CN211350608U - Auxiliary device for reducing wafer adsorption warping degree and projection photoetching machine - Google Patents

Abstract

The utility model provides a can reduce auxiliary device and projection lithography machine that wafer adsorbs angularity, the utility model discloses an auxiliary device is including compressing tightly base member and elevating system, it passes through the coupling portion and links to each other with elevating system to compress tightly the base member, it can follow vertical direction up-and-down motion to compress tightly the base member under elevating system's control. The utility model discloses a can reduce auxiliary device and projection lithography machine that wafer adsorbs angularity can press the warpage piece at the slide holder bench through the clamping ring, can make and form airtight chamber between wafer and the slide holder bench, accomplishes vacuum adsorption, can guarantee simultaneously that its flatness after adsorbing reaches the level of normal wafer.

Description

Auxiliary device for reducing wafer adsorption warping degree and projection photoetching machine

Technical Field

The utility model relates to a semiconductor manufacturing field, in particular to reduce device and projection lithography machine that photoetching substrate adsorbs angularity.

Background

In semiconductor manufacturing, a wafer is largely warped due to some processes which are relatively easy to generate stress, such as ion implantation, film deposition, pattern definition, high temperature, and the like. The projection photoetching machine can not normally absorb vacuum, and normal production is influenced.

In order to solve the problem of wafer warpage, the traditional methods mainly have two types, namely, the process flow is improved; and secondly, the adsorption capacity of the photoetching machine is improved. Because of the particularities of some processes, particularly in the field of compound semiconductors, wafer warpage is difficult to solve by process flow improvement, we tend to increase the vacuum adsorption capacity of the lithography machine.

In the prior art, a tray is added, and a slide holder adsorbs the tray, so that the photoetching machine cannot trigger vacuum alarm. However, this approach is less practical because, after increasing the thickness of the tray, the upper surface of the wafer can be out of focus in the lithography machine, resulting in pattern distortion. Moreover, the wafer has poor flatness due to warpage, which affects the line width uniformity of the lithographic pattern.

There is also a technique of exposing by transferring a normal sheet onto a stage and then replacing a warped sheet onto the stage, but in this manner, the wafer is exposed also in a warped state, and the uniformity of the line width of the lithographic pattern is particularly poor.

SUMMERY OF THE UTILITY MODEL

The adsorption effect to warping piece among the prior art is unsatisfactory to and warping piece vacuum adsorption rear surface defects such as unevenness, the utility model provides a can reduce the wafer and adsorb auxiliary device of warping degree and be provided with auxiliary device's projection lithography machine.

The utility model discloses the first aspect provides a can reduce auxiliary device that wafer adsorbs angularity, including compressing tightly base member and elevating system, it links to each other with elevating system through the coupling to compress tightly the base member, it can follow vertical direction up-and-down motion under elevating system's control to compress tightly the base member.

In one embodiment, the lifting mechanism is a cylinder capable of moving up and down, and the pressing base is connected with a piston of the cylinder through the connecting part.

In one embodiment, the shape of the compression matrix is the same as the shape of the wafer on the stage.

In one embodiment, the compression matrix is a compression ring.

In one embodiment, the outer diameter of the pressure ring is larger than the outer diameter of the wafer and the inner diameter of the pressure ring is smaller than the outer diameter of the wafer.

In one embodiment, the material of the compact base is a rigid material that does not generate particles when pressing the wafer, and is preferably ceramic, silicon carbide, or metal.

In one embodiment, the coupling is removably connected to the cylinder piston.

The second aspect of the present invention provides a projection lithography machine, including the first aspect of the present invention any one of the devices for reducing the absorption warpage of the wafer.

In one embodiment, the raising and lowering of the raising and lowering mechanism is controlled by a solenoid valve.

In one embodiment, the lifting of the lifting structure is controlled by lifting a thimble of the projection lithography machine or a vacuum value of the projection lithography machine.

In one embodiment, the pressing substrate of the auxiliary device is higher than the projection lithography machine stage at the high position of the lifting mechanism, and the pressing substrate can enable the pressing substrate to press the wafer at the low position of the lifting mechanism.

In one embodiment, the pressing base body of the auxiliary device is 1-3 cm higher than the slide holder at the high position of the lifting mechanism.

Compared with the prior art, the utility model discloses a can reduce auxiliary device and projection lithography machine that the wafer adsorbs the angularity can press the warpage piece at the slide holder bench through the clamping ring, can make and form airtight chamber between wafer and the slide holder, accomplishes vacuum adsorption, can guarantee simultaneously that its flatness after adsorbing reaches the level of normal wafer.

The technical features mentioned above can be combined in various technically feasible ways to produce new embodiments, as long as the objects of the invention are achieved.

Drawings

The invention will be described in more detail hereinafter on the basis of non-limiting examples only and with reference to the accompanying drawings. Wherein:

FIG. 1 shows a schematic diagram of a prior art projection lithography machine;

fig. 2 is a schematic structural diagram of an auxiliary device capable of reducing the warpage of wafer adsorption according to the present invention;

FIG. 3 is a schematic view of a projection lithography machine according to the present invention;

fig. 4-6 show different working states of the projection lithography machine according to the present invention.

In the drawings, like components are denoted by like reference numerals. The figures are not drawn to scale.

Wherein the reference numerals are:

10. an auxiliary device for reducing the warping degree of the wafer adsorption; 1. compressing the substrate; 2; a lifting mechanism; 3. a connecting part; 4. a slide stage; 5. a wafer; 6. a thimble; 7. a vacuum machine 8 and a positioning bolt; 9. a vacuum gauge; 10. a lifting solenoid valve; 11. pressing a ring; 12. a thimble electromagnetic valve; 21. a cylinder; 22. a cylinder piston; 20. a projection lithography machine.

Detailed Description

The invention will be described in further detail with reference to the drawings and specific examples. It should be noted that, as long as no conflict is formed, the embodiments and the features in the embodiments of the present invention may be combined with each other, and the technical solutions formed are all within the scope of the present invention.

Unless defined otherwise, technical or scientific terms used herein shall have the ordinary meaning as understood by those of ordinary skill in the art to which the invention belongs. The use of the terms "comprising" or "including" and similar terms in the present application is intended to mean that the elements or items listed before or after the term include the elements or items listed after the term and their equivalents, without excluding other elements or items. In the description of the present invention, the terms "upper", "lower", "vertical", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, only for convenience of description and simplification of description, and do not indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and when the absolute position of the object to be described is changed, the relative positional relationship may also be changed accordingly, and thus, should not be construed as limiting the present invention.

The parts not mentioned in the utility model can be realized by adopting or using the prior art for reference.

The structure of the conventional projection lithography machine is shown in fig. 1, the stage of the projection lithography machine is a very flat structure, generally the height difference of the whole stage is within 1.5um, and the focusing range of the projection lithography machine is generally about 500 um.

Therefore, the utility model provides an auxiliary device 10 that can reduce the wafer and adsorb the angularity. As shown in fig. 2, the utility model discloses an auxiliary device 10 that can reduce wafer absorption warpage, including compressing tightly base member 1 and elevating system 2, compress tightly base member 1 and link to each other with elevating system 2 through junction 3, compress tightly base member 1 and can follow vertical direction up-and-down motion under elevating system 2's control.

When the warped wafer is placed on the wafer carrier, the gap between the wafer and the wafer carrier is too large, so that the contact area is small, vacuum leakage is caused, and the wafer cannot be normally adsorbed. Use at this moment through the utility model discloses a compressing tightly among the auxiliary device base member presses the warpage piece at the slide holder bench, can make and form airtight chamber between wafer and the slide holder bench, accomplishes vacuum adsorption.

In a more preferred embodiment, the lifting mechanism 2 is a movable cylinder 21 capable of moving up and down, and the pressing base 1 is connected with a piston 22 of the cylinder 21 through a connecting part 3.

In a preferred embodiment, the compression matrix 1 is a compression ring 11.

Preferably, the shape of the pressing ring 11 is the same as that of the wafer on the stage 4. More preferably, the outer diameter of the pressing ring 11 is larger than the outer diameter of the wafer, and the inner diameter of the pressing ring 11 is smaller than the outer diameter of the wafer. For example, the outer diameter of the pressure ring 11 is 1.5 to 2.5mm (preferably 2mm) larger than the outer diameter of the wafer, and the inner diameter of the pressure ring 11 is 1.5 to 2mm (preferably 1.5mm) smaller than the outer diameter of the wafer.

In a preferred embodiment, the material of the pressing ring 11 is a rigid material that does not generate particles when pressing the wafer, and may be, but is not limited to, ceramic, silicon carbide, or metal.

In a preferred embodiment, the coupling 3 is removably connected to the cylinder piston 22 to facilitate periodic cleaning or replacement.

In an alternative embodiment, the pressure ring 11 can be replaced or formed by a plurality of mechanically controlled snap-in connections forming the pressure matrix 1, for example in the shape of a wafer.

In an alternative embodiment, the cylinder 21 that moves up and down may also be a motor, a guide rail, or an electromagnet that can move up and down, as long as the pressing base 1 can be driven to move up and down.

The second aspect of the present invention provides a projection lithography machine 20, including any of the first aspect of the present invention the auxiliary device 10 for reducing the wafer adsorption warpage.

As shown in FIG. 3, the projection lithography machine 20 of the present invention includes a lithography machine stage 4, and an auxiliary device 10 is disposed above the stage 4. Wherein the press ring 11 of the auxiliary device 10 is higher than the slide holder 4 at the high position of the cylinder piston 22, and the press ring 11 can enable the press ring 11 to press the wafer 5 at the low position of the cylinder piston 22. That is, when the air cylinder 21 is contracted, it is ensured that the pressing ring 11 presses the wafer 5, and when the air cylinder 21 is moved reversely, a certain distance is maintained between the pressing ring 11 and the wafer 5.

Preferably, the movement of the cylinder 21 is controlled by an elevation control solenoid valve 10, and the elevation control solenoid valve 10 is connected to a pin control solenoid valve 12 controlling the pin 6 such that the pressing ring 11 is elevated as the pin 6 is elevated.

More preferably, as shown in fig. 4, the projection lithography machine 20 further comprises a PLC control circuit, an input end of the PLC control circuit is connected to the vacuum gauge 9 of the stage 4, an output end of the PLC control circuit is connected to the lift control solenoid valve 10, and when the vacuum value of the stage 4 is higher than a set value, the lift control solenoid valve 10 starts to operate to control the pressing ring 11 to descend.

Preferably, the press ring 11 is 1-3 cm higher than the slide holder at the high position of the cylinder piston 22. More preferably 2 cm. The distance can be adjusted slightly according to different photoetching machines, and the wafer transmission and the internal optical path of the equipment are not influenced.

Fig. 4 to 6 are schematic diagrams of the projection lithography machine according to the present invention at different stages. Utilize the utility model discloses a projection lithography machine 20 working procedure as follows:

the wafer 5 is transferred onto the wafer stage 4 by the robot arm, at this time, the thimble 6 supports the wafer 5, and the pressing ring 11 is located at the highest position, that is, the pressing ring 11 is at a certain distance from the wafer 5, as shown in fig. 4;

the thimble 6 descends, the wafer 5 contacts the slide holder 4, the compression ring 11 compresses the edge of the wafer 5, and simultaneously the slide holder 4 is opened in vacuum, as shown in fig. 5;

the wafer 5 is attached to the stage 4 as shown in fig. 6.

The utility model discloses a projection lithography machine has added supplementary vacuum adsorption structure in the slide holder of traditional projection lithography machine, compares traditional vacuum adsorption's slide holder only, can flare up the level of normal wafer with the flatness of piece of warping, has guaranteed the resolution and the accuracy of photoetching figure.

Thus far, it should be recognized by those skilled in the art that while the present invention has been described with reference to preferred embodiments, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the present invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. The present invention is not limited to the particular embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims (10)

1. The utility model provides a reduce auxiliary device of wafer absorption warpage, its characterized in that, is including compressing tightly base member and elevating system, compress tightly the base member and link to each other with elevating system through the junction, compress tightly the base member and can follow vertical direction up-and-down motion under elevating system's control.

2. The auxiliary device for reducing the suction warpage of a wafer as claimed in claim 1, wherein the pressing base has the same shape as the wafer.

3. The auxiliary device for reducing the warpage of wafer adsorption of claim 2, wherein the lifting mechanism is a cylinder capable of moving up and down, and the pressing substrate is connected to a piston of the cylinder through the connection portion.

4. The auxiliary device for reducing the wafer adsorption warpage according to claim 2 or 3, wherein the pressing base is a pressing ring.

5. The auxiliary device for reducing the wafer adsorption warpage according to claim 4, wherein the outer diameter of the pressure ring is larger than the outer diameter of the wafer, and the inner diameter of the pressure ring is smaller than the outer diameter of the wafer.

6. The auxiliary device for reducing the warpage of wafer adsorption of claim 3, wherein the coupling portion is detachably connected to the cylinder piston.

7. A projection lithography machine comprising the auxiliary device for reducing the warpage of wafer adsorption according to any one of claims 1 to 6.

8. The projection lithography machine according to claim 7, wherein the elevation of the elevation mechanism is controlled by a solenoid valve.

9. The projection lithography machine according to claim 7 or 8, wherein the lifting of the lifting structure is controlled by lifting of a thimble of the projection lithography machine or a vacuum level of the projection lithography machine.

10. The projection lithography machine of claim 9, wherein the pressing substrate of the auxiliary device is higher than a stage of the projection lithography machine at a high position of the lifting mechanism, and the pressing substrate is enabled to press the wafer at a low position of the lifting mechanism.

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