JP2000150352A - Manufacture of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the manufacture of a semiconductor device which removes a resist-unapplied section from the surface of a semiconductor substrate, and also is applicable to the fine processing of a pattern, too. SOLUTION: This is the manufacture of a semiconductor substrate which forms a resist-applied film on the top surface of a semiconductor substrate 3 by placing a semiconductor substrate 3 on a rotary table 2, and arranging a mobile nozzle 14 above this semiconductor substrate 3, and dropping resist from this nozzle 14. At this time, the resist-applied film is made by dropping resist while shifting the nozzle 14 in the center direction from the periphery of the rotating semiconductor substrate 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a semiconductor device, and more particularly to a method of manufacturing a semiconductor device in which a resist is dropped on a semiconductor substrate mounted on a rotary table to form a resist coating film.

[0002]

2. Description of the Related Art As is well known, when a semiconductor substrate is finely processed using a pattern, a photolithography technique is used. In this technology, a photosensitive organic substance (resist) is applied to the surface of a semiconductor substrate, and a portion of the resist surface that is irradiated with light and a portion that is not irradiated by a photomask are formed, and the semiconductor substrate is selectively processed in a subsequent process. Is made possible.

[0003] A resist coater has been conventionally used as one method of applying a resist on the surface of the semiconductor substrate. FIG. 5 schematically shows the structure of this resist coater. In the figure, reference numeral 10 denotes an entire resist coater, and a rotary table 2 is attached to an upper end of a vertically provided rotary shaft 1. On the turntable 2, a semiconductor substrate 3 is placed. A fixed type nozzle 4 is provided above the turntable 2, and a tip 4 a of the nozzle 4 faces the semiconductor substrate 3 at a fixed interval. Further, the nozzle 4 is connected to a resist supply source (not shown) so that a predetermined amount of resist can be dropped on the semiconductor substrate 3. The rotary table 2 is surrounded by a cover 5, and exhaust is performed through an exhaust pipe 6 provided below the cover 5.

In the resist coater 10 configured as described above, a resist is dropped from the nozzle 4 onto the semiconductor substrate 3 mounted on the turntable 2 to apply the resist.
FIG. 4 shows the state of the semiconductor substrate 3 after the application of the resist.

In FIG. 1, a resist-coated surface 3a, which is one main surface of a semiconductor substrate 3, must have a resist applied to the entire substrate. However, the resist uncoated portions 3b and 3c are partially generated. Since such a semiconductor substrate 3 cannot be sent to the next step, it is necessary to remove the resist and apply the resist again by the resist coater 10.

Various investigations were made on the causes of the uncoated portions 3b and 3c in FIG. 4 and the following was found. (1) As shown in FIG. 7, the relationship between the depth of the groove on the surface of the semiconductor substrate 3 and the thickness of the resist is determined by the depth D of the grooved groove and the thickness T of the applied resist as shown in FIG. Tends to have uncoated portions. That is, when T> D, the resist is applied to the entire surface. However, when T <D, an uncoated portion tends to occur. (2) As shown in FIG. 8, when the angle between the bottom surface and the side wall of the groove is θ, no uncoated portion is generated when θ <60 to 70 °, but as shown in FIG. When the angle θ between the bottom surface and the side surface is θ> 60 to 70 °, an uncoated portion tends to occur.

By the way, to eliminate the factors shown in FIG. 7, it is sufficient to increase the thickness of the resist as described above. Conversely, if the resist is set to be thick, it becomes difficult to process a fine pattern. There are elements. Further, as shown in FIG. 8, when the angle θ is reduced, there is a problem that the groove width per line becomes large and a pattern having a high density becomes difficult.

On the other hand, the present inventor has examined the causes of these problems by changing the nozzle from a fixed type to a movable type, and at the same time, the moving speed, moving direction,
The experiment was conducted by changing the rotation speed of the rotary table and the like.
In particular, the nozzle is conventionally of a fixed type as shown in FIG. Then, a predetermined amount of resist is dropped on the upper surface of the semiconductor substrate 3 on the turntable 2 at the center of the semiconductor substrate 3, and thereafter, as shown in FIG. Further, at time t2, the rotation speed is increased to R2, and after a predetermined time has elapsed, the operation is performed such that the rotation is reduced at time t3 to end the operation. Conventionally, there is also a coating method in which the nozzle moves from the center to the outside, but the thickness of the resist varies greatly, and it is not suitable especially for fine processing.

[0009]

In the conventional resist coating method using a resist coater, the uncoated portion of the resist is easily generated on the resist-coated surface of the semiconductor substrate 3 as shown in FIG. In order to cope with the above (1), there are a method of increasing the thickness T of the resist as shown in FIG. 7 and a method of setting θ <60 to 70 ° as shown in FIG. 8, but it is difficult to perform fine processing of the pattern. There were issues to be solved.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a method of manufacturing a semiconductor device which can eliminate a non-coated portion of a resist on a semiconductor substrate surface and is suitable for fine processing of a pattern. It is intended to provide.

[0011]

Means for Solving the Problems The present invention has been made to solve the above problems, and a first invention is to place a semiconductor substrate on a turntable and to place the semiconductor substrate above the semiconductor substrate. A method of manufacturing a semiconductor device, comprising disposing a nozzle and dropping a resist from the nozzle to form a resist coating film on the upper surface of the semiconductor substrate. The method is characterized in that a resist is dropped onto the semiconductor substrate while being moved toward the center to form a resist coating film on the semiconductor substrate.

According to a second aspect of the present invention, while the resist is dropped from the nozzle, the number of rotations of the turntable is 10
After the dropping of the resist is completed, the number of rotations of the rotary table is set to 100 to 3000 rpm.
It is characterized in that the number of rotations is in the range of 0 to 3000 rpm or more.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail.
First, FIG. 10 shows the relationship between the moving direction of the nozzle and the application state of the number of rotations at the time of resist dropping. As a result of the above, condition * 1,
* 2 and * 3 proved that no paint residue occurred. Next, FIG. 2 and FIG. 3 show the results of the conditions as viewed from the variation of the resist coating film. In FIG. 2, the horizontal axis shows the nozzle moving speed (mm / sec), and the vertical axis shows the variation in the resist thickness (Å).

FIG. 1A is a graph when the nozzle is moved from the center to the outer periphery. (B) is a graph when the nozzle is moved from the outer peripheral portion to the central portion. In FIG. 3, the horizontal axis represents the rotation speed (r
pm), and the vertical axis represents the variation (Å) in the resist thickness.

FIG. 1A is a graph when the nozzle is moved from the center to the outer periphery. (B) is a graph when the nozzle is moved from the outer peripheral portion to the central portion.

From the above results, it has been found that the optimum conditions viewed from the variation of the resist film should satisfy the following items. Move the nozzle from the outer periphery to the center. The moving speed of the nozzle is 20 mm / sec or more. The number of rotations of the rotary table during low-speed rotation is 1000 to 300
It must be in the range of 0 rpm. After the above-described low-speed rotation, high-speed rotation is performed because the resist spreads over the entire surface of the semiconductor substrate 3 and is necessary to cause excess resist to scatter from the outer peripheral portion of the semiconductor substrate 3.

Based on the above results, in the present invention, conditions were set using a resist coater as shown in FIG. That is, the resist coater 10 is disposed above the semiconductor substrate 3 placed on the turntable 2 so as to face the semiconductor substrate 3,
The nozzle 14 has a tip 14a so as to be able to move horizontally from the outside to the inside. Note that the other configuration is the same as the conventional one, and the description thereof will be omitted.

The resist coaster 10 constructed as described above.
The resist is dropped onto the semiconductor substrate 3 by moving the nozzle 14 from the outer peripheral portion of the semiconductor substrate 3 toward the center to form a resist coating film on the semiconductor substrate 3. Preferably, the rotation speed of the turntable is in the range of 1000 to 3000 rpm while the resist is dripped from the nozzle 14, and the rotation speed is higher than the above range after the dripping of the resist is completed.

[0019]

According to the present invention, when a resist is applied under the above-described conditions, the uncoated portion of the resist is eliminated, and there is an excellent effect that the resist pattern can be miniaturized.

[Brief description of the drawings]

FIG. 1 is a schematic view of a resist coater used in a method of manufacturing a semiconductor device according to the present invention.

FIG. 2 is a graph showing a relationship between a nozzle moving speed and a resist thickness variation.

FIG. 3 is a graph showing a relationship between an initial rotation speed of a turntable and a variation in resist thickness.

FIG. 4 is a plan view of a semiconductor substrate formed by a conventional resist coating method in which a resist uncoated portion is formed.

FIG. 5 is a schematic view of a resist coater used in a conventional resist coating method.

FIG. 6 is a time chart showing the relationship between the lapse of the rotation time of the turntable and the number of rotations in the resist coater.

FIG. 7 is a graph showing a relationship between a thickness T of a resist applied to a semiconductor substrate and a depth D of a groove.

FIG. 8 is a cross-sectional view showing a state of a resist film formed when the angle between the bottom surface and the side surface of the groove formed on the surface of the semiconductor substrate is θ <60 to 70 °.

FIG. 9 is a cross-sectional view showing a state of a resist film formed when the angle between the bottom surface and the side surface of the groove formed on the surface of the semiconductor substrate is θ> 60 to 70 °.

FIG. 10 is a diagram illustrating a relationship between a moving direction of a nozzle and a rotation at the time of resist dropping.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Rotary axis 2 ... Rotary table 3 ... Semiconductor substrate 5 ... Cover 6 ... Exhaust pipe 14 ... Nozzle

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H025 AB16 EA05 4D075 AC64 AC84 DA08 DC22 4F042 AA07 EB18 5F046 JA02 JA13

Claims (2)

[Claims] A semiconductor substrate mounted on a rotary table;
A method of manufacturing a semiconductor device, comprising: disposing a nozzle above the semiconductor substrate; and dripping a resist from the nozzle to form a resist coating film on the upper surface of the semiconductor substrate. A method of manufacturing a semiconductor device, comprising: forming a resist coating film on the semiconductor substrate by dropping a resist while moving the resist from an outer peripheral portion toward a central portion. 2. While the resist is dropped from the nozzle, the number of rotations of the rotary table is 1000 to 3000 rpm.
m, and after the dropping of the resist is completed,
The rotation speed of the rotary table is 1000-3000 rpm
2. The method for manufacturing a semiconductor device according to claim 1, wherein the number of rotations is equal to or higher than the range.