JPS6231817B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention involves supplying, for example, a photoresist solution, a developer solution, or an etching solution to the surface of a substrate such as a semiconductor substrate, glass, or ceramic from a nozzle provided above the substrate while rotating the substrate. The present invention relates to a rotary surface treatment apparatus that performs surface treatments such as applying a photoresist agent, developing, or etching the substrate.

For example, the apparatus shown in FIG. 1 has been conventionally used as an example of an apparatus for applying a photoresist agent to the surface of a semiconductor substrate. FIG. 1 is a side sectional view showing the main parts of this conventional device. In this conventional apparatus, the photoresist liquid supplied from the nozzle 10 is adsorbed by aligning the center with the vacuum chuck 11.
When the resist solution is dropped onto the center of the surface of the rotating substrate 12 to be processed, the dropped resist solution moves from the center toward the periphery due to the centrifugal force applied from the rotating substrate 12. A coating film of photoresist agent is formed on the surface of the substrate 12, but at this time, the surplus liquid, that is, the waste liquid is scattered as droplets in the tangential direction from the edge of the substrate 12, and furthermore, this waste liquid splash is , collides with the back surface of the inclined plate 13 and is atomized when deflected, becoming atomized, and this atomized waste liquid flows toward the annular duct 15 from the exhaust duct 14 to the annular duct 15 where forced exhaust is performed. It is brought in through the extraction hole 17 and discharged to the outside on a radially flowing air current. In order to prevent residual atomized waste liquid from being attracted and attached to the front and back surfaces of the substrate 12, which are subjected to negative pressure by being rotated at high speed, the outward radial airflow is An annular duct 15 having a sufficient capacity compared to the exhaust duct 14 is provided on the outer periphery of the storage container for the substrate 12 to be processed so as to be formed as uniformly as possible around the substrate 12. An inert gas such as N ₂ gas is radially blown toward the back surface of the substrate 12 as shown by the arrow from an annular introduction path provided around the substrate 12 , merges with the radial airflow, and flows into the annular duct 15 . It is made to flow out. In this case, the waste liquid that falls from the inclined plate 13 in granular form, or the waste liquid that has become atomized and adheres to the inclined plate 13 or the annular duct 15, grows into droplets and then falls, is accumulated at the bottom. , and are discharged from the drain pipe 18 to the outside.

In this way, in conventional apparatuses, an annular duct 1 with sufficient capacity for the exhaust duct 14 is used in order to generate a radial air flow as uniformly as possible around the rotated substrate 12 to be processed.
5 is provided on the outer periphery of the storage container for the substrate to be processed 12,
Furthermore, in order to ensure that the waste liquid droplets from the substrate 12 to be processed are diverted outward and diagonally downward, the slope of the slope plate 13 is set at a gentle slope of about 30 degrees, and the length up to the annular duct 15, i.e. Although the outer diameter of the inclined plate is set large,
Due to this structure, it is difficult to downsize the device.

By the way, the substrate to be processed 12, for example, a silicon wafer, has conventionally been in the shape of a disk with a diameter of about 3" or 4", but now a substrate with a diameter of 5" is also used, and it is also used to perform the various treatments described above. In order to further improve product performance, stricter demands are being made to make the atmosphere in processing rooms, or clean rooms, dust-free, and the running costs of clean rooms are increasing significantly. In this current situation,
In order to improve productivity while improving product performance, there is a demand for a small rotary surface treatment device that is compatible with compact clean rooms.

The present invention has been made in response to the above-mentioned demand, with the purpose of solving the drawbacks of the conventional rotary surface treatment apparatus, which are large and difficult to miniaturize, and providing a compact apparatus. The device is equipped with a bowl-shaped container, a nozzle provided above the center of the container, and a vacuum chuck that rotates in the center of the container, and the nozzle is applied to the surface of the substrate while rotating the substrate adsorbed to the chuck. In a rotary surface treatment apparatus that performs surface treatment by supplying a treatment liquid from the substrate, the bowl-shaped container has a hole in the upper surface and a gently sloped surface connected to the hole, and an annular bottom portion surrounding the chuck and provided with an exhaust duct and a drain conduit, and an annular saucer having an outer circumferential radius approximately equal to the rotation radius of the substrate; A rectifying plate is attached to the inner circumferential portion of the annular bottom portion, and the outer peripheral end of the inclined surface edge portion is located on an eccentric circumference with respect to the rotation center of the substrate, and An annular duct is formed by the bottom part and the rectifier plate, and when the air in the annular duct is forcibly exhausted from the exhaust duct, the outward radial airflow generated in the vertical space near the substrate is directed to the upper cover and the rectifying plate. The present invention relates to a rotary surface treatment device in which the airflow is allowed to pass through a gap that is formed between the end portions of the inclined surfaces of the current plates and narrows as it approaches the exhaust duct.

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

FIG. 2 is a side sectional view of the main parts of this apparatus, and FIG. 3 is a plan view showing a cross section taken along the lower surface of the substrate to be processed in the direction of the arrow with the top cover removed.

The container 20 that houses the substrate 12 to be processed, which is concentrically attracted to the vacuum chuck 11 and rotated, has a hole 21 that is slightly larger than the substrate 12, and an upper lid 22 that has a gently sloped surface portion and a curved surface portion that follow the hole 21.
An annular bottom portion 23 having an inverted triangular cross-sectional shape,
23'. The annular bottom portions 23, 23' have their outer circumferential portions bent upward to form an engaging portion with the upper lid 22, and their inner circumferential portions similarly bent to form a guiding outer cylindrical portion 24 around the vacuum chuck 11. ing. The guide outer cylinder part 24 includes an outer tube 25 that concentrically houses the rotating shaft of the vacuum chuck 11, and is connected to the outer tube 25 that concentrically houses the rotation axis of the vacuum chuck 11.
1, and an outer edge portion 27' with a gently sloped surface on its outer periphery.
A rectifying plate 27 consisting of a ring-shaped receiving plate 27'' whose outer diameter is slightly smaller than the outer diameter of the substrate 12 is fitted therein.

The current plate 27, as shown in FIG.
The saucer 27'' is located at the rotation center O of the vacuum chuck 11.
Although it is formed concentrically with the inclined surface edge 2
The outer peripheral end of 7' has a diameter D-D from the rotation center O.
It forms a circumference of radius R centered at O', which is eccentrically e to the right in the upper view. This current plate 27
Since the upper lid 22 in which the is housed is formed rotationally symmetrically with respect to the axis passing through the rotation center O, the inclined surface edge 2
The distance (gap) in the horizontal plane between the outer circumferential end of 7' and the inner wall surface of the upper lid 22 is maximum B on the left side of diameter D-D and minimum B' on the right side, and this B and
B' has a relationship of B - B' = 2e, and in the middle, as shown in Figure 3, it gradually decreases clockwise in the upper half and counterclockwise in the lower half. It is being done.

This means that the length of the inclined surface edge 27' of the current plate 27 gradually increases, contrary to the above-mentioned gap. In the embodiment, the inclination angle of the inclined surface edge 27' is maximum (for example, α = 20 degrees) on the left side and minimum (for example, α' = 15 degrees) on the right side, as shown in the figure,
The angle of inclination of the inclined surface portion of the upper lid 22 is made to approximately match the maximum inclination angle of the inclined surface edge portion 27' of No. 7. Note that there is no need to be so particular about the inclination angle of the current plate 27;
The left and right sides of the figure may be the same.

The annular bottom parts 23, 23' are formed in an annular shape such that the bottom part 23 is the shallowest and the bottom part 23' is the deepest.As shown in the figure, the exhaust duct 14 is provided to slightly protrude from the bottom part 23'. A drain pipe 18 is provided flush with the bottom part of the exhaust duct 14, which is offset from the center O by, for example, about 45 degrees.

In the conventional apparatus, the annular duct 15 was provided at the outer periphery of the storage container for the substrate 12 to be processed, but in this embodiment apparatus, the annular duct 15 was provided at the lower part of the upper lid 22, the rectifying plate 27, and the bottom part. 23 and 23', and the annular duct 15 is incorporated into the storage container 20 for the substrates to be processed 12, so that the conventional apparatus in which the substrates to be processed 12 each having an outer diameter of 5'', for example, are set. Comparing this device with the conventional device, this device is made smaller by approximately the size of the annular duct 15 of the conventional device.

A cover 16 having a hole 17 is detachably attached to the upper lid 22.

Next, the operation of this apparatus will be explained using an example in which a photoresist agent is applied to a semiconductor substrate.

First, the substrate 12 is attracted to the vacuum chuck 11 with its centers aligned, rotated at high speed, and forcedly evacuated from the exhaust duct 14. Next, when a photoresist liquid is dropped from the nozzle 10 onto the center of the surface of the substrate 12, the dropped photoresist liquid is applied to the substrate 12 which is rotating at high speed.
Since centrifugal force is applied by
A coating film of the photoresist agent is formed on the surface of the substrate 12 by moving from the center toward the periphery thereof. At this time, the excess liquid, that is, the waste liquid, scatters in the form of droplets in the tangential direction from the edge of the substrate 12. All of this waste liquid splash collides with the back surface of the inclined surface portion of the upper lid 22, and is deflected outward and diagonally downward.
A portion further collides with the inclined surface edge 27' of the current plate 27, and becomes fine and atomized.

As mentioned above, since forced exhaust is provided from the exhaust duct 14, the hole 17 in the cover 16,
Next, the outside air brought into the storage container 20 through the hole 21 of the upper lid 22 is an outward radial airflow that passes through the gap formed between the sloped surface portion of the upper lid 22 and the sloped surface edge 27' of the rectifying plate 27. The gas flows into the annular duct 15, flows clockwise within the annular duct in the upper half of FIG. 3 and counterclockwise in the lower half of FIG. 3, and is discharged to the outside from the exhaust duct 14.

In this case, the gap flow path formed between the sloped surface portion of the upper lid 22 and the sloped surface edge 27' of the baffle plate 27, through which the radial airflow passes when flowing into the annular duct 15, is connected to the exhaust duct 14 as described above. Since the opening width of the annular duct 15 is gradually narrowed as it approaches the exhaust duct 14, the closer the suction force of the exhaust duct 14 acts, the greater the flow resistance. Pressure loss is reduced, and the uniformity of the outward radial airflow generated around the rotated substrate 12 to be processed is maintained. This uniformity is further maintained by increasing the cross-sectional area of the annular duct 15 closer to the exhaust duct 14.

In this way, in the space above and below the outer periphery of the substrate 12, an outward radial airflow is formed on the rotating substrate 1.
2, the atomized waste liquid is carried by the airflow without being left behind, passes through the annular duct 15, and is discharged to the outside from the exhaust duct 14 along with the exhaust.

Since the atomized waste liquid is carried by the radial airflow and removed from the upper and lower spaces near the substrate 12, a portion of the atomized waste liquid becomes negative pressure due to the high speed rotation of the substrate 12. The phenomenon of attracting and adhering to the front and back surfaces of 12 is suppressed. In particular, an inert gas such as N ₂ gas is radially blown onto the back surface of the substrate 12 from the outer tube 25 and the guide inner cylindrical portion 26 in advance to merge with the radial air flow and flow out into the annular duct 15. In particular, adhesion of atomized waste liquid is thoroughly eliminated.

A part of the mist of waste liquid adheres to the inclined surfaces of the upper lid 22 and the rectifying plate 27 and the inner wall surface of the annular duct 15, but this adhering waste liquid grows into droplets and is deposited on the bottom part 23, which forms part of the annular duct 15. Flowing down to the annular valley floor,
The waste liquid collects on the annular bottom 23' side, but since the exhaust duct 14 is slightly protruded from the bottom of the valley, all the collected waste liquid is discharged to the outside from the drain pipe 18.

When processing a small substrate 12 with a diameter of 4'' or 3'', the rectifying plate 27 is placed on the substrate 1 to be processed.
What is necessary is to prepare one adapted to the size of 2 and to fit it into the guide outer cylindrical part 24 respectively. Particularly when processing a substrate 12 having a diameter of 3'', it is desirable to fit the upper lid 22 into the engaging portions of the annular bottom portions 23, 23'.

Further, when the substrate 12 to be processed is square, the length of the diagonal line may be treated as being equivalent to the diameter of a circular substrate.

As is clear from the above description, in the rotary surface treatment apparatus according to the present invention, a treatment liquid is supplied to the surface of the rotary surface treatment apparatus during rotation, and the substrate to be surface treated is set inside the housing. Since the annular duct is installed inside the container, it can be made smaller in size than the conventional container in which the annular duct is provided on the outer periphery. Then, the passage gap for the airflow flowing radially outward into the annular duct taken into the storage container is created between the upper cover and the edges of the sloped surfaces of the rectifying plate, whose outer peripheral edge is eccentric with respect to the upper cover. Since this gap narrows as it approaches the exhaust duct 14, the closer the suction force of the exhaust duct acts, the greater the flow resistance and the lower the pressure loss. Therefore, in the space above and below the outer periphery of the substrate being rotated,
Since an outward radial airflow is uniformly formed around the substrate, the atomized waste liquid can be carried on the airflow without being left behind, pass through the annular duct, and be discharged to the outside from the exhaust duct along with the exhaust air. .

In the above explanation, the number of exhaust ducts is one, but even if there are two or more exhaust ducts, if the exhaust duct part is the narrowest and the space between the two exhaust ducts is wide. good.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view of a conventional rotary surface treatment apparatus, FIG. 2 is a side sectional view of an embodiment of the apparatus according to the present invention, and FIG. 3 is a cross section taken along the lower surface of the substrate to be treated in the direction of the arrow. FIG. 10... Nozzle, 11... Vacuum chuck, 12
...Substrate to be processed, 14...Exhaust duct, 15...
Annular duct, 18... Drain pipe, 20... Bowl-shaped container, 21... Extraction hole, 22... Top lid, 23, 2
3'... Annular bottom, 27... Rectifying plate, 27'... Inclined surface edge, 27''... Annular saucer.

Claims (1)

[Claims] 1.Equipped with a bowl-shaped container, a nozzle provided above the center, and a vacuum chuck rotating in the center of the container, the processing liquid is applied to the surface of the substrate from the nozzle while rotating the substrate adsorbed to the chuck. In a rotary surface treatment device that supplies and performs surface treatment, the bowl-shaped container is provided with a hole in the top surface,
The upper lid has an inclined surface in contact with the upper lid and is formed rotationally symmetrically with respect to the rotational axis of the processing substrate, and an annular bottom that surrounds the chuck and is provided with an exhaust duct, and is approximately equal to the rotational radius of the substrate. A rectifying plate comprising an annular saucer having the same outer radius and an inclined surface edge following the same, the outer peripheral end of the inclined surface edge being located on an eccentric circumference with respect to the rotation center of the substrate, is connected to the inner periphery of the annular bottom. A gap is formed between the sloped end portions of the rectifier plate and the upper cover, and the gap narrows as it approaches the circumferential angular arrangement position of the exhaust duct, and the lower part of the upper cover, A rotary surface treatment apparatus characterized in that an annular duct connected to the gap is formed by an annular bottom portion and the current plate.