JPH02132444A - Coating device for coating semiconductor wafer with liquid - Google Patents

Abstract

PURPOSE:To prevent unnecessary liquid from dripping on a wafer by providing nozzles for applying plural kinds of liquid, and selecting a necessary nozzle and dripping desired liquid. CONSTITUTION:When the semiconductor wafer 36 is held on a wafer chuck 45, a nozzle operating mechanism 73 starts operating to move moving bases 78 and 82 and a nozzle which supplies the desired liquid among the nozzles 30a - 30d, e.g. nozzle 30a is conveyed to the top surface of the wafer 46 by nozzle holding members 90a and 90b. Resist liquid 50, on the other hand, is put in a temperature controller 53 from an entrance 54 to control the temperature, and a specific amount of liquid is dripped over the entire surface of the wafer 46 from the discharge hole of the nozzle 30a through a tube 37. Then, the chuck 45 is rotated to scatter the resist liquid 50 over the entire surface of the wafer 46. Then, the nozzle 30a, etc., is returned to a stand-by position and the wafer 46 is carried out.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a coating device for coating a semiconductor wafer with a liquid, and in particular, it relates to a coating device for coating a semiconductor wafer with a resist liquid to be coated. This invention relates to the mechanism of a liquid supply nozzle.

(Prior Art) In recent years, as the degree of integration of semiconductor devices such as ICs or LSIs has increased, there has been a trend toward further miniaturization of processing processes. Along with this, the coating process of applying a resist solution to a semiconductor wafer and the development process thereof have also become complicated.

Normally, in the resist solution application process and developer solution application process,
A spin coater is used. A spin coating device has a plurality of liquid supply nozzles in order to meet the demands of a complicated coating process. In other words, the same coating device is equipped with a plurality of resist solution supply nozzles (high-resolution resist, resist with dye, high heat resistance resist, etc.) and developer solution supply nozzles, and a nozzle operation mechanism is used to supply resist solutions according to each process. A necessary nozzle is selected from among the plurality of nozzles, and a desired liquid is dropped onto the semiconductor wafer from the selected nozzle.

As shown in FIG. 7, in the conventional coating device, an air cylinder 2 and a guide 2a are provided on the base 1 along the surface of the base 1, and a rod of the cylinder 2 is connected to one end of the arm 3. Two nozzles 4 and 5 are attached to the other end (tip) of the arm 3.

In this conventional coating device, when the nozzles 4 and 5 are not in use, the arm 3 is moved to one side of the base 1 and is placed on standby at a standby position shown by a two-dot chain line in the figure. When using the nozzles 4 and 5, move the arm 2a toward the center of the base 1,
The nozzle 4 or 5 is positioned directly above the center position of the semiconductor wafer 7. The semiconductor wafer 7 is held by a wafer chuck (not shown) placed inside the cup 6. The arm 3 is stopped at a predetermined position, and a predetermined amount of resist liquid is dropped from the nozzle 4 onto the center position of the semiconductor wafer 7, for example. Then, the semiconductor wafer 7 is rotated to uniformly disperse the resist liquid over the entire surface of the semiconductor wafer 7. That is, by controlling the stop position of the arm 3, one of the nozzles 4 and 5 is selected.

(Problem to be Solved by the Invention) However, in the coating apparatus described above, the resist liquid may fall onto the semiconductor wafer from the nozzle that is not in use (for example, nozzle 5). Furthermore, the resist liquid dries in the liquid passage of the unused nozzle, increasing the viscosity of the liquid and causing uneven coating. As a result, there is a drawback that a resist layer having a uniform desired thickness cannot be formed on the surface of a semiconductor wafer.

FIG. 8 shows another conventional coating device. In this type of apparatus, a cup 13 having a wafer chuck (not shown) is provided approximately in the center of the base 8, and a first arm 10 and a second arm 15 are arranged to sandwich the cup 13 from both the left and right sides. are arranged respectively. Each arm 10. 1
One end of the motor 5 is supported by a support shaft, and each support shaft is connected to a drive shaft of a motor 9, 14 via a gear or a belt. A first nozzle 11 is provided at the other end (tip) of the first arm 10, and a first nozzle 11 is provided at the other end (tip) of the second arm 15.
A second nozzle 16 is provided at the tip. Each nozzle 11. Containers 12 and 17 for resist solution storage are provided below the tips of the nozzles 16, respectively, to prevent the resist solution in each nozzle from drying out.

In this type of conventional device, either the first nozzle 11 or the second nozzle l6 is selected.

For example, when using the first nozzle 11, the arm IO is rotated around the spindle to position the nozzle 11 directly above the center position of the semiconductor wafer 7.

Next, a predetermined amount of resist liquid is dropped onto the semiconductor wafer 7 from the nozzle 11, and the semiconductor wafer 7 is rotated to uniformly disperse the resist liquid over the entire surface of the semiconductor wafer 7.

However, the above-mentioned type of coating device has a drawback in that as the number of nozzles increases, the nozzle operating mechanism becomes larger and more complex. Furthermore, when the number of nozzles increases, there is a problem that interference occurs between the arms, making it impossible to ensure reliable operation.

By the way, in order to keep the amount of liquid dropped onto the semiconductor wafer constant, the liquid passage in the liquid supply nozzle has a special shape to prevent air bubbles from being mixed into the liquid. Furthermore, since the liquid temperature also affects the coating film thickness, the liquid inside the nozzle may be adjusted to an appropriate temperature.

Conventional nozzles have a built-in tube made of fluoroethylene resin, such as PFA (tetrafluoroethylene resin) or soft PTFE (tetrafluoroethylene resin), and the tip of this resin tube is used as a liquid supply passage. use.

However, the conventional nozzle has a drawback that the resist liquid adheres to the thick part of the tube at the tip of the tube, and this dries and solidifies, narrowing the liquid supply port and changing the amount of liquid dropped.

Furthermore, during handling of semiconductor wafers or when replacing the cup of a coating device, the nozzle collides with the semiconductor wafer, cup, or other components, resulting in deformation or damage of the nozzle. In this case, if the nozzle is damaged, it takes a lot of time to replace, install, and adjust the nozzle because the nozzle itself is a piping tube.

In order to eliminate such inconveniences of conventional nozzles, the 9th
As shown in the figure, a nozzle tip 11 for discharging liquid is attached to the tip of a stainless steel tube 10, and a tip 1
There is a nozzle that has been modified so that the liquid is dropped through the nozzle. That is, since the tip of the tip 11 is made thinner, liquid will not adhere to the tip. Nozzle tip 11
For example, a tube made of fluoroethylene resin such as tetrafluoroethylene resin (PFA) or trifluorochloride ethylene resin (PCTFE) is used.

However, in the conventional nozzle described above, since the tube 10 is made of stainless steel, air bubbles mixed in the tube 10 cannot be visually confirmed. In addition, nozzle tip l1
Since it is attached by being press-fitted to the tip of the tube 10, there is a drawback that the press-fit portion deteriorates after long-term use, and gas enters into the liquid passage through the loosened press-fit portion, causing bubbles.

An object of the present invention is to prevent unnecessary liquid from falling onto the semiconductor wafer when only the necessary liquid supply nozzles are selected from among many types of liquid supply nozzles to drip liquid onto the semiconductor wafer. The object of the present invention is to provide a coating device capable of dropping a necessary type and amount of liquid.

Another object of the present invention is to provide a liquid supply nozzle for a coating device that can prevent air bubbles from entering the liquid in order to obtain a liquid film of uniform thickness without causing uneven coating. The purpose is to

[Structure of the invention]

(Means for Solving the Problems) The present invention includes a plurality of liquid supply nozzle means for dropping various liquids onto a subject by being supplied with a liquid from a liquid supply source, and a plurality of liquid supply nozzle means for dripping various liquids onto a subject, and when the liquid supply nozzle means is not used. , a nozzle standby container in which the liquid near the discharge port of the liquid supply nozzle means is maintained in a predetermined state and kept on standby, and a necessary number of liquids are supplied from among the liquid supply nozzle means waiting in the nozzle standby container. The present invention is characterized by comprising a nozzle operating means for selecting only the nozzle means and transporting it to the subject, and applying a liquid to the subject only by the liquid supply nozzle means carried by the nozzle operating means.

(Function) The present invention improves throughput by providing a plurality of nozzles for applying a plurality of types of liquids, selecting these nozzles for each liquid, and applying a desired liquid to a processing object.

(Examples) Hereinafter, various examples of the present invention will be described with reference to the drawings regarding coating apparatuses used in the resist liquid coating process.

As shown in FIG. 1, a semiconductor wafer 46 is held by suction by a wafer chuck 45, and a nozzle 30 for dropping resist liquid faces the upper surface of the semiconductor wafer 46. The wafer chuck 45 is supported by a motor 44 so as to be rotatable about a vertical axis. The rotation speed and rotation time of the motor 44 are controlled by a computer system controller.

Nozzle 30 is held by holder 48 .

One end of a hose 51 is connected to the temperature controlled water inlet in the holder 48, and one end of a hose 52 is connected to the temperature controlled water outlet. The other end of the hose 51 is connected to an outlet 58 of the temperature control device 53. On the other hand, the other end of the hose 52 is connected to a manifold 59.
It is connected to the. Manifold 59 has a valve 60 and a drain 62. The manifold 59 and the temperature control device 53 are communicated via the valve 60, so that the temperature control water 47 is returned to the device 53. Also, manifold 5
A part of the temperature-controlled water 47 in the drain 62 is discharged through the drain 62.

The temperature control device 53 is provided with four liquid supply systems. Each liquid supply system includes a nozzle 30, a liquid supply tube 17. 54 and a heat exchanger 55. The tube 17 is provided within the hose 51.

As shown in FIG. 2, a wafer chuck 45 is mounted on the base 20.
and a nozzle operating mechanism 73.

A cup 21 is provided to surround a semiconductor wafer 46 on a wafer chuck 45. The cup 2l is constructed to prevent liquid separated from the semiconductor wafer 46 due to centrifugal force from scattering around.

Furthermore, an opening 22 is formed above the cup 21 for carrying the semiconductor wafer 46 into and out of the coating apparatus.

A nozzle operating mechanism 73 is provided adjacent to the cup 21. This nozzle operating mechanism 73 includes a pair of nozzle holding members 90a, 90b, and nozzle holding members 90a, 90.
b along the X-axis, Y-axis, and Z-axis, respectively, and four types of nozzles 30a, 30b, 30c when not in use.
, 30d are kept on standby.

The nozzle holding members 90a and 90b are mounted on a moving plate 88, and the moving plate 88 is further mounted on a moving table 82. One nozzle holding member 90b is an air cylinder 91
The piston is connected to the piston rond and is moved along the X axis. As a result, the mutual distance between the nozzle holding member 90a and the nozzle holding member 90b changes, and the nozzle 30 is held by being opened and closed like tweezers.

Furthermore, the moving plate 88 is connected to the piston rod of the air cylinder 87, and is moved up and down along the Z-axis.

Furthermore, the moving table 82 is connected to a part of the belt 86 and guided and moved along the guide rail 79 in the X-axis direction.

Support members 80, 8] are provided at both ends of the guide rail 79, and the rail 79 is supported on the movable table 78.

A motor 84 is provided on the moving table 78, and a pulley 83 is fitted into the drive shaft of the motor 84. A pulley 85 is also attached to the support member 81 on the other side. A belt 96 is stretched between pulleys 83 and 85.

Further, the movable table 78 is connected via a nut (not shown) to a pole screw 76 that is rotationally driven by a motor 75, and is guided and moved along the guide rail 74 in the Y-axis direction. The guide rail 74 and ball screw 76 are
The base 2 is supported by a pair of support members 77 at each end.
Supported on 0.

A nozzle standby container 100 is provided between the wafer chuck 45 and the nozzle operating mechanism 73. There are four openings 97a, 97b, 97 on the top surface of the nozzle standby container 100.
c, 1] 97d is formed. Openings 97a, 97b, 97c
, 97d are arranged along the X axis, and the nozzles/lz30a, 30b, 30c, 30d (7
) The tip is inserted into the container 100.

Next, the nozzle standby container 100 will be described in detail with reference to FIG.

A solvent bath 102 containing a solvent such as thinner is provided in the middle of the body 101 of the container 100,
The upper chamber 103 is filled with vapor volatilized from the organic solvent 107 stored in the solvent bath 102 . An opening 105 is formed in the solvent bath 102, and the opening 1
05, the upper chamber 103 and lower chamber 104 of the container communicate with each other. The opening 105 is formed below the nozzle insertion openings 97a to 97d. The nozzles 30a to 30d on standby are placed in the volatilized vapor of the organic solvent 107 to prevent the processing liquid in the nozzles, such as the resist liquid, from drying out, and droplets that drip down into the lower chamber 104 through the opening 105. It is designed to fall and be discharged through a drain 106.

Next, the droplet nozzle will be described with reference to FIGS. 4 and 5. In addition, since each of the four nozzles has practically the same configuration, the first nozzle 30a will be described here as a representative, and the description of the other nozzles will be omitted.

As shown in FIG. 4, the nozzle 30a is attached to the lower part of the holder 48. This holder 48 is hollow, and two hose joints 129 and 131 are formed in the upper part of the holder 48. Each hose joint 129, 1
31 each have a hose 51. 52 are connected.

As shown in FIG. 1, the upstream end of the hose 51 is connected to the water supply port 58 of the temperature control device 53, and the downstream end of the hose 52 is connected to the inlet of the manifold 59.

That is, the temperature-controlled water 4 is introduced into the holder 48 through the hose 51.
7 flows in, and temperature-controlled water 47 flows into the holder 4 through the hose 52.
It is designed to flow from 8 onwards. A resist liquid supply tube 37 is inserted into one of the hoses 51, and the temperature of the resist liquid 5o in the tube 37 is controlled by temperature control water 47.

As shown in FIG. 5, a nozzle tip 112 is attached to the tip of the nozzle 3o. A male thread 119 is formed at the base end of the tip 112, and this male thread 119 is screwed into a female thread 121 of a nut 122.

A seal ring 120 is provided between the nut 122 and the liquid supply tube 37. The upper tapered surface 123 of the seal ring 120 and the tapered surface of the nut 122 are in contact with each other. The more the nozzle tip 112 is screwed into the nut 122, the more the seal ring 120 tightens around the tube 3.
7 and the gap is sealed by a ring 120.

The liquid inlet portion 114 of the nozzle tip 112 is connected to the tube 37.
is drawn toward the liquid discharge port 115 side,
A tapered portion 116 is formed. In addition, the liquid discharge port 11
5 is formed in a trumpet shape to prevent the liquid 50 from falling during standby. In this case, it is preferable that the liquid discharge port 115 be formed into a thin knife-edge shape.

Note that the liquid supply tube 37 is made of tetrafluoroethylene resin (PFA). In addition, the seal ring 12
0 is made of soft polytetrafluoroethylene resin (PTFE).

Next, with reference to FIGS. 1 to 3, from the container 100 to the first
A case will be described in which the nozzle 30a is taken out and a resist liquid is applied to the semiconductor wafer 46.

ω A transport mechanism (not shown) transports the unprocessed semiconductor wafer 46 into the cup 21 through the opening 22 and places it on the wafer chuck 45 . A semiconductor wafer 46 is sucked and held by a wafer chuck 45 .

(2) When the setting of the semiconductor wafer 46 is completed, an operation start signal is transmitted from the computer system (not shown) to the nozzle operating mechanism 73, and the nozzle operating mechanism 73 starts operating. In this case, the computer system includes a mechanism 7.
3 is a first nozzle 9 for supplying high-resolution resist, for example for dropping.
Programming data for selecting 7a is input in advance.

The resist liquid may be of a spray type.

(2) Based on computer control, the motor 75 rotates the screw 76 to move the moving table 78 backward in the Y-axis direction (that is, move the nozzle holding members 90a, 90b away from the position of the wafer chuck 45).

(a) Next, the belt 86 is driven by the motor 84 to move the moving table 82 in the X-axis direction, and the nozzle holding member 9
0a and 90b are positioned above and near the first nozzle 30a selected by the program in the nozzle standby container 100.

(2) Operate the air cylinder 9I to move one nozzle holding member 90b away from the other member 90a (opening operation of nozzle holding members 90a, 90b).

0 The moving table 78 is moved forward in the Y-axis direction, and the holding members 90a and 90b are positioned directly above the nozzle 97a within the XY plane.

(2) The moving table 88 is lowered by the cylinder 87 and stopped so that the first nozzle 97a is located between the holding members 90a and 90b.

(8) Holding members 90a, 90 by cylinder 9l
b is closed, and the first nozzle 97a is held by the members 90a and 90b.

■ The moving table 88 is raised by the cylinder 87, and the first
The nozzle 97a is lifted from the container 100 and stopped at a predetermined height.

(10) Next, the motor 75 is driven to move the moving table 78 to Y.
After retreating in the axial direction, the moving table 82 is moved in the X-axis direction by driving the motor 84, and the first nozzle 97a is moved onto the semiconductor wafer 4 while being held by the members 90a and 90b.
Position it on the center line of 6.

(11) The movable table 78 is moved forward in the Y-axis direction by driving the motor 75, and the first nozzle 97a is positioned directly above the center position of the semiconductor wafer 46.

(12) Lowering the moving plate 88 by driving the cylinder 87 and bringing the first nozzle 97a closer to the semiconductor wafer 46;
The nozzle 97a is stopped when the distance from the liquid discharge port 115 of the nozzle 97a to the upper surface of the wafer 46 reaches a predetermined distance.

(13) Next, a process for supplying the resist liquid 50 to the first nozzle 30a will be described with reference to FIG.

The resist liquid 50 enters the temperature control device 53 from the inlet 54 via a valve (not shown) of a liquid tank (not shown) and a sack pack valve (not shown). Inside the temperature control device 53,
The resist liquid 50 is adjusted to a predetermined temperature by a heat exchanger 55. The heat exchanger 55 is made of a metal tube with a high heat exchange rate.

Next, the resist liquid 50 flows through the tube 37 from the outlet 58 of the temperature control device 53, and flows through the liquid discharge port 11 of the nozzle 30a.
A predetermined amount is extruded from 5. This becomes a droplet and falls toward the center position of the semiconductor wafer 46.

(14) The motor 44 rotates the wafer chuck 45 at a predetermined rotational speed in the range of, for example, 1000 to 6000 RPM. As a result, the dropped resist solution is dispersed over the entire surface of the semiconductor wafer 46, forming a coating layer of the resist solution with a predetermined thickness.

(15) When coating with the resist liquid is completed, follow the above processes (3) to (l2) in reverse and apply the first nozzle 3.
0a is returned to the opening 97a of the container 100, and the nozzle holding members 90a and 90b are placed on standby at predetermined positions.

(16) After returning the nozzle 30a to the standby position, the suction and holding of the semiconductor wafer 46 by the wafer chuck 45 is released, and the semiconductor wafer 46 is carried out from the coating device by a handling device (not shown).

(l7) When applying a developer to the semiconductor wafer 46 thereafter, the exposed semiconductor wafer 46 is held by suction by the wafer chuck 45, and for example, the fourth nozzle 30
d is transported by the nozzle operating device 73 to the center position of the semiconductor wafer 46, and a predetermined amount of developer is applied to the semiconductor wafer 46.

According to the first embodiment, only one of the plurality of droplet dropping nozzles is selected depending on the process and the type of wafer, and only the selected nozzle is transferred onto the semiconductor wafer. , the other nozzles are waiting in the container. Therefore, it is possible to avoid an accident in which unnecessary liquid falls onto the semiconductor wafer, and the occurrence of uneven coating can be prevented.

Further, the nozzle tip 112 and nut 122 are
Stainless steel or trifluorochloroethylene resin (PCTF)
It is made of high-strength resin such as E). In this case, P
CTFE has high hardness and high processing accuracy, so it has excellent shape stability of the liquid discharge port 115, and is also suitable for pressing the soft seal ring 120.

Furthermore, even when a tube made of tallow, which generally has poor shape stability, is used as the tube 37, a liquid-tight state can be formed and maintained by deforming the seal ring 120.
The sealing action functions effectively as a whole.

Further, the tube 37 and the chip 112 can be easily and reliably brought into close contact with each other, and even if the chip 112 is damaged, it can be easily attached and detached.

Furthermore, the passage 113 for the liquid discharged from the nozzle is not formed with uneven parts that are likely to cause liquid pools or air bubbles, and the inner surfaces of the tube 37 and the tip 112 are also continuously connected, so that there is no liquid pool or bubbles. Air bubbles will no longer form.

Therefore, a stable discharge amount can be obtained.

Next, a second embodiment will be described with reference to FIG. Note that explanations and illustrations of parts common to the second embodiment and the first embodiment will be omitted.

In the coating apparatus of this second embodiment, the nozzle operating mechanism is changed. A fixed shaft 123 is fixed on the base 20, and a first arm 124 is provided to be rotatable around the fixed shaft 123. The fixed shaft 123 is connected to a drive shaft of a motor (not shown). Note that the fixed shaft 123 is provided on the longitudinal extension of the nozzle standby container 100.

Further, a second arm 125 is connected to the first arm 124 via a shaft 126. That is, the first and second arms 124 and 125 form a nozzle operating mechanism consisting of a multi-joint arm. Nozzle holding members 90a and 90b are attached to the tips of this multi-jointed arm. Note that the multi-joint arm is bent as shown in the figure around the fixed shaft 123, and a member 90a provided at the tip thereof is bent.
, 90b may be located at each nozzle holding location of the container 100.

In the device of the second embodiment, the first
The arm 124 is rotated by a predetermined angle, and the holding member 90a is
, 90b, the third nozzle 30c is held and transported to a position directly above the center position of the semiconductor wafer 46, and a predetermined amount of resist liquid is dropped onto the wafer 46.

According to the second embodiment, the nozzle operating mechanism installed on the base can be downsized.

In addition, in the above embodiment, the case where one nozzle is selected from among four nozzles has been explained, but the present invention is not limited to this, and it is possible to select a plurality of nozzles such as two, three, five, etc. It is also possible to select one or two nozzles from a menu of groups.

〔Effect of the invention〕

As explained above, according to the coating device and nozzle of the present invention, it is possible to reliably drop the required amount of liquid onto a semiconductor wafer, and it is possible to uniformly apply the liquid without causing uneven coating. .

Therefore, the reliability of the coating process is improved, and the productivity of semiconductor wafers can be improved.

[Brief explanation of drawings]

FIG. 1 shows a schematic configuration of a coating device according to an embodiment of the present invention, and is a diagram for explaining the flow of liquid within the device.
FIG. 2 is a plan view schematically showing a coating device according to an embodiment of the present invention, FIG. 3 is a longitudinal cross-sectional view showing the inside of a nozzle standby container of the coating device according to an embodiment of the present invention, and FIG. FIG. 5 is an enlarged vertical cross-sectional view showing the nozzle tip of the coating device according to the embodiment of the present invention, and FIG. 6 is a vertical sectional view showing the nozzle of the coating device according to the embodiment of the invention. A plan view schematically showing a coating device according to another embodiment, FIG. 7 is a plan view schematically showing a conventional coating device, and FIG. 8 is a plan view schematically showing another type of conventional coating device. , FIG. 9 is a partial vertical cross-sectional view showing a part of the tip of a conventional liquid dropping nozzle with a portion thereof cut away. 46...Wafer 45...Chuck 30
... Nozzle 55 ... Heat exchanger diagram diagram diagram diagram diagram

Claims (1)

[Claims] Liquid is supplied from a liquid supply source, and a plurality of liquid supply nozzle means for supplying various liquids to the object to be processed, and a plurality of liquid supply nozzle means near the discharge port of the liquid supply nozzle means when the liquid supply nozzle means are not used. At least one liquid supply nozzle means is selected from among a nozzle standby container in which the liquid is kept on standby while maintaining the liquid in a predetermined state, and a liquid supply nozzle means waiting in the nozzle standby container, and this is used as the test object. 1. A coating apparatus for applying a liquid to a semiconductor wafer, comprising: a nozzle operating means for conveying a liquid to a semiconductor wafer; and a coating apparatus for applying a liquid to a semiconductor wafer.