JPH04278517A - Spinner cup - Google Patents

Abstract

PURPOSE:To uniformly form a thin film of organic material, by newly installing an upper surface cup of a chamber type on a semiconductor wafer of large area, purging the vicinity of the peripheral part of a region where the film thickness of the organic material on the peripheral part of the wafer is increased, with gas having the action restraining vaporization of solvent in the organic material, and purging, on the contrary, the vicinity of a region in the central part where the film thickness is decreased, with gas having the action accelerating vaporization of solvent in the organic material. CONSTITUTION:In a spinner cup, four regions 21a, 21b, 21c, 21d which are positioned above a 8-inch wafer 11 and divided by cylindrical members 18a, 18b, 18c, 18d arranged in a concentric circles type toward the circumferential direction from the rotary center in the case of rotation of said wafer 11, and pipings 19a, 19b, 19c, 19d capable of feeding different gasses to said regions are installed. The gas is supplied from each region to an organic material surface on the wafer 11 surface when the wafer 11 is rotated.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to semiconductor devices (hereinafter referred to as L
This invention relates to a spinner cup in a spin coater (rotary coating device) used in forming thin films of photoresist, polyimide, spin-on glass (hereinafter referred to as SOG), etc. in the manufacturing process of SI (hereinafter referred to as SOG).

0002

[Prior Art] Conventionally, technologies in this field include:
For example, there were the following. FIG. 3 is a diagram illustrating a method of forming a thin film of photoresist, polyimide, SOG, etc. (hereinafter referred to as organic material), which is called the conventional spin coating method.

First, as shown in FIG. 3A, a wafer-shaped semiconductor substrate 1 (hereinafter referred to as a wafer) is attracted to a spin chuck 2. As shown in FIG. The spin chuck 2 is
It is connected to a rotating shaft 3 of a motor (not shown). Further, the organic material 7 is dropped onto the wafer 1 from the dropping nozzle 4 located above the wafer 1 .

Next, as shown in FIG. 3(b), the spin chuck 2 and the wafer 1 rotate at a high speed as the rotating shaft 3 of the motor rotates at a high speed, and the dropped organic material 7 is transported through the centrifugal process. Due to the force, a thin film of organic material 7 is formed on the wafer 1.
'. Here, the organic material scattered from the edge of the wafer 1 during high-speed rotation is collected by the spin cup 5 and flows down to the drain port 6.

Further, the inside of the spin cup 5 is normally maintained in an evacuated state, and although not shown, an evacuating means is used to
After all, exhaust is performed from the drain port 6. Generally, the wafer 1 has a diameter of 4 inches (10.16 cm) to 6 inches (15.24 cm), and the spin coating method facilitates the formation of a thin film of an organic material.

[0006]

[Problems to be Solved by the Invention] Normally, the thin film 7' of an organic material is required to be formed uniformly over the entire surface of the wafer 1 with little difference in film thickness. It is affected by the rate of evaporation of a solvent (for example, an organic solvent such as ethyl cellosolve acetate or xylene) contained in the organic material during spin coating. Therefore, the viscosity and temperature of the organic material when it is dropped onto the wafer 1, the temperature of the spin chuck 2, the temperature of the wafer 1, the wafer 1
It is necessary to control many factors, such as the temperature and humidity around the wafer 1, the exhaust pressure around the wafer 1, and the sequence of rotation speed and acceleration when the wafer 1 rotates at high speed. By doing so, it became possible to form a uniform thin film on the wafer 1 having a diameter of 4 inches to 6 inches.

However, 8 inches (20.32 c
m) diameter wafer, it is difficult to form a uniform thin film over the entire surface of the 8-inch wafer by controlling only the above factors using the conventional spin coating method.
There is a problem in that the film becomes thick near the periphery of the 8-inch wafer. In other words, when an 8-inch wafer is spin-coated, the speed difference between the center and the periphery during high-speed rotation becomes large, and the speed at which the solvent evaporates at the very high speed portion of the periphery becomes extremely high. This is because the viscosity of the organic material also becomes faster and higher during high-speed rotation compared to the center part.

[0008] The present invention solves the problem that when forming a thin film of an organic material by spin coating on a large-area 8-inch wafer as described above, the film thickness inevitably becomes thick in the peripheral area. For this reason, a new chamber-shaped upper cup was installed on the 8-inch wafer, and in the area where the film thickness becomes thicker around the 8-inch wafer, a gas that has the effect of suppressing the evaporation of the solvent in the organic material is used. , by purging the vicinity of the periphery, and in the region where the film thickness is thinner in the center, by purging the vicinity with a gas that has the effect of promoting the evaporation of the solvent in the organic material. It is an object of the present invention to provide a spinner cup that can form a uniform thin film even on inch wafers.

[0009]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides a spinner cup that is located above a semiconductor wafer, and that is located above a semiconductor wafer in the circumferential direction from the center of rotation when the semiconductor wafer rotates. Two or more areas separated by concentrically located cylindrical members, piping capable of sending different gases to the two or more areas, and a surface of the semiconductor wafer that supplies the gas from each area when the semiconductor wafer rotates. A means for supplying the organic material is provided.

[0010] Furthermore, two or more areas separated by a cylindrical member located above the semiconductor wafer and located concentrically in the circumferential direction from the center of rotation of the semiconductor wafer; Piping capable of individually discharging gas present in two or more regions; and means for discharging gas from each region when the semiconductor wafer rotates and adjusting the state of the gas supplied to the organic material on the surface of the semiconductor wafer. It is designed to provide the following.

[0011]

[Operation] According to the present invention, as described above, the spinner cup used in the spin coating method is newly provided with a chamber-like upper cup, so that the evaporation of the solvent in the organic material during high-speed rotation is uniform. The gas that can maintain the organic material is divided into regions and purged from the upper cup, and the evaporation of the solvent in the organic material is controlled in each region.

[0012] Therefore, even on a large-area 8-inch wafer, a uniform thin film can be formed.

[0013]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a configuration diagram of a spin coater showing an embodiment of the present invention, and FIG. 2 is a perspective view of a spinner cup showing an embodiment of the present invention. FIG. 1 shows a state in which a large-area 8-inch wafer 11 is attracted onto a spin chuck 12 and an organic material 20 is dropped from a nozzle 13.

Here, a newly attached chamber-shaped upper cup 16 is provided above the wafer. This upper surface cup 16 consists of a chamber upper surface portion 17a and a chamber side surface portion 17b, and is further installed concentrically with the rotation center of the spin chuck 12 that is to divide the upper part of the wafer 11 into four areas in the circumferential direction. Three cylindrical members 18a to 18c are attached to the chamber upper surface portion 17a. These cylindrical members 18a to 18c form four individual regions 21a, 21b, 21c, and 21d.

Furthermore, pipes 19a to 19d are connected to the upper surface portion 17a of the chamber in correspondence with regions 21a, 21b, 21c, and 21d arranged sequentially from the inside. Therefore,
Different gases can be individually fed into each region 21a, 21b, 21c, and 21d. Further, the nozzle 13 is connected to the center of the upper surface portion 17a of the chamber, and is installed so that the opening for dropping the organic material is located at the center of the 8-inch wafer 11 from the center of the region 21a.

In the above embodiment, the area is divided into four areas, but the number is not limited to four areas, and the number can be set as necessary. Furthermore,
Although the pipes 19a to 19d are also provided at one location in each region in this embodiment, they may be provided at multiple locations if necessary. Such a chamber-shaped top cup 1
When attaching 6 and performing spin coating, usually 8
In the region 21d where the film thickness of the organic material becomes thick at the periphery of the inch wafer 11, the solvent in the organic material (for example,
For example, a gas containing a large amount of ECA ethyl cellosolve acetate, xylene, and chlorobenzene is purged through the pipe 19a so as to suppress the evaporation of the solvent in the organic material. Control the thickness of the material so that it does not become too thick. On the other hand, in the region 21a where the film thickness of the organic material at the center of the wafer becomes thin, for example, a somewhat high temperature N2 gas is purged through the pipe 19a so as to promote the evaporation of the solvent in the organic material. By doing so, the evaporation of the solvent in the organic material is activated to prevent the film thickness from becoming thin.

[0017] With this configuration, the film thickness of the organic material can be controlled in accordance with the area. Further, organic material scattered from the edge of the 8-inch wafer 11 during high-speed rotation is collected by the spin cup 14 and flows down to the drain port 15. Although not shown, it goes without saying that a control system is provided that detects the rotation of the motor that drives the spin chuck 12, opens the hubs of the pipes 19a to 19d, and supplies desired gas to each pipe.

Furthermore, the 8-inch wafer 11 is removed from the nozzle 13.
After supplying the organic material 20 to the organic material 20, the rate of evaporation of the solvent may be controlled by controlling the gas in each region of the top cup 16. Further, the present invention is not limited to the above embodiments, and various modifications can be made based on the spirit of the present invention, and these are not excluded from the scope of the present invention.

[0019]

As described in detail above, according to the present invention, several regions are divided in the circumferential direction within the wafer plane by the chamber-shaped upper surface cup on the wafer upper surface, and the organic material is Since the purge is performed with a gas that can control the evaporation rate of the solvent, when forming a thin film of organic material on a large 8-inch wafer, the film may be thicker at the periphery of the wafer or may be thicker at the center. This prevents the film from becoming thinner, and the film thickness of the organic material can be made uniform.

Furthermore, by setting the type of gas to be purged, the amount of purge, and the temperature suitable for each region, it is possible to easily control the film thickness of the organic material corresponding to each region. Can be done. Furthermore, there are many different situations in which the organic material film thickness at the wafer periphery becomes thick, depending on the material and viscosity of the organic material, the type of solvent, the target film thickness, etc., but the present invention By freely selecting the type of purge gas, purge amount, and temperature accordingly, it is possible to suit most cases appropriately.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a spin coater showing an embodiment of the present invention.

FIG. 2 is a perspective view of a spinner cup showing an embodiment of the present invention.

FIG. 3 is a diagram illustrating a thin film forming method using a conventional spin coating method.

[Explanation of symbols]

11 8-inch wafer 12 Spin chuck 13 Nozzle 14 Spin cup 15 Drain port 16 Chamber-shaped upper surface cup 17a Chamber upper surface portion 17b Chamber side surface portions 18a to 18c Three cylindrical members 19a to 19d
Piping 20 Organic material

Claims (2)

[Claims] Claim 1: (a) Two or more areas separated by cylindrical members located above a semiconductor wafer and located concentrically in the circumferential direction from the center of rotation of the semiconductor wafer; (b) piping capable of sending different gases to the two or more regions; and (c) means for supplying gas from each region to the organic material on the surface of the semiconductor wafer when the semiconductor wafer rotates. A spinner cup characterized by: (a) Two or more areas located above a semiconductor wafer and separated by a cylindrical member located concentrically in the circumferential direction from the center of rotation of the semiconductor wafer; (b) piping capable of individually discharging the gas present in the two or more regions; and (c) piping capable of discharging the gas from each region when the semiconductor wafer rotates, and discharging the gas from the organic material on the surface of the semiconductor wafer. A spinner cup characterized by comprising means for adjusting the state of supplied gas.