WO2019015006A1

WO2019015006A1 - Pressure reducing and drying device and pressure reducing and drying method

Info

Publication number: WO2019015006A1
Application number: PCT/CN2017/098166
Authority: WO
Inventors: 龚成波
Original assignee: 武汉华星光电半导体显示技术有限公司
Priority date: 2017-07-18
Filing date: 2017-08-18
Publication date: 2019-01-24
Also published as: CN107315325B; CN107315325A

Abstract

A pressure reducing and drying device and a pressure reducing and drying method. The pressure reducing and drying device comprises: a working chamber (10), a workbench (21), air extraction holes (30), air inlet holes (40) and air inlet hole valves (50); the workbench (21) is provided in the working chamber (10), an air extraction hole (30) is provided at each of the four corners of the workbench (21), at least one air inlet hole (40) is provided corresponding to each air extraction hole (30) and adjacent to the latter, each air inlet hole (40) being provided with an air inlet hole valve (50); when extracting air through the air extraction holes (30), protective gases are introduced from the air inlet holes (40) to around the air extraction holes (30), decreasing the speed of extracting the volatilized photoresist solvent at the edges of the substrate through the air extraction holes (30), thereby improving the uniformity of volatilization of the photoresist solvent, avoiding the influence of non-uniform volatilization of the photoresist solvent on the line width in the development process, ensuring the uniformity of the line width in the development process.

Description

Vacuum drying equipment and vacuum drying method

Technical field

The present invention relates to the field of display technology, and in particular, to a vacuum drying apparatus and a vacuum drying method.

Background technique

With the development of display technology, flat display devices such as liquid crystal displays (LCDs) and organic light emitting displays (OLEDs) have high image quality, power saving, thin body and wide application range. The advantages are widely used in various consumer electronic products such as mobile phones, televisions, personal digital assistants, digital cameras, notebook computers, desktop computers, etc., and become the mainstream in display devices.

Both the liquid crystal display and the organic light emitting diode display often use a photolithography process in the manufacturing process, the purpose of which is to sequentially pass the metal or non-metal film layer on the glass substrate through photoresist coating, mask exposure, development and After the etching process, it is not damaged at its corresponding position, thereby achieving the purpose of forming a pattern on the glass substrate. Photoresist coating is an important process in the lithography process. To ensure the fluidity and coating performance of the photoresist, about 80% of the photoresist is a volatile solvent, and solvent removal must be performed after coating. In the current step, the solvent removal is mainly carried out by a combination of first drying under reduced pressure and then heating and baking. Among them, the vacuum drying can remove the volatile solvent in the photoresist by pressure reduction, so that the fluidity of the photoresist is weakened and can be uniformly distributed on the substrate.

Referring to FIG. 1 and FIG. 2, in the process of drying under reduced pressure, in order to avoid the adsorption of impurities in the VCD chamber during pumping, and at the same time ensuring the pumping effect, the vacuum drying equipment is pumped. The gas vacuum hole 200 can neither be placed higher than the substrate 300 nor placed under the substrate 300, and can only be placed at a position slightly lower than the substrate 300 at the edge of the substrate 300. However, when the vacuum hole 200 is placed at the edge of the substrate 300 for pumping, the edge of the substrate 300 is close to the vacuum hole 200, the pumping speed is fast, the middle of the substrate 300 is away from the vacuum hole 200, the pumping speed is slow, and the edge of the substrate 300 is pumped. The inconsistency between the gas velocity and the pumping speed in the middle of the substrate 300 may cause the solvent content in the middle of the edge of the substrate 300 and the substrate 300 to be inconsistent. When the macroscopic inspection is performed, it is found that the color of the edge of the substrate 300 and the middle of the substrate 300 are different. When the subsequent development process is performed, since the solvent content in the middle of the edge of the substrate 300 and the substrate 300 is inconsistent, the edge line width (Critical Dimesion, CD) of the substrate 300 is small. The intermediate line width of the substrate 300 is large, and the line uniformity (CD Uniformity) is deteriorated.

Summary of the invention

It is an object of the present invention to provide a vacuum drying apparatus capable of improving the uniformity of evaporation of a photoresist solvent and ensuring uniformity of line width of a developing process.

Another object of the present invention is to provide a method for drying under reduced pressure, which can improve the uniformity of evaporation of the solvent of the photoresist and ensure the uniformity of the line width of the development process.

In order to achieve the above object, the present invention provides a vacuum drying apparatus comprising: a working chamber, a work table, a suction hole, an air inlet hole, and an air inlet valve;

The working table is disposed in the working chamber, and each of the four corners of the working table is provided with a suction hole, and each of the air suction holes is provided with at least one air inlet hole adjacent to the air suction hole, and each air inlet hole An air inlet valve is provided on the upper;

The worktable is configured to place a substrate to be dried, the plane of the air suction hole is higher than an upper surface of the worktable and lower than an upper surface of the substrate;

The air vent is used for pumping and depressurizing the working chamber, the air inlet hole is for introducing a shielding gas into the working chamber, and the air inlet valve is used for controlling the air intake of each air inlet hole. flow.

Corresponding to each of the air suction holes, at least two air inlet holes adjacent to the air suction holes are provided, and the distance between the at least two air inlet holes and the corresponding air suction holes is different.

For each of the intake ports adjacent to the same exhaust hole, the intake port valve controls an intake flow rate of the intake port that is closer to the suction hole than an intake air flow of the intake port that is farther from the extraction hole.

The intake port valve controls the intake air flow rate of the intake port to decrease as the length of the suction hole is increased.

The air inlet valve is an electromagnetic control valve.

The invention also provides a method for drying under reduced pressure, comprising the following steps:

Step S1, providing a vacuum drying device and a substrate to be dried, the vacuum drying device comprising: a working chamber, a working table, a suction hole, an air inlet hole, and an air inlet valve;

The substrate is placed on the workbench, the plane of the air venting hole is higher than the upper surface of the working table and lower than the upper surface of the substrate;

Step S2, the suction hole suction reduces the pressure in the working chamber to volatilize the photoresist solvent on the substrate, and draws the evaporated photoresist solvent away from the working cavity; While pumping, the air inlet hole passes the shielding gas into the working chamber according to a preset intake air flow rate under the control of the air inlet port valve, and reduces the pumping hole to be evaporated from the edge of the substrate. Rear The speed of the photoresist solvent.

In the step S1, each of the air suction holes is provided with at least two air inlet holes adjacent to the air suction holes, and the distance between the at least two air inlet holes and the corresponding air suction holes is different.

In the step S2, for each intake hole adjacent to the same exhaust hole, the intake port valve controls the intake flow rate of the intake hole near the suction hole to be larger than the intake hole far from the suction hole. Intake flow.

In the step S2, the intake port valve controls the intake air flow rate of the intake hole to decrease as the length of the suction hole is increased.

In the step S1, the air inlet valve is an electromagnetic control valve.

The invention also provides a vacuum drying device comprising: a working chamber, a working table, a suction hole, an air inlet hole, and an air inlet valve;

The air vent is used for pumping and depressurizing the working chamber, the air inlet hole is for introducing a shielding gas into the working chamber, and the air inlet valve is used for controlling the air intake of each air inlet hole. flow;

Wherein, each of the air venting holes is provided with at least two air inlet holes adjacent to the air venting holes, and the distance between the at least two air inlet holes and the corresponding air venting holes is different;

Wherein, for each intake hole adjacent to the same exhaust hole, the intake port valve controls an intake flow rate of the intake hole near the suction hole to be larger than an intake flow rate of the intake hole far from the extraction hole. ;

Wherein, the intake port valve controls the intake air flow rate of the air intake hole to decrease as the length of the air suction hole is increased;

Wherein, the air inlet valve is an electromagnetic control valve.

Advantageous Effects of Invention: The present invention provides a vacuum drying apparatus comprising: a working chamber, a work table, a suction hole, an air inlet hole, and an air inlet valve, the work table being disposed in the working chamber, Each of the four corners of the worktable is provided with an air venting hole, and each of the air venting holes is provided with at least one air inlet hole adjacent to the air venting hole, and each of the air inlet holes is provided with an air inlet valve, While the air vent is pumping, the shielding gas is introduced into the periphery of the air venting hole to reduce the speed of the venting hole from the edge of the substrate to evaporate the photoresist solvent, thereby improving the photoresist. The uniformity of solvent evaporation avoids the influence of the unevenness of the evaporation of the photoresist solvent on the line width of the developing process and ensures the uniformity of the line width of the developing process. The invention also provides a method for drying under reduced pressure, It can improve the uniformity of the evaporation of the photoresist solvent and ensure the uniformity of the line width of the development process.

DRAWINGS

The detailed description of the present invention and the accompanying drawings are to be understood,

In the drawings,

Figure 1 is a plan view of a conventional vacuum drying apparatus;

Figure 2 is a side view of a conventional vacuum drying apparatus;

Figure 3 is a plan view of the vacuum drying apparatus of the present invention;

Figure 4 is a side view of the vacuum drying apparatus of the present invention;

Figure 5 is a flow chart of the reduced pressure drying method of the present invention.

Detailed ways

In order to further clarify the technical means and effects of the present invention, the following detailed description will be made in conjunction with the preferred embodiments of the invention and the accompanying drawings.

Referring to FIG. 3 and FIG. 4, the present invention provides a vacuum drying apparatus comprising: a working chamber 10, a table 21, a suction hole 30, an air inlet 40, and an air inlet valve 50;

The working table 21 is disposed in the working chamber 10. The four corners of the working table 21 are respectively provided with an air venting hole 30, and each of the air venting holes 30 is provided with at least one air inlet hole adjacent to the air venting hole 30. 40, each of the air inlet holes 40 is provided with an air inlet valve 50.

Specifically, the working table 21 is used for placing the substrate 20 to be dried. In order to avoid the impurities adsorbed into the working cavity 10 during pumping, and at the same time ensuring the pumping effect, the plane in which the suction holes 30 are disposed is slightly lower than the above. The upper surface of the substrate 20, preferably, the plane in which the air vent 30 is located is higher than the upper surface of the table 21 and lower than the upper surface of the substrate 20. In detail, the plane ratio of the air vent 30 is The upper surface of the substrate 20 is 1 to 2 mm lower.

Specifically, the substrate 20 is coated with a photoresist, and the photoresist includes a photoresist solvent.

It should be noted that the air vent 30 is used for pumping the working chamber 10 to reduce the air pressure in the working chamber 10, so that the photoresist solvent on the substrate 20 is volatilized, and the evaporated light is evaporated. The working chamber 10 is extracted by a glue solvent.

It is important that the air inlet hole 40 is configured to pass a shielding gas into the working chamber 10 to reduce the velocity of the photoresist solvent after the evacuation hole 30 is evacuated from the edge of the substrate 20. In the case where the pumping flow rate of the air venting hole 30 is constant, the air inlet hole 40 is provided with a shielding gas around the air venting hole 30, and the shielding gas is again drawn by the air venting hole 30 after being opened. Guide The photoresist solvent contained in the gas extracted by the air vent 30 is reduced, that is, the air volume of the air vent 30 in the present invention includes the air in the working chamber, the evaporated photoresist solvent, and the protective gas that is introduced. In the three parts, the shielding gas is added compared with the prior art, and when the pumping flow rate is constant, the partially evaporated solvent solvent which should be extracted is replaced by the shielding gas, thereby reducing the air venting hole 30. The velocity of the photoresist solvent evaporated from the edge of the substrate 20 finally causes the edge of the substrate 20 to coincide with the velocity of the photoresist solvent in the center of the substrate 20, avoiding VCD The generation of mura ensures the uniformity of the line width of the subsequent development process.

Preferably, the shielding gas is nitrogen gas or an inert gas.

Further, the air inlet valve 50 is used to control the intake air flow rate of each air inlet hole 40, and the precise control of the intake air flow rate of the air inlet hole 40 prevents the excessive air intake from affecting the lithography after the evaporation. The peptizing agent is discharged while ensuring that the amount of intake air is sufficient to balance the difference in the extraction speed of the photoresist solvent at the center of the substrate 20 and the edge of the substrate 20. Preferably, the inlet port valve 50 is an electromagnetically controlled valve.

Further, the intake air flow rate of the air inlet hole 40 and the evaporation amount of the photoresist solvent are very small compared to the pumping flow rate of the air suction hole 30, and do not cause an influence on the air flow direction, and The air inlet hole 40 is disposed at a position adjacent to the air suction hole 30 to ensure that the air suction hole 30 can timely extract the shielding gas that is introduced into the air inlet hole 40 to replace a part of the photoresist solvent by the shielding gas. The extraction is performed to reduce the velocity at which the evacuation hole 30 is evacuated from the edge of the substrate 20 to the volatilized photoresist solvent.

Specifically, in a preferred embodiment of the present invention, each of the air venting holes 30 is provided with at least two air inlet holes 40 adjacent to the air venting holes 30, and the at least two air intake holes 40 correspond thereto. The distance between the suction holes 30 is different. At this time, for each of the intake holes 40 adjacent to the same exhaust hole 30, the intake port valve 50 controls the intake flow rate of the intake port 40 close to the exhaust hole 30 to be greater than the distance from the exhaust hole 30. The intake air flow rate of the intake port 40.

At the same time, the intake port valve 50 also controls the corresponding change in the intake air flow rate of the intake port 40 according to the difference in the length of time that the air suction hole 30 is exhausted. Specifically, the intake air flow rate of the air intake hole 40 follows The increase in the length of the suction of the suction port 30 is reduced, and preferably, the flow rate of the intake air of the intake port 40 is gradually decreased by a predetermined ratio.

Further, the air inlet valve 50 also controls the air intake hole 40 to stop the intake air when the intake air time reaches a preset total intake air time. In general, the pumping process of the air venting holes 30 is sequentially: a slow pumping phase, a pumping flow rate greater than a fast pumping phase of the slow pumping phase, an equilibrium phase in which the air pressure in the working chamber 10 is constant, and a pre-exhaustion air pumping phase. In the final pumping phase, in which the photoresist solvent volatilization amount is at a maximum stage in the slow pumping stage, generally the preset total air intake time is equal to the duration of the slow pumping phase.

Specifically, in order to ensure a better air intake effect, it is preferable that the plane of the air inlet hole 40 is slightly higher than the plane of the air suction hole 30, so that the shielding gas that the air inlet hole 40 is able to pass can be described. The suction holes 30 are evacuated in time.

Referring to FIG. 5, based on the above-mentioned vacuum drying apparatus, the present invention also provides a vacuum drying method, comprising the following steps:

Step S1, providing a vacuum drying apparatus and a substrate 20 to be dried, the vacuum drying apparatus comprising: a working chamber 10, a table 21, a suction hole 30, an air inlet 40, and an air inlet valve 50;

The working table 21 is disposed in the working chamber 10. The four corners of the working table 21 are respectively provided with an air venting hole 30, and each of the air venting holes 30 is provided with at least one air inlet hole adjacent to the air venting hole 30. 40, each of the air inlet holes 40 is provided with an air inlet valve 50;

The substrate 20 is placed on the table 21, and the plane of the air vent 30 is higher than the upper surface of the table 21 and lower than the upper surface of the substrate 20.

Step S2, the pumping holes 30 pump down to reduce the pressure in the working chamber 10, so that the photoresist solvent on the substrate 20 is volatilized, and the volatilized photoresist solvent is pumped away from the working chamber 10; While the air suction hole 30 is pumping, the air inlet hole 40 is introduced into the working chamber 10 according to a preset intake air flow rate under the control of the air inlet port valve 50, and the air suction hole 30 is reduced. The velocity of the volatilized photoresist solvent is extracted from the edge of the substrate 20.

It should be noted that, in the case where the pumping flow rate of the air venting hole 30 is constant, the air intake hole 40 is around the air venting hole 30 in a case where the pumping flow rate of the air venting hole 30 is constant. The shielding gas is introduced, and the shielding gas is again drawn by the air venting holes 30 after being introduced, thereby causing the photoresist solvent contained in the gas extracted by the air venting holes 30 to be reduced, that is, the venting holes 30 of the present invention. The pumping capacity includes three parts of the air in the working chamber, the evaporated photoresist solvent, and the protective gas that is introduced. Compared with the prior art, the shielding gas is added, and when the pumping flow rate is constant, the pumping gas should be taken out. The partially evaporated photoresist solvent is replaced by a shielding gas, thereby reducing the velocity of the extraction solvent 30 from the edge of the substrate 20 after evaporation of the photoresist solvent, ultimately resulting in the substrate 20 The edge is in the same speed as the photoresist solvent in the center of the substrate 20, avoiding the generation of VCD mura, and ensuring the uniformity of the line width of the subsequent development process.

Preferably, the shielding gas is nitrogen gas or an inert gas.

Further, in the step S2, the intake air flow rate of each air intake hole 40 is controlled by the air inlet valve 50, and the precise control of the intake air flow rate of the air inlet hole 40 prevents the excessive intake air from affecting the volatile state. The photoresist solvent is discharged while ensuring that the amount of intake air is sufficient to balance the difference in the extraction speed of the photoresist solvent at the center of the substrate 20 and the edge of the substrate 20. Preferably, the inlet valve 50 For electromagnetic control of the valve.

In summary, the present invention provides a vacuum drying apparatus including: a working chamber, a work table, a suction hole, an air inlet hole, and an air inlet valve, wherein the work table is disposed in the working cavity, Each of the four corners of the workbench is provided with an air venting hole, and each of the air venting holes is provided with at least one air inlet hole adjacent to the air venting hole, and each of the air inlet holes is provided with an air inlet valve, which is At the same time as the air venting, the shielding gas is introduced into the periphery of the air venting hole to reduce the speed of the venting hole from the edge of the substrate to evaporate the photoresist solvent, thereby improving the photoresist solvent. The uniformity of volatilization avoids the influence of the unevenness of the evaporation of the photoresist solvent on the line width of the developing process and the uniformity of the line width of the developing process. The invention also provides a vacuum drying method, which can improve the uniformity of the solvent evaporation of the photoresist and ensure the uniformity of the line width of the developing process.

In the above, various other changes and modifications can be made in accordance with the technical solutions and technical concept of the present invention, and all such changes and modifications are within the scope of the claims of the present invention. .

Claims

A vacuum drying device comprising: a working chamber, a working table, a suction hole, an air inlet hole, and an air inlet valve;

The working table is disposed in the working chamber, and each of the four corners of the working table is provided with a suction hole, and each of the air suction holes is provided with at least one air inlet hole adjacent to the air suction hole, and each air inlet hole An air inlet valve is provided on the upper;

The worktable is configured to place a substrate to be dried, the plane of the air suction hole is higher than an upper surface of the worktable and lower than an upper surface of the substrate;

The air vent is used for pumping and depressurizing the working chamber, the air inlet hole is for introducing a shielding gas into the working chamber, and the air inlet valve is used for controlling the air intake of each air inlet hole. flow.
The reduced-pressure drying apparatus according to claim 1, wherein each of the suction holes is provided with at least two intake holes adjacent to the suction holes, and the at least two intake holes and corresponding suction holes thereof The distance between them is different.
The reduced-pressure drying apparatus according to claim 2, wherein, for each of the intake holes adjacent to the same exhaust hole, the intake port valve controls the intake flow rate of the intake port closer to the suction hole to be greater than the distance The suction flow is far from the intake air flow of the intake hole.
The reduced-pressure drying apparatus according to claim 1, wherein the intake port valve controls the intake air flow rate of the intake port to decrease as the length of time in which the suction port is evacuated increases.
The reduced-pressure drying apparatus according to claim 1, wherein said intake port valve is an electromagnetically controlled valve.
A method of drying under reduced pressure, comprising the following steps:

Step S1, providing a vacuum drying device and a substrate to be dried, the vacuum drying device comprising: a working chamber, a working table, a suction hole, an air inlet hole, and an air inlet valve;

The working table is disposed in the working chamber, and each of the four corners of the working table is provided with a suction hole, and each of the air suction holes is provided with at least one air inlet hole adjacent to the air suction hole, and each air inlet hole An air inlet valve is provided on the upper;

The substrate is placed on the workbench, the plane of the air venting hole is higher than the upper surface of the working table and lower than the upper surface of the substrate;

Step S2, the suction hole suction reduces the pressure in the working chamber to volatilize the photoresist solvent on the substrate, and draws the evaporated photoresist solvent away from the working cavity; At the same time of pumping, the air inlet hole passes the shielding gas into the working chamber according to a preset intake air flow rate under the control of the air inlet port valve, and reduces the air venting hole to be evaporated from the edge of the substrate. Rear The speed of the photoresist solvent.
The vacuum drying method according to claim 6, wherein in the step S1, at least two air intake holes adjacent to the air suction holes are provided for each of the air suction holes, and the at least two air intake holes are provided. The distance between the corresponding suction holes is different.
The reduced-pressure drying method according to claim 7, wherein in the step S2, for each of the intake holes adjacent to the same exhaust hole, the intake port valve controls the intake of the intake hole close to the suction hole. The air flow rate is greater than the intake air flow rate of the air intake opening farther from the air venting hole.
The reduced-pressure drying method according to claim 6, wherein in the step S2, the intake port valve controls the intake air flow rate of the intake port to decrease as the length of time in which the suction port is evacuated increases.
The reduced-pressure drying method according to claim 6, wherein in the step S1, the intake port valve is an electromagnetic control valve.
A vacuum drying device comprising: a working chamber, a working table, a suction hole, an air inlet hole, and an air inlet valve;

The working table is disposed in the working chamber, and each of the four corners of the working table is provided with a suction hole, and each of the air suction holes is provided with at least one air inlet hole adjacent to the air suction hole, and each air inlet hole An air inlet valve is provided on the upper;

The worktable is configured to place a substrate to be dried, the plane of the air suction hole is higher than an upper surface of the worktable and lower than an upper surface of the substrate;

The air vent is used for pumping and depressurizing the working chamber, the air inlet hole is for introducing a shielding gas into the working chamber, and the air inlet valve is used for controlling the air intake of each air inlet hole. flow;

Wherein, each of the air venting holes is provided with at least two air inlet holes adjacent to the air venting holes, and the distance between the at least two air inlet holes and the corresponding air venting holes is different;

Wherein, for each intake hole adjacent to the same exhaust hole, the intake port valve controls an intake flow rate of the intake hole near the suction hole to be larger than an intake flow rate of the intake hole far from the extraction hole. ;

Wherein, the intake port valve controls the intake air flow rate of the air intake hole to decrease as the length of the air suction hole is increased;

Wherein, the air inlet valve is an electromagnetic control valve.