WO2023216463A1

WO2023216463A1 - Silicon wafer bearing device in photoetching device

Info

Publication number: WO2023216463A1
Application number: PCT/CN2022/114996
Authority: WO
Inventors: 王军; 张利; 朱啸爽
Original assignee: 北京华卓精科科技股份有限公司; 北京优微精密测控技术研究有限公司
Priority date: 2022-05-11
Filing date: 2022-08-26
Publication date: 2023-11-16
Also published as: CN115096031A; CN115096031B

Abstract

A silicon wafer bearing device in a photoetching device. The silicon wafer bearing device comprising a bearing body (100), a water channel being formed in the bearing body (100), wherein the water channel is provided with a front-end water channel section (110), a middle water channel section and a rear-end water channel section (130) which are in communication in sequence; the front-end water channel section (110) extends to the middle of the bearing body (100) from an edge part close to the bearing body (100); the end of the front-end water channel section (110) that is close to the edge of the bearing body (100) is a cooling liquid inlet (111), and the other end of the front-end water channel section (110) is in communication with one end of the middle water channel section; the other end of the middle water channel section is in communication with one end of the rear-end water channel section (130), and the other end of the rear-end water channel section (130) is a cooling liquid outlet (131); the rear-end water channel section (130) surrounds the periphery of the middle water channel section; and the front-end water channel section (110) is internally provided with a first barrier strip (112), which is arranged in an extending direction of the front-end water channel section (110) and divides the front-end water channel section (110) into at least two first shunt channels (113).

Description

Silicon wafer carrying device in photolithography equipment

Cross-references to related applications

This application claims priority to the Chinese patent application with application number 2022105084629 and titled "A silicon wafer carrying device in lithography equipment" submitted to the China Patent Office on May 11, 2022, the entire content of which is incorporated by reference. in this application.

Technical field

The present application relates to the technical field of silicon wafer cooling, and specifically to a silicon wafer carrying device in a photolithography equipment.

Background technique

The silicon wafer carrying device in the lithography equipment is an important component in the ultra-precision lithography equipment and is a key factor that directly affects the success of the silicon wafer exposure, which is the molding object of the lithography machine.

Currently, there are two types of load-bearing devices for cooling silicon wafers: external cooling systems and built-in cooling systems. For the application of photolithography equipment, space and precision requirements are involved. At present, more built-in cooling water channels are used, and the built-in cooling water channels are used. The cooling liquid is passed through to achieve the effect of cooling the silicon wafer placed on the silicon wafer carrying device in the photolithography equipment. However, the temperature of the cooling water path in the silicon wafer carrying device in existing photolithography equipment is uneven, which can easily lead to exposure quality defects or the risk of scrapping the silicon wafer.

To sum up, how to overcome the above-mentioned defects of the silicon wafer carrying device in the existing photolithography equipment is an urgent technical problem to be solved by those skilled in the art.

Contents of the invention

The purpose of this application is to provide a silicon wafer carrying device in a photolithography equipment to alleviate the technical problem of temperature imbalance existing in the silicon wafer carrying device in the photolithography equipment in the prior art.

The silicon wafer carrying device in the photolithography equipment provided by this application includes a carrying body, and a water channel is provided inside the carrying body. The water channel has a front-end water channel section, a middle water channel section, and a back-end water channel section that are connected in sequence.

The front water channel section extends from a position close to the edge of the carrier body to the middle of the carrier body. One end of the front water channel section close to the edge of the carrier body is a cooling liquid inlet. The other end is connected to one end of the middle water channel section, the other end of the middle water channel section is connected to one end of the rear end water channel section, the other end of the rear end water channel section is a coolant outlet, and the rear end water channel Segments surround the periphery of the central waterway segment.

A first baffle bar is provided in the front-end water channel section, the first baffle bar is arranged along the extension direction of the front-end water channel section, and the first baffle bar is configured to separate the front-end water channel section into at least Two first diversion channels.

Preferably, as an implementation manner, the first baffle bar is configured to separate the front-end water channel section into two first diversion channels with equal cross-sectional areas;

And/or, the ratio of the sum of the cross-sectional areas of each first branch channel to the cross-sectional area of the middle water channel section ranges from 0.8 to 1.

Preferably, as an implementation manner, the carrier body is an integrally formed structure, and/or the carrier body is made of silicon carbide, aluminum oxide, or silicon nitride, and/or the coolant outlet is close to The cooling liquid inlet is provided, and/or the ratio of the volume of the water channel to the volume of the carrier ranges from 3% to 10%.

Preferably, as an implementation method, the middle water channel section includes several rings of annular water channel sections, and the corresponding rings of the annular water channel sections have openings to form two ends; the innermost ring of the annular water channel section and The front water channel sections are connected, the annular water channel sections of each circle are connected in sequence from the inside to the outside through the two open ends, and the annular water channel section of the outermost circle is connected with the rear end water channel section.

Preferably, as an implementation method, the parts near both ends of the front-end water channel section are arc-shaped water channels, and the middle part is a straight water channel, and the arc-shaped water channel and the linear water channel make a smooth transition;

And/or, the liquid inlet end of the innermost annular water channel section is tangent to the liquid outlet end of the front end water channel section;

Preferably, as an implementation manner, the open ends of two adjacent rings of the annular water channel sections are connected through a first arc-shaped transition section;

And/or, the outermost annular water channel section and the rear end water channel section are connected through a second arc-shaped transition section;

And/or, the trajectory of the rear end water channel section is circular.

Preferably, as an implementation manner, the difference between the cross-sectional area of the first arc-shaped transition section and the cross-sectional area of the annular water channel section is greater than zero, and the cross-sectional area of the second arc-shaped transition section is The difference from the cross-sectional area of the annular water channel section is greater than zero.

Preferably, as an implementation manner, the cross-sectional areas for fluid to pass through the front-end water channel section, the annular water channel section and the rear-end water channel section are all equal.

Preferably, as an implementation manner, a second baffle bar is provided in the outermost ring of the annular water channel section, and the second baffle bar is provided along the extension direction of the annular water channel section. The baffles are configured to divide the outermost annular water channel section into at least two second diverting channels.

Preferably, as an implementation manner, the spacing between two adjacent rings of the annular water channel segments is a first spacing, and the spacing between the outermost ring of the annular water channel segments and the rear end water channel segment is a second spacing, any The absolute value of the difference between the two first spacings is greater than zero, and the absolute value of the difference between any one of the first spacings and the second spacing is greater than zero.

Compared with the existing technology, the beneficial effects of this application are:

The silicon wafer carrier device in the lithography equipment provided by this application has a water channel inside the carrier body, which is more in line with the space and precision requirements in the application of lithography equipment.

It should be noted that when the external coolant first enters the front-end water channel section from the coolant inlet of the water channel, the flow rate is relatively fast. The setting of the first baffle bar blocks the incoming coolant and at the same time strengthens the front-end water channel of the carrier body. The stiffness of the segment can further alleviate the problem of structural deformation caused by water flow impact, thereby reducing the local surface shape change of the silicon wafer and improving the exposure quality of the silicon wafer. In addition, the water flow at the inlet of the coolant is relatively fast. If it is placed close to the edge of the carrier, it will not easily cause the carrier to deform. Indirectly, it will also alleviate the problem of local surface shape changes of the silicon wafer and facilitate the improvement of the surface area of the silicon wafer. Type accuracy, thereby improving the exposure quality of silicon wafers.

In particular, locating the coolant inlet close to the edge of the carrier body has less impact on the temperature field than locating it in the middle. Correspondingly, the end coolant outlet of the rear end water channel section at the periphery , of course, will also be close to the edge of the carrier, and will have less impact on the temperature field. Therefore, the temperature of each part of the carrier will be more balanced, which can ensure a balanced temperature on the lower surface of the silicon wafer. In turn, the silicon wafer placed on the carrier will be It is not easy to cause local facial changes.

In addition, the front-end water channel section is used to direct the coolant flowing in from the coolant inlet at the edge to the middle of the carrier, and then flows along the middle water channel section to the peripheral rear-end water channel section. In this way, the silicon wafer can be cooled better The effect is to improve the exposure quality of silicon wafers.

Description of the drawings

In order to explain the embodiments of the present application or the technical solutions in the prior art more clearly, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are only This is an embodiment of the present application. For those of ordinary skill in the art, other drawings can be obtained based on the provided drawings without exerting creative efforts.

Figure 1 is a water channel layout diagram of a carrier provided by an embodiment of the present application;

FIG. 2 is a cross-sectional view of a carrier carrying silicon wafers provided by an embodiment of the present application.

Explanation of reference symbols:

100-carrying body; 110-front water channel section; 111-coolant inlet; 112-first baffle bar; 113-first diversion channel; 120-annular water channel section; 121-second baffle bar; 122-second Split channel; 130-rear end water channel section; 131-coolant outlet; 140-first arc-shaped transition section; 150-second arc-shaped transition section; 200-silicon wafer.

Detailed ways

The technical solution of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of protection of this application.

In the description of this application, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "front", "back", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the purpose of To facilitate the description of the present application and to simplify the description, it is not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present application.

The present application will be described in further detail below through specific implementation examples and in conjunction with the accompanying drawings.

Referring to Figures 1 and 2, this embodiment provides a silicon wafer carrying device in a photolithography equipment, which includes a carrying body 100. A water channel is provided inside the carrying body 100, and the water channel has a front-end water channel section 110, a middle section, and a front-end water channel section 110 that are connected in sequence. Channel section and rear channel section 130. The front water channel section 110 extends from a position close to the edge of the carrier 100 to the middle of the carrier 100 . One end of the front water channel section 110 close to the edge of the carrier 100 is the coolant inlet 111 , and the other end of the front water channel section 110 is connected to the middle water channel. One end of the middle water channel section is connected to one end of the rear end water channel section 130 , the other end of the rear end water channel section 130 is the coolant outlet 131 , and the rear end water channel section 130 surrounds the periphery of the middle water channel section. A first baffle bar 112 is disposed in the front-end water channel section 110 . The first baffle bar 112 is disposed along the extension direction of the front-end water channel section 110 . The first baffle bar 112 is configured to separate the front-end water channel section 110 into at least two first baffle bars 112 . Diversion channel 113.

The silicon wafer carrying device in the lithography equipment provided by this embodiment has a water channel inside the carrying body 100, which is more in line with the space and precision requirements in the application of lithography equipment.

It should be noted that when the external coolant first enters the front-end water channel section 110 from the coolant inlet 111 of the water channel, the flow rate is relatively fast. The arrangement of the first baffle 112 blocks the incoming coolant and at the same time strengthens the carrier body. The stiffness of the front-end water channel section 110 of the silicon wafer 100 further alleviates the problem of structural deformation caused by water flow impact, thereby reducing the local surface shape change of the silicon wafer 200 and improving the exposure quality of the silicon wafer 200 . In addition, the water flow at the coolant inlet 111 is relatively fast, and it is arranged close to the edge of the carrier 100, which will not easily cause the carrier 100 to deform. Indirectly, it will also alleviate the problem of local surface changes of the silicon wafer 200 and facilitate improvement. The surface shape accuracy of the silicon wafer 200 is improved, thereby improving the exposure quality of the silicon wafer 200 .

In particular, arranging the coolant inlet 111 close to the edge of the carrier 100 has less impact on the temperature field than arranging it in the middle; accordingly, the end of the rear end water channel section 130 at the periphery Of course, the coolant outlet will be close to the edge of the carrier 100 and will have less influence on the temperature field. Therefore, the temperature of each part of the carrier 100 is relatively balanced, which can ensure a balanced temperature on the lower surface of the silicon wafer. Furthermore, when placed on the carrier The silicon wafer 200 on the silicon wafer 100 is less likely to cause local surface shape changes.

In addition, the front water channel section 110 is used to guide the cooling liquid flowing in from the cooling liquid inlet 111 at the edge to the middle of the carrier 100, and then flows along the middle water channel section to the peripheral rear end water channel section 130. In this way, the silicon wafer 200 can A better cooling effect is obtained, which facilitates improving the exposure quality of the silicon wafer 200 .

Specifically, the first baffles 112 can be used to divide the front water channel section 110 into two first branch channels 113 with equal cross-sectional areas to further optimize the buffering effect.

Optionally, the ratio range of the sum of the cross-sectional areas of each first branch channel 113 and the cross-sectional area of the middle water channel section can be set to 0.8-1, which can not only achieve a better buffering effect, but also ensure Coolant flow rate to ensure proper cooling effect.

In particular, the carrier 100 can be configured as a one-piece structure. On the one hand, the single material of the carrier 100 can be ensured, and the expansion coefficients and thermal conductivities of various parts of the carrier 100 will not be different due to different materials. , the carrier 100 itself is not easy to deform; on the other hand, the carrier 100 is not spliced, and the carrier 100 will not be deformed due to the splicing process. Therefore, the silicon wafer 200 placed on the carrier 100 is not easy to change in surface shape. .

The carrier 100 provided in this embodiment can be made of a material close to the physical properties of the silicon wafer 200. In this way, it can adapt to the material requirements of thermal conductivity and expansion coefficient performance required by the exposure environment of the silicon wafer 200, and reduce the physical properties of the material itself. The deformation effect on the silicon wafer 200 caused by different characteristics. In addition, because the selected material has similar physical properties to the silicon wafer 200, it will not bring ion contamination to the silicon wafer 200.

Specifically, silicon carbide, aluminum oxide or silicon nitride can be used as the material of the carrier 100. Of course, other materials with similar physical properties to the silicon wafer 200 can also be selected to manufacture the carrier 100.

Preferably, the cooling liquid outlet 131 can be disposed close to the cooling liquid inlet 111 so that the temperature of various parts of the carrier 100 is more balanced, which can further alleviate the problem of local surface shape changes of the silicon wafer 200 .

Specifically, the ratio range of the volume of the water channel to the volume of the carrier 100 can be set to 3%-10% to ensure better silicon wafer exposure quality.

In addition, the trajectory of the water channel can be set as a smooth curve to reduce the impact of the coolant on the side wall of the water channel, and alleviate the problem of the deformation of the carrier 100 caused by the impact of the water flow on the side wall of the water channel. Therefore, the silicon wafer 200 is less likely to be deformed. The problem of local facial shape changes.

In the specific structure of the above-mentioned middle water channel section, several rings of annular water channel sections 120 can be provided. The corresponding rings of these annular water channel sections 120 all have openings, that is, the annular water channel section 120 is a non-closed loop structure with two ends; The annular water channel sections 120 of the circle are connected with the front water channel section 110. The annular water channel sections 120 of each circle are connected in sequence from the inside to the outside through the two open ends, and the outermost ring annular water channel section 120 is connected with the rear water channel section 130.

It should be noted that the trajectory of the central water channel section is set as a number of sequentially connected annular water channel sections 120. On the one hand, the cooling liquid arriving at the central water channel section rotates and flows back and forth from the inside to the outside, cooling the silicon wafer 200. The effect is better; on the other hand, the annular design reduces the impact force of the coolant carried by the side wall of the water channel as much as possible, thus further improving the exposure quality of the silicon wafer 200 .

Specifically, the liquid inlet end of the innermost annular water channel section 120 and the liquid outlet end of the front end water channel section 110 can be set to be tangential, so as to reduce the turning angle at the transition and reduce steering as much as possible, thereby reducing The impact of water flow alleviates the deformation problem caused by impact.

Correspondingly, the open ends of two adjacent rings of annular water channel sections 120 can be connected through the first arc-shaped transition section 140; in addition, the outermost ring of annular water channel sections 140 and the rear end water channel section 130 can be connected through the second arc-shaped transition section 140. The transition section 150 is connected, and the trajectory of the rear end water channel section 130 can also be set to be circular. The above setting can not only reduce the turning angle at the transition, but also reduce the steering to the greatest extent and reduce the impact force of the water flow as much as possible. At the same time, Makes the coolant flow smoother.

Optionally, the cross-sectional area of the first arc-shaped transition section 140 can be set to be larger than the cross-sectional area of the annular water channel section 120. Correspondingly, the cross-sectional area of the second arc-shaped transition section 150 can be set to be larger than the annular water channel section. 120 cross-sectional area.

It should be noted that when the water flow flows through the first arc-shaped transition section 140 and the second arc-shaped transition section 150, there is a turn, and the flow resistance is large, which increases the first arc-shaped transition section 140 and the second arc-shaped transition section. The cross-sectional area of 150 can reduce the flow resistance, make the coolant flow more stable, and ensure the temperature uniformity to a certain extent, thereby ensuring the surface accuracy of the entire silicon wafer 200.

Optionally, the cross-sectional areas for fluid passage of the front-end water channel section 110, the annular water channel section 120, and the rear-end water channel section 130 are all set to be equal, so as to reduce the impact of water flow on the side walls of the water channel, thereby reducing the load-bearing capacity. The degree of deformation of the body 100 makes it difficult for the silicon wafer 200 to cause local surface shape changes.

Optionally, the parts near both ends of the front water channel section 110 can be set as an arc water channel, and the middle part of the front end water channel section 110 can be set as a straight water channel, so as to smoothly transition the arc water channel and the straight water channel, with less steering, and at the same time, make The flow of coolant is also smoother.

Preferably, a second baffle bar 121 can be disposed in the outermost annular water channel section 120, and the second baffle bar 121 is disposed along the extension direction of the annular water channel section 120, and the second baffle bar 121 is used to The outermost annular water channel section 120 is divided into at least two second branch channels 122 .

It should be noted that the arrangement of the second spacer bars 121 can reduce the temperature gradient of the carrier 100 and improve the exposure quality of the silicon wafer 200 .

The distance between two adjacent rings of annular water channel segments 120 is defined as the first spacing, and the spacing between the outermost ring of annular water channel segments 120 and the rear end water channel segment 130 is defined as the second spacing. The difference between any two first spacings is The absolute value of is set to be greater than zero, that is, the size of any first spacing is different; at the same time, the absolute value of the difference between any first spacing and the second spacing is set to be greater than zero, that is, the size of any first spacing is The sizes are different from the second spacing. In this way, the silicon wafer 200 placed on the carrier 100 can obtain a better exposure effect.

A control board with a temperature sensor, heating wire, etc. is installed under the carrier, which can control the silicon wafer exposure environment at 22℃±0.1℃, with temperature stability ≤35mK/25s, and surface deformation of the silicon wafer less than 7.2nm. , in order to achieve the optimal configuration that is beneficial to the silicon wafer exposure work.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The technical solutions described in the foregoing embodiments can still be modified, or some or all of the technical features can be equivalently replaced; and these modifications or substitutions do not deviate from the essence of the corresponding technical solutions from the technical solutions of the embodiments of the present application. scope.

Industrial applicability

The silicon wafer carrying device in the photolithography equipment provided in this embodiment is not easily deformed and has a balanced temperature, which can improve the surface accuracy of the silicon wafer, thereby improving the exposure quality of the silicon wafer.

Claims

A silicon wafer carrying device in photolithography equipment, characterized by comprising a carrying body (100), a water channel is provided inside the carrying body (100), and the water channel has front-end water channel sections (110) that are connected in sequence, The middle channel section and the rear channel section (130);

The front water channel section (110) extends from a position close to the edge of the carrier body (100) to the middle of the carrier body (100). One end of the edge is the coolant inlet (111), the other end of the front end water channel section (110) is connected with one end of the middle water channel section, and the other end of the middle water channel section is connected with the rear end water channel section (130 ) is connected to one end of the rear end water channel section (130), and the other end of the rear end water channel section (130) is the coolant outlet (131), and the rear end water channel section (130) surrounds the periphery of the middle water channel section;

A first barrier bar (112) is provided in the front-end water channel section (110), and the first barrier bar (112) is provided along the extension direction of the front-end water channel section (110). The first barrier bar (112) The strip (112) is configured to divide the front water channel section (110) into at least two first diversion channels (113).
The silicon wafer carrying device in the lithography equipment according to claim 1, wherein the first baffle bar (112) is configured to separate the front-end water channel section (110) into two sections with equal cross-sectional areas. said first shunt channel (113).
The silicon wafer carrying device in the photolithography equipment according to claim 1 or 2, characterized in that the sum of the cross-sectional areas of each of the first branch channels (113) is equal to the cross-sectional area of the middle water channel section. The ratio range is 0.8-1.
The silicon wafer carrying device in the photolithography equipment according to any one of claims 1 to 3, characterized in that the carrying body (100) is an integrally formed structure.
The silicon wafer carrying device in the photolithography equipment according to any one of claims 1 to 4, characterized in that the material of the carrying body (100) is silicon carbide, aluminum oxide or silicon nitride.
The silicon wafer carrying device in the lithography equipment according to any one of claims 1 to 5, characterized in that the cooling liquid outlet (131) is located close to the cooling liquid inlet (111);
The silicon wafer carrying device in the photolithography equipment according to any one of claims 1 to 6, characterized in that the ratio of the volume of the water channel to the volume of the carrying body (100) ranges from 3% to 10%. .
The silicon wafer carrying device in the photolithography equipment according to any one of claims 1 to 7, characterized in that the middle water channel section includes a plurality of annular water channel sections (120), and the annular water channel section (120) corresponds to The annular shapes have openings, forming two ends; the annular water channel section (120) of the innermost ring is connected with the front water channel section (110), and the annular water channel section (120) of each ring passes through the two open ends. They are connected in sequence from the inside out, and the outermost annular water channel section (120) is connected with the rear end water channel section (130).
The silicon wafer carrying device in the photolithography equipment according to claim 8, characterized in that the parts near both ends of the front-end water channel section (110) are arc-shaped water channels, and the middle part is a straight water channel, and the arc-shaped water channel Smooth transition with the straight water channel.
The silicon wafer carrying device in the photolithography equipment according to claim 8 or 9, characterized in that the liquid inlet end of the innermost annular water channel section (120) and the outlet of the front end water channel section (110) Liquid ends are tangent.
The silicon wafer carrying device in the lithography equipment according to any one of claims 8 to 10, characterized in that the open ends of two adjacent rings of the annular water channel sections (120) pass through the first arc-shaped transition section (140) ) connected.
The silicon wafer carrying device in the photolithography equipment according to any one of claims 8 to 11, characterized in that the outermost annular water channel section (120) and the rear end water channel section (130) pass through the third The two arc-shaped transition sections (150) are connected.
The silicon wafer carrying device in the lithography equipment according to any one of claims 8 to 12, characterized in that the trajectory of the rear end water channel section (130) is annular.
The silicon wafer carrying device in the lithography equipment according to claim 11, characterized in that the cross-sectional area of the first arc-shaped transition section (140) is larger than the cross-sectional area of the annular water channel section (120).
The silicon wafer carrying device in the lithography equipment according to claim 12, characterized in that the cross-sectional area of the second arc-shaped transition section (150) is larger than the cross-sectional area of the annular water channel section (120).
The silicon wafer carrying device in the lithography equipment according to any one of claims 8-15, characterized in that the front-end water channel section (110), the annular water channel section (120) and the rear-end water channel section The cross-sectional areas of (130) for fluid to pass through are all equal.
The silicon wafer carrying device in the lithography equipment according to any one of claims 8 to 16, characterized in that a second barrier bar (121) is provided in the outermost annular water channel section (120), The second baffle bar (121) is arranged along the extension direction of the annular water channel section (120), and the second baffle bar (121) is configured to separate the outermost ring of the annular water channel section (120). It is at least two second branch channels (122).
The silicon wafer carrying device in the photolithography equipment according to any one of claims 8 to 17, characterized in that the spacing between two adjacent rings of the annular water channel sections (120) is a first spacing, and all the distances in the outermost ring are The distance between the annular water channel section (120) and the rear end water channel section (130) is a second distance. The absolute value of the difference between any two first distances is greater than zero. The difference between any one of the first distances and The absolute values of the differences between the second intervals are all greater than zero.