JP2854716B2 - Exposure equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus.

[0002]

2. Description of the Related Art In a semiconductor manufacturing process, there is a photolithography process for forming a pattern on a thin film laminated on a semiconductor wafer. In the photolithography process, a resist is applied to a uniform thickness on a semiconductor wafer using a spin coater or the like, and projected and exposed through a patterned mask.
After the development, the resist thin film is formed in a pattern shape. In these exposure steps, pattern projection exposure is performed by irradiating ultraviolet rays. In the developing step, a developing solution is used.
After developing and removing the resist other than the resist that has hardened by the light reaction, place the semiconductor wafer on a hot plate and heat it so that the resist pattern shape remaining as a positive or negative pattern can be maintained with high accuracy. ,
The resist remaining after the irradiation of ultraviolet rays is cured.

[0003]

However, in such a photolithography process, as the degree of integration of the semiconductor integrated circuit device is required, uniformity of the pattern formation is also required with ultra-high accuracy. Therefore, in an exposure apparatus that irradiates ultraviolet rays while heating such a semiconductor wafer in a chamber, the semiconductor wafer is placed horizontally on a hot plate,
2. Description of the Related Art Processing is performed in a chamber that is kept airtight by a quartz plate lid that transmits ultraviolet light. Then, a gas flow such as N ₂ gas is generated in the chamber by the inlet and exhaust ports provided on the side wall of the chamber, and the solvent of the resist generated by vaporization by heat is removed, and the resist solvent and the like adhere to the quartz plate. As a result, it is possible to prevent the intensity of the irradiation light for exposure from changing, thereby preventing the processing by exposure from becoming non-uniform.

However, N ₂ supplied into the chamber is
Since the gas needs a considerable flow rate, the semiconductor wafer 4 on the quartz plate 2 and the hot plate 3 in the chamber 1 as shown in FIG.
When an N ₂ gas flow is generated in between, a temperature difference occurs between a part (central part) 5 where a large amount of N ₂ gas flow hits the semiconductor wafer 4 and a part (peripheral part) 6 where only a small amount is supplied. I will. As a result, the exposure processing became uneven.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned drawbacks, and it is possible to reduce the adhesion of a solvent or the like of a resist generated by being vaporized to an introduction window, so that the object to be exposed can be treated at a uniform temperature. An object of the present invention is to provide an exposure apparatus that can perform the exposure.

[0006]

In order to achieve the above object, an exposure apparatus according to the present invention comprises a light source for exposing an object to be exposed, a light introduction window and the object to be exposed. And a chamber provided with a mounting table provided with a heating device for heating, wherein at least the inner wall surface of the introduction window has a temperature setting means for setting a temperature higher than the ambient temperature of the object to be exposed.

Further, the temperature setting means may include an introduction window comprising a pair of parallel plates through which light from the light source is transmitted, and a temperature-adjusted gas flow may be formed between the introduction windows. Alternatively, the temperature setting means may be provided with a vertical movement mechanism for raising the mounting table when the object to be exposed is not processed by the light source.

[0008]

The exposure apparatus of the present invention is mounted on a mounting table provided with a heating device in a chamber having an introduction window made of a quartz plate or the like for transmitting light from an exposure light source and keeping the inside airtight. The exposed object is exposed. Gas supply means for generating a gas flow in the chamber is provided in order to prevent gas generated by heating the object to be exposed to the introduction window as a solid, and at this time, a large amount of gas is applied. Temperature setting means for adjusting the temperature of the introduction window by the action of a thermophoretic force so that the temperature of the object to be exposed to the object to be exposed does not become non-uniform and a small amount of gas can sufficiently prevent adhesion. The temperature of the introduction window is adjusted to be higher than the temperature of the mounting table to prevent adhesion of generated gas. As the temperature setting means, the introduction window is formed of a pair of parallel plates that transmit light from the light source to form a two-layer structure, and a gas stream heated to a high temperature flows through a gap between the two-layer structure. As another temperature setting means, the mounting table is raised to heat the introduction window when the exposure processing of the object to be exposed is not performed. Since the deposits attached to the introduction window can be removed in this manner, the flow rate of the gas flow generated in the chamber can be reduced,
Uniform processing can be performed without causing a temperature distribution on the object to be exposed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the exposure apparatus of the present invention is applied to a pattern curing apparatus after development will be described with reference to the drawings. FIG.
The pattern curing device 7 shown in FIG. 1 mainly includes a light source device 8 having a light source and a chamber 10 having a hot plate 9 as a mounting table having a heating device for heating a semiconductor wafer as an object to be exposed. The light source device 8 includes an ultraviolet lamp 11 such as an arc lamp or an incandescent lamp, which is a light source for generating ultraviolet light of a predetermined wavelength, and a reflecting mirror 13 for preventing the ultraviolet light 12 from being scattered from the ultraviolet lamp 11. The chamber 10 into which the ultraviolet light 12 from the light source device 8 is incident is provided with an insertion port 16 into which the semiconductor wafer 14 supported by the transfer arm 15 is inserted, so that the semiconductor wafer 14 can be carried into and out of the chamber 10. I have. A shutter 17 for opening and closing the insertion opening 16 is provided to be connected to the vertical movement mechanism. The hot plate 18 in the chamber 10 can heat the semiconductor wafer 12 to a desired temperature by a resistance heating element embedded therein. The hot plate 9 is provided with, for example, three through holes for support pins 18 connected to a vertical movement mechanism (not shown). Around the through holes, a sliding member such as polytetrafluoroethylene is attached. When the semiconductor wafer slides, the friction is reduced to facilitate the vertical movement, the semiconductor wafer 12 is raised on the hot plate 9, and is transferred to and from the transfer arm 15, and the hot wafer 9 is lowered.
A semiconductor wafer is mounted thereon.
Further, a gas flow N ₂ of nitrogen gas is provided on the side wall of the chamber 10.
And a gas supply means 21 having a purge gas inlet 19 connected to a nitrogen gas supply device for generating gas in the chamber 10 and a purge gas exhaust port 20 connected to an exhaust device (not shown). The purge gas introduction port 19 is provided in an introduction pipe 22 for accommodating N ₂ gas supplied from a nitrogen gas supply device, and is provided so as to blow out into the chamber 10 at a constant pressure. The inlet 19 may be provided in a slit shape instead of a hole.

As shown in FIG. 2, the lid 23 for keeping the inside of the chamber 10 airtight is an introduction window 24 formed of a quartz plate which is a set of parallel plates forming a temperature setting means.
a and 24b are provided in a two-layer structure in which two layers are provided. The ultraviolet rays 12 from the light source device 8 are transmitted through the introduction windows 24a and 24b so that the semiconductor wafer 14 can be exposed. A supply device 2 for supplying heated gas, for example, an inert gas such as N ₂ , air, etc., between the quartz plates 24 a and 24 b of the lid 23.
5 is provided, and while the gas supplied between the introduction windows 24a and 24b is exhausted from the exhaust port 27 connected to an exhaust device (not shown), the supply port 26 is higher by 10 ° C. than the temperature in the chamber 10. The introduction window 24b is heated to such a temperature. When the introduction windows 24a and 24b are set higher by 10 ° C., a thermophoretic force acts on the particles due to the temperature difference, and it has been confirmed by experiments that if the temperature difference is larger than 3 ° C., for example, the particles do not deposit. The interval between the introduction windows 24a and 24b is determined by the flow rate of the heated gas.
0 mm is preferred.

In order to expose the semiconductor wafer 14 with the pattern curing device 7 having such a configuration, the semiconductor wafer 14 supported by the transfer arm 15 is carried into the chamber 10 through the insertion opening 16 in which the shutter 17 is opened. Then, the support pins 18 are raised and the semiconductor wafer 1 is
4 and the transfer arm 15 is retracted and the shutter 17
Is closed, and the inside of the chamber 10 is kept airtight. The support pins 18 are lowered, and the semiconductor wafer 14 is placed on the hot plate 9 set at a temperature of 200 ° C. Light source device 8
When the ultraviolet rays 12 are emitted from the ultraviolet lamp 11, the ultraviolet rays 12 pass through the introduction windows 24a and 24b of the lid 23 and irradiate the semiconductor wafer to perform an exposure process. Chamber 10
N ₂ gas supplied from N ₂ gas supply member is introduced into the chamber 10 from the purge gas inlet port 19 within the exhaust port 2
A gas flow is formed by exhausting the gas from 0, and the vaporized solvent of the resist applied to the semiconductor wafer 14 generated by heating is sent out of the chamber 10 from the exhaust port 20 together with the gas. At this time, 210 ° C. higher than the temperature of the hot plate 9 by 10 ° C. between the introduction windows 24 a and 24 b of the lid 23.
N ₂ gas heated to is supplied from the gas supply unit 25, to heat the inlet window 24b to 210 ° C.. Thus, the temperature of the hot plate 9, that is, the temperature of the chamber 1
By setting the temperature higher than the temperature in 0 ° C. by 10 ° C., a thermophoretic force acts on the particles, thereby preventing the particles from adhering to and contaminating the surface of the introduction window 24b. Therefore, the introduction window 24b
The surface of the semiconductor wafer 14 can always be maintained in a clean state, so that there is no inconvenience such as a change in the intensity of ultraviolet irradiation due to the attachment of contaminants, and the semiconductor wafer 14 can be exposed to light with a uniform light intensity. The flow rate of the N ₂ gas supplied into the chamber 10 from the purge gas inlet 19 is 20 to 3
From about 0 l / min to about 10 to 15 l / min, it can be reduced by about half, so that the semiconductor wafer is not cooled by the large amount of N ₂ gas in the chamber 10 as in the prior art.
A uniform exposure process can be performed without causing a temperature difference in the semiconductor wafer surface.

As another embodiment, as shown in FIG. 3, the lid 28 of the chamber 10 has a single-layer structure having only the introduction window 24a. Is provided. Vertical movement mechanism 2
9 allows the hot plate 9 to approach the introduction window 24a up to 2-3 mm. Then, one semiconductor wafer 14 is loaded into the chamber 10, exposure processing is performed while forming a N ₂ gas flow into the chamber 10 from the purge gas inlet 19, and the semiconductor wafer 14 is unloaded from the chamber 10, 9 is moved up and down to a distance of 2 to 3 mm to the introduction window 24a by operating the vertical movement mechanism 29. Then, the introduction window 24a is heated to a higher temperature than the inside of the chamber 10 so that the semiconductor wafer 14
Is removed from the introduction window 24a by thermophoretic force due to the solidification and adhesion of the resist solvent and the like generated during the heat treatment. At this time, the N ₂ gas is supplied into the chamber 10 from the purge gas inlet 19, and the particles separated from the inlet window 24a through the outlet 20 are exhausted together with the N ₂ gas. This operation may be performed each time one semiconductor wafer 14 is processed, or may be performed after several semiconductor wafers 14 are processed.

By cleaning the lid in this manner, uniform exposure can be performed at all times. When processing the semiconductor wafer 14, the exposure process can be performed without allowing a large amount of N ₂ gas to flow out, and the temperature of the semiconductor wafer is not affected. Since it is not uniform, uniform exposure processing can be performed. In the above embodiment, an example in which the present invention is applied to the exposure step of a resist film formed on a semiconductor wafer is described. However, the present invention can be applied to any exposure apparatus such as LCD manufacturing and printed circuit board manufacturing.

[0014]

As is clear from the above description, according to the exposure apparatus of the present invention, since the temperature setting means for adjusting the temperature of the introduction window to a temperature higher than that of the chamber is provided, a resist or the like is provided on the introduction window by the thermophoretic action. The solvent can be prevented from evaporating and adhering, and the contamination of the introduction window can be prevented, and the exposure process can be performed with a small amount of purge gas. Therefore, uniform processing can be performed while maintaining uniform temperature of the semiconductor wafer, and a high-quality product can be efficiently manufactured.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of an exposure apparatus of the present invention.

FIG. 2 is a diagram showing a main part of the embodiment shown in FIG. 1;

FIG. 3 is a diagram showing another embodiment.

FIG. 4 shows a conventional example.

[Explanation of symbols]

7: Pattern hardening device 9: Hot plate (mounting table, heating device) 10: Chamber 11: Ultraviolet lamp (light source) 14: ... Semiconductor wafers 24a, 24b ... Introduction window (one set of parallel plates, temperature setting means) 29 ... Vertical moving mechanism (temperature setting means)

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 21/027 H01L 21/3065

Claims (3)

(57) [Claims] 1. An exposure apparatus comprising: a light source for exposing an object to be exposed; and a chamber provided with a mounting table provided with a window for introducing the light and a heating device for mounting and heating the object to be exposed. , Wherein at least the inner wall surface of the introduction window has a temperature setting means for setting a temperature higher than the ambient temperature of the object to be exposed. 2. The apparatus according to claim 1, wherein said temperature setting means includes an introduction window made of a set of parallel plates transmitting light from said light source, and a temperature-adjusted gas flow is formed between said introduction windows. The exposure apparatus according to claim 1, wherein 3. The exposure apparatus according to claim 1, wherein said temperature setting means includes a vertical movement mechanism for raising said mounting table when said object to be exposed is not processed by said light source.