JP2759369B2 - Liquid processing apparatus and liquid processing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a liquid processing apparatus and a liquid processing method for an object to be processed.

[Related Art and Problems to be Solved by the Invention] Conventionally, in a resist coating device or a developing device in a semiconductor wafer manufacturing process, a certain amount of resist or a developing solution is dropped on a semiconductor wafer from a nozzle to mount the semiconductor wafer. A spin coater is used in which the placed chuck is rotated at a high speed of several thousand rotations per minute to apply these resists on the entire surface of the semiconductor wafer. In these apparatuses, when the resist dropped on the central portion of the semiconductor wafer is spin-coated, the resist spreads to the peripheral portion and is applied to the entire surface of the semiconductor wafer. At this time, excess liquid is scattered from the peripheral edge of the semiconductor wafer, but a part of the liquid flows to the back surface of the semiconductor wafer. It is well known that the transfer of the resist adhered to the back surface becomes a source of dust and particles in a later step. As a countermeasure for this, there is a back surface cleaning apparatus for removing the resist that has reached the back surface.
These are described in JP-A-56-45022 and JP-A-56-83027. The back surface cleaning apparatus removes these contaminants by simultaneously spraying a resist on the front surface and simultaneously spraying a solvent for the resist, for example, acetone, ethyl ceresolve acetate, butyl acetate, or the like, onto the periphery of the back surface of the semiconductor wafer. However, such a solvent has a low boiling point and is easily vaporized even at room temperature, so that the peripheral portion of the semiconductor wafer is deprived of heat of vaporization and the temperature decreases. Therefore, in the application of a resist on the surface of a semiconductor wafer, a portion having a low temperature becomes thick and a portion having a high temperature becomes a thin coating film due to a temperature distribution generated on the semiconductor wafer, and a coating film having a uniform film thickness cannot be obtained. Such unevenness of the coating film has resulted in a decrease in the quality of the semiconductor wafer.

The present invention has been made in order to solve the above-mentioned drawbacks, and removes a resist wrapped around the back surface to eliminate a contamination source, and also maintains the temperature uniformity of the entire surface of the semiconductor wafer and reduces the film thickness of the coating film. It is an object of the present invention to provide a liquid processing apparatus and a liquid processing method for manufacturing a uniform and improved quality semiconductor wafer.

[Means for Solving the Problems] In order to achieve the above object, a liquid processing apparatus according to the present invention includes a chuck for mounting and fixing an object to be processed, a rotating mechanism for rotating the chuck, and coating on the surface of the object to be processed. A processing liquid supply nozzle for supplying a processing liquid whose temperature has been adjusted to at least a peripheral portion of a back surface of a processing object rotated by a rotation mechanism; And a means for controlling the temperature of the object to be processed, preferably a liquid recovery means for recovering the processing liquid on the outer periphery of the processing liquid supply means.

Further, in the liquid processing method of the present invention, when the object to be processed is placed on the chuck, and the chuck is rotated to apply the coating liquid to the surface of the object to be processed, the temperature is adjusted at least at the periphery of the back surface of the object to be processed. The processing liquid is ejected and supplied to remove the processing liquid flowing around the back surface of the processing target and to control the temperature of the processing target.

[Operation] The coating liquid dropped on the central portion of the object to be processed is rotated to a high speed to extend the object to the peripheral portion. Some of the coating solution stretched to the peripheral part goes around the peripheral part on the back side,
The processing liquid heated by the temperature control means is ejected to remove the coating liquid which has flowed in, and is removed. Therefore, even if heat of vaporization is removed from the processing object by evaporation with the processing liquid having a low boiling point, the temperature of the processing liquid is adjusted to be high and is canceled out, so that the entire surface of the processing object has a uniform temperature. In addition, since the ejection area of the processing liquid is formed on the entire back surface except for the mounting table supporting the processing target, the temperature of the entire processing target can be adjusted. Therefore, a film having a uniform thickness can be obtained.

Embodiment An embodiment in which the liquid processing apparatus and the liquid processing method of the present invention are applied to a resist coating apparatus for manufacturing a semiconductor wafer will be described with reference to the drawings.

The resist coating apparatus shown in FIG. 1 is provided with a disk-shaped chuck 3 on which a semiconductor wafer 1 to be processed is placed and fixed by vacuum suction or the like and fixed to a rotating shaft of a motor 2. A discharge nozzle 5 movable by the scanner 4 is provided above the chuck 3. When the resist, which is a coating liquid, is not discharged at a tip of the discharge nozzle 5 for a predetermined time or more and is hardened by contacting air for a long time. , Dummy dispensing can be performed. The discharge nozzle 5 is connected to a resist supply system 6, and the resist supply system 6 interlocks a pump 9 such as a bellows pump and a pump 9, such as a bellows pump, for supplying a predetermined amount of the resist 8 stored in the resist storage container 7. Valve V1, which is opened and closed
After the resist 8 is discharged from the discharge nozzle 5, the resist is drawn back into the discharge nozzle 5, and comprises a suck-back valve 11 for preventing dripping or solidification of the resist.

In order to prevent the resist from scattering outside the apparatus at the time of applying the resist, a cup 12 is provided as a processing container surrounding the chuck 3. The cup 12 can be moved up and down, and when the semiconductor wafer 1 is loaded, it is lowered from the position shown in the figure.
The chuck 3 is exposed to facilitate loading and unloading. Also cup
A discharge pipe (not shown) is connected to a lower portion of the pipe 12. Further, the cup 12 is provided with a back surface cleaning device 13 for the semiconductor wafer 1. As shown in FIG. 2, the back surface cleaning device 13 includes a pipe 16 through which a cleaning agent 14 as a processing liquid is supplied from a cleaning agent supply system 15.
And circulating water 17 such as pure water as a temperature control means
A double tube 18 surrounding the semiconductor wafer 1 is provided, and a cleaning agent whose temperature has been adjusted is ejected from a nozzle 19 serving as a processing liquid supply means on the back surface of the semiconductor wafer 1. Circulating water 17 is a drain pipe
It returns through 20 and is cycled again. Further, the nozzle 19 is provided with a liquid reservoir 21 which is a liquid collecting means for collecting liquid droplets adhered to the outer periphery of the nozzle 19 and absorbing water into a drain.

The operation of the back surface cleaning apparatus using the resist coating apparatus having the above configuration will be described.

When the semiconductor wafer 1 is sucked and supported on the chuck 3 by a transfer mechanism (not shown), the cup 12 rises as shown in FIG. 1, and a certain amount of resist is dropped from the discharge nozzle 5 from the resist supply system 6. . The motor 2 rotates at, for example, 4000 revolutions / minute, the resist is extended to the peripheral portion of the semiconductor wafer 1, and further scatters from the edge, and at the same time, wraps around the back surface. At that time, a certain amount of the cleaning agent is jetted from the nozzle 19 from the cleaning agent supply system 15 and dissolves and removes the resist that has flowed around the back surface. The cleaning agent 14 may be appropriately selected according to the temperature of the resist to be applied and the vaporization temperature of the cleaning agent so that a uniform temperature is maintained by the cooling rate of the semiconductor wafer and the like. Prevent cooling. Therefore, since the semiconductor wafer 1 does not have a temperature difference between the central part and the peripheral part, when the temperature control means is provided in the case of a semiconductor wafer having a diameter of 150 mm as shown in FIG. Thus, it is possible to obtain a uniform resist coating film which does not cause the nonuniformity of the film thickness (the peripheral portion becomes thicker) shown by the broken line when the temperature is not adjusted in the conventional case.

The above description is an embodiment of the present invention, and the present invention is not limited to a resist coating device, but includes a developing device and the like.
It goes without saying that the present invention can be applied to all devices that require back surface cleaning.

Further, the temperature control means is not limited to a means for adjusting the temperature by circulating water, and other known temperature adjustment means may be used.

[Effects of the Invention] As is clear from the above description, according to the liquid processing apparatus and the liquid processing method of the present invention, since the temperature control means of the cleaning agent is provided, the temperature of the peripheral portion of the processing object is prevented from lowering. And a uniform temperature can be maintained over the entire surface. For this reason, a uniform product can be produced, and production with good yield can be achieved.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a liquid processing apparatus of the present invention, and FIG.
FIG. 3 is a view showing one embodiment of the liquid processing apparatus of the present invention, and FIG. 3 is a view explaining one embodiment. 1 ... Semiconductor wafer (object to be processed) 8 ... Resist (coating liquid) 13 ... Backside cleaning device 14 ... Cleaning agent (processing liquid) 17 ... Circulating water (temperature adjusting means)

Claims (3)

(57) [Claims] A chuck for mounting and fixing an object to be processed, a rotating mechanism for rotating the chuck, a nozzle for discharging a coating liquid onto the surface of the object to be processed, and a chuck for preventing the coating liquid from scattering. A processing liquid supply unit that supplies a processing liquid whose temperature has been adjusted to at least a peripheral portion of the back surface of the processing object rotated by the rotation mechanism, and a temperature control unit of the processing object. A liquid processing apparatus, characterized in that: 2. The apparatus according to claim 1, further comprising a liquid recovery means for recovering said processing liquid on an outer periphery of said processing liquid supply means.
The liquid processing apparatus according to any one of the preceding claims. 3. A processing liquid having a temperature adjusted at least on a peripheral portion of a back surface of the object to be processed when the object to be processed is placed on a chuck and the chuck is rotated to apply a coating liquid to the surface of the object to be processed. And discharging the liquid to remove the processing liquid flowing around the back surface of the processing object, and controlling the temperature of the processing object.