the photomask 5. The mask holder 6 can suck and fix the photomask 5 by releasing air between the photomask 5 and the mask holder 6 by a vacuum pump (not shown) through the suction groove 6a. A photomask 5 corresponding to each layer such as a black matrix layer, R, G, and B layers is appropriately attached to the mask holder 6.
[0022]
2A and 2B are a plan view of the photomask 5 viewed from the CF substrate 2 side and a cross-sectional view showing the CF substrate 2 side up, respectively. The photomask 5 includes, for example, a transparent substrate 5a and a light shielding film 5b. The transparent substrate 5a is made of, for example, glass, and the light shielding film 5b is made of, for example, chromium. A mask pattern is formed on the light shielding film 5b by photolithography.
[0023]
The photomask 5 has four pattern surfaces 4... 4 for simultaneously exposing the four exposure regions 2 b. Therefore, as shown in FIG. 5A, exposure is performed in one shot for four exposure regions 2b... 2b in one shot region 2a.
[0024]
The photomask 5 has a groove 8 provided on the surface of the CF substrate 2 and a hole 11 provided in the groove 8. The groove 8 is provided so as to intersect two straight lines connecting the edges 5f and 5f facing each other of the photomask 5, and is provided between the pattern surfaces 4.
[0025]
FIG. 2C shows an enlarged cross section between the pattern surfaces 4 and 4 when the photomask 5 exposes a negative resist. As shown in the figure, the cross-sectional shape of the groove 8 is formed into a smooth concave shape without corners, and is formed deeper than the thickness of the light shielding film 5b. In the negative resist photomask 5, as shown in FIG. 2C, a light shielding film 5 b is provided between the pattern surfaces 4 and 4. However, in the positive resist photomask 5, the pattern surface 4 is provided. The light shielding film 5b between the four is removed. Similarly, in the hole 11, in the photomask 5 for negative resist, the light shielding film 5 b is left in the hole 11, and in the photomask 5 for positive resist, the light shielding film 5 b in the hole 11 is removed. In the hole 11 of the photomask 5 for negative resist, for example, by making a hole obliquely with respect to the light shielding film 5b, the gas may pass while the light beam from the light source 7 may not be transmitted.
[0026]
Various settings such as the width, depth, and cross-sectional shape of the groove 8 may be appropriately set according to various conditions such as the size and shape of the photomask and the size of the proximity gap. For example, when the size of the photomask 5 is 500 to 800 mm × 500 to 920 mm, the width of the groove 8 may be 10 mm and the depth may be 1 mm. Similarly, various settings such as the width and cross-sectional shape of the hole 11 may be set as appropriate. The groove 8 and the hole 11 may be formed in the photomask 5 by various methods. For example, it may be formed by machining, or may be formed by photolithography. When forming by machining, it may be formed by sand blasting or may be formed using a grindstone.
[0027]
The pattern surface 4 of the photomask 5 is enlarged and shown in FIGS. 3 (a) and 3 (b). FIGS. 3A and 3B show a photomask 5 for the black matrix layer when a positive type resist is used for the black matrix layer. The pattern surface 4 has transmissive portions 5c... 5c that can transmit the light beam from the light source 7 from which the light shielding film 5b is removed. Grooves 5d... 5d are provided on the surface of the transparent substrate 5a in the transmission part 5c. Various settings such as the depth and cross-sectional shape of the grooves 5d... 5d may be appropriately set according to various conditions such as the size and shape of the photomask 5 and the size of the proximity gap. For example, the depth may be several tens to 100 μm. The groove 5d may be formed by various methods. For example, the groove 5d may be formed by removing the light shielding film 5b to form the transmission part 5c and then etching the transparent substrate 5a in the transmission part 5c using a glass etchant. May be.
[0028]
4A and 4D are enlarged views of the pattern surface 4 of the photomask 5 for the R, G, and B layers. These drawings show the photomask 5 when a negative resist is used for the R, G, and B layers. Similarly to the black matrix photomask 5, the R, G, B layer photomask 5 is provided with a groove 5 d in the transparent substrate 5 a in the transmissive portion 5 c.
[0029]
The operation of the exposure apparatus 1 having the above configuration will be described.
[0030]
FIG. 6 is a flowchart showing a procedure of exposure processing executed by the control device 10. This process is started, for example, when the CF substrate 2 is placed on the stage 3.
[0031]
First, the control device 10 controls the operation of the driving device 9 to move the stage 3 in the horizontal direction so that any one of the shot regions 2a... 2a is positioned below the photomask 5 (step S1). At this time, the gap between the photomask 5 and the substrate 2 is, for example, 300 to 500 μm. In step S2, the stage 3 is raised so that the photomask 5 and the CF substrate 2 face each other through the proximity gap P (see FIG. 1). The size of the proximity gap is, for example, 80 to 150 μm. In step S3, the light source 7 is driven to perform exposure through the photomask 5. In step S4, the stage is lowered until the gap between the photomask 5 and the CF substrate 2 becomes the gap (300 to 500 μm) in step S1. In step S5, it is determined whether or not the exposure has been completed for all the shot areas 2a... 2a. If it is determined that the exposure has not been completed, steps S1 to S4 are repeated, and the remaining shot areas 2a. The exposure is executed sequentially.
[0032]
According to the exposure apparatus 1, since the gas between the photomask 5 and the CF substrate 2 is supplied / exhausted through the groove portion 8, the hole portion 11 and the groove portion 5d during the raising / lowering of the stage in steps S2 and S4, the exposure apparatus 1 can quickly The photomask 5 and the CF substrate 2 can be separated or brought close to each other. For example, in a conventional photomask, it takes 2 to 3 seconds for separation or proximity of the photomask, and 50 to 70 seconds are required when exposing 4 to 6 shot areas. However, according to the photomask 5 of the exposure apparatus 1, the photomask can be brought close to or separated from each other in one second or less, and an improvement in production amount of 30 to 40% is expected.
[0033]
Moreover, since the cross-sectional shape of the groove part 8 is formed in the smooth concave shape without a corner, there exists the following merit. For example, when the light shielding film 5b is formed after the groove 8 is formed in the transparent substrate 5a and the light shielding film 5b of the groove 8 is left (when the photomask 5 exposes the negative resist), the groove 8 A light-shielding film material such as chrome is easily attached and coating is easy. During coating, chrome and the like do not accumulate in the corners. When the light shielding film 5b in the groove 8 is removed (when the photomask 5 is exposed to a positive resist), the side wall of the groove 8 is perpendicular to the photomask (for example, the cross section of the groove 8). If the shape is rectangular), the parallel light applied to the photomask 5 is not transmitted through the side wall of the groove 8 and the groove 8 is transferred to the substrate. However, in the groove 8 of the above-described embodiment, the side wall is inclined. Therefore, such inconvenience does not occur.
[0034]
The present invention is not limited to the above embodiment, and may be implemented in various forms as long as it is substantially the same as the technical idea of the present invention.
[0035]
The photomask 5 can be applied to photomasks having various pixel arrangements, and may be, for example, a delta arrangement or a square arrangement. Further, the present invention can be applied to a photomask that performs exposure on various substrates. For example, the exposure may be performed on a TFT substrate.
[0036]
The photomask 5 is not limited to the one provided with four pattern surfaces 4... 4 but may be provided with less than four or five or more. Moreover, as shown in FIG. 7, there may be one pattern surface.
[0037]
【The invention's effect】
As described above, according to the present invention, when the substrate is separated from the photomask, gas is introduced from the outside to the proximity gap through the groove, so that compared to the case where the groove is not provided. Promptly, the pressure in the proximity gap recovers from negative pressure to normal pressure. In addition, the proximity gap pressure increases when the substrate and the photomask are brought close to each other. However, the proximity gap pressure quickly becomes the same as the outside because the gas in the proximity gap is exhausted to the outside through the groove. Recover to moderate pressure. For this reason, the substrate and the photomask can be separated or brought close to each other at a relatively high speed without causing the photomask to shift or drop off, thereby improving the throughput of the exposure apparatus.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a configuration of a proximity exposure apparatus of the present invention.
2 is a plan view of the photomask of the exposure apparatus of FIG. 1 as viewed from the substrate side, and a cross-sectional view showing the substrate side up. FIG.
3 is an enlarged plan view and a cross-sectional view of a part of the photomask in FIG. 2. FIG.
4 is an enlarged plan view and a cross-sectional view showing a part of the photomask in FIG. 2. FIG.
FIG. 5 is a view showing a substrate exposed by the exposure apparatus of FIG. 1;
6 is a flowchart showing a procedure of exposure processing executed by the control device of the exposure apparatus in FIG. 1;
FIG. 7 is a view showing a modification of the photomask of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Exposure apparatus 2 Board | substrate 4 Pattern surface 5 Photomask 5a Transparent substrate 5b Light-shielding film 5d Groove part 5e Hole part 8 Groove part 11 Hole part

Claims (3)

In the negative resist photomask that faces the substrate to be exposed through the proximity gap at the time of exposure,
A groove for supplying and exhausting gas between the proximity gap and the outside on the surface facing the substrate, an opening provided on the surface facing the substrate provided in the groove, and communicating with the outside on the back side of the surface. Air supply / exhaust holes, a transparent substrate, and a light shielding film that is provided on a surface of the transparent substrate facing the substrate and is etched in a transmission portion to form a device pattern ,
The photomask is characterized in that the air supply / exhaust hole is formed by opening a hole obliquely with respect to the light shielding film so as to allow gas to pass through but not transmit light flux . The said surface of the substrate opposite to the side of the front Symbol transparent substrate, a photomask according to claim 1, characterized in that the groove in the transmissive portion in the pattern of the device is provided. In an exposure apparatus that performs exposure with a substrate and a photomask facing each other through a proximity gap,
An exposure apparatus comprising the photomask according to claim 1.

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