JPH0568094B2 - - Google Patents

Description

[Detailed Description of the Invention] ≪Industrial Application Field≫ This invention applies a photoresist solution, a developer, an etching solution, etc. to the surface of a semiconductor substrate, a glass substrate for liquid crystal, etc. (hereinafter referred to as a substrate) while rotating the substrate. Alternatively, the present invention relates to a rotary surface treatment apparatus that performs surface treatment on a substrate by supplying a liquid dopant agent or the like from a nozzle provided above the substrate.

<<Prior art>> As this type of rotary surface treatment apparatus, conventional examples include the one shown in FIG. 2 proposed by the present applicant (Japanese Unexamined Patent Publication No. 63-77569; hereinafter referred to as conventional example 1);
Alternatively, the one shown in FIG. 3 (Japanese Patent Publication No. 53-37189, hereinafter referred to as conventional example 2) is known.

In conventional example 1, as shown in FIG. 2, a spin chuck 101 rotates while holding a substrate W substantially horizontally.
, a nozzle 102 provided above the spin chuck 101 to supply the processing liquid to the substrate W, and a scattering prevention cup 1 provided to surround the rotating substrate W to recover the processing liquid and prevent the processing liquid from scattering.
04, and an exhaust means 120 for evacuating the inside of the anti-scattering cup 104.
4 is an upper cup 1 which is provided with an outside air intake port 105a at the upper part and guides the processing liquid droplets downward on an inclined surface 105b.
05, a drainage zone 107 inscribed in the lower peripheral wall 105c of the upper cup 105, and this drainage zone 10.
A lower cup 106 has a ring-shaped exhaust zone 108 defined inside the spin chuck 101, and below the spin chuck 101, the airflow A flowing down from the outside air intake port 105a is rectified and guided to the lower cup by an inclined rectifying surface 103a. A circular rectifying member 103 is provided, an exhaust zone 108 is located below the circular rectifying member 103, and the liquid drain zone 107 and exhaust zone 108 are communicated with each other through an aperture opening 108a formed in the partition wall of both zones for exhaustion. It is configured. Note that the reference numeral 117 is an exhaust duct.

In conventional example 2, as shown in FIG. 3, the lower half of the casing 204 is formed as a shatterproof cup,
A spin chuck 201 is provided inside the spin chuck 201, an air flow guide plate 203 is horizontally arranged below the substrate W held by the spin chuck 201, an annular air injection nozzle 211 is provided below the air flow guide plate 203, and the substrate W is
The structure is such that air _A2 is blown onto the lower surface of the substrate W to prevent droplets of the surface treatment liquid from adhering to the back surface of the substrate W. Note that in FIG. 3, reference numeral 220 is a gas supply nozzle that sprays the airflow A onto the upper surface of the substrate W, and 217 is an exhaust port opened in the casing 204.

<<Problems to be Solved by the Invention>> In the above-mentioned conventional example 1, the exhaust zone 108 is provided in a ring shape below the circular flow straightening member, and the drain zone 107 is partitioned on the outer periphery of the exhaust zone 108, and both zones 107, 108 are communicated through a diaphragm opening 108a, so that the airflow A flowing down from the periphery of the substrate W is uniform, and the film thickness of the photoresist etc. can be formed uniformly and with high precision. There are some difficulties.

There is a problem in that a part of the airflow A flowing down from the periphery of the substrate W flows into the space between the substrate W and the circular current plate 103, and droplets of the processing liquid adhere to the back surface of the substrate W.

On the other hand, although the conventional example 2 does not have the above problems, the exhaust port 217 is connected to the side wall 20 of the casing 204.
4b and located above the spin chuck 201, there is a problem that droplets of the processing liquid are blown up above the substrate W by the exhaust flow B, and then re-attached to the surface of the substrate W. In addition, the exhaust duct is attached to the casing 20 as shown in Figure 2.
4 may be opened at the bottom of the substrate W, but even in that case, since the structure is such that the air A ₂ is sprayed from the air injection nozzle 211 provided below the airflow guide plate 203 to the lower surface of the substrate W, the peripheral edge of the substrate W may be opened. The airflow flowing further down is not uniform and tends to cause turbulence. For this reason, it is not possible to form a coating film uniformly and with high precision.

The present invention was developed in consideration of these circumstances, and the technical problem is to prevent droplets of processing liquid from adhering to the back surface of the substrate while ensuring uniformity of surface treatment of the substrate. do.

<Means for Solving the Problems> In order to solve the above problems, the present invention improves the conventional rotary surface treatment apparatus as described below.

That is, in the substrate rotary surface treatment apparatus of Conventional Example 1, the scattering prevention cup is surrounded by an outer cup,
A detour passage through which the airflow flows is formed between the anti-scattering cup and the outer cup, and the detour passage is communicated between the substrate inside the anti-scattering cup and the inclined rectifying surface of the circular rectifying member. That is.

<<Operation>> In the present invention, the detour flow path formed between the anti-scattering cup and the outer cup is communicated between the substrate and the inclined rectifying surface of the circular rectifying member, so that the detour flow path is formed between the scattering prevention cup and the outer cup, and the detour flow path is communicated between the substrate and the inclined rectifying surface of the circular rectifying member. The airflow creates a negative pressure in the detour channel. Therefore, the airflow flowing through this detour flow path flows along the lower side of the substrate toward the peripheral edge and merges with the downstream airflow, but unlike the conventional example, the airflow is not caused by blowing, so the downstream airflow No disturbance occurs. As a result, uniformity of the surface treatment of the substrate is ensured, and no treatment liquid droplets adhere to the back surface of the substrate.

<<Example>> FIG. 1 is a longitudinal cross-sectional view of a rotary surface treatment apparatus showing an example of the present invention.

As shown in FIG. 1, this rotary surface treatment apparatus includes a spin chuck 1 that rotates while holding a substrate W substantially horizontally, and a nozzle 2 provided above the spin chuck 1 for supplying a processing liquid 2a to the substrate W. , placed below the substrate held by the spin chuck 1,
A circular rectifying member 3 that rectifies and guides the downstream airflow A with an inclined rectifying surface 3a, and a scattering prevention cup that is provided to surround the rotating substrate W and is useful for recovering the processing liquid 2a and preventing scattering of processing liquid droplets. 5, an outer cup 10 surrounding the anti-scattering cup 4, and an exhaust means 20.
It is equipped with the following.

The anti-scattering cup 4 includes an upper cup 5 which is provided with an outside air intake port 5a at the upper part and which guides processing liquid droplets downward on an inclined surface 5b, and a lower peripheral wall 5c of the upper cup 5 which removably receives and supports the upper cup 5. It consists of a drain zone 7 inscribed in the drain zone 7 and a lower cup 6 in which a ring-shaped exhaust zone 8 is defined inside the drain zone 7.

The exhaust zone 8 is provided in a ring shape below the circular straightening member 3, and the exhaust zone 8 communicates with the exhaust zone 8 through a slit opening 8a formed around the exhaust zone 8. zone 8
It is configured to exhaust air from an exhaust duct 17 provided inside. Note that reference numeral 16 in FIG. 1 is a drain drain provided within the drain zone 7.

The outer cup 10 surrounds the anti-scattering cup 4 and forms a detour passage 11 between the outer cup 10 and the anti-scattering cup 4 through which part of the airflow A flows. This detour flow path 1
1 is between the lower surface of the substrate W held by the spin chuck 1 and the inclined rectifying surface 3a of the circular rectifying member 3.
The airflow A ₁ flowing down from the periphery of the substrate W creates a negative pressure in the gap and the detour flow path 11 . In other words, the airflow A ₂ flowing through this detour flow path 11 flows toward the periphery under the substrate W and merges with the downstream airflow A ₁ , but since this is not caused by blowing, turbulence of the downstream airflow A ₁ occurs. do not have.

Next, the operation of this device will be explained.

First, the substrate W is centered on the spin chuck 1 and held by suction, and is forcibly evacuated from the exhaust duct 17.

Next, for example, photoresist liquid 2a is discharged from the nozzle 2 onto the center of the upper surface of the substrate W, and the substrate W is immediately rotated. Then, as the substrate W rotates, a coating film of the photoresist liquid is formed on the surface of the substrate W, and the excess liquid is scattered as droplets from the periphery of the substrate W. These droplets collide with the inclined surface 5b of the upper cup 5 and are guided outward and diagonally downward, and some of them further collide with the inclined rectifying surface 3a of the circular rectifying member 3 and are guided to the lower cup 6.

On the other hand, since the air is forcibly exhausted from the exhaust duct 17 by the exhaust means 20, the outside air intake port 5a
The outside air A flowing into the anti-scattering cup 4 flows in the radial direction along the upper surface of the substrate W, becomes a downstream airflow _A1 passing around the periphery of the substrate W, and flows down along the inclined rectifying surface 3a of the circular rectifier plate 3. .

On the other hand, the airflow _A2 flowing through the detour channel 11 due to negative pressure flows out radially through the space between the upper edge of the inclined rectifying surface 3a and the lower surface of the substrate W, and
Merges with A ₁ . This prevents the processing liquid droplets from going around and adhering to the back surface of the substrate W.
Then, the downstream airflow A ₁ passes through the drainage zone 7 of the lower cup 6, flows into the exhaust zone 8 while facing ventilation resistance by the throttle opening 8a, and enters the exhaust duct 1.
It is exhausted from 7.

In other words, since the downstream airflow _A1 is exhausted through the diaphragm opening 8a, the airflow A on the substrate W becomes a uniform flow in all directions, and no unevenness occurs in the coating film.

<<Effects of the Invention>> As is clear from the above explanation, in the present invention, the anti-scattering cup is surrounded by an outer cup, a detour flow path is formed between the two cups, and a detour is formed between the lower surface of the substrate and the inclined rectifying surface. Since they are connected, the following effects are achieved.

(a) The airflow flowing through the detour flow path flows from the bottom side of the substrate toward the peripheral edge due to the negative pressure, and can prevent the processing liquid droplets from going around and adhering to the back surface of the substrate.

(b) The airflow that flows from the bottom of the substrate toward the peripheral edge merges with the downstream airflow, but unlike the conventional example, the downstream airflow is not disturbed by blowing, so the uniformity of the surface treatment of the substrate is ensured. can do.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a rotary surface treatment apparatus according to the present invention, and FIGS. 2 and 3 are longitudinal sectional views of rotary surface treatment apparatuses according to Conventional Example 1 and Conventional Example 2, respectively. 1... Spin chuck, 2... Nozzle, 3...
Circular rectifying member, 3a... Inclined rectifying surface, 4... Scattering prevention cup, 5... Upper cup, 5a... Outside air intake, 6... Lower cup, 7... Drainage zone, 8...
Exhaust zone, 8a... Throttle opening, 10... Outer cup, 11... Detour flow path.

Claims (1)

[Claims] 1. A spin chuck that holds and rotates a substrate;
A nozzle provided above the spin chuck to supply processing liquid to the substrate; a scattering prevention cup provided surrounding the rotating substrate for collecting the processing liquid and preventing scattering of processing liquid droplets; and a circular rectifying member that rectifies and guides the airflow flowing down from the outside air intake port provided at the upper part of the shatterproof cup below the spin chuck to the lower cup at the bottom of the shatterproof cup using an inclined rectifier surface. The shatterproof cup is surrounded by an outer cup, a detour flow path is formed between the shatterproof cup and the outer cup, and the detour flow path is formed by tilt rectification between the substrate inside the shatterproof cup and the circular rectifier member. A rotary surface treatment device for a substrate, characterized in that it communicates with a surface.