JPH0346222A - Resist supply device - Google Patents

Abstract

PURPOSE:To eliminate the irregularity of resist itself and to suppress the scattering of pattern sizes due to difference of devices by a method wherein a resist tank, a filter and a plurality of resist coating devices are provided, and the same resist is supplied to a plurality of resist-coating devices through the same filter. CONSTITUTION:Pipelines are concentrically arranged on a resist tank 11, a filer 12 and a plurality of resist-coating devices 14a to 14c, and the same resist is fed to a plurality of resist-coating devices through the same filter. The dimensional irregularity of resist and pattern is caused by the difference between lots of the used resist and the variation of sensitivity originated in clogging of the resist photosensitive compound on the filter used in each device. As a result, the irregularity of the resist itself between the devices can be eliminated, the irregularity of pattern sizes between the devices can be suppressed, and stabilized IC characteristics and excellent yield rate can be obtained.

Description

[Detailed Description of the Invention] [Summary] Regarding a resist solution supply device, particularly a resist intensive supply device in lithography technology in the IC manufacturing process, it is possible to eliminate variations in the resist itself of each device and to prevent patterns caused by differences in the devices used. The aim is to provide a resist supply device that can suppress dimensional variations. ■Resist tanks, one filter, and multiple resist coating devices are centrally connected via piping, and the same resist is distributed through the same filter to multiple units. The present invention includes a resist supply device characterized in that the resist supply device is configured to supply the resist to a resist coating device.

[Industrial application field]

The present invention relates to a resist solution supply device, and more particularly to a resist intensive supply device for lithography technology in an IC manufacturing process.

In recent years, as ICs have become more highly integrated and patterns have become finer, there has been a demand for higher precision in pattern dimensions.

However, from the perspective of realizing mass production of ICs,
The use of multiple devices for the same purpose is unavoidable, and it is therefore necessary to reduce variations between individual devices.

[Conventional technology]

In conventional resist coating apparatuses used in photolithography, resist solution is supplied to each of a plurality of apparatuses by supplying the resist from a bottle or the like.

A conventional resist supply device will be described with reference to FIG. 2. A bottle 21 containing a resist 22 is sent to a pump 24 via a pipe 23, and the resist pressurized to a constant pressure by the pump is then passed through a pipe 23. The wafer 2 is then sent to the filter 25 via the pipe 23 from the nozzle
7. In addition, in the same figure, 28 is a cup,
29 is a rotating chuck on which the wafer 27 is fixed. While the chuck 29 and therefore the wafer 27 are rotating, the resist is fed onto the wafer and is uniformly applied onto the resist wafer by centrifugal force (spin code). Next, known exposure and development are performed to obtain a desired resist pattern, and etching is performed using this resist pattern as a mask. The configuration shown in FIG. 2 will hereinafter be simply referred to as an apparatus.

[Problem to be solved by the invention]

However, in conventional resist supply devices, each cup contains a bottle containing one resist. Therefore,
Due to changes in resist sensitivity caused by opening of the loft lid of the resist entering each device, clogging of photosensitive components of the resist in the chemical filter, etc., variations in the resist itself between devices occur, making it difficult to match the resist coating devices between the devices. This resulted in variations in pattern dimensions.

Therefore, pattern dimensions vary depending on the apparatus used for resist coating. In resist supply, one of the devices shown in FIG. 2 is called a loft, and a certain resist is supplied to all of the lofts,
Next, when exposing and developing, when trying to obtain a resist pattern with a certain line width for a certain loft,
The number of seconds for which light having a desired intensity of, for example, 300 mW/ctA should be irradiated is measured. This required amount of exposure energy is called threshold energy and is expressed by Eth. As mentioned above, when the intensity of light is kept constant, Eth is expressed in terms of time. The results measured by the inventor using three devices showed variations as shown in the table below.

Equipment I Equipment ■ Equipment ■ Resist thin film (in) 11963.8 1
190? , 4 11934.3Eth (sec
) 0.183 0.176 0.172 Now, to explain the above-mentioned variations in resist sensitivity, the biggest factor in the variation between resist lofts is the manufacturing variation of the resist, and it is not possible to always produce exactly the same resist.

The variation in sensitivity due to this is normally ±5%.

The above data is data for each device, and the resists used are from the same lot. The reason for this variation is thought to be that the sensitivity component of the resist is clogged in the filter, and that there is a difference between devices.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a resist supplying apparatus that can eliminate variations in the resist itself of each apparatus and suppress variations in pattern dimensions due to differences in the apparatuses used.

[Means to solve the problem]

The above-mentioned problem is characterized in that one resist tank, one filter, and a plurality of resist coating devices are centrally connected by piping, and the same resist is supplied to the plurality of resist coating devices through the same filter. Solved by resist supply device.

[Effect]

An embodiment of the present invention is shown in FIG. 1, in which 11 is a resist tank, 12 is a filter, 13 is a pipe, and 14a.

14b and 14c are resist coating devices. In the present invention, since the same resist is supplied to the plurality of devices 14a, 14b, 14c through the same filter 12,
Even if the resist is applied using each device, the same resist film can be formed.

〔Example〕

Hereinafter, the present invention will be specifically explained with reference to illustrated embodiments.

In the present invention, resist is supplied from one resist tank 11. The resist tank 11 is made of, for example, SUS.
Make using. Resist tank 11 is connected by piping 13 to only one filter 12 .

As the filter 12, for example, a Millipore Wafer Guard 0.2n filter commercially available from Millipore Japan ■ was used. This filter 12 is connected to a plurality of (three in the illustrated example) resist coating devices ff114a,
14b and 14c. Each of these resist coating devices is of a known construction consisting of a nozzle, a cup, a rotary chuck, etc. as shown in FIG.

The variation in Eth of the resist applied by a plurality of apparatuses when the resist is supplied by the conventional method is as already shown.

In the resist coating shown in the table, even though the bre-bake temperature and time were the same, there was a considerable difference in Eth due to the difference in the coating equipment used. For example, with equipment I and equipment line width of 0.
A difference of 0.05 μs was observed. As mentioned above, this is thought to be due to the difference in loft of the resist used and the change in sensitivity caused by the degree of clogging of resist photosensitive components in the filters used in each device. If a resist centralized piping supply device is used, the difference between these devices can be suppressed.

When using the apparatus shown in FIG. 1, it is placed in a desired resist tank 11 and the above-mentioned Eth is measured using, for example, the resist coating device 14a. , after which the device 14
A resist is applied to a predetermined thickness using resists a, 14b+14c, and predetermined exposure and development are performed. According to the inventor's experiments, the process was carried out after measuring <Eth as described above, but the film thickness and Eth were the same as in the conventional example.
No variation was observed.

Further, according to the present invention, not only can differences between apparatuses be suppressed, but also variations over time in resist loft opening can be reduced by replenishing the resist tank. That is, when, for example, about half of the resist for the loft is used and then the resist of lot B is added, loft A and lot B are mixed, so that the change over time in loft opening becomes smaller.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to eliminate variations in the resist itself between devices, suppress variations in pattern dimensions between devices, and contribute to stable IC characteristics, yield, etc. big. In addition,
Although three resist coating apparatuses are used in the illustrated example, the scope of application of the present invention is not limited thereto, and any number of apparatuses required for the process can be used.

[Brief explanation of drawings]

FIG. 1 is a configuration diagram of an embodiment of the present invention. FIG. 2 is a configuration diagram of a conventional example. In the figure, 11 is a resist tank, 12 is a filter 13 is piping, 14a, 14b, 14c shows. is resist coating equipment

Claims (1)

[Claims] One resist tank (11), one filter (1
2) and a plurality of resist coating devices (14a, 14b,
14c) is arranged centrally through a piping (13), and the same resist is supplied to a plurality of resist coating devices through the same filter (12).