JPH10323633A - Substrate treatment device and scatter preventing cup - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the electric leak generated by the scatter of cleaning liquid outside a cup and the contamination of a substrate generated by the splash of the cleaning liquid in a rotating substrate treatment device. SOLUTION: A cleaning liquid such as pure water is supplied from a nozzle onto the upper face of a substrate W retained by a chuck 50 and rotated to rotate and clean the substrate W. The cleaning liquid splashed from the surface of the substrate W by the rotation centrifugal force collides with an inner wall face 11 of an upper cup 10 and bounces back. The oblique angle θ of the inner wall face 11 to the substrate W is set in the range of 30 deg.C-60 deg.C, and the range of angle is determined by the actual measurement. Used cleaning liquid is not formed into mist hung over outside the cup nor bounced droplets onto the substrate W, but are dropped downward in the cup and collected on the lower section of the cup by adopting the above range of angle. The leak from an electric system and the contamination of the substrate outside the cup can be prevented by the arrangement.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention provides a processing liquid to a substrate for a precision electronic device such as a semiconductor substrate or a liquid crystal substrate (hereinafter referred to as a "substrate"), and performs various processes such as cleaning on the substrate surface. The present invention relates to a substrate processing apparatus.

[0002]

2. Description of the Related Art In an apparatus for performing cleaning by supplying a cleaning liquid (typically pure water) to a substrate while rotating the substrate, a cleaning liquid used for cleaning (hereinafter referred to as "used cleaning liquid") is used. The substrate is discharged from the substrate to the outer peripheral side of the substrate by centrifugal force caused by the rotation. Then, a scattering prevention cup is used for the purpose of preventing the used cleaning liquid from scattering widely around the substrate.

FIG. 9 is a partial sectional view showing a conventional anti-scattering cup C0. The cup C0 has a cylindrical shape whose wall surface extends in a substantially vertical direction. The substrate W is held substantially horizontally by the chuck 5 and is rotated horizontally.
A collides with the inner wall surface of the cup C0 and falls downward. Then, the used washing liquid FA is collected and discharged at the lower part of the cup C0.

[0004]

However, in the post-use cleaning liquid FA, there is a portion that does not fall down after colliding with the inner wall surface of the cup C0 but scatters inside and outside the cup C0.
Of these, the used washing liquid scattered outside the cup C0 becomes mist FM and reaches the electric system of the apparatus, which may cause an electric leakage.

A portion of the used cleaning liquid FA which bounces toward the center of the substrate W is a droplet FD.
Fall on. Such a droplet FD is a droplet of the used cleaning liquid, and also contains a large amount of particles inside because the dirt on the inner wall surface is also picked up by the collision with the cup C0. Therefore, such a droplet FD causes contamination of the substrate W.

[0006] Such a problem occurs not only in a rotary cleaning apparatus for a substrate using pure water as a cleaning liquid, but also in a general substrate processing apparatus for supplying a processing liquid while rotating the substrate.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the above-mentioned problems in the prior art, in which splashes and mist of a processing solution do not bounce out of a cup and onto a substrate, and can effectively prevent electric leakage and substrate contamination. It is an object of the present invention to provide a processing device and a scattering prevention cup therefor.

[0008]

According to a first aspect of the present invention, there is provided a substrate processing apparatus for performing a predetermined processing by supplying a processing liquid to the substrate while rotating the substrate. Rotation holding means for rotating the substrate while holding the substrate substantially horizontally, b) a shatterproof cup surrounding the substrate held by the substrate rotation holding means and having an open top, and c) a processing liquid on the surface of the substrate. And a processing liquid supply unit for supplying the processing liquid.

The angle formed by at least a part of the inner wall surface of the scattering prevention cup and the substrate held by the rotation holding means is in the range of 30 ° to 60 °. I have.

According to a second aspect of the present invention, in the substrate processing apparatus of the first aspect, the scattering prevention cup has a hollow frustoconical shape b-1) inwardly inclined, and at least the processing on the substrate is performed. When supplying the liquid, the inclined side wall portion surrounding the periphery of the substrate, and b-2) a collecting portion that is provided continuously below the inclined side wall portion and collects the processing liquid supplied to the substrate. The angle formed by the inner surface of the inclined side wall portion and the substrate is 3
The angle is in the range of 0 ° to 60 °.

Further, according to a third aspect of the present invention, in the substrate processing apparatus of the second aspect, the scattering prevention cup is connected to an upper end portion of the inclined side wall portion so that an upper opening of the cup is formed. It further has an annular top plate projecting inward.

A typical example of such a substrate processing apparatus is a substrate cleaning apparatus using pure water.

According to the fifth and sixth aspects of the present invention, there is provided a scattering prevention cup usable in these substrate processing apparatuses.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings.

<A. Schematic Configuration of Substrate Processing Apparatus> First, a schematic configuration of a substrate processing apparatus according to an embodiment of the present invention will be described with reference to FIG. The substrate processing apparatus 1 in this embodiment is configured as a rotary cleaning apparatus for a semiconductor substrate (wafer) W, and uses pure water as a cleaning liquid. In the center of the apparatus 1, a spin chuck 50 for vacuum-sucking and holding the substrate W in a substantially horizontal state is provided.
The rotation shaft 51 of the spin chuck 50 is rotated by a motor M, so that the spin chuck 5 is rotated.
With 0, the substrate W rotates about this axis 51 in a horizontal plane.

A cleaning supply nozzle 41 for supplying a cleaning liquid such as pure water to the vicinity of the center of the substrate W is arranged, and the substrate surface is scanned and cleaned while supplying such a cleaning liquid. A rotary cleaning brush 42 is provided. During the rotary cleaning, the rotary cleaning brush 42 descends to the height of the imaginary line in FIG.

On the other hand, a scattering prevention cup C made of resin is provided to prevent the used cleaning liquid from scattering around and to collect the used cleaning liquid and guide it to a predetermined cleaning liquid recovery path. The spin chuck 50 and the substrate W are accommodated in the scattering prevention cup C. However, when the substrate W is carried in and out of the spin chuck 50, the rotating cleaning brush 4
Reference numeral 2 denotes a horizontal rotation, which is retracted outside the area above the cup C, and the scattering prevention cup C is lowered by the lifting drive mechanism 60, so that the spin chuck 50 is relatively exposed from the upper opening S of the cup C. It will be in a state of having done. The transfer of the substrate W to and from the spin chuck 50 is performed by a transfer robot (not shown).
Done by

The scattering prevention cup C is roughly divided into an upper cup 10 and a lower cup (collecting portion) 20. The lower end of the upper cup 10 is connected to the lower cup 20 and is integrated therewith. Further, at the upper end of the upper cup 10, a horizontal annular top plate 30 projecting toward the inside of the upper opening S is integrally provided.

The upper cup 10 has an inner wall surface 11 having a shape corresponding to the side surface of the truncated hollow cone. At the time of the rotary cleaning, the relative height of the substrate W is included in the vertical range H of the inner wall surface 11.

The lower cup 20 is in the form of a bottomed container having a drain hole 21 and the like, and its central portion is connected to a hollow cup support tube T. In this cup support tube T,
The rotating shaft 51 already described penetrates. The cup C and the support tube T are not connected to the spin chuck 50, and the cup C does not rotate even if the spin chuck 50 rotates.

<B. Detailed Configuration and Operation of Cup C> FIG. 2 is a partially enlarged view of the vicinity of the upper cup 10 of the cup C of FIG. The inner wall surface 11 of the upper cup 10 is an inner surface of an inclined side wall portion inclined inward from the vertical direction, and the angle θ formed by the inner wall surface 11 with the main surface of the horizontal substrate W is 30 ° to 60 °. It has an angle value selected from the range of ゜. In the device 1 of this embodiment, θ = 45 °.

The upper cup 10 has a substantially rotationally symmetrical shape with respect to the rotation axis of the substrate W, and the above-described angular relationship is established at each part of the inner wall surface 11 of the upper cup 10 around the substrate W. Further, since the upper cup 10 of this embodiment has a truncated conical surface shape, its cross section is linear as shown in FIG. 2, and the above-mentioned angular relationship is established over each part of the vertical range H in FIG.

In rotating cleaning of the substrate W, the cleaning liquid F is supplied onto the substrate W from the nozzle 41 of FIG. 1 and brush cleaning by the brush 42 is performed. At this time, as shown in FIG.
Is the upper cup 10 due to the centrifugal force caused by the rotation of the substrate W.
The used cleaning liquid FA jumps out toward the inner wall surface 11 and collides with the inner wall surface 11.

However, since the inner wall surface 11 has an inclined surface inclined inward, the used cleaning solution FA does not scatter on the outside of the cup C or on the substrate W.
From the substrate W toward the lower side of the substrate W. Then, it is collected by the lower cup 20 of FIG.

Therefore, the used cleaning solution FA is supplied to the cup C
Does not fly out of the substrate and become mist or scattered droplets, and do not return to the main surface of the substrate W. As a result, no electric leakage occurs in the electric system due to the cleaning liquid mist outside the cup C, and no dirty used cleaning liquid adheres to the main surface of the substrate W and recontaminates the substrate W. .

In this embodiment, since the top plate 30 is provided, the mist can be more effectively prevented from scattering outside the cup.

<C. Range Conditions of Angle θ and Experimental Example> By setting the inclination angle θ to any value, a sufficient scattering prevention effect can be obtained when the cleaning liquid collides with the inner wall surface 11 of the cup C. This cannot be predicted by a simple mechanical reflection calculation due to the property that the cleaning liquid is a liquid. Therefore, it is preferable to know an appropriate range of the angle θ by actual measurement.

Under such circumstances, the inventor of the present invention actually measured various values of the angle θ, and the results are as follows (see also FIGS. 4 and 5 in which these are graphed). .

The actual measurement is based on the number NP of the residual particles on the substrate; the density NM of the mist scattered outside the cup (unit: number / C
F); for two quantities: However, CF is "cubic feet" and the metric scale is also shown in FIG.

When θ = 90 °: NP = 50, NM = 10000; When θ = 70 °: NP = 10, NM = 4000; When θ = 60 °: NP = 0, NM = 100; when θ = 45 °: NP = 0, NM = 90; when θ = 30 °: NP = 0, NM = 90; of which θ = 90 ° corresponds to the prior art of FIG. .

As can be seen from these results, as the angle θ decreases, both the number NM of the residual particles on the substrate and the density NP of the mist outside the cup decrease. In particular, the decrease in the number of mist and particles at angles below about θ = 60 ° is remarkable.

Therefore, based on such an actual measurement result,
In the present invention, first, the first condition of “the angle θ is set to 60 ° or less” is imposed.

As can be seen from FIGS. 4 and 5, the smaller the angle θ is, the better the result is. Therefore, from this actual measurement alone, it will be preferable that the lower limit value of the angle θ be close to zero.

However, as a practical matter, if the angle θ is set to a value close to 0 °, for example, as shown in FIG.
Therefore, the plane size D of the entire cup C must be extremely large.

This is an undesirable situation. that is,
The size of the substrate W to be processed by the substrate processing apparatus 1 tends to increase with the times. For example, a semiconductor wafer as the substrate W has a size of 5 inches, 8 inches to 12 inches (300 m).
m) It is related to the growth of wafers over time. In such a situation, not only the plane space occupied by the substrate W itself becomes large, but also the transport space thereof becomes large. Therefore, it is important to prevent the plane size of the entire apparatus, that is, the foot space, from increasing.
Therefore, it is necessary to avoid as much as possible the remarkable increase in the plane size D of the scattering prevention cup.

Therefore, the present invention imposes a second condition that "the lower limit of the angle θ is 30 degrees". At such an angle, the increase in the plane size of the cup C is within an allowable range, and the prevention of scattering of mist and the like and the prevention of the increase in the plane size are balanced.

As described above, in the embodiment of FIGS. 1 and 2, θ = 45 °, and the angle of inclination (taper angle) from the (substantially horizontal substrate W) (main surface of) the substrate W in the present invention. θ in the range of 30 ° to 60 ° ”. When priority is given to the prevention of scattering, an angle close to 30 ° is adopted as much as possible. To prevent the scattering while placing importance on the demand for increasing the plane size, an angle value close to 60 ° may be used. An angle of 45 ° represents an intermediate choice between these.

<D. Modifications> In the embodiment shown in FIGS. 1 and 2, the inner wall surface of the upper cup 10 has a single frustoconical surface. However, as shown in FIG. The inner wall surface may have a multi-stage base. In this case, at least a part of the inner wall surface (for example, the inner wall surface 1 in FIG. 7)
The angle θ between 1b) and the main surface of the substrate W may be in the range of 30 ° to 60 °.

When the upper cup is formed as a curved surface (for example, a dome-shaped cut-off spherical surface) as shown in FIG. 8, the local inclination angle θ at any arbitrary position is in the range of 30 ° to 60 °. Should be there. In the example of FIG. 8, this condition is satisfied near the inner wall portion 11c.

In other words, the substrate W on the inner wall surface of the cup
It is only necessary that at least a part of the region around the region has an inclination angle θ with respect to the main surface of the substrate W in the range of 30 ° to 60 °.

Further, the above embodiment is directed to a substrate cleaning apparatus using pure water as a processing liquid, but cleaning liquids and processing liquids other than pure water are as follows.

In other words, strictly speaking, the scattering direction of the droplets on the inner wall surface of the cup varies to some extent depending on the viscosity of the processing solution and the like. . However, the angle range of 30 ° to 60 ° is applicable to many types of processing liquids for the following reasons.

First, a processing liquid having a higher viscosity than pure water generally has less scattering. This is because when it collides with the inner wall surface 11 of the upper cup, the adhesion to the inner wall surface is relatively strong. Therefore, the angle range of 30 ° to 60 ° obtained for pure water has a sufficient scattering prevention effect for these high-viscosity treatment liquids.

On the other hand, for a treatment liquid having a viscosity lower than that of pure water, for example, when θ = 60 °, there is a possibility that scattering is not sufficiently prevented. In this case, the inclination angle θ is made smaller than 60 °, and the range is limited to the lower angle side, for example, in the range of 330 ° to 45 °.

In any case, the angle range of 30 ° to 60 ° obtained from actual measurement of pure water is not limited to this pure water, but can be applied to many treatment liquids. Therefore, the present invention is applicable to a general substrate processing apparatus including a substrate cleaning apparatus.

[0046]

As described above, in the substrate processing apparatus according to the first aspect of the present invention, the angle between at least a part of the inner wall surface of the cup and the substrate is selected within the range of 30 ° to 60 °. In addition, it is possible to prevent the used processing liquid from scattering outside the cup and onto the substrate surface, and it is possible to effectively prevent contamination of the substrate and leakage of electric system.

Further, according to the second aspect of the invention, the same effects as those of the first aspect can be obtained without imposing any remarkable conditions on the collecting portion of the cup.

Further, according to the third aspect of the present invention, the provision of the annular top plate projecting toward the inside of the upper opening of the cup can further effectively prevent the processing liquid from scattering outside the cup.

In the invention of claim 4, claims 1 to 3
With regard to pure water washing as a typical application example of the invention, the effects of the inventions of claims 1 to 3 can be obtained.

Further, according to the fifth and sixth aspects of the present invention, there is provided a scattering prevention cup which can be incorporated in a substrate processing apparatus having the above-mentioned features.

[Brief description of the drawings]

FIG. 1 is a schematic view of a substrate processing apparatus according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of the scattering prevention cup of FIG. 1;

FIG. 3 is a partially enlarged view illustrating an operation of preventing scattering of a used cleaning liquid in the scattering prevention cup of FIG. 1;

FIG. 4 is a graph showing measured values of the relationship between the inclination angle of the cup and the number of scattered mist outside the cup.

FIG. 5 is a graph showing actually measured values of the relationship between the inclination angle of the cup and the number of particles remaining on the substrate.

FIG. 6 is an explanatory view of an increase in the plane size of the scattering prevention cup.

FIG. 7 is a view showing another example of the scattering prevention cup of the present invention.

FIG. 8 is a view showing still another example of the scattering prevention cup of the present invention.

FIG. 9 is a view for explaining a conventional scattering prevention cup and its problems.

[Explanation of symbols]

 C Scatter prevention cup W Substrate θ Angle between inner wall surface of upper cup and substrate F Cleaning liquid FA Used cleaning liquid S Upper opening of cup 1 Substrate cleaning device (substrate processing device) 10 Upper cup 11 Inner wall surface 20 Lower cup (collection) Part) 30 annular top plate 50 spin chuck

Claims (6)

[Claims] 1. A substrate processing apparatus for performing a predetermined processing by supplying a processing liquid to the substrate while rotating the substrate, comprising: a) rotation holding means for rotating the substrate while holding the substrate substantially horizontally; B) a scattering prevention cup surrounding the substrate held by the substrate rotation holding means and having an open top, c) processing liquid supply means for supplying a processing liquid to the surface of the substrate,
The angle formed by at least a part of the inner wall surface of the scattering prevention cup and the substrate held by the rotation holding means is in the range of 30 ° to 60 °. A substrate processing apparatus characterized by the above-mentioned. 2. The substrate processing apparatus according to claim 1, wherein the scattering prevention cup has a shape of b-1) a hollow truncated cone that is inclined inward, and at least around the substrate when the processing liquid is supplied to the substrate. And b-2) a collecting part that is provided below the inclined side wall part and collects the processing liquid supplied to the substrate, and an inner surface of the inclined side wall part. And the angle formed by the substrate,
A substrate processing apparatus characterized in that the angle is in the range of 30 ° to 60 °. 3. The substrate processing apparatus according to claim 2, wherein the scattering prevention cup is b-3) an annular shape that is connected to an upper end of the inclined side wall and protrudes toward the inside of the upper opening of the cup. A substrate processing apparatus further comprising a top plate. 4. The substrate processing apparatus according to claim 1, wherein the processing liquid is pure water. 5. A scattering prevention cup which is open at an upper portion and surrounds a substrate housed and held substantially horizontally, and prevents scattering of a processing liquid supplied onto the substrate, wherein: a) an inwardly inclined cup. An inclined side wall portion having a hollow truncated cone shape and capable of accommodating the substrate in a substantially horizontal state; andb) a collecting portion which is provided continuously below the inclined side wall portion and collects a processing liquid supplied to the substrate. When the substrate is accommodated substantially horizontally in the cup, the angle formed by the inner surface of the inclined side wall portion and the substrate is 3 degrees.
An anti-scattering cup, wherein the angle is in the range of 0 ° to 60 °. 6. The shatterproof cup according to claim 5, further comprising: c-3) an annular ceiling connected to an upper end portion of said inclined side wall portion and projecting toward an inside of an upper opening of said cup. A scattering prevention cup comprising a plate portion.