JPH0817700A - Application of resist and resist applying device - Google Patents

Abstract

PURPOSE:To prevent the quality of a resist film from being deteriorated-even if the consumption of a resist solution is decreased by a method wherein the solvent only of the resist solution is applied on the surface of a wafer held by a wafer holding means and the resist solution is applied on the surface, which is applied with the solvent only, of the wafer. CONSTITUTION:A semiconductor wafer 11 is placed on a wafer chuck 12 and a dispense nozzle 14 is moved in such a way that a solvent nozzle 14a is arranged over the center part of the surface of the wafer 11. The chuck 12 is rotated to start the rotation of the wafer 11 and the same liquid as a solvent, which is used for a resist solution, is fed on the whole region of the surface of the wafer 11 through the nozzle 14a. Then, the nozzle 14 is moved in such a way that a resist nozzle 14b is positioned over the center part of the surface of the wafer 11, a resist solution is discharged through the nozzle 14b and the wafer 11 is rotated. An application of the resist solution is at least made before the solvent fed on the wafer 11 is volatilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resist coating method and a resist coating apparatus used in a semiconductor device manufacturing process or the like.

[0002]

2. Description of the Related Art An example of the structure of a conventional resist coating apparatus will be described with reference to FIG.

In the resist coating apparatus shown in the figure, a wafer chuck 5 for sucking and holding a semiconductor wafer 51.
2 is rotationally driven by a spin motor 53. The semiconductor wafer 51 is provided above the wafer chuck 52.
A resist nozzle 54 for dropping the resist solution on the surface of the is provided. This resist nozzle 54 is
The nozzle motor 55 moves between the center of the surface of the semiconductor wafer 51 and the outside of the end. The cup 56 is configured to cover the periphery of the wafer chuck 52.
The cup 56 is provided with a discharge port 56a for discharging the resist solution that has flown outward from the surface of the semiconductor wafer 51 during the resist coating process.

Next, a process of applying a resist on the surface of the semiconductor wafer 51 with the resist applying apparatus having such a structure will be described.

First, the semiconductor wafer 51 is placed on the wafer chuck 52 and fixed by suction. Next, by driving the nozzle motor 55, the resist nozzle 54 is moved to above the central portion of the surface of the semiconductor wafer 51. Then, the rotation of the wafer chuck 52 by the drive of the spin motor 53 is started. As a result, the rotation of the semiconductor wafer 51 is started. Subsequently, when the resist solution is discharged from the resist nozzle 54, the resist solution is transferred to the semiconductor wafer 51.
It is dripped and spread on the surface of and the excess resist solution is splashed to the outside. The removed resist solution is collected by the cup 56 and discharged from the discharge port 56a.

[0006]

In such a conventional resist coating method and resist coating apparatus, most of the resist solution discharged from the resist nozzle 54 is spattered from the surface of the semiconductor wafer 51 to the outside. . For this reason, the conventional resist coating method and resist coating apparatus have a drawback in that the amount of resist solution that is not coated on the surface of the semiconductor wafer 51 and is discarded is very large. Since the resist solution is expensive, a large amount of the resist solution that is not applied and is discarded causes an increase in manufacturing cost.

Normally, 90% or more of the resist solution discharged from the resist nozzle 54 is discarded. That is, 10 times or more of the resist solution actually applied to the surface of the semiconductor wafer 51 is discarded.

Impurities are mixed in the resist solution which is once used in the resist coating step and discarded,
Also, since some of the solvent volatilizes and the concentration changes,
It is impossible to reuse. Here, if the concentration of the resist solution changes, it cannot be reused because the film thickness changes due to this concentration change.

On the other hand, when the amount of the resist solution discharged from the resist nozzle 54 is reduced in order to reduce the amount of the resist solution used, the speed at which the resist solution spreads on the surface of the semiconductor wafer 51 becomes slow. Will end up.
Therefore, the rotation speed of the semiconductor wafer 51 (that is, the drive speed of the spin motor 53) must be increased in order to finish the coating before the solvent of the resist solution evaporates. In this case, the rotation speed of the semiconductor wafer 51 is reduced. It becomes difficult for the resist solution to enter the grooves formed on the surface,
It becomes difficult to form a uniform and good resist film.

On the other hand, if the amount of the solvent of the resist solution is increased and the concentration thereof is lowered in order to finish the coating before the solvent of the resist solution is volatilized, the thickness of the formed resist film becomes thin and the desired thickness is obtained. It becomes difficult to obtain the film thickness.

The present invention has been made in view of the above-mentioned drawbacks of the prior art, and a resist coating method and a resist coating apparatus which do not deteriorate the quality of a resist film even if the amount of the resist solution used is reduced. The purpose is to provide.

[0012]

[Means for Solving the Problems]

(1) A resist coating method according to the first invention comprises a solvent coating step of coating only a solvent of a resist solution on the surface of a wafer held by a wafer holding means, and a surface of the wafer coated with only the solvent. And a resist coating step of coating the resist solution. (2) A resist coating apparatus according to a second aspect of the present invention is a wafer holding unit that holds a wafer, a wafer rotating unit that rotates the wafer held by the wafer holding unit, and a solvent of a resist solution on the surface of the wafer. A solvent supply means for supplying only the resist solution and a resist solution supply means for supplying the resist solution to the surface of the wafer are provided. (3) A resist coating method according to the third invention comprises a solvent supplying step of supplying only a solvent of a resist solution to an atmosphere gas of a space surrounding a wafer held by a wafer holding means, and the resist solution on a surface of the wafer. A resist coating step of coating, and a solvent discharging step of discharging the solvent in the atmosphere gas after the resist solution supplied to the surface of the wafer in the resist coating step spreads to the outer peripheral portion of the wafer, It is characterized by having. (4) A resist coating apparatus according to a fourth aspect of the present invention is a wafer holding unit that holds a wafer, a wafer rotating unit that rotates the wafer held by the wafer holding unit, and the wafer holding unit that holds the wafer. A sealing unit that forms a sealed space surrounding the wafer, a solvent supply unit that supplies a solvent of the resist solution to the atmosphere gas of the sealed space formed by the sealing unit, and a resist that supplies the resist solution to the surface of the wafer. It is characterized by comprising a solution supply means and a solvent discharge means provided in the sealing means for discharging the solvent supplied by the solvent supply means.

[0013]

[Action]

(1) According to the resist coating method of the first invention, the solvent of the resist solution can be applied to the surface of the wafer to slow down the evaporation rate of the solvent in the resist solution. Even if the amount is reduced, it is not necessary to increase the rotation speed of the wafer rotating means. Therefore, when the resist solution is applied to the surface of the wafer in the subsequent process, a uniform and good resist film can be obtained even if the supply amount of the resist solution is reduced. Moreover, since it is not necessary to reduce the concentration of the resist solution, a highly accurate resist film thickness can be obtained. That is, according to the first invention, the quality of the resist film is not deteriorated even if the amount of the resist solution used is reduced. (2) According to the resist coating apparatus of the second invention, the solvent of the resist solution is supplied to the surface of the wafer by the solvent supply means while rotating the wafer held by the wafer holding means by the wafer rotating means, After that, the resist solution can be supplied to the surface of the wafer by the resist solution supply means. Therefore, since the resist coating can be performed using the resist coating method according to the first aspect of the present invention, the quality of the resist film is not deteriorated even if the amount of the resist solution used is reduced. (3) According to the resist coating method of the third aspect of the invention, since the solvent of the resist solution is supplied into the atmosphere gas surrounding the wafer, the rate of volatilization of the resist solution can be slowed down. Therefore, even if the supply amount of the resist solution is reduced, it is not necessary to increase the rotation speed of the wafer rotating means. Therefore, in a subsequent step, when the resist solution is applied to the surface of the wafer by supplying the resist solution to the surface of the rotating wafer, even if the supply amount of the resist solution is reduced, a uniform and good resist is obtained. A membrane can be obtained. Moreover, since it is not necessary to reduce the concentration of the resist solution, a highly accurate resist film thickness can be obtained.
That is, according to the third invention, the quality of the resist film is not deteriorated even if the amount of the resist solution used is reduced. (4) According to the resist coating apparatus of the fourth invention, the wafer held by the wafer holding means is sealed by the sealing means, and the resist is supplied by the solvent supply means into the atmospheric gas in the sealed space obtained by the sealing means. The solvent of the solution can be supplied. Then, after that, the resist solution can be applied to the surface of the wafer by the solution supply means. Further, the solvent can be discharged by the solvent discharging means. Therefore, the resist coating can be performed using the resist coating method according to the third aspect of the present invention, so that the quality of the resist film does not deteriorate even if the amount of the resist solution used is reduced.

[0014]

Embodiments of the present invention will be described below.

(Embodiment 1) As Embodiment 1, an embodiment of the resist coating method according to the first invention (Claim 1) and the resist coating apparatus according to the second invention (Claim 2) will be described.

FIG. 1 is a sectional view schematically showing the structure of a resist coating apparatus according to this embodiment.

In the resist coating apparatus shown in FIG. 1, a wafer chuck 1 for sucking and holding a semiconductor wafer 11
2 is rotationally driven by a spin motor 13. Further, a dispense nozzle 14 is arranged above the wafer chuck 12. This dispense nozzle 14
Is provided with a solvent nozzle 14a for dropping a solvent onto the surface of the semiconductor wafer 11 and a resist nozzle 14b for dropping a resist solution onto the surface of the semiconductor wafer 11.

The dispensing nozzle 14 is moved between the center portion on the surface of the semiconductor wafer 11 and the end portion outside thereof by a nozzle moving means (not shown). Further, this nozzle moving means is used for the solvent nozzle 14a when dropping the solvent.
Is moved above the center of the semiconductor wafer 11, and when the resist solution is dropped, the dispense nozzle 14 is moved so that the resist nozzle 14b is positioned above the center of the semiconductor wafer 11. .

The cup 16 is configured to cover the periphery of the wafer chuck 12. The cup 16 is provided with a discharge port 16a for discharging the resist solution that has flown outward from the surface of the semiconductor wafer 11 during the resist coating process.

The type and concentration of the resist solution is not particularly limited, but here, OFPR86 manufactured by Tokyo Ohka
A case of using 00AC having a viscosity of 40 cp will be described. In this resist solution, ECA is used as a solvent.
(Ethyl cellosolve acetate) is used.

Next, a method of coating a resist on the surface of the semiconductor wafer 11 by using the resist coating apparatus having the above structure will be described. First, the semiconductor wafer 11 is placed on the wafer chuck 12 and fixed by suction. Next, by driving the nozzle moving means, the solvent nozzle 1
The dispensing nozzle 14 is moved so that 4a is arranged above the central portion of the surface of the semiconductor wafer 11. The drive of the spin motor 13 is started and the wafer chuck 12 is rotated. As a result, the rotation of the semiconductor wafer 11 is started. As shown in FIG. 2A, the same liquid as the solvent 21 used in the resist solution (ECA in this case) is supplied from the solvent nozzle 14 a to the entire surface of the semiconductor wafer 11. As a result, this solvent is transferred to the semiconductor wafer 11
It is dripped on the surface of and uniformly spread, and a solvent film as shown in FIG. 2 (b) is obtained. At this time, excess solvent is blown outside. The removed solvent is collected by the cup 16 and discharged from the discharge port 16a. Then, the drive of the spin motor 13 is stopped to stop the rotation of the semiconductor wafer 11. Next, by driving the nozzle moving means, the dispense nozzle 14 is moved so that the resist nozzle 14 b is located above the central portion of the surface of the semiconductor wafer 11. Subsequently, as shown in FIG. 3A, the resist solution 31 is discharged from the resist nozzle 14b. Then, the drive of the spin motor 13 is started to rotate the semiconductor wafer 11. As a result, this resist solution spreads uniformly on the surface of the semiconductor wafer 11. Such application of the resist solution is performed at least on the semiconductor wafer 1
Before the solvent above 1 is volatilized. At this time, the excess resist solution is blown to the outside, collected in the cup 16, and discharged from the discharge port 16a. After that, FIG.
As shown in (b), the solvent evaporates and the resist film 3
A semiconductor wafer 11 having 1'is obtained. Finally, the drive of the spin motor 13 is stopped to stop the rotation of the semiconductor wafer 11.

As described above, according to this embodiment, since the solvent of the resist solution is applied to the surface of the semiconductor wafer 11, the volatilization rate of the resist solution can be slowed down. Therefore, it is not necessary to increase the rotation speed of the spin motor 13 even if the supply amount of the resist solution is reduced.
That is, in the subsequent process, the rotating semiconductor wafer 1
When the resist solution is supplied to the surface of No. 1, even if the supply amount of the resist solution is reduced, a uniform and good resist film can be obtained.

Further, according to the present embodiment, since it is not necessary to reduce the concentration of the resist solution, uniform coating can be performed and a highly accurate resist film thickness can be obtained.

According to the study by the present inventor, when the resist solution as described above is used, the supply amount of the resist solution at one time can be reduced from the conventional 0.9 cc to 0.6 cc (semiconductor). The rotation speed of the wafer 11 and the concentration of the resist solution were the same as in the conventional case).

(Embodiment 2) As Embodiment 2, an embodiment of the resist coating method according to the third invention (Claim 3) and the resist coating apparatus according to the fourth invention (Claim 4) will be described.

FIG. 4 is a sectional view schematically showing the structure of the resist coating apparatus according to this embodiment.

In the resist coating apparatus shown in the figure, a wafer chuck 4 for sucking and holding a semiconductor wafer 41.
2 is rotationally driven by the spin motor 43. In addition, the wafer chuck 42 includes the wafer chuck 42.
A rotating plate 44 that rotates together with the rotating plate 44 is provided. Also,
An inner lid 45 is arranged above the wafer chuck 42. The inner lid 45 uses the cylinder 46 to form the side wall 4
By lowering 5a until it contacts the rotating plate 44,
An enclosed space surrounding the semiconductor wafer 41 held by the wafer chuck 42 is formed. Then, the inner lid 45 rotates together with the rotary plate 44.

A resist nozzle 47 is provided on the upper surface of the inner lid 45.
a and a solvent nozzle 47b are provided. The resist nozzle 47a is arranged so that the resist solution can be dropped onto the central portion of the surface of the semiconductor wafer 41 held by the wafer chuck 42. Further, the solvent nozzle 47b is used to supply the solvent into the atmosphere gas in the closed space so that the solvent concentration of the atmosphere gas becomes a saturated concentration.

The cup 48 is constructed so as to cover the periphery of the wafer chuck 42. The cup 48 is provided with a discharge port 48a for discharging the resist solution that has been blown outside from the surface of the semiconductor wafer 41 during the resist coating process.

Also in this embodiment, the type and concentration of the resist solution are not particularly limited as in the case of the above-mentioned Embodiment 1, but the viscosity of OFPR8600AC manufactured by Tokyo Ohka Co., Ltd. is 40%.
Use the one from cp. ECA (ethyl cellosolve acetate) is used as the solvent.

Next, a method of applying a resist on the surface of the semiconductor wafer 41 by using the resist applying apparatus having such a configuration will be described. First, the semiconductor wafer 41 is placed on the wafer chuck 42 and is fixed by suction. Next, the cylinder 46 is driven to lower the inner lid 45. Then, the inner lid 45 and the rotary plate 44 form a closed space surrounding the semiconductor wafer 41 held by the wafer chuck 42. Then, the same liquid (here, ECA) as the solvent used for the resist solution is supplied to the atmospheric gas in the closed space from the solvent nozzle 47b. Then, the solvent concentration in this atmosphere gas is set to a saturated concentration. Next, from the resist nozzle 47a, the semiconductor wafer 41
The resist solution is discharged onto the surface of the. Then, the drive of the spin motor 43 is started and the semiconductor wafer 41 is rotated. As a result, the resist solution spreads evenly on the surface of the semiconductor wafer 41. At this time, since the atmospheric gas in the closed space contains a solvent having a saturated concentration, the solvent in the resist solution does not evaporate. Then, when the resist solution reaches the outer peripheral portion of the semiconductor wafer 41, the cylinder 46 is driven to raise the inner lid 45, and the sealed space is unsealed. As a result, the atmospheric gas containing the solvent is discharged, and the solvent in the resist solution begins to volatilize. At this time, the excess resist solution is blown to the outside, collected by the cup 48, and discharged from the discharge port 48a. The determination as to whether or not the resist solution has reached the outer peripheral portion of the semiconductor wafer 41 is made, for example, by the elapsed time (usually 0.
About 5 seconds).

In this way, by starting the volatilization of the solvent in the resist solution after the resist solution reaches the outer peripheral portion of the semiconductor wafer 41, the uniformity of the film thickness of the resist film can be further improved. . Finally, the drive of the spin motor 43 is stopped to stop the rotation of the semiconductor wafer 41.

As described above, according to this embodiment, since the solvent is supplied into the atmosphere gas surrounding the semiconductor wafer 41, the volatilization rate of the resist solution can be reduced. Therefore, even if the supply amount of the resist solution is reduced, it is not necessary to increase the rotation speed of the spin motor 43. Therefore, when the resist solution is applied to the surface of the semiconductor wafer 41 in the subsequent step, a uniform and good resist film can be obtained even if the supply amount of the resist solution is reduced.

Further, since it is not necessary to reduce the concentration of the resist solution, a highly accurate resist film thickness can be obtained.

Further, according to this embodiment, the solvent in the resist solution is started to volatilize by opening the seal after the resist solution reaches the outer peripheral portion of the semiconductor wafer 41. The thickness uniformity can be further improved.

[0036]

As described in detail above, according to the present invention, there is provided a resist coating method and a resist coating apparatus which do not deteriorate the quality of a resist film even if the amount of resist solution used is reduced. You can This makes it possible to reduce the manufacturing cost of the semiconductor device.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing the configuration of a resist coating apparatus according to a first embodiment.

2A and 2B are views for explaining application of a solvent in Example 1, where FIG. 2A is a sectional view of the apparatus showing the supply of the solvent to the wafer surface, and FIG. 2B is a wafer showing the state of the applied solvent. FIG.

3A and 3B are views for explaining application of a resist solution in Example 1, where FIG. 3A is a sectional view of the apparatus showing the supply of the resist solution to the wafer surface, and FIG. 3B is a state of the applied resist solution. FIG.

FIG. 4 is a sectional view schematically showing the configuration of a resist coating apparatus according to a second embodiment.

FIG. 5 is a cross-sectional view schematically showing a configuration example of a conventional resist coating apparatus.

[Explanation of symbols]

 11 Semiconductor Wafer 12 Wafer Chuck 13 Spin Motor 14 Dispensing Nozzle 14a Solvent Nozzle 14b Resist Nozzle 16 Cup 16a Discharge Port 41 Semiconductor Wafer 42 Wafer Chuck 43 Spin Motor 44 Rotating Plate 45 Inner Lid 45a Sidewall 46 Cylinder 47a Resist Nozzle 47b Solvent Nozzle 48 Cup 48a outlet

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI technical display location G03F 7/16 501 // B05C 11/08 (72) Inventor Nobu Hitoshi Tani Hitoshi Kawasaki, Kanagawa Prefecture Komukai-Toshiba-cho 1 Stock Company, Toshiba Tamagawa Plant

Claims (4)

[Claims] 1. A solvent applying step of applying only a solvent of a resist solution to a surface of a wafer held by a wafer holding means, and a resist applying step of applying the resist solution to a surface of the wafer applied only with the solvent. And a resist coating method comprising: 2. A wafer holding means for holding a wafer, a wafer rotating means for rotating the wafer held by the wafer holding means, and a solvent supplying means for supplying only a solvent of a resist solution to the surface of the wafer. A resist coating apparatus comprising: a resist solution supply unit that supplies the resist solution to the surface of the wafer. 3. A solvent supplying step of supplying only a solvent of a resist solution to an atmosphere gas in a space surrounding the wafer held by the wafer holding means, and a resist applying step of applying the resist solution to the surface of the wafer, A resist discharging step of discharging the solvent in the atmospheric gas after the resist solution supplied to the surface of the wafer in the resist coating step spreads to the outer peripheral portion of the wafer; Application method. 4. A wafer holding means for holding a wafer, a wafer rotating means for rotating the wafer held by the wafer holding means, and a hermetic seal forming a hermetically sealed space surrounding the wafer held by the wafer holding means. Means, a solvent supply means for supplying a solvent of the resist solution to the atmospheric gas in the closed space formed by the sealing means, a resist solution supply means for supplying the resist solution to the surface of the wafer, and the solvent supply means And a solvent discharging unit provided in the sealing unit for discharging the solvent supplied by the resist coating apparatus.