CN210573184U

CN210573184U - Photoresist drying device

Info

Publication number: CN210573184U
Application number: CN201921844380.1U
Authority: CN
Inventors: 袁元; 袁文旭; 程潇
Original assignee: Yangtze Memory Technologies Co Ltd
Current assignee: Yangtze Memory Technologies Co Ltd
Priority date: 2019-10-30
Filing date: 2019-10-30
Publication date: 2020-05-19
Anticipated expiration: 2029-10-30

Abstract

The utility model provides a photoresist drying device for the photoresist of stoving coating on the wafer, photoresist drying device includes: at least one upper drying plate, at least one lower drying plate and a control device; the upper drying plate and the lower drying plate are arranged at intervals, and the wafer is arranged between the upper drying plate and the lower drying plate; the control device is respectively connected with the upper drying plate and the lower drying plate and controls the upper drying plate and the lower drying plate to be heated so as to dry the photoresist. The utility model has the advantages that the stress release of the wafer is uniform, and the dried photoresist is prevented from warping and even cracking; the flow speed of the solvent volatilized from the photoresist is accelerated, and the relative uniformity of the key size of the wafer formed in the subsequent process is ensured; the heating time of a single wafer is greatly shortened, the production efficiency is improved, and the time cost is saved.

Description

Photoresist drying device

Technical Field

The utility model relates to a semiconductor manufacturing field especially relates to a photoresist drying device.

Background

In the 3D NAND process, in order to reduce the number of masks and save the photolithography time, a method of combining one photolithography process with multiple etchings is usually adopted. The photoresist is coated by a glue spreader and then needs to be baked to volatilize the solvent in the photoresist, so that the photoresist is ensured to have enough hardness to resist the impact of ion beams in the subsequent etching-removal (Etch-Trim) process, and the etched step layer lines are uniform and straight. With the development of 3D NAND, the number of steps is more and more, the requirement on the thickness of the photoresist is higher and higher, and then the requirement on drying after the photoresist is coated is higher and higher.

The current drying method can cause the photoresist at the center and the edge of the wafer and the photoresist on the upper surface and the upper surface of the wafer to be heated unevenly, so that the hardness degree of the dried photoresist is different, even the photoresist is likely to crack, the critical dimension of the wafer formed by the subsequent etching process is different, and the yield of the wafer is affected.

SUMMERY OF THE UTILITY MODEL

The utility model aims to solve the technical problem that a photoresist drying device is provided, it can make the photoresist on the wafer be heated evenly, avoids the hard degree of the photoresist after drying to have the difference, and can shorten the stoving time.

In order to solve the above problem, the utility model provides a photoresist drying device for the photoresist of stoving coating on the wafer, photoresist drying device includes: at least one upper drying plate, at least one lower drying plate and a control device; the upper drying plate and the lower drying plate are arranged at intervals, and the wafer is arranged between the upper drying plate and the lower drying plate; the control device is respectively connected with the upper drying plate and the lower drying plate and controls the upper drying plate and the lower drying plate to be heated so as to dry the photoresist.

Further, the upper bake plate is sized to: the orthographic projection of the upper drying plate is suitable for covering the orthographic projection of the wafer in the direction vertical to the wafer.

Further, the lower drying plate is sized to: the orthographic projection of the lower drying plate is suitable for covering the orthographic projection of the wafer in the direction vertical to the wafer.

Further, the cross sections of the upper drying plate and the lower drying plate are both circular.

Further, the photoresist drying device comprises a plurality of upper drying plates which are stacked, and the upper drying plates are positioned on the same side of the lower drying plate in the arrangement direction of the upper drying plates and the lower drying plates.

Further, the photoresist drying device comprises a plurality of lower drying plates which are stacked, and the lower drying plates are positioned on the same side of the upper drying plate in the arrangement direction of the upper drying plate and the lower drying plate.

Further, the upper drying plate is composed of a plurality of sub-blocks arranged in a matrix, the sub-blocks are mechanically connected, and the control device can respectively control the sub-blocks to heat up.

Further, the lower drying plate is composed of a plurality of sub-blocks arranged in a matrix, the sub-blocks are mechanically connected, and the control device can respectively control the sub-blocks to heat up.

Furthermore, the photoresist drying device also comprises at least one side drying plate, the side drying plate is arranged corresponding to the interval between the upper drying plate and the lower drying plate, and the control device is connected with the side drying plate and controls the temperature of the side drying plate to be raised so as to dry the photoresist.

Further, the side drying plate is composed of a plurality of sub-blocks arranged in a matrix, the sub-blocks are mechanically connected, and the control device can respectively control the sub-blocks to heat up.

The utility model has the advantages that the photoresist drying device heats the upper part and the lower part of the wafer simultaneously, firstly, the upper surface and the lower surface of the wafer are heated uniformly, and the stress release of the wafer caused by heating is uniform, thereby avoiding the dried photoresist from warping and even cracking; secondly, the flow speed of a solvent volatilized from the photoresist is accelerated, so that the photoresist in the central area of the wafer can be dried, the hardness degrees of the photoresist at the edge and the central area of the wafer are basically the same after drying, the critical dimension of the wafer formed in the subsequent process is ensured to be relatively uniform, and the yield and the performance of the wafer are improved; and thirdly, the heating time of a single wafer is greatly shortened, the production efficiency is improved, the time cost is saved, and the efficiency of producing the wafers on a large scale is greatly improved.

Drawings

FIG. 1 is a schematic structural diagram of a first embodiment of a photoresist drying apparatus according to the present invention;

FIG. 2 is a schematic structural diagram of a second embodiment of the photoresist drying apparatus of the present invention;

FIG. 3 is a schematic structural diagram of a third embodiment of the photoresist drying apparatus of the present invention;

FIG. 4 is a schematic structural diagram of a fourth embodiment of the photoresist drying apparatus of the present invention;

FIG. 5 is a schematic structural diagram of a fifth embodiment of the photoresist drying apparatus of the present invention.

Detailed Description

The following describes in detail the embodiments of the photoresist drying device provided by the present invention with reference to the accompanying drawings.

The utility model discloses photoresist drying device is used for the photoresist of stoving coating on the wafer. Wherein the photoresist is coated on at least the upper surface of the wafer. In the following embodiments, the photoresist is coated on the upper surface of the wafer as an example. It is understood that the position of the photoresist coating may be determined according to an actual process. For the sake of clarity, the structure of the photoresist drying apparatus of the present invention is illustrated in the drawings, wherein a wafer 20 is illustrated, and a photoresist 21 is coated on the upper surface of the wafer 20.

Fig. 1 is a schematic structural diagram of a first embodiment of the photoresist drying apparatus of the present invention, please refer to fig. 1, the photoresist drying apparatus of the present invention includes at least an upper drying plate 10, at least a lower drying plate 11 and a control device 12.

The control device 12 is connected to the upper drying plate 10 and the lower drying plate 11, respectively, and controls the upper drying plate 10 and the lower drying plate 11 to be heated.

For example, the method of controlling the temperature of the upper drying plate 10 and the lower drying plate 11 by the control device 12 is illustrated, when the temperature of the upper drying plate 10 and the lower drying plate 11 needs to be raised, the control device 12 powers on the upper drying plate 10 and the lower drying plate 11, and the temperature of the upper drying plate 10 and the lower drying plate 11 is raised; when the upper drying plate 10 and the lower drying plate 11 need to be kept at constant temperature for a certain time, the control device 12 supplies constant current to the upper drying plate 10 and the lower drying plate 11, and the upper drying plate 10 and the lower drying plate 11 are kept at constant temperature; when the upper drying plate 10 and the lower drying plate 11 need to be cooled, the control device 12 cuts off the conductive paths of the upper drying plate 10 and the lower drying plate 11, and the upper drying plate 10 and the lower drying plate 11 are naturally cooled.

The method for controlling the temperature of the upper drying plate 10 and the lower drying plate 11 by the control device 12 is not limited to the above method, and a person skilled in the art may use other methods to control the temperature of the upper drying plate 10 and the lower drying plate 11 by the control device 12.

The upper drying plate 10 and the lower drying plate 11 are arranged at intervals, and the wafer 20 is arranged between the upper drying plate 10 and the lower drying plate 11. The upper drying plate 10 corresponds to the upper surface of the wafer 20, and the lower drying plate 11 corresponds to the lower surface of the wafer 20, that is, the upper drying plate 10 is disposed above the wafer 20, and the lower drying plate 11 is disposed below the wafer 20. When the upper drying plate 10 and the lower drying plate 11 are heated, and the wafer is heated by the upper drying plate 10 and the lower drying plate 11, the photoresist 21 coated on the wafer 20 is heated until the photoresist 21 is dried.

The utility model discloses photoresist drying device heats wafer 20's top and below simultaneously, makes wafer 20's upper surface and lower surface are heated evenly, wafer 20 is even owing to be heated and the stress release who produces to avoid the 21 warpage of photoresist after drying, the fracture even.

In addition, if only one drying plate is used to dry the photoresist 21, the solvent in the photoresist 21 in the central region of the wafer 20 flows at a low speed due to the flow characteristic limitation of the solvent volatilized from the photoresist 21, and the photoresist 21 in the central region is difficult to dry. And the utility model discloses photoresist drying device is right the top and the below of wafer 20 heat simultaneously, have accelerated the flow velocity of the solvent that volatilizes from among the photoresist 21, make 20 central zone's photoresist 21 of wafer also can be dried, the back of drying the edge of wafer 20 and central zone's photoresist 21's hard degree is the same basically for the anti sculpture ability of photoresist 21 is strengthened, has guaranteed that the critical dimension of the wafer that forms is even relatively in the follow-up processing procedure, improves the yield and the performance of wafer.

Moreover, the photoresist drying device heats the upper part and the lower part of the wafer 20 simultaneously, so that the heating time of a single wafer is greatly shortened, the production efficiency is improved, the time cost is saved, and the efficiency of producing the wafer in a large scale is greatly improved.

Further, in order to ensure the uniformity of heating the wafer 20 by the photoresist drying apparatus, the size of the upper drying plate 10 is configured as follows: in a direction perpendicular to the wafer 20, an orthographic projection of the upper drying plate 10 is adapted to cover the orthographic projection of the wafer 20, and the lower drying plate 11 is sized to: in the direction perpendicular to the wafer 20, the orthographic projection of the lower drying plate 11 is adapted to cover the orthographic projection of the wafer 20.

Referring to fig. 1, in the first embodiment, in the Y direction, an orthogonal projection a of the upper drying plate 10 coincides with an orthogonal projection B of the wafer 20, and an orthogonal projection C of the lower drying plate 11 coincides with the orthogonal projection B of the wafer 20. Fig. 2 is a schematic structural diagram of a second embodiment of the photoresist drying apparatus of the present invention, please refer to fig. 2, in the second embodiment, an area of an orthogonal projection a of the upper drying plate 10 is larger than an area of an orthogonal projection B of the wafer 20, and the orthogonal projection B of the wafer 20 is located in an area of the orthogonal projection a of the upper drying plate 10; the area of the orthographic projection C of the lower drying plate 11 is also larger than that of the orthographic projection B of the wafer 20, and the orthographic projection B of the wafer 20 is located in the area of the orthographic projection C of the lower drying plate 11.

Further, in the first embodiment of the present invention, the shapes of the upper drying plate 10 and the lower drying plate 11 are the same as the shape of the wafer 20, so as to further ensure the uniformity of heating the wafer 20 by the photoresist drying apparatus. For example, if the wafer 20 is circular, the cross-sections of the upper drying plate 10 and the lower drying plate 11 are both circular.

FIG. 3 is a schematic structural diagram of a third embodiment of the photoresist drying apparatus of the present invention. Referring to fig. 3, the third embodiment is different from the first embodiment in that, in the third embodiment, the photoresist drying apparatus includes a plurality of upper drying plates 10 stacked in layers and a plurality of lower drying plates 11 stacked in layers. In the arrangement direction of the upper drying plate 10 and the lower drying plate 11, the upper drying plate 10 is located on the same side of the lower drying plate 11, the lower drying plate 11 is located on the same side of the upper drying plate 10, the upper drying plate 10 is sequentially arranged in the direction perpendicular to the wafer 20, and the lower drying plate 11 is sequentially arranged in the direction perpendicular to the wafer 20. The upper drying plates 10 and the lower drying plates 11 can further promote the flow of solvent molecules volatilized from the photoresist 21, so that the photoresist 21 on the edge and the central area of the wafer 20 has similar drying conditions, and the dried photoresist 21 has consistent hardness; meanwhile, the heating time of a single wafer can be further shortened, and the production efficiency is improved.

Further, in order to distinguish the heating in the different areas of wafer 20, the utility model discloses still provide photoresist drying device's fourth embodiment. FIG. 4 is a schematic structural diagram of a fourth embodiment of the photoresist drying apparatus of the present invention. Referring to fig. 4, the fourth embodiment is different from the first embodiment in that the upper drying plate 10 is composed of a plurality of sub-blocks 10A, the sub-blocks 10A are arranged in a matrix, the sub-blocks 10A are mechanically connected, and the control device 12 can control the sub-blocks 10A to heat up respectively to heat different regions of the wafer 20. The lower drying plate 11 is composed of a plurality of sub-blocks 11A, the sub-blocks 11A are arranged in a matrix, the sub-blocks 11A are mechanically connected, and the control device 12 can control the sub-blocks 11A to be heated up respectively so as to heat different regions of the wafer 20 respectively. When a certain area of the wafer 20 needs to be intensively heated, the opening number of the sub-blocks 10A of the upper drying plate 10 and the opening number of the sub-blocks 11A of the lower drying plate 11 corresponding to the certain area can be increased; when a certain region of the wafer 20 needs to be heated weakly, the number of the sub-blocks 10A of the upper drying plate 10 and the number of the sub-blocks 11A of the lower drying plate 11 corresponding to the region may be decreased.

In order to further guarantee the photoresist drying device is right the homogeneity of wafer 20 heating, the utility model discloses still provide photoresist drying device's fifth embodiment. FIG. 5 is a schematic structural diagram of a fifth embodiment of the photoresist drying apparatus of the present invention. Referring to fig. 5, the fifth embodiment is different from the first embodiment in that the photoresist drying apparatus further includes at least one side drying plate 13, and the side drying plate 13 is disposed corresponding to the interval between the upper drying plate 10 and the lower drying plate 11, that is, the side drying plate 13 is disposed around the side of the wafer 20. The control device 12 is connected to the side surface drying plate 13, and controls the side surface drying plate 13 to heat up to dry the photoresist 21. Further, in this embodiment, the side drying plate 13 is composed of a plurality of sub-blocks 13A, the sub-blocks 13A are arranged in a matrix, the sub-blocks 13A are mechanically connected to each other, and the control device 12 can control the sub-blocks 13A to heat up, so that the side drying plate 13 can heat different regions of the wafer 20. In another embodiment of the present invention, the side drying plate 13 is an integral ring structure, which surrounds the side of the wafer 20 for a circle, and thus heats the wafer 20.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The utility model provides a photoresist drying device for dry coating is at the photoresist on the wafer, its characterized in that, photoresist drying device includes:

at least one upper drying plate, at least one lower drying plate and a control device;

the upper drying plate and the lower drying plate are arranged at intervals, and the wafer is arranged between the upper drying plate and the lower drying plate;

the control device is respectively connected with the upper drying plate and the lower drying plate and controls the upper drying plate and the lower drying plate to be heated so as to dry the photoresist.

2. The photoresist drying apparatus of claim 1, wherein the upper plate is sized to: the orthographic projection of the upper drying plate is suitable for covering the orthographic projection of the wafer in the direction vertical to the wafer.

3. The photoresist drying apparatus of claim 1, wherein the lower drying plate is sized to: the orthographic projection of the lower drying plate is suitable for covering the orthographic projection of the wafer in the direction vertical to the wafer.

4. The photoresist drying apparatus of claim 1, wherein the upper and lower drying plates are circular in cross-section.

5. The photoresist drying apparatus according to claim 1, wherein the photoresist drying apparatus comprises a plurality of upper drying plates stacked on each other, and the upper drying plates are located on the same side of the lower drying plate in an arrangement direction of the upper drying plates and the lower drying plate.

6. The photoresist drying apparatus according to claim 1, wherein the photoresist drying apparatus comprises a plurality of lower drying plates stacked on each other, and the lower drying plates are located on the same side of the upper drying plates in an arrangement direction of the upper drying plates and the lower drying plates.

7. The photoresist drying apparatus according to claim 1, wherein the upper drying plate is composed of a plurality of sub-blocks arranged in a matrix, the sub-blocks are mechanically connected to each other, and the control device is capable of controlling the temperature of the sub-blocks to be raised, respectively.

8. The photoresist drying apparatus of claim 1, wherein the lower drying plate is composed of a plurality of sub-blocks arranged in a matrix, the sub-blocks are mechanically connected to each other, and the control device is capable of controlling the temperature of the sub-blocks to be raised respectively.

9. The photoresist drying device according to any one of claims 1 to 8, further comprising at least one side drying plate, wherein the side drying plate is disposed corresponding to an interval between the upper drying plate and the lower drying plate, and the control device is connected to the side drying plate and controls the side drying plate to increase in temperature to dry the photoresist.

10. The photoresist drying apparatus according to claim 9, wherein the side drying plate is composed of a plurality of sub-blocks arranged in a matrix, the sub-blocks are mechanically connected to each other, and the control device is capable of controlling the temperature of the sub-blocks to be raised individually.