JPH07263336A - Developing method - Google Patents

Abstract

PURPOSE:To provide a developing method by which the width, etc., of lines formed on the surface of a semiconductor wafer can be made uniform. CONSTITUTION:A developing solution is supplied to a substrate 3 to be treated by scanning the spray of the solution from a nozzle 6a while the substrate 3 is rotated by means of a rotating mechanism 5. While the solution is supplied, a shutter 11 is opened and a treatment chamber 2 is evacuated to a degree of vacuum of about 10-20 mmH O Thereafter the rotation of the substrate 3 and scanning of the spray are stopped and a photosensitive film of a photoresist, etc., formed on the surface of the substrate 3 is developed by using a paddle during a preset developing time of, for example, 30 seconds. During the developing process, the shutter 11 is closed and the degree of vacuum is adjusted to such a value that desired uniformity can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for developing a substrate to be processed such as a semiconductor wafer.

[0002]

2. Description of the Related Art Generally, in a developing apparatus for developing a substrate to be processed such as a semiconductor wafer, a processing chamber in which a substrate to be processed having a photosensitive film such as a photoresist is formed, And means for bringing the substrate to be processed into contact with the developing solution for a predetermined development time to cause a predetermined chemical change in the photosensitive film to perform development.

Then, a substrate to be processed such as a semiconductor wafer is arranged on a mounting table arranged in the processing chamber, and a rinse liquid such as a developing solution and pure water is sequentially supplied to the substrate to be processed from a spray nozzle or the like. , Develop. In addition, since the developer usually has a bad effect on the human body, the developer should be kept at 10% during processing to prevent the developer from scattering due to spraying.
Exhaust from the processing chamber is performed by an exhaust device or the like with an exhaust amount of about 20 mmH ₂ O.

[0004]

However, in the developing method using the above-described conventional developing device, when the size of the substrate to be processed becomes large, the developing state becomes non-uniform within the surface of the substrate to be processed. When a fine pattern is formed on a semiconductor wafer by using the technique, there is a problem that the line width and the like formed on the surface of the semiconductor wafer become non-uniform.

The present invention has been made in response to such a conventional situation. Even a large substrate to be processed can be developed so that the in-plane development state becomes uniform, and fine processing is performed on a semiconductor wafer. An object of the present invention is to provide a developing method capable of making uniform the line width and the like formed on the surface of a semiconductor wafer even when forming a pattern.

[0006]

According to a developing method of the present invention, a processing chamber in which a substrate to be processed having a photosensitive film formed thereon is placed is held at a rotary table while being exhausted at a predetermined exhaust amount. And supplying the developing solution to the surface of the substrate to be processed while rotating the substrate to be processed at a first rotation speed, and stopping the supply of the developing solution and stopping the rotary table to exhaust the inside of the processing chamber. In the processing chamber by reducing the amount of exhaust gas so that the uniformity of the development processing of the substrate to be processed becomes a desired range, and developing the substrate to be processed with the developing solution supplied to the surface of the substrate to be processed. Supplying the rinse liquid to the surface of the substrate to be processed while increasing the exhaust amount and rotating the rotary table at the second rotation speed higher than the first rotation speed; and stopping the supply of the rinse liquid. After doing Serial rotates the rotary table at the faster than the second rotational speed a third rotational speed, characterized by a step of drying the surface of the substrate to be processed.

[0007]

[Function] Fourth, the vertical axis represents developer temperature, and the horizontal axis represents development time
The graph in the figure shows the temperature change of the developing solution at the set temperature of 25 ° C. when the 6-inch semiconductor wafer actually developed by the present inventors is developed using the conventional developing method. The solid line A, the dotted line B, The chain line C indicates the temperature change of the developing solution at the center of the semiconductor wafer, at a position 30 mm away from the center in the peripheral direction, and at a position 30 mm away from this position in the peripheral direction. As shown in this graph, the temperature of the developing solution drastically decreases as it goes toward the peripheral portion of the substrate to be processed, and this temperature drop of the developing solution causes unevenness of the developing state of the substrate to be processed. It was found to be the cause of.

In the developing method of the present invention, the developing step in which the substrate to be processed is brought into contact with the developing solution to cause a predetermined chemical change in the photosensitive film, and the uniformity of the developing process of the substrate to be processed is within a desired range. The amount of exhaust gas is reduced to a certain level to suppress the temperature drop of the developing solution and suppress the occurrence of temperature non-uniformity of the developing solution within the surface of the substrate to be processed. be able to.

[0009]

Embodiments of the developing method of the present invention will be described below with reference to the drawings.

FIG. 1 shows the construction of a developing device 1 of an embodiment to which the developing method of the present invention is applied. In the developing device 1 in this embodiment, a mounting table 4 for adsorbing and holding a substrate 3 to be processed such as a semiconductor wafer by a vacuum chuck or the like is arranged in the processing chamber 2, and the substrate 4 to be processed is mounted on the mounting table 4. A rotating mechanism 5 for rotating the table with the mounting table 4 is connected.

A nozzle 6a and a rinse nozzle 7a are arranged above the mounting table 4, and these nozzles 6a and 7a are arranged.
The developing solution and the rinsing solution are supplied from the developing solution supplying section 6 and the rinsing solution supplying section 7 toward the substrate 3 to be processed via the.

A waste liquid discharge opening 8 and an exhaust opening 10 connected to an exhaust device 9 are arranged in the lower portion of the processing chamber 2. Between the exhaust device 9 and the exhaust opening 10. ,
A shutter 11 that opens and closes the exhaust path is inserted.

The mounting table 4, the rotation mechanism 5, the developing solution supply section 6, the rinse solution supply section 7, and the shutter 11 are connected to a control section 12 which is composed of a microcomputer or the like, and is controlled by the control section 12. To be done.

A developing method of an embodiment using the developing device 1 having the above structure will be described.

That is, first, the substrate 3 to be processed is placed on the mounting table 4 by a transfer device (not shown), the vacuum chuck of the mounting table 4 is operated, and the substrate 3 to be processed is suction-held on the mounting table 4. .

Next, the rotating mechanism 5 rotates the substrate 3 to be processed at, for example, 10 rpm to 40 rpm, and the developing solution supply section 6 supplies the developing solution to the substrate 3 to be processed while spray-scanning from the nozzle 6a. . During this time, the shutter 1
1 is opened, and the processing chamber 2 is exhausted with an exhaust amount of about 10 to 20 mmH ₂ O.

After that, rotation and spray scanning are stopped, and a photosensitive film such as a photoresist formed on the surface of the substrate to be processed by paddle development for a predetermined developing time such as 30 seconds set in advance. Development. In the present embodiment, the shutter 11 is closed by the control unit 12 during this developing process so that the exhaust from the processing chamber 2 is almost zero. In addition, the exhaust amount at this time is set to an exhaust amount with which desired uniformity can be obtained, as described later.

After that, the substrate 3 to be processed is rotated at a rotation speed higher than the rotation speed in the developing solution supply step, for example, a rotation speed of about 500 rpm to 2000 rpm, and the rinse liquid supply unit 7 is rotated.
Then, a rinse liquid such as pure water is supplied to the surface of the substrate 3 to be processed from the rinse nozzle 7a. At this time, the shutter 11 is opened and the processing chamber 2 is exhausted with an exhaust amount of about 10 to 20 mmH ₂ O.

After performing the above-described rinsing operation for a predetermined time of, for example, about 10 to 20 seconds, the supply of the rinsing liquid is stopped, and the substrate 3 to be processed is rotated at a rotation speed higher than that during the developing step. For example, the number of rotations is increased to about 3000 rpm to 5000 rpm to remove the liquid adhering to the surface of the substrate 3 to be processed by centrifugal force, and the liquid is dried. During this time, the shutter 11 is opened,
Exhaust from the processing chamber 2 with an exhaust volume of about 10 to 20 mmH ₂ O.

When the substrate 3 to be processed is dried, the rotation mechanism 5 is stopped and the substrate 3 to be processed is unloaded from the processing chamber 2 by a transfer device (not shown).

The graph of FIG. 2 in which the vertical axis represents the developing solution temperature and the horizontal axis represents the developing time is a set temperature when a 6-inch semiconductor wafer actually developed in the developing method of this embodiment is developed.
The solid line D, the dotted line E, and the alternate long and short dash line F indicate the temperature change of the developing solution at 25 ° C., respectively, at the central portion of the semiconductor wafer, at a position 30 mm away from the central portion in the peripheral direction, and further from this position in the peripheral direction 30 mm The change in temperature of the developing solution at the open position is shown.

As shown in this graph, in the developing device of this embodiment, the temperature drop of the developing solution during development is less than in the case of the conventional developing device shown in the graph of FIG. It is possible to reduce the difference in temperature of the developing solution due to the difference in the positions of the central portion and the peripheral portion of the semiconductor wafer.

In this embodiment, the exhaust from the processing chamber 2 during the developing time was set to almost zero, but the vertical axis represents the variation of the line width formed in the semiconductor wafer surface, and the horizontal axis represents the exhaust amount. as shown by the solid line G in the graph of FIG. 3 that, during the development process the exhaust amount 10 to 20 mm H ₂ O in the conventional development method, 5mmH ₂ O or less, even preferably reduced below 1mmH ₂ O, The development state can be made more uniform than in the conventional case. Therefore, data on the relationship between the line width variation in the wafer surface and the exhaust amount as shown in FIG.
Desired uniformity (line width variation) of the exhaust volume during the development process
If the exhaust amount is such that the developer mist or the like can be prevented from leaking to the outside.

[0024]

As described above, in the developing method of the present invention,
Even with a large substrate to be processed, development processing can be performed so that the development state in the substrate surface is more uniform than in the conventional development method. Even when forming a fine pattern on a semiconductor wafer, the semiconductor wafer surface It is possible to make uniform the line width and the like formed in.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a developing device of an embodiment to which a developing method of the present invention is applied.

FIG. 2 is a graph showing a temperature change of a developing solution in a developing process performed using the developing device shown in FIG.

FIG. 3 is a graph showing the relationship between the variation in line width formed on the surface of a semiconductor wafer and the exhaust amount.

FIG. 4 is a graph showing a temperature change of a developing solution in a conventional developing method.

[Explanation of symbols]

1 ... Developing device, 2 ... Processing chamber, 3 ... Substrate to be processed, 4
…… Mounting table, 6 …… Developer supply part, 9 …… Exhaust device, 1
0 ... Exhaust opening, 11 ... Shutter, 12 ... Control section.

Claims (2)

[Claims] 1. A process chamber, in which a substrate to be processed having a photosensitive film formed on its surface is placed, is evacuated at a predetermined exhaust amount,
Supplying a developing solution to the surface of the substrate to be processed while rotating the substrate to be processed held on a rotary table at a first rotation speed; stopping the supply of the developing solution and stopping the rotary table; A step of reducing the exhaust gas in the processing chamber to an exhaust amount such that the uniformity of the development processing of the substrate to be processed is within a desired range, and developing the substrate to be processed with the developer supplied to the surface of the substrate to be processed; Supplying an rinsing liquid to the surface of the substrate to be processed while increasing the exhaust amount in the processing chamber and rotating the rotary table at a second rotation speed higher than the first rotation speed; A step of rotating the rotary table at a third rotation speed higher than the second rotation speed after stopping the supply of the liquid to dry the surface of the substrate to be processed. Method. 2. The exhaust amount from the processing chamber during the developing process
The developing method according to claim 1, wherein the developing amount is at least 5 mmH ₂ O or less.