JPH0585224B2 - - Google Patents

Description

[Detailed description of the invention]

[0001]

[Field of Industrial Application] The present invention relates to a nozzle that drips a liquid onto the surface of a workpiece, etc., and particularly in cases where solutes in the dropped liquid are precipitated around the periphery of the nozzle tip, or where the dropped liquid is concentrated at the nozzle tip. The present invention relates to a droplet nozzle that can prevent liquid dripping from occurring.

[0002]

2. Description of the Related Art A nozzle for dropping a liquid onto the surface of an object to be processed is widely used for dropping a coating liquid for forming a photoresist or a metal oxide film, or a coating liquid containing a diffusing agent. For example, in the process of manufacturing ICs, LSIs, etc., in order to apply a semiconductor diffusing agent onto a wafer, as shown in FIG. A coating liquid containing the agent is dropped, and the wafer 11 is rotated at high speed by a spinner 10, so that the surface of the wafer 11 is uniformly coated with the diffusing agent by centrifugal force.

【0003】

However, when the coating liquid is dropped from the nozzle 12, some of the coating liquid remains on the peripheral edge 12a of the nozzle tip due to the influence of surface tension. Here, since the coating liquid consists of a solution in which a diffusing agent is dissolved in a solvent such as an organic solvent, the coating liquid remaining on the nozzle tip periphery 12a only evaporates as time passes, gradually condenses, and finally The solute precipitates. If such condensed coating liquid or precipitates fall onto the wafer, uneven coating will occur, leading to the production of defective products, which is extremely disadvantageous in terms of product yield.

[0004] In order to eliminate the above-mentioned disadvantages, conventionally, the tip of the nozzle is wiped using a sponge, cloth, or something impregnated with a solvent to prevent the concentrated liquid or precipitate from falling.

[0005] However, such conventional methods have no choice but to rely on manual labor, which poses problems in terms of mass production.
Furthermore, if the space between the nozzle and the spinner is narrow, wiping is difficult and there is a high risk of foreign matter falling onto the wafer surface. Furthermore, the coating process and the processes preceding and following it cannot be performed mechanically, which is a cause of hindering complete automation.

[0006] In view of the above-mentioned problems, the present inventors
The present invention was made to effectively solve this problem, and its purpose is to provide a droplet nozzle in which the dropped liquid does not become concentrated at the tip of the nozzle, or solutes do not precipitate at the tip. It is on offer.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention includes a nozzle for dropping a solution, a large-diameter pipe through which the solution flows, and a plurality of pipes arranged to surround the outer periphery of the large-diameter pipe. The lower end of the small diameter pipe is positioned above the lower end of the large diameter pipe, the lower end of the small diameter pipe is cut diagonally, and the lowest part of this lower end is placed above the lower end of the large diameter pipe. The gist of this is that it faces large diameter pipes.

[0008]

[Operation] The cleaning solvent supplied to the small diameter pipe moves from the lower end of the small diameter pipe to the outer periphery of the large diameter pipe, and washes the lower end of the large diameter pipe while flowing down the outer periphery.

【0009】

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0010] FIG. 1 is a longitudinal sectional view of a coating device to which such a nozzle is applied according to the present invention, and FIG. 2 is a sectional view taken along the line 2-2 in FIG. The lower end 3a of the small diameter pipe 3 is located higher than the lower end of the large diameter pipe 2, and the large diameter pipe 2 includes, for example, A diffusing agent coating liquid and a cleaning solvent are made to flow down into the small diameter pipe 3, respectively.

[0011] FIG. 3 is an enlarged view of the essential parts of such a nozzle according to the present invention, in which the shape of the lower end 3a of the small diameter pipe 3 attached to the outer circumferential surface of the large diameter pipe 2 is inclined toward the outer circumferential surface of the large diameter pipe 2. The small diameter pipe 3 has a shape cut downward, and the lowermost portion 3b of the lower end 3a of the small diameter pipe 3 is in contact with the large diameter pipe 2.

[0012] The operation of the droplet nozzle having the above configuration will be described next. As described above, the nozzle 1 is placed over the center of the wafer 11 placed on the spinner 10 while maintaining a predetermined distance from the center, and the dispersing agent coating liquid is dripped from the tip of the large diameter tube 2, and the spinner 10 is rotated. urge Then, the dropped diffusing agent coating liquid is uniformly applied to the surface of the wafer 11 by centrifugal force.

[0013] When the coating liquid is dropped, some of the coating liquid remains on the lower end peripheral portion 2a of the large-diameter pipe 2 due to surface tension, and as the solvent evaporates, the residual liquid condenses or the diffusing agent Since it precipitates as a solid, it is necessary to remove it.

[0014] Therefore, a cleaning solvent is supplied from above to the plurality of small diameter pipes 3 disposed on the outer peripheral surface of the large diameter pipe 2.

[0015] Figures 4a and b are operational diagrams of such a nozzle according to the present invention, in Figure 4a, the cleaning solvent L1
reaches the lower end 3a of the small diameter pipe 3 due to the falling action of gravity (arrow).

[0016] Here, since the lower end portion 3a is cut diagonally, the cleaning solvent L1 flows along the slope (arrow), and as a result, the cleaning solvent L1 flows through the lowermost portion 3b to the outer periphery of the large diameter pipe 2. Thereafter, the cleaning solvent flows down the outer peripheral surface of the large-diameter pipe 2, dissolving and washing away the concentrated liquid or precipitate remaining on the lower peripheral edge 2a (arrow).

[0017] FIG. 4b shows a case where the entire nozzle is tilted by an angle θ with respect to the perpendicular line L2, and even in this case, the cleaning solvent L1 flows down as shown by the arrow along the slope of the lower end 3a of the small diameter pipe 3. . This is small diameter pipe 3
This is because the lower end 3a of the pen is cut diagonally and has a shape similar to a pen tip.

[0018] By the way, since it is not preferable to drop the solvent, which is the cleaning liquid, directly onto the spinner 10 during cleaning, in practice, cleaning is performed using the discharge device 5 as shown in FIG. That is, the discharge device 5 consists of a funnel-shaped receiving portion 6 that is sufficiently larger than the overall shape of the nozzle 1 and a discharge pipe 8 that communicates with a hole 7 provided at the bottom of the funnel-shaped receiving portion 6.
is located directly below the nozzle 1 during cleaning, and is configured to move to the side of the nozzle during dripping.

[0019] Next, a specific experimental example will be shown below. Experimental example 1 The diameter of the large diameter pipe is 1.5 mm, the diameter of the small diameter pipe is 0.3 mm,
An apparatus as shown in FIG. 1 was constructed using a nozzle in which the lower end of the large diameter tube protruded 5 mm from the lower end of the small diameter tube. Then, the large diameter pipe of the above nozzle was made by Tokyo Ohka Kogyo Co., Ltd.
OCD (Silica film coating liquid: SiO ₂ equivalent concentration 5.9
%) as a coating solution, ethyl alcohol was supplied to the small diameter tube, and 1 ml of OCD was dropped onto the wafer from the large diameter tube. Thereafter, the receiver of the discharge device was positioned below the nozzle, and 3 ml of ethyl alcohol was poured through the small diameter pipe to clean the lower end of the nozzle.

[0020] As a result, even after 30 minutes had passed after cleaning, no precipitation of solid matter or concentration of the dripped liquid was observed at the lower end of the nozzle. Furthermore, even when the same operation was repeated many times, the same good results as above were obtained.

Experimental Example 2 In order to compare the effects of using a conventional nozzle with the above experimental example, a conventional nozzle (diameter
The same coating solution as above was applied dropwise using a 1.5 mm diameter tube. As a result, white solute was observed to be deposited at the lower end of the nozzle about 2 minutes after dropping.

[0022] Note that the above description and experimental examples are merely examples of the implementation of the present invention, and it is optional whether or not to use it in combination with a discharge device. For example, if a discharge device is not used, a spinner may be provided. The rotary device or the nozzle may be made laterally movable to prevent the cleaning liquid from falling onto the spinner surface during cleaning.

[0023] Furthermore, although the illustrated example shows an example of dropping a semiconductor diffusing agent coating liquid, the present invention is of course not limited to this, and can be widely applied as a droplet nozzle using a solvent that volatilizes easily. Add what you can do.

【0024】

Effects of the Invention As is clear from the above description, according to the present invention, a nozzle for dropping a solution such as a coating liquid is connected to a large diameter pipe through which the solution flows down, and a cleaning solvent is supplied to the outer periphery of this large diameter pipe. The lower end of the small diameter pipe is placed above the lower end of the large diameter pipe, the lower end of the small diameter pipe is cut diagonally, and the lowest part of this lower end faces the large diameter pipe. This prevents the solution from concentrating or the solute from precipitating at the lower end of the nozzle, thereby reliably preventing uneven coating and improving product yield.

[0025] Furthermore, in the present invention, since the lower end of the small diameter pipe is cut diagonally, the cleaning solvent can flow down evenly even if the nozzle is slightly inclined.

[0026] Also, since manual wiping etc. are no longer necessary, the coating process and the processes that precede and follow this can be performed continuously, allowing for complete automation.
Furthermore, it exhibits many advantages such as being able to provide an inexpensive nozzle that has a simple structure and is easy to manufacture.

[Brief explanation of the drawing]

[Fig. 1] Vertical side view of a coating device to which a nozzle according to the present invention is applied.

[Figure 2] Cross-sectional view taken along line 2-2 in Figure 1

[Fig. 3] Enlarged view of main parts of the nozzle according to the present invention

[Fig. 4] Action diagram of the nozzle according to the present invention

[Fig. 5] Partially longitudinal side view showing a conventional example

[Explanation of symbols]

1... Nozzle, 2... Large diameter pipe, 2a... Lower end of large diameter pipe, 3... Small diameter pipe, 3a... Lower end of small diameter pipe, 3b... Lowermost part of small diameter pipe.

Claims (1)

[Claims] [Claim 1] A small diameter pipe for flowing a cleaning solvent is provided around a large diameter pipe for flowing a solution, and the lower end of this small diameter pipe is positioned above the lower end of the large diameter pipe. A droplet nozzle, characterized in that the lower end of the small diameter pipe is cut diagonally, and the lowest part of the lower end faces the large diameter pipe.