JP2002093748A - Imprinting apparatus and imprinting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imprinting apparatus and an imprinting method using it, capable of repeatedly pressing on the same substrate and transcribing a mold pattern over the entire substrate with high fidelity. SOLUTION: The apparatus comprises a sample platform 6 for lading a substrate 4, a head 2 to which a mold 1 is loaded, a sample stage 7 capable of moving a sample platform 6, so as to face an arbitrary position of the substrate 4 loaded on the sample platform 6 to the head 2, temperature control mechanism 8-1 and 8-2 for independently controlling the temperature of the head 2 and the sample platform 6 through heating and cooling, a pressing mechanism 3 for pressing the mold 1 on the substrate 4 with arbitrary pressure, and a UV-curing system 9 for irradiating UV light to only the pressed region for curing only the transcribed pattern formed on the relevant region, where alternate repeating of pressing and UV curing enables transcription of the pattern over the entire substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an imprint apparatus and an imprint method for transferring an arbitrary pattern by pressing a mold on a substrate to be processed.

[0002]

2. Description of the Related Art In recent years, high integration of semiconductor integrated circuits and optical circuits has been realized at remarkable speed. Technically supporting this is the advance in lithography technology that projects a pattern corresponding to these elements onto a silicon substrate or the like. For industrial use, photolithography using ultraviolet light as a light source has been mainly used, and the light source wavelength is 436 nm for g-line of an ultra-high pressure mercury lamp, 365 nm for i-line, KrF
The resolution has been improved by shortening the excimer laser to 248 nm. A shorter wavelength 193 nm ArF excimer laser was also developed. However, these devices and the device manufacturing process using them are very expensive, so that they cannot be applied to the manufacture of various types of devices in small quantities in terms of cost.

On the other hand, an imprint apparatus that presses a mold onto a substrate to be processed and a device manufacturing method using the same do not require expensive parts and devices such as a projection lens, and the process is simple. There is an advantage that the cost is reduced. From this, it is expected that the range of application will expand in the future.

In a conventional imprint apparatus and imprint method, when a mold is pressed onto a substrate on which a polymer film such as a resist film is formed, the temperature of the substrate is usually raised and the mold is pressed. is there. By increasing the temperature of the substrate to be processed, the variability of the polymer film is increased, and there is an advantage that the press pressure is reduced and the fidelity of the press is increased.

[0005]

However, if the temperature is raised after pressing, the mold pattern formed on the polymer film will begin to fluidize over time, and the desired pattern shape will not be obtained. Had occurred.
For this reason, measures are taken to lower the temperature of the substrate to be processed to near normal temperature after pressing. Raise the temperature of the substrate again,
When pressing is repeatedly performed on the same substrate, there is a problem that the pattern cannot be transferred to the entire surface of the substrate because fluidization of the previous pattern occurs.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and it is possible to repeatedly press the same substrate, and to transfer a high-fidelity mold pattern onto the entire surface of the substrate. An object of the present invention is to provide a printing apparatus and an imprint method using the same.

[0007]

An imprint apparatus according to the present invention presses a mold having a pattern formed on a substrate having a polymer film formed thereon, and transfers the pattern of the mold to the polymer film. In the apparatus, a sample stage on which the substrate is mounted, a head on which the mold is mounted, and a sample capable of moving the sample stage such that an arbitrary position of the substrate mounted on the sample stage is opposed to the head. A stage, a temperature control mechanism for heating and cooling the head and the sample stage to independently control the temperature, a press mechanism for pressing the substrate and the mold at an arbitrary pressure, and only a pressed area. Is irradiated with ultraviolet rays to cure only the transfer pattern formed in the area.
A V cure system, and the pattern transfer to the entire substrate is enabled by alternately repeating press and UV cure.

[0008] The imprinting method of the present invention is a method for imprinting, in which a pattern-formed mold is pressed on a substrate on which a polymer film is formed, and the pattern of the mold is transferred to the polymer film. Using a UV-crosslinkable resist that causes crosslinking by irradiating UV rays while adding the polymer as the polymer film, the temperature of the head on which the mold is mounted and the temperature of the sample table on which the substrate is mounted is determined by the glass transition temperature of the resist. The mold and the substrate are pressed against each other in a state where the temperature is controlled to a higher temperature, and the mold is pressed.After pressing, the temperature of the sample stage is lowered to a temperature lower than the glass transition temperature of the resist, and the two are separated from each other. Then, while irradiating only the pressed area with ultraviolet rays, the sample stage is heated from a temperature lower than the glass transition temperature to a temperature higher than the glass transition temperature to cure only the transfer pattern. And performing pattern transfer to the substrate by performing a V curing.

[0009] The imprint method of the present invention is characterized in that, in the imprint method of pressing a mold on which a pattern is formed on a substrate on which a polymer film is formed and transferring the pattern of the mold to the polymer film, Using a UV-crosslinkable resist that causes crosslinking by irradiating UV rays while adding the polymer as the polymer film, the temperature of the head on which the mold is mounted and the temperature of the sample table on which the substrate is mounted is determined by the glass transition temperature of the resist. The mold and the substrate are pressed against each other in a state where the temperature is controlled to a higher temperature, and the mold is pressed.After pressing, the temperature of the sample stage is lowered to a temperature lower than the glass transition temperature of the resist, and the two are separated from each other. Then, while irradiating only the pressed area with ultraviolet rays, the sample stage is heated from a temperature lower than the glass transition temperature to a temperature higher than the glass transition temperature to cure only the transfer pattern. Performs V curing, further characterized by performing the pattern transfer to the entire substrate by repeating the press and UV cured alternately while changing the location of the substrate.

[0010]

Embodiments of the present invention will be described below.

FIG. 1 is a schematic view illustrating a typical embodiment of an imprint apparatus and an imprint method according to the present invention, wherein 1 is a mold, 2 is a mold mounting head, 3 is a press mechanism,
4 is a substrate, 5 is a polymer film, 6 is a sample stage, 7 is a sample stage, 8-1 and 8-2 are temperature control mechanisms of a mold and a substrate, 9 is a UV cure system, 10 is an ultraviolet light source, 11
Denotes an aperture, 12 denotes an ultraviolet light path, and 13 denotes ultraviolet light.

First, a mold 1 was used in which a convex columnar pattern was etched to a height of 0.7 μm on a silicon substrate by dry etching and then cut into 4 mm squares. This was adhered to the mold head 2 using a heat-resistant adhesive. As a material of the polymer film 5 to be press-transferred, a chemically amplified negative resist SAL for electron beam lithography, which is a resist cross-linked by irradiating ultraviolet rays while applying heat.
601 (Shipley) was used. The glass transition temperature of the SAL601 resist is 120 to 140C.

As the substrate 4, a 4-inch silicon substrate was used. A resist was spin-coated on the substrate to a thickness of 0.3 μm, baked on a hot plate at 105 ° C. for 120 seconds, and then mounted on the sample table 6 by vacuum suction.

Prior to pressing, the temperature control mechanisms 8-1 and 8-2 were heated and temperature controlled so that the temperatures of the mold head 2 and the substrate 4 were 160 ° C. and 180 ° C., respectively. Next, pressing was performed by pressing down the mold head 2 using the press mechanism 3. Pressing was started at the above temperature, and pressing was performed for 10 minutes so that the pressure became 50 MPa. Five minutes before the end of the press, the substrate temperature was lowered to 70 ° C. by flowing cooling water through the temperature control mechanism 8-2, and the two were separated. In addition, the substrate temperature at the time of separating the both is set to be equal to or lower than the glass transition temperature, but is preferably lower than 100 ° C. If the temperature is higher than 100 ° C., peeling of the resist may occur.

Subsequently, the sample stage 7 was driven to control the sample stage 6 to be at a predetermined position of the UV cure system 9. Here, the substrate temperature was raised from 70 ° C. to 110 ° C. in 2 minutes while irradiating the pressed 4 mm square with ultraviolet rays, and held for 1 minute, and then heated to 180 ° C. in 2 minutes. When irradiating with ultraviolet light, the aperture 11 whose size is changed to a passage of ultraviolet light emitted from the ultraviolet light source 10 is used.
And the ultraviolet light path 12 to provide an irradiation area of 4 m
m. An ultra-high pressure mercury lamp was used as the ultraviolet light source 10. The wavelength bands are 436 nm for g-line and 365 n for I-line.
m, and the intensity was about 50 mW / cm ² .

The SAL on which the template has been transferred by UV irradiation
With the 601 pattern, crosslinking and curing of the resist proceeded, and the shape of the pressed pattern did not change even when the temperature was raised to 180 ° C again. UV cure is 320 UV light source
The effect was more prominent when a lot of short wavelength components of nm or less were included. After the completion of the UV curing, the sample table 6 was returned to the pressing position again, the position on the substrate was changed, the pressing was performed, and the UV curing was performed again. By repeating this step, a 20-region template pattern could be formed on the 4-inch substrate.

The effect of the UV cure according to the present invention is SAL
The highest effect was obtained with a negative resist such as 601 cross-linked by heat, ultraviolet rays, electron beams, and X-rays, particularly a chemically amplified negative resist. Novolak-based diazonaphthoquinone sensitizers, which have been used in the conventional UV-sensitive positive type resists, also showed a considerable improvement effect.

On the other hand, when UV curing is not performed, when the temperature is raised to 180 ° C. again, among the patterns pressed before, the finer the pattern, the more the pattern flow occurs, and it is impossible to form the pattern repeatedly. Met.

In this embodiment, the UV cure system 9 is used.
Are arranged apart from the press mechanism 3, but it is obvious that the integration becomes more efficient.

[0020]

As described above, the imprint apparatus and the imprint method using the same according to the present invention can be used to imprint a mold on a polymer film substrate such as a resist film. By pressing the mold while the sample stage on which the head and the substrate are mounted is heated to a temperature higher than the glass transition temperature of the polymer film, a high-fidelity press can be performed at a low press pressure. Thereafter, by lowering the temperature of the substrate below the glass transition temperature of the polymer film and separating them, pattern deformation can be prevented, and the polymer film can be prevented from peeling off from the substrate and adhering to the mold.

Further, by irradiating only the pressed region with ultraviolet rays, the substrate is heated from a temperature lower than or equal to the glass transition temperature of the polymer film to a temperature higher than the glass transition temperature. . By curing the press pattern, measures are taken to prevent the pressed pattern from being deformed even when heated again, so that the mold can be repeatedly pressed on the same substrate.

For this reason, by using the imprint apparatus and the imprint method of the present invention, the productivity is increased and the production cost is greatly reduced.

Further, since the heat treatment is finally performed at a temperature equal to or higher than the glass transition temperature during the UV curing, even if it is introduced without a pretreatment into a high temperature process having a glass transition temperature or higher, such as etching, which is performed after pattern formation, There is an advantage that pattern deformation does not occur and problems such as gas emission are eliminated.

[Brief description of the drawings]

FIG. 1 is a schematic diagram illustrating a typical embodiment of an imprint apparatus and an imprint method according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Mold, 2 ... Mold head, 3 ... Press mechanism, 4 ... Substrate, 5 ... Polymer film, 6 ... Sample stand, 7 ... Sample stage, 8- 1, 8-2: temperature control mechanism, 9: UV cure system, 10: ultraviolet light source, 11: squeezing, 12: ultraviolet light path, 13: ultraviolet light.

Claims (3)

[Claims] 1. An apparatus for pressing a mold on which a pattern is formed on a substrate on which a polymer film is formed, and transferring the pattern of the mold to the polymer film, comprising: a sample stage on which the substrate is mounted; A head on which the mold is mounted, a sample stage capable of moving the sample table so that an arbitrary position of the substrate mounted on the sample table faces the head, and heating the head and the sample table A temperature control mechanism for cooling and independently controlling the temperature, a press mechanism for pressing the substrate and the mold at an arbitrary pressure, and irradiating only the pressed area with ultraviolet light to form the area. An imprint apparatus comprising: a UV cure system for curing only a transfer pattern. 2. An imprinting method in which a pattern-formed mold is pressed on a substrate on which a polymer film is formed, and the pattern of the mold is transferred to the polymer film. UV-cross-linking resist, which causes cross-linking as a result, is used as the polymer film, and the temperature of the head on which the mold is mounted and the sample stage on which the substrate is mounted are controlled to a temperature higher than the glass transition temperature of the resist. In this state, the mold and the substrate are pressed against each other to press the mold, and after the pressing, the temperature of the sample stage is lowered to a temperature lower than the glass transition temperature of the resist to separate them from each other. Only the transfer pattern is cured by heating the sample stage from a temperature lower than the glass transition temperature to a temperature higher than the glass transition temperature while irradiating only the ultraviolet rays to the sample stage.
An imprint method comprising performing V-curing, and further performing pattern transfer onto a substrate by alternately repeating pressing and UV curing while changing the location of the substrate. 3. An imprinting method of pressing a mold on which a pattern is formed on a substrate on which a polymer film is formed, and transferring the pattern of the mold to the polymer film, irradiating ultraviolet rays while applying heat. UV-cross-linking resist, which causes cross-linking as a result, is used as the polymer film, and the temperature of the head on which the mold is mounted and the sample stage on which the substrate is mounted are controlled to a temperature higher than the glass transition temperature of the resist. In this state, the mold and the substrate are pressed against each other to press the mold, and after the pressing, the temperature of the sample stage is lowered to a temperature lower than the glass transition temperature of the resist to separate them from each other. Only the transfer pattern is cured by heating the sample stage from a temperature lower than the glass transition temperature to a temperature higher than the glass transition temperature while irradiating only the ultraviolet rays to the sample stage.
An imprint method, wherein pattern transfer is performed on the entire substrate by performing V cure.