JP2000102770A - Washer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform cleaning of the surface and groove inside of a substrate at the same time and also to prevent fine particles once removed from being restuck to enable performing washing of high cleaning degree. SOLUTION: This washer is equipped with a substrate holding part for holding a substrate W and a washing utensil disposed on the surface of the substrate W so as to make it slidable. The washing utensil has a high pressure nozzle 36 for jetting high pressure washing liquid toward the substrate W and a cylindrical washing body 42 surrounding the periphery of the high pressure nozzle 36. In this way, scrub washing and high pressure liquid washing of the substrate are performed at the same time to perform cleaning of the surface and the groove inside of the substrate at the same time and also by feeding liquid from inside the washing body, fine particles are prevented from being restuck due to the concentration of the soil of the washing body to enable washing of high washing degree.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a cleaning device,
In particular, the present invention relates to a cleaning apparatus suitable for cleaning a substrate requiring a high degree of cleanliness, such as a semiconductor substrate, a glass substrate, and a liquid crystal panel.

[0002]

2. Description of the Related Art In recent years, as the degree of integration of semiconductor devices has increased, the wiring of circuits on a semiconductor substrate has become finer, and the distance between the wirings has become smaller. However, in the processing of a semiconductor substrate, particles such as fine particles of semiconductor pieces, dust, and crystalline projections may adhere. If particles larger than the distance between the wirings exist on the semiconductor substrate, problems such as short-circuiting of the wirings will occur.
Only particles sufficiently smaller than the distance between wirings are allowed on the substrate. Such a situation is the same in the process of processing a glass substrate used as a mask or the like or a substrate such as a liquid crystal panel. With such demands, there is a need for a cleaning technique for dropping even finer submicron-level particles from a semiconductor substrate or the like.

For example, as a method of cleaning a semiconductor substrate after polishing with a high degree of cleaning, scrub cleaning is performed by rubbing a cleaning body composed of a brush or sponge on the substrate, or high-pressure water (high-speed jet flow) is applied to the substrate. Cavitation is performed by injecting air and generating bubbles by cavitation. In the cabin jet cleaning, it is necessary to supply low-pressure water to the outer periphery of high-pressure water in order to generate bubbles due to cavitation.

[0004]

However, while scrub cleaning is effective for dirt adhering to the surface of the substrate, it is not necessarily effective for removing residual fine particles adhering inside fine grooves on the surface of the substrate. Not valid. Further, when the amount of fine particles adhering to the cleaning body increases, there is also a problem that the fine particles easily adhere to other portions.

On the other hand, the cabin jet cleaning is effective for removing fine particles remaining inside the fine grooves on the substrate surface, but the structure is complicated, for example, by flowing the cleaning water to the inner and outer two layers, and the amount of the cleaning water is also small. growing. Further, there is also a problem that it is difficult to remove dirt or the like fixed on the surface of the substrate.

[0006] This is the same in other cleaning,
Although one of the cleaning of the substrate surface and the inside of the groove can be satisfied, none of them can satisfy both at the same time. Therefore, a plurality of stages of cleaning have been performed.

The present invention has been made in view of the above circumstances, and simultaneously performs cleaning of the surface of a substrate and the inside of a groove, and prevents reattachment of particles once removed, thereby performing high-cleaning cleaning. It is an object of the present invention to provide a cleaning device that can perform the cleaning.

[0008]

According to one aspect of the present invention, there is provided a substrate holding portion for holding a substrate, and a cleaning tool slidably provided on a surface of the substrate, wherein the cleaning tool comprises a high-pressure cleaning liquid. A high-pressure nozzle for injecting the liquid toward the substrate, and a cylindrical cleaning body surrounding the high-pressure nozzle.

[0009] Thus, the cleaning body slides while the lower end surface of the cleaning body is in contact with the surface of the rotating substrate, and at the same time, the high-pressure cleaning liquid is jetted from the high-pressure nozzle toward the substrate surface, thereby scrubbing the substrate. The cleaning and the high-pressure liquid cleaning are performed simultaneously to efficiently remove the fine particles adhering to the substrate surface and the fine particles in the groove, respectively. Since the high-pressure cleaning liquid is covered by the cleaning body, it is prevented from absorbing static electricity and gas, and since it is a self-cleaning type in which the liquid is supplied from the inside of the cleaning body, the dirt of the cleaning body does not thicken. Less risk of recontamination.

Preferably, the substrate holding unit is rotated, and the cleaning tool is attached to the tip of the swing arm and is swung to increase the relative movement amount. As the cleaning liquid, ultrapure water is preferably used, and a cleaning body having flexibility and a certain degree of liquid permeability such as a sponge is used.

In a preferred aspect of the present invention, the pressure of the high-pressure cleaning solution injected from the high-pressure nozzle toward the substrate is 1 to 15 MPa. As a result, water is contained in the cleaning body, and as a result, an inner high-speed flow and an outer low-speed flow in contact with the inner surface are present, and so-called cavitation occurs in which bubbles are generated due to a large speed difference near the interface. As a result, it is possible to increase the ability to remove fine particles of the washing water and the washing ability.

Another aspect of the present invention comprises a high-pressure nozzle for jetting a high-pressure cleaning liquid toward a substrate, and a hollow body surrounding the high-pressure nozzle, and the hollow body and the substrate are jetted from the high-pressure nozzle. A space for holding the cleaning liquid is formed, and the cleaning liquid ejected from the high-pressure nozzle passes through the cleaning liquid held in the space and collides with the surface of the base material.

With the above arrangement, the high-pressure cleaning liquid is jetted from the high-pressure nozzle to the substrate, and the space formed by the hollow body and the substrate is filled with the cleaning liquid. The high-pressure cleaning liquid ejected from the high-pressure nozzle passes through the cleaning liquid under static pressure held in the space. For this reason, a large velocity difference is generated near the interface between the cleaning liquid filled under the static pressure and the high-pressure cleaning liquid ejected from the high-pressure nozzle passing through the cleaning liquid under the static pressure, and bubbles are generated by cavitation.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a perspective view showing the overall configuration of the cleaning apparatus of the present invention. As shown in FIG. 1, the cleaning apparatus includes a spin chuck 10 that horizontally holds a semiconductor substrate W as an object to be cleaned and rotates the semiconductor substrate W at a required number of rotations. The substrate W is held by the spin chuck 10 with the cleaning surface facing upward. On the other hand, on the side of the spin chuck 10, a support shaft 12 having a swing arm 14 extending at the upper end in a horizontal direction is mounted so as to be vertically movable and rotatable.

At the tip of the swing arm 14, a substantially cylindrical housing 16 is held. FIG. 2 is an enlarged sectional view showing a main part of FIG. As shown in FIG.
A rotating shaft 18 extending in the vertical direction is rotatably held inside the housing 16 by bearings 17a and 17b held by a bearing holding member 17, and a driven bevel gear 20a is attached to an upper end of the rotating shaft 18. . On the other hand, the drive shaft 2 extending in the horizontal direction is
2 is provided with a bearing casing 23 rotatably supported by bearings 23a and 23b, and a driving bevel gear 20b meshed with the driven bevel gear 20a is attached to the tip of the driving shaft 22. The drive shaft 22 is connected to a drive source such as a motor provided at the base end of the swing arm 14 or the like.

A ring-shaped member 24 in which a flow path 24a for supplying high-pressure water is formed is provided below the rotary shaft 18, and an inlet 24b of the flow path 24a is connected to a high-pressure hose via a joint 26. 28 are connected. The high-pressure hose 28 extends through the inside of the housing 16 to the outside. A pressurizing pump such as a plunger pump (not shown) is provided in the middle of the high-pressure hose 28, and the water flowing through the pressurizing pump is 1 to 15 MPa (10 MPa).
１５０150 kgf / cm ² ), preferably 5 to 10 MPa
(50 to 100 kgf / cm ² ).

Between the rotating shaft 18 and the ring-shaped member 24,
A ring-shaped liquid reservoir 30 extending in the circumferential direction is formed. FIG. 3 is a sectional view taken along line AA of FIG. FIG.
As shown in (1), a radial flow path 32a extending from the annular liquid reservoir 30 to the axis is formed in the rotating shaft 18, and thereby a rotary joint 33 is formed. The radial flow path 32a further communicates with an axial flow path 32b that extends downward along the axis, thereby forming a high-pressure liquid flow path 32 that opens to a high-pressure nozzle mounting portion 34 at the lower end of the rotating shaft 18. I have.

A high-pressure nozzle 36 having a small-diameter nozzle hole 36a at its tip is screwed and attached to the high-pressure nozzle mounting portion 34. FIG. 4 is a view showing the tip of the high-pressure nozzle 36 having the nozzle hole 36a. The nozzle hole 36a is
As shown in FIG. 4 (a), the tip may be of a jet nozzle type which spreads outward, or as shown in FIG. 4 (b), the tip may be of a straight type. The diameter of the nozzle hole 36a is, for example, about 0.2 to 0.4 mm.
At a time of 2 mm, the flow rate of the high-pressure liquid is set to be about 210 ml / min.

On the other hand, a liquid-proof plate 39 is fixed to the lower portion of the rotating shaft 18 by a fixing sleeve 38 to prevent the cleaning liquid splashed from the substrate W from entering the opening of the housing 16. At the tip of the fixing sleeve 38, a cylindrical scrub cleaning body 42 made of PVA sponge or the like is used.
Is mounted so as to surround the high-pressure nozzle 36. The tip of the cleaning body 42 is attached so as to extend below the tip of the high-pressure nozzle 36. PVA sponge has excellent liquid absorbency due to extremely fine continuous pores, is flexible, and is less likely to fall off than fiber products.

Next, a method of using the cleaning apparatus configured as described above will be described. First, the substrate W is transferred onto the spin chuck 10 by a robot arm or the like, and the spin chuck 1 is moved.
At 0, the substrate W is held and rotated at a predetermined rotation speed. Next, with the swing arm 14 raised, the swing arm 14
Is swung to almost the center position of the substrate W.

In this state, the swing arm 14 is lowered while rotating the rotating shaft 18 to rotate the cleaning body 42, and the lower end of the cleaning body 42 is pressed against the surface to be cleaned of the rotating substrate W with a predetermined pressure. At the same time, a cleaning liquid such as ultrapure water is jetted from the high-pressure nozzle 36 toward the substrate W at a high pressure of about 1 to 15 MPa. Then, by swinging the swing arm 14, the cleaning body 42 is swung between both outer edges so that the cleaning body 42 passes through the center portion of the substrate W at a predetermined speed, and the scrub cleaning and the high-pressure liquid cleaning of the substrate W are performed in parallel. Do it. The swing of the swing arm 14 is repeated a predetermined number of times.

At this time, in the space surrounded by the cleaning body 42, the high-pressure water from the high-pressure nozzle 36 directly hits the surface of the substrate W to wash out the fine particles existing in the grooves on the surface. High pressure nozzle 36
Is surrounded by the cleaning body 42, so that high-pressure water from the high-pressure nozzle 36 is prevented from absorbing gas in the atmosphere, and therefore, molecular contamination and the like due to gas components can be prevented. The mist generated by the high pressure water cleaning is
Since it does not go outside from the internal space of No. 2, the diffusion of mist can be suppressed.

A high-pressure liquid is supplied from the high-pressure nozzle 36 to the substrate W, and the lower end of the cleaning body 42 is brought into contact with the substrate W so that the lower end of the high-pressure nozzle 36, the inner wall of the cleaning body 42 and the space 42b surrounded by the substrate W are superposed. Fill with a cleaning solution such as pure water. Space 42b
A so-called cavitation in which a large velocity difference exists near the interface between the cleaning liquid filled under static pressure and the high-pressure liquid ejected from the high-pressure nozzle 36 passing through the cleaning liquid under static pressure, causing friction and generating bubbles. Occurs. Cleaning body 4
Even if the lower end of 2 is not brought into contact with the substrate W but is brought close to the substrate W, bubbles due to cavitation are generated. Substrate W
On the other hand, when the lower end of the cleaning body 42 is brought closer, the distance between the substrate W and the lower end of the cleaning body 42 is set so that the amount flowing out of the gap between them is smaller than the flow rate of the high-pressure liquid supplied from the high-pressure nozzle 36. I do. When the cleaning body 42 is brought into proximity without contacting the substrate W, the cleaning body 42 does not need to be made of a liquid-absorbing material such as sponge, and may be a hollow body for filling the space 42b with the cleaning liquid. Bubbles due to cavitation last for a predetermined time and then collapse near the surface of the substrate W, thereby increasing the ability to remove fine particles of the cleaning liquid and the cleaning ability.

Further, in this cleaning device, fine particles and the like adhering to the cleaning body 42 are sequentially removed by supplying a liquid from the inside of the cleaning body 42. That is, since the cleaning apparatus is of a self-cleaning type, contamination of the cleaning body 42 is reduced. There is little risk of recontamination due to concentration.

After washing for a predetermined time, the swing arm 1
4 and the supply of the high-pressure liquid are stopped, and the swing arm 14 is stopped.
Is lifted up and evacuated from above the substrate W, and then the spin chuck 10 is rotated at a high speed to spin dry. When performing the next cleaning step, the rotation of the substrate W is stopped, and the substrate W is transported to the next step so as not to dry the surface to be cleaned.

In this embodiment, ultrapure water is used as the cleaning liquid. However, a chemical liquid such as ammonia water and dilute hydrofluoric acid or ozone pure water is supplied to perform chemical cleaning and mechanical cleaning by cavitation. Alternatively, the contamination on the substrate may be removed. In addition, by using a liquid such as carbon dioxide-dissolved pure water whose specific resistance has been reduced by adding an ionizing substance to high-pressure ultrapure water, static electricity generated when the high-pressure liquid collides with the substrate is reduced, The circuit formed on the substrate may be protected from electrostatic destruction and particle adhesion.

[0027]

As described above, according to the present invention,
The scrub cleaning of the substrate and the high-pressure liquid cleaning are performed in parallel to simultaneously clean the surface of the substrate and the inside of the groove, and the liquid is supplied from inside the cleaning body, so that fine particles are re-adhered due to concentration of dirt on the cleaning body. Can be provided, and a cleaning apparatus capable of performing cleaning with a high degree of cleaning can be provided.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view of a main part of FIG.

FIG. 3 is a sectional view taken along line AA of FIG. 2;

FIG. 4 is a diagram showing a further enlarged main part of FIG. 2;

[Explanation of symbols]

 Reference Signs List 10 spin chuck 14 swing arm 18 rotation shaft 24 ring-shaped member 28 high-pressure hose 32 high-pressure liquid flow path 33 rotary joint 34 high-pressure nozzle mounting part 36 high-pressure nozzle 38 fixed sleeve 39 liquid-proof plate 42 cleaning body W substrate

Claims (3)

[Claims] 1. A substrate holding portion for holding a substrate, comprising: a cleaning tool slidably provided on a surface of the substrate; the cleaning tool jetting a high-pressure cleaning liquid toward the substrate; A cleaning device having a cylindrical cleaning body surrounding the periphery of the high-pressure nozzle. 2. The cleaning apparatus according to claim 1, wherein the pressure of the high-pressure cleaning liquid injected from the high-pressure nozzle toward the substrate is 1 to 15 MPa. 3. A high-pressure nozzle for jetting a high-pressure cleaning liquid toward a substrate, and a hollow body surrounding the high-pressure nozzle, wherein the hollow body and the substrate define a space for holding the cleaning liquid jetted from the high-pressure nozzle. A cleaning apparatus formed, wherein the cleaning liquid ejected from a high-pressure nozzle passes through the cleaning liquid held in the space and collides with the surface of the base material.