JP3894979B2 - Exposure equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exposure apparatus used for transferring a predetermined pattern to a resist applied to a semiconductor wafer.
[0002]
[Prior art]
Conventionally, an exposure apparatus has been used to transfer a mask pattern formed on a reticle onto a resist coated on the surface of a semiconductor wafer.
As shown in FIG. 2, the exposure apparatus includes an ultraviolet light source 1, a shutter 2, a reticle 4 on which a mask pattern 3 is formed, a reduction projection lens 5, and an XY stage 6. On this XY stage 6, a semiconductor wafer 7 coated with a resist, which is an object of pattern transfer, is mounted.
[0003]
In order to transfer the pattern onto the semiconductor wafer 7 using this apparatus, first, ultraviolet rays are irradiated from the ultraviolet light source 1 to the reticle 4 on which the mask pattern 3 is formed via the shutter 2. At this time, the ultraviolet rays applied to the reticle 4 are shielded by the light shielding portion of the mask pattern 3. The ultraviolet rays that have passed through the area other than the light shielding area of the mask pattern 3 are reduced and projected onto the resist applied to the surface of the semiconductor wafer 7 on the XY stage 6 by the reduction projection lens 5 and exposed.
[0004]
By this exposure, a hardened or softened region is formed in the resist applied to the surface of the semiconductor wafer 7, and a part of the resist is removed in the next development process. As a result, the mask pattern 3 is transferred to the resist.
[0005]
[Problems to be solved by the invention]
By the way, in order to change the pattern to be transferred, the mask pattern 3 has to be replaced with the reticle 4 because the mask pattern 3 is formed on the reticle 4.
Therefore, the reticle 4 needs to be replaced, and after the replacement, the alignment of the reticle 4 must be accurately performed. When changing the pattern to be transferred, it takes time and labor from replacement of the reticle 4 to exposure. Was.
[0006]
The reticle 4 has a mask substrate 3 formed on a quartz substrate with a metal thin film, for example, chrome plating, which is expensive to manufacture. In particular, the number of types of patterns to be transferred has increased. It has become.
In view of the above-described problems, an object of the present invention is to provide an exposure apparatus capable of improving work efficiency in an exposure process and reducing costs.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration. That is, the exposure apparatus of the present invention is an exposure apparatus that irradiates a photosensitive material coated on a semiconductor wafer to transfer a mask pattern, and which is irradiated with an ultraviolet light source and light generated from the ultraviolet light source. A plurality of transmissive image display devices capable of forming an arbitrary mask pattern according to the optical fiber for transmitting the light transmitted through the transmissive image display device, and a reduction projection lens for receiving the light transmitted by the optical fiber, An optical fiber is provided for each cell unit of the transmissive display device, and is characterized in that the sectional area on the reduction projection lens side is smaller than the sectional area on the transmissive image display device side .
[0008]
The exposure apparatus of the present invention is characterized in that the transmissive image display device is a liquid crystal display device.
According to the exposure apparatus of the present invention, a mask pattern to be transferred to a photosensitive material applied to a semiconductor wafer is realized by a transmission type image display apparatus that can form a region that transmits or blocks light by a drive signal. Since the mask pattern can be freely formed, it is not necessary to replace or store the reticle.
[0009]
In addition, a plurality of transmissive image display devices are used, and an optical fiber is installed in each cell of each transmissive image display device, and these are bundled to form one mask pattern. Since the area can be made smaller than the cross-sectional area on the transmissive image display device side, a higher-density mask pattern can be formed.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be specifically described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same part as the past, or an equivalent part.
As shown in FIG. 1, the exposure apparatus of the present invention includes an ultraviolet light source 1, a shutter 2, a reduction projection lens 5, and an XY stage 6, and a control device 9 instead of a conventional reticle. A plurality of transmissive display devices 8 connected to each other by wiring 11 are installed. A region for transmitting or shielding light is formed on the transmissive display device 8 by the drive signal from the control device 9, and an arbitrary mask pattern 3 can be realized.
[0011]
Each transmissive display device 8 is provided with an optical fiber 10 for each cell unit, and the optical fibers 10 are gathered near the reduction projection lens 5 to form a bundle of optical fibers 10. The mask pattern 3 displayed on each transmissive display device 8 is formed as a single mask pattern by the bundle of optical fibers 10.
In order to transfer the pattern to the resist applied to the semiconductor wafer 7 using the exposure apparatus of the present invention, the following procedure is performed. First, after dropping a resist, which is an organic polymer photosensitive material, onto the semiconductor wafer 7, the semiconductor wafer 7 is rotated at a high speed (several thousand rpm), and the resist is applied to a thickness of about 1 μm by centrifugal force. A semiconductor wafer 7 is set at a predetermined position on the XY stage 6.
[0012]
Next, mask pattern data (image data) stored in a storage medium such as a floppy disk is read into the control device 9, and an arbitrary mask pattern is selected from the plurality of mask pattern data. The control device 9 generates a drive signal that can control the transmissive display device 8 in units of cells in accordance with the selected mask pattern data.
[0013]
The transmissive display device 8 is composed of a liquid crystal display device, in which liquid crystal is injected between transparent substrates on which transparent electrodes orthogonal to each other are formed, thereby forming a matrix cell. The drive signal generated by the control device 9 is sent to the transmissive display device 8 via the wiring 11, and the orientation of molecules changes in units of cells according to this drive signal, and the light transmission pattern changes. By changing the light transmission pattern, a region for transmitting or shielding light can be formed on the transmissive display device 8, and an arbitrary mask pattern 3 can be realized.
[0014]
Then, the ultraviolet light emitted from the ultraviolet light source 1 is applied to the transmissive display device 8 on which the mask pattern 3 is formed via the shutter 2. At this time, the shutter 2 is used for controlling the exposure time. For example, since the wavelength of the ultraviolet light source 1 becomes unstable until a certain time has elapsed after the power is turned on, the shutter 2 is closed during that period, and the shutter 2 is opened after the wavelength is stabilized. Thereafter, the exposure time is adjusted by opening and closing the shutter 2 without turning off the power of the ultraviolet light source 1.
[0015]
The ultraviolet light irradiated on the transmissive display device 8 is partially shielded by the mask pattern 3, and the ultraviolet light irradiated outside the light shielding region of the mask pattern 3 passes through the transmissive display device 8 and is guided to the optical fiber 10. It is burned. Since the optical fiber 10 is provided for each cell unit of the transmissive display device 8, the light transmitted or shielded by the mask pattern 3 is faithfully guided to the optical fiber 10.
[0016]
The optical fibers 10 provided in the plurality of transmission type display devices 8 are bundled together above the reduction projection lens 5, and the ultraviolet rays transmitted through the plurality of transmission type display devices 8 are reduced as a single mask pattern here. Guided to 5.
The ultraviolet rays guided to the reduction projection lens 5 are reduced and projected, reduced and projected onto a resist coated on the surface of the semiconductor wafer 7 on the XY stage 6 and exposed. Since the semiconductor wafer 7 is mounted on the XY stage 6, an arbitrary position of the semiconductor wafer 7 can be exposed by moving in parallel. By this exposure, a hardened or softened region is formed by the resist applied to the surface of the semiconductor wafer 7, and a part of the resist is removed in the development process of the next step, and as a result, the mask pattern 3 is transferred to the resist.
[0017]
In the exposure apparatus of the present invention, in particular, by guiding the ultraviolet rays to the reduction projection lens 5 with the optical fiber 10, the cross-sectional area of the optical fiber 10 on the reduction projection lens 5 side can be made smaller than the cross-sectional area on the transmission type image display device 6 side. This makes it possible to form a higher-density mask pattern.
[0018]
【The invention's effect】
As described above, according to the exposure apparatus of the present invention, the mask pattern to be transferred to the photosensitive material coated on the semiconductor wafer is realized by the transmission type image display apparatus capable of forming a light transmitting or shielding area by the driving signal. By doing so, an arbitrary mask pattern can be freely formed, so that reticle replacement and storage are not required.
[0019]
In addition, by using a plurality of transmissive image display devices, installing optical fibers so as to correspond to the respective transmissive image display devices, and bundling them to form one mask pattern, the optical fiber on the reduction projection lens side Since the cross-sectional area can be made smaller than the cross-sectional area on the transmissive image display device side, a higher-density mask pattern can be formed.
[Brief description of the drawings]
FIG. 1 is an explanatory view showing an exposure apparatus of the present invention.
FIG. 2 is an explanatory view showing a conventional exposure apparatus.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ultraviolet light source 2 Shutter 3 Mask pattern 5 Reduction projection lens 6 XY table 7 Semiconductor wafer 8 Transmission type display apparatus 9 Control apparatus 10 Optical fiber

Claims (2)

In an exposure apparatus that irradiates a photosensitive material applied on a semiconductor wafer to transfer a mask pattern, an ultraviolet light source and an arbitrary mask pattern are formed according to a drive signal irradiated with light generated from the ultraviolet light source. A plurality of transmissive image display devices, an optical fiber that transmits light transmitted through the transmissive image display device, and a reduction projection lens that receives light transmitted through the optical fiber, the optical fiber being a cell unit of the transmissive display device An exposure apparatus provided for each, wherein the cross-sectional area on the reduction projection lens side is smaller than the cross-sectional area on the transmission image display apparatus side . 2. The exposure apparatus according to claim 1, wherein the transmissive image display device is a liquid crystal display device.

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