JPH1167645A - Resist-developing method in photolithography - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize reduction in developing failures due to bubbles in the developer in resist developing method. SOLUTION: A vessel 2 used to contain developer 1 is released to atmospheric condition through holes provided or is a closed type vessel, in which the inside is kept under a negative pressure with a vacuum pump, etc. The surface of a wafer 5 within a resist-developing device 4 is coated by free drop due to gravity, with the developer 1 via a piping 3 soaked in the developer 1. Within the piping 3, a valve 6 for adjusting the flow rate of the developer 1 is provided in the course of the piping 3, and moreover a nozzle 7 is also provided in the neighboring region of wafer 5 in the outlet side of the piping 3, so that the developer 1 is uniformly supplied on the surface of the wafer 5. The flow rate of the developer 1 on the wafer 5 is adjusted to be 0.5 to 1.0 L/min through the valve 6 via the nozzle 7. In the present invention, a vessel 2 containing the developer 1 is located at a position higher than the position of the wafer 5, when it is coated with the developer 1. Since the vessel 2 is located at a position higher than the position of wafer 5, the surface of wafer 5 is coated by free drop due to gravity, with the developer 1 being contained in the vessel 2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for developing a resist in photolithography, and more particularly to reducing development defects caused by bubbles in a developer.

[0002]

2. Description of the Related Art As a general resist developing method in a conventional photolithography process, FIG.
(A) and (b) show. In FIG. 3A, a pipe 13 is provided on the surface of the developer 11 in a closed container 12 containing the developer 11.
And pressurized with nitrogen gas 14 or the like. The pressurized nitrogen gas 14 transfers the developing solution 11 to the wafer 1 in the resist developing device 16 through a pipe 15 immersed in the developing solution 11.
7 Apply by pressure to the surface. A valve 18 for adjusting the flow rate of the developer 11 is provided in the pipe 15, and a nozzle 19 is provided near the wafer 17 on the outlet side of the pipe 15 so that the developer 11 is evenly applied to the surface of the wafer 17. Provided. The nitrogen gas 14 in the pipe 13 is pressurized at a pressure (for example, atmospheric pressure) at the outlet of the nozzle 19 by 0.5 to 3.0 kgf / cm.
Add about ^two . Nozzle 19 on the surface of wafer 17
Is adjusted by the valve 18 so that the flow rate of the developer 11 becomes 0.5 to 1.0 L / min.

In FIG. 3B, the surface of the developer 21 in a closed container 22 containing the developer 21 is pressurized with a nitrogen gas 24 or the like via a pipe 23. The pressurized nitrogen gas 24
The developer 21 is stored in a buffer tank 30 which is a closed container via a pipe 25 immersed in the developer 21. Adjustment of the flow rate of the developer 21 during storage is performed by a valve 28. The surface of the developing solution 21 in the buffer tank 30 containing the developing solution 21 is pressurized with a nitrogen gas 32 or the like via a pipe 31. The pressurized nitrogen gas 32 applies the developer 21 to the surface of the wafer 27 in the resist developing device 26 under pressure through a pipe 33 immersed in the developer 21. A valve 34 for adjusting the flow rate of the developing solution 21 is provided in the pipe 33, and a nozzle 29 is provided near the wafer 27 on the outlet side of the pipe 33 so that the developing solution 21 is evenly applied to the surface of the wafer 27. Provided. The pressurization of the nitrogen gas 24 and the nitrogen gas 32 in the pipe 23 and the pipe 31 is performed at a pressure (for example, atmospheric pressure) of the outlet of the nozzle 29 and the outlet of the pipe 25 by 0.5 to more.
3.0 kgf / cm ^{2 is} added. Wafer 2
7 through the nozzle 29 to apply the developer 21 to 0.5-1.
It is adjusted by the valve 34 so that the flow rate becomes 0 L / min.

[0004]

In the conventional resist developing method, since the inside of the container containing the developing solution is pressurized with nitrogen gas or the like, nitrogen gas or the like dissolves in the developing solution. The developer in which the nitrogen gas or the like is dissolved is released to the atmosphere when coated on the wafer, so that the dissolved nitrogen gas or the like is bubbled again and contains these bubbles. Then, the bubbles adhere to the resist film on the wafer, thereby hindering the development of the resist by the developing solution, and as a result, there is a problem that a development defect is generated.

In the processing liquid application method disclosed in Japanese Patent Application Laid-Open No. Hei 5-13320, a liquid supply nozzle for supplying a processing liquid from a large number of pores is arranged so as to be in close proximity to the surface of a substrate to be processed. The processing liquid is supplied to the surface of the substrate to be processed in a liquid film form from the fine holes, and the processing liquid is applied to the surface of the substrate to be processed by relatively moving the substrate to be processed and the liquid supply nozzle. Even this method is not a solution to suppress the dissolved nitrogen gas and the like from becoming bubbles again, and a mechanism for relatively moving the substrate to be processed and the liquid supply nozzle to remove bubbles generated again is not provided. It is not a complicated and simple method.

Accordingly, in view of the above problems, the present invention provides a resist developing method aimed at reducing development defects caused by bubbles in a developer.

[0007]

SUMMARY OF THE INVENTION The present invention advantageously solves the problems of the prior art, and includes a resist development step in a photolithography step of a semiconductor device.
Place the container containing the developer at a position higher than the wafer position when applying it on the wafer, or store it at a position higher than the wafer position when applying the developer on the wafer before applying the developer on the wafer. The resist developing method in photolithography is characterized in that it is applied onto the wafer by free fall due to gravity, and the pressure applied to the developer is equal to the atmospheric pressure or negative pressure as a condition for storing the developer. And a resist developing method in photolithography.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention relates to a method of applying a developer by pressurizing the inside of a developer container and applying the developer by pressurizing the inside of the developer container, which has been used in the prior art. Developed by installing at a position higher than the wafer position or storing it at a position higher than the wafer position at the time of applying the developer onto the wafer once before applying it to the wafer, and applying it on the wafer by free fall by gravity The purpose is to reduce development defects caused by bubbles in the liquid.

FIG. 1 is a schematic diagram showing a resist developing method in photolithography according to a first embodiment of the present invention. As the container 2 containing the developer 1, a container having a hole and opened to the atmosphere, or a closed container having a negative pressure inside by a vacuum pump or the like is used. The developer 1 is applied to the surface of the wafer 5 in the resist developing device 4 by gravity by a free fall through a pipe 3 immersed in the developer 1. A valve 6 for adjusting the flow rate of the developing solution 1 is provided in the middle of the pipe 3, and a nozzle 7 is provided near the wafer 5 on the outlet side of the pipe 3 so that the developing solution 1 is uniformly applied to the surface of the wafer 5. Provided. Developing solution 1 on the surface of wafer 5 through nozzle 7
Is adjusted by the valve 6 so that the flow rate becomes 0.5 to 1.0 L / min. In the present invention, the container 2 containing the developer 1
At a position higher than the position of the wafer 5 when the developer 1 is applied. By installing the developer 1 in a position higher than the position of the wafer 5, the developer 1 in the container 2 can be applied to the surface of the wafer 5 by free fall due to gravity. At this time, the inside of the container 2 is provided with a hole and opened to the atmosphere, or a closed type in which the inside is negatively pressured by a vacuum pump or the like, so that the pressure is equal to or lower than the atmospheric pressure.

[0010] For this reason, in the prior art, a pressurizing step of nitrogen gas was required as a means for transporting the developing solution, but is unnecessary in the present invention. Further, in the prior art, since the pressure in the container containing the developing solution is higher than the pressure at the time of applying the developing solution to the wafer by the pressurizing step of nitrogen gas, the developing solution is applied from the container containing the developing solution. While a part of the air or nitrogen gas dissolved in the developer is generated as bubbles due to the pressure drop until, in the present invention, a part of the air or nitrogen gas dissolved in the developer is bubbled. Will not occur as. Since the inside of the container 2 of the present invention is set to be equal to the atmospheric pressure or a negative pressure, there is no pressure drop from the inside of the container containing the developing solution to the application of the developing solution unlike the prior art. Part of the air or nitrogen gas dissolved therein never occurs as bubbles.

FIG. 2 is a schematic diagram showing a resist developing method in photolithography according to a second embodiment of the present invention, in which means for storing a developing solution before coating is added. The surface of the developer 101 in the closed container 102 containing the developer 101 is filled with nitrogen gas 10 through a pipe 104.
Pressurize with 3 mag. The pressurized nitrogen gas 103 is passed through a pipe 105 immersed inside the developer 101, and the developer 101 is provided with a hole and opened to the atmosphere, or a closed type in which the inside is negatively pressured by a vacuum pump or the like. Store in the container 2. Adjustment of the flow rate of the developer 101 during storage is performed by a valve 106.
The pressurization of the nitrogen gas 103 in the pipe 104 depends on the pressure (atmospheric pressure or negative pressure) at the outlet of the pipe 105, the vessel 2 and the closed vessel 10.
A pressure corresponding to a potential energy potential due to a height difference from ^{2 is} applied by about 0.5 to 3.0 kgf / cm ² . Developing solution 10
Since the pressure in the container 102 containing the container 1 is higher than the pressure in the closed container 2 whose internal pressure is negatively reduced by a vacuum pump or the like, the pressure of the developer 101 from the closed container 102 to the container 2 decreases. As a result, a part of the air or nitrogen gas dissolved in the developer 101 is generated as bubbles in the container 2.

As described above, the developer 1 in the closed container 102
Even if air or nitrogen gas is sufficiently dissolved in the container 01, it is sufficiently degassed in the closed container 2 which is open to the atmosphere or has a negative pressure inside by a vacuum pump or the like. If the air is sufficiently degassed, part of the air or nitrogen gas dissolved in the developer 101 on the surface of the wafer 5 will never be generated as bubbles.

[0013]

According to the present invention, it is possible to reduce development defects caused by bubbles in a developing solution, which has been caused in the prior art, and to obtain an effect of improving the yield in the manufacture of semiconductor devices. .

[Brief description of the drawings]

FIG. 1 is a schematic view showing a resist developing method in photolithography according to a first embodiment of the present invention.

FIG. 2 is a schematic view showing a resist developing method in photolithography according to a second embodiment of the present invention.

FIG. 3 is a view showing a general resist developing method in a conventional photolithography process.

[Explanation of symbols]

 1,101 developer 2 container 3,104,105 piping 4 resist developing device 5 wafer 6,106 valve 7 nozzle 102 closed container 103 nitrogen gas

Claims (2)

[Claims] In a resist developing process in a photolithography process of a semiconductor device, a container containing a developing solution is placed at a position higher than a wafer position when applying the developing solution on a wafer, or the developing solution is applied to the wafer. A resist developing method in photolithography, wherein the resist is temporarily stored at a position higher than the position of the wafer at the time of application onto the wafer, and is applied onto the wafer by free fall due to gravity. 2. A resist developing method in photolithography according to claim 1, wherein the condition for storing the developer is that the pressure applied to the developer is equal to atmospheric pressure or negative pressure. .