JPH02156627A - Resist coating device - Google Patents

Abstract

PURPOSE:To easily execute a precise control operation of a resist discharge amount by a method wherein an adjustment mechanism is installed at a resist sucking-back mechanism and a piston movement is adjusted finely. CONSTITUTION:A piston 63 is lowered by the air from an air introduction port 65 at a sucking-back mechanism 6 used to suck a resist remaining at a discharge nozzle after the resist has been discharged; a resist liquid of a definite amount is discharged from the discharge nozzle. A supply of the air is stopped; the piston 63 comes into contact with the tip of a spindle of a pushing-up adjustment mechanism 68 by using a spring 67; the piston stands still; also a diaphragm 62 is displaced upward; a volume of a liquid chamber 61 is increased; the resist liquid on the side of the discharge nozzle is sucked by an amount corresponding to a movement of the piston 63. A position of a spindle of this mechanism 68 is adjusted with a micrometer or the like installed at the mechanism 68; a stop position of the piston 63 is adjusted finely. Thereby, it is possible to control a resist discharge amount easily and precisely.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a resist coating apparatus for forming a resist film in a semiconductor manufacturing process.

[Prior Art] In the photoresist process of semiconductor manufacturing, a uniform resist film is formed on a wafer substrate. As such means, there is a resist coating device that drips a certain amount of resist solution and performs spin coating.

As a means of dropping a certain amount of resist liquid like a
It is equipped with a pump that sucks up a certain amount of resist from a container containing resist, a backflow prevention valve, a valve, and a discharge nozzle, and further includes a suckback device that sucks the resist remaining in the nozzle after discharging the resist. The resist inside the container is
When the pump operates, a certain amount of liquid is sucked in, passes through a check valve, and then is discharged from the nozzle tip onto the wafer via a valve and a suck-back device.

Then, when discharging the processing liquid is finished, the operation of the pump is stopped, the discharge of the resist is cut off by the valve, and the remaining liquid in the nozzle is pulled back several steps toward the suckback device by the suckback device, and the resist is removed from the tip of the nozzle. This prevents any excess drops from falling onto the wafer.

As shown in FIG. 4, such a suckback device is provided with a diaphragm 15 inside the main body facing a liquid chamber 18 which is a flow path for resist liquid, and this diaphragm 15 is movable up and down near the center. It is connected and fixed to the tip of a rod 14 which is fixedly attached to the piston 13.

When discharging the resist liquid, the diaphragm 15 is pushed down via the piston 13 by supplying air from the air port 20, but after discharging the resist liquid, the piston 13 is pushed down by the spring 1.
The diaphragm 15 comes into contact with the adjustment screw 12 pushed up by the piston 13 and stops at rest.
4 and is displaced. Therefore, this diaphragm 15
The volume of the liquid chamber 18 changes (increases) by the displacement of , and the resist liquid from the discharge nozzle is pulled back as a suckback amount.

[Problems to be Solved by the Invention] By the way, this amount of suckback is usually as small as about 10 mm3, and requires fine control depending on the type, viscosity, and temperature of the resist solution used. In this method, the displacement of the diaphragm is adjusted by turning the adjustment screw 12 to adjust the contact position of the piston 13, but there is a limit to the pitch of the adjustment screw 12, making fine adjustment difficult. .

On the other hand, in order to control the resist coating amount, electrical control is performed using an electromagnetic valve or the like (JP-A-54-61476, JP-A-55-78529, JP-A-59-1)
00525 (Japanese Patent Application Laid-Open No. 1982-121620), and one in which a resist container is provided with a pressure reducing device (Japanese Patent Application Laid-open No. 121620/1982), these devices have the disadvantage of being complicated and expensive.

Furthermore, such adjustments are not always carried out;
- There is a need for a highly accurate and reliable mechanical adjustment mechanism that does not vary during the coating process under the same conditions once the temperature is set.

SUMMARY OF THE INVENTION It is an object of the present invention to solve these conventional problems and provide a resist coating device that has an extremely simple configuration and can finely control the amount of suckback and, ultimately, the amount of resist applied.

[Means for Solving the Problems] A resist coating device of the present invention that achieves the above object includes a resist supply mechanism that feeds a certain amount of resist and discharges it from a discharge nozzle, and a resist coating device that removes resist remaining in the discharge nozzle after discharge. The resist coating apparatus is characterized in that the suckback mechanism includes an adjustment mechanism that finely adjusts the amount of movement of the piston.

[Operation] The suckback device moves the piston at the lowest position during resist supply to the highest position determined by the adjustment mechanism during suckback, thereby displacing the diaphragm fixed to the piston and increasing the volume of the chamber in which the resist stays. The resist remaining in the nozzle is suctioned, and the suction amount (suckback amount) is determined by the amount of movement of the piston. The adjustment mechanism that determines the topmost position of the piston consists of a micrometer or other mechanism that can be finely adjusted, so by adjusting this adjustment mechanism according to the type of resist, coating conditions, etc., it can be achieved with an accuracy of, for example, 1/100I11. The movement of the piston can be controlled, and the amount of suckback can be minutely controlled.

[Example] Hereinafter, an example of the resist coating apparatus of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the resist liquid 2 is stored in a container 1, and a check valve 3 serves as a supply mechanism for delivering a certain amount of the resist liquid 2 to a discharge nozzle 7, and prevents backflow of the resist liquid.
A pump 4 for sucking a certain amount of resist from the container 1 and a valve 5 for closing the flow path after delivering the resist are connected to the container 1. Further, a suckback device 6 is provided between the valve 5 and the discharge nozzle 7 for sucking the resist liquid remaining in the discharge nozzle 7 after discharging the resist.

As shown in FIG. 2, the suckback device 6 has a liquid chamber 61 that serves as a flow path for the resist liquid in the main body 60.
A diaphragm 62 is provided facing 1. The diaphragm 62 is fixed to one end of a rod 64 fixed to the piston 63, and is displaced as the piston 63 moves up and down, thereby displacing the volume of the liquid chamber 61. The piston 63 is connected to the cylinder 6 of the main body by air introduced from the air inlet 65.
6, is urged upward by a spring 67, and is restricted from moving upward by the lower end of an adjustment mechanism 68, thereby adjusting the amount of movement. The adjustment mechanism 68 consists of a micrometer head 80 (FIG. 3), for example, and a barrel 8.
1 by rotating the simple spindle 83.

It can move in the vertical direction, and by using the circumferential memory 83a of the simple 83 and the scale 81a of the barrel 81, it is possible to control the amount of movement of the spindle 82 with an accuracy of, for example, about 1/100.

The micrometer head 80 can be attached to the suckback device 6 using a lock nut 84 or the like instead of the adjustment rod of a conventional suckback device, and an O-ring or the like is interposed between the bushing 69 of the main body and the spindle 82 to prevent air leakage. Prevent leaks. The tip of the spindle 82 of the micrometer head 80 attached to the suckback body in this way restricts the upward movement of the piston 63 and determines the amount of movement thereof.

Next, the operation of the registration device including the suckback device configured as described above will be explained.

First, when discharging the resist solution, the pump 4 operates to suck a certain amount of the resist solution 2 from the container 1 through the check valve 3, and sends it out to the discharge nozzle 7 via the open valve 5 and the suckback device 6. . At this time, air is introduced into the suckback device 6 from the air inlet 65, and the piston 63 is in a lowered state due to the pressure of this air. As a result, a certain amount of resist liquid is discharged from the discharge nozzle 7 and dropped onto the wafer 8. The wafer 8 is rotated by a known spin coater, and the dropped resist liquid is applied to the wafer 8.
It spreads as a uniform resist film on top.

On the other hand, at the same time as the discharge, the valve 5 is closed and the flow of the resist liquid into the liquid chamber 61 of the suckback device 6 is blocked.
Furthermore, the supply of air to the air inlet 65 is also cut off.

As a result, the piston 63 comes into contact with the tip of the spindle 82 of the push-up adjustment mechanism 68 by the spring 67 and becomes stationary. Along with this, the diaphragm 62 fixed to the rod 64 of the piston 63 is also displaced upward, increasing the volume of the liquid chamber 61.

Since the inflow side of the liquid chamber 61 is virtually closed when the valve 5 is closed, the resist liquid 2 on the discharge nozzle 7 side is sucked by the increase in volume due to the displacement of the diaphragm 62.

This suction amount (suckback amount) is determined by the amount of movement of the piston 63, but this amount of movement depends on the type of resist liquid used and other conditions.
By moving the zero spindle 82, minute adjustments can be made while checking with the circumferential memory 83a and the linear scale 81a. In this case, memories 81a, 83
Since there is a, the reproducibility of the adjustment is good.

In this embodiment, a micrometer head is used as the WA adjustment mechanism 68, but any mechanism other than a micrometer may be used as the adjustment mechanism as long as the amount of vertical movement of the piston can be minutely adjusted. Needless to say, it can be done.

Further, in this embodiment, a pump is used as the resist supply mechanism, but a pressurized supply mechanism or the like may be used as appropriate for the resist supply mechanism.

[Effects of the Invention] As is clear from the above explanation, the present invention makes it possible to extremely easily control the amount of resist discharged precisely by improving the conventional suck valve device, and to produce highly uniform resist discharge onto a semiconductor wafer. A resist film can be formed.

Furthermore, according to the present invention, since the adjustment is made based on the memory of the adjustment mechanism, the adjustment reproducibility is good.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the resist coating device of the present invention, FIG. 2 is a sectional view showing an embodiment of the suckback device of the present invention, and FIG. 3 is a sectional view of the same essential parts. FIG. 4 is a sectional view of a suckback device in a conventional resist coating device. 4... Pump (resist supply mechanism) 6...
... Suckback mechanism 63 ... Piston 68.80 ... Adjustment mechanism

Claims (1)

[Claims] In a resist coating device that includes a resist supply mechanism that sends out a certain amount of resist and discharges it from a discharge nozzle, and a suckback mechanism that sucks the resist remaining in the discharge nozzle after discharge, the suckback mechanism is configured to move the piston. A resist coating device characterized by being equipped with an adjustment mechanism for finely adjusting the amount.