CN117572732A - Leveling auxiliary device and leveling method - Google Patents

Abstract

The invention discloses a leveling auxiliary device, which includes: a mask plate adsorption platform for adsorbing a mask plate. A through hole is provided in the center of the mask plate adsorption platform and a plurality of slide grooves are arranged circumferentially along the through hole, wherein The silicon wafer can be lifted from below the mask adsorption table through the through hole, and the number of the plurality of chutes is greater than or equal to 3; and a plurality of leveling components, each leveling component is arranged in the plurality of chutes. In a chute, each leveling assembly includes a small ball and a control member, and the diameter of the small balls in each leveling assembly is the same, wherein the control member of each leveling assembly can control the corresponding small ball to slide to the mask plate with the silicon wafer. A method of passive leveling using a leveling assist device is also disclosed.

Description

Leveling auxiliary device and leveling method

Technical field

The invention relates to the field of semiconductor equipment, and in particular to a leveling auxiliary device and a passive leveling method.

Background technique

In the semiconductor field, processing of semiconductor devices often involves photolithography processes. In order to improve the exposure quality, the parallelism between the mask plate and the silicon wafer must be ensured, which requires the use of a leveling device.

Most traditional leveling devices use complex devices, such as sensors, motors, cameras, etc., with complex structures, high costs, and complicated leveling operations. The leveling device can also be leveled by directly contacting the mask and the silicon wafer for leveling, but often due to the photoresist on the upper surface of the silicon wafer, they stick together after contact and are difficult to separate.

In view of the above-mentioned shortcomings of the prior art, it is desired to provide an improved leveling auxiliary device and passive leveling method.

Contents of the invention

A brief overview of one or more aspects is given below to provide a basic understanding of these aspects. This summary is not an extensive overview of all contemplated aspects and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

The invention provides a leveling auxiliary device, which includes: a mask plate adsorption platform for adsorbing a mask plate. A through hole is provided in the center of the mask plate adsorption platform and a plurality of slide grooves are arranged circumferentially along the through hole, wherein The silicon wafer can be lifted from below the mask adsorption table through the through hole, and the number of the plurality of chutes is greater than or equal to 3; and a plurality of leveling components, each leveling component is arranged in the plurality of chutes. In a chute, each leveling assembly includes a small ball and a control member, and the diameter of the small balls in each leveling assembly is the same, wherein the control member of each leveling assembly can control the corresponding small ball to slide to the mask plate with the silicon wafer.

In some embodiments, the through hole is a circular through hole, and the diameter of the circular through hole is larger than the silicon wafer.

In some embodiments, the control member of each leveling assembly includes a spring, a stop member, and a cylinder.

In some embodiments, one end of the reed of each leveling assembly is provided with a fixing hole, the small ball is bonded in the fixing hole, the other end of the reed is provided with a connecting hole, and the reed is fixed to the reed through screws and the connecting hole. The limiter is provided with a cylinder fixing groove and a cylinder fixing hole. The connecting rod of the cylinder is fixed in the cylinder fixing groove and is locked by screws and cylinder fixing holes.

In some embodiments, the control member of each leveling assembly pushes the ball out of the fixing hole through the movement of the cylinder to slide between the mask plate and the silicon wafer.

In some embodiments, the thickness of the reed is between 0.09mm and 0.12mm.

In some embodiments, the material of the pellets includes ceramic or metal.

In some embodiments, the plurality of chute grooves are evenly distributed along the through hole.

In some embodiments, the mask plate adsorption platform absorbs the mask plate through adsorption grooves or adsorption holes.

The present invention also provides a method for passive leveling using the aforementioned leveling auxiliary device, which includes: adsorbing the mask plate on the mask plate adsorption platform; allowing the silicon wafer to pass through the through hole of the mask plate adsorption platform and move from the bottom of the mask plate adsorption platform. Rise; when the silicon wafer rises to a distance from the mask plate adsorption stage that meets the preset conditions, control the corresponding small ball to slide between the mask plate and the silicon wafer through the control part of each leveling component; and make the The silicon wafer continues to rise until the top of each ball contacts the mask and the bottom contacts the silicon wafer.

The technical solution of the present invention is to arrange at least three small balls with the same diameter between the silicon wafer and the mask plate. When the silicon wafer rises to a certain height, the top of the small ball contacts the mask plate and the bottom contacts the silicon wafer, thereby realizing the silicon wafer operation. Passive leveling with mask. The leveling auxiliary device of the present invention can quickly realize passive leveling between the silicon wafer and the mask plate, and has a simple structure and low cost.

Description of the drawings

The characteristics, nature and advantages of the present invention will become more apparent when the detailed description set forth below is understood in conjunction with the accompanying drawings. In the drawings, identical reference characters are identified accordingly throughout. It is to be noted that the figures described are schematic and non-limiting only. In the drawings, the dimensions of some components may be exaggerated and not drawn to scale for illustrative purposes.

Figure 1 shows a schematic diagram of the mask adsorption platform of the leveling auxiliary device of the present invention.

Figures 2 to 4 show schematic structural views of the leveling assembly of the leveling auxiliary device of the present invention.

Figure 5 shows an example method of passive leveling using the leveling aid of the present invention.

Figure 6 shows a schematic diagram of the ball sliding during passive leveling using the leveling auxiliary device of the present invention.

Fig. 7 shows a side view of the system during passive leveling using the leveling auxiliary device of the present invention.

Figure 8 shows a side view of the system after passive leveling using the leveling auxiliary device of the present invention.

Detailed ways

In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the described exemplary embodiments. However, it will be apparent to one skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other exemplary embodiments, well-known structures have not been described in detail to avoid unnecessarily obscuring the concepts of the present disclosure. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. At the same time, various aspects described in the embodiments can be combined arbitrarily without conflict.

As mentioned above, the leveling device in the prior art has a complex structure, high cost, and complicated leveling operations.

The present invention proposes a low-cost leveling auxiliary device that can quickly achieve leveling of silicon wafers and masks. In the present invention, at least three small balls are arranged between the silicon wafer and the mask plate. When the silicon wafer rises to a certain height, the tops of the small balls contact the mask plate, and the bottoms of the small balls contact the silicon wafer. At this time, the distance between the silicon wafer and the mask is equal to the diameter of the ball, thereby achieving passive leveling between the silicon wafer and the mask.

The leveling auxiliary device of the present invention includes two parts: a mask plate adsorption platform and a leveling assembly. Figure 1 shows a schematic diagram of the mask adsorption platform of the leveling auxiliary device of the present invention.

The mask plate adsorption stage is used to absorb the mask plate. Specifically, the mask plate adsorption stage can adsorb the mask plate through the adsorption groove. In other implementations, the mask plate adsorption stage can also absorb the mask plate through adsorption holes (not shown in Figure 1).

As shown in Figure 1, a circular through hole is provided in the center of the mask adsorption stage. The diameter of the circular through hole is larger than the diameter of the silicon wafer, so that the silicon wafer can rise from below the mask adsorption stage into the circular through hole. Or below.

It should be noted that although circular through holes are shown in FIG. 1 , this is only exemplary and not limiting. In specific implementations, other shapes of through holes (such as polygons, ellipses, irregular shapes, etc.) can also be used.

As further shown in Figure 1, three chute grooves are provided on the mask plate adsorption table, and the three chute grooves are evenly distributed along the circumferential direction of the circular through hole. In the present invention, a leveling assembly (not shown in Figure 1) may be provided in each chute. The leveling assembly will be described in further detail below in conjunction with Figures 2-4.

It should be noted that although three chutes evenly distributed along the through hole are shown in FIG. 1 , this is only exemplary. In specific implementation, those skilled in the art can implement the chute in different ways according to actual conditions. For example, more than three chutes (eg, four, five, etc.) may be used, the chutes may be distributed non-uniformly along the through hole, and so on.

During the process of the silicon wafer rising from below the mask plate adsorption stage, leveling between the silicon wafer and the mask plate can be achieved through a leveling component disposed in the chute of the mask plate adsorption stage. The specific structure of the leveling assembly will be explained below with reference to Figures 2-4.

Figure 2 shows a schematic diagram of the leveling assembly of the leveling assist device of the present invention.

Taking the three chutes in Figure 1 as an example, a corresponding leveling component can be provided in each of the three chutes, where each leveling component includes a small ball and an associated control piece.

For ease of explanation, a leveling assembly in a chute is shown in FIG. 2 . As shown in the figure, the leveling assembly includes a small ball and a control part. The control part is used to control the movement of the small ball and may include a spring, a limiter and a cylinder.

When there is no need to level the silicon wafer and the mask, the leveling component is inactive. At this time, the ball can be located in the chute and the cylinder is not activated. As shown in the figure, the ball is located on the reed in the chute rather than between the silicon wafer and the mask. The cylinder is in the retracted state without extending and drives the ball to slide away from the chute.

When the silicon wafer and mask need to be leveled, the leveling component is in working condition. At this point, the cylinder can be activated for movement. When the cylinder extends out and contacts the ball, it can push the ball out of the chute and slide between the silicon wafer and the mask plate, thereby achieving passive leveling between the silicon wafer and the mask plate.

It should be noted that although the present invention describes a specific structure of the control member including a reed, a limiting member and a cylinder, the present invention is not limited thereto. In actual implementation, those skilled in the art can also use other mechanical structures to implement the control component. For example, the control member may be a closed container containing pellets. When leveling of the wafer and mask is not required, the pellets can be placed in a closed container. When the wafer and mask need to be leveled, the ball can be released (e.g., popped, pushed out, etc.) to the outside of the closed container and slid between the wafer and mask.

Figure 3 shows a schematic diagram of the reed in the leveling assembly of the present invention.

In a preferred embodiment of the present invention, the thickness of the reed is 0.09mm to 0.12mm.

As shown in the figure, one end of the reed is provided with a fixing hole. When the leveling assembly is in an inoperative state, the small ball can be bonded in the fixing hole, so that the small ball will not slide away from the spring plate without external force. When the leveling assembly is in working condition, the ball can be driven (for example, by a cylinder) to leave the fixing hole and slide away from the spring to a position between the silicon wafer and the mask plate.

As further shown in Figure 3, the other end of the reed (the other end opposite to the end where the fixing hole is located) is provided with a connecting hole. As an example, three connection holes are shown in Figure 3 . The reed can be fixed to the stopper in the leveling assembly through screws and connecting holes.

Figure 4 shows a schematic diagram of the stopper in the leveling assembly of the present invention.

As shown in the figure, the limiting piece is a T-shaped piece.

The reed can be fixedly connected to the reed fixing hole on the top of the stopper. For example, the connecting holes on both sides of the reed can be aligned with the reed fixing holes on the top of the stopper, and the two can be tightly connected through screws.

In addition, the limiter is also provided with a cylinder fixing groove and a cylinder fixing hole. The connecting rod of the cylinder is fixed in the cylinder fixing groove, and the connecting rod of the cylinder is locked through the screw and the cylinder fixing hole.

It should be noted that the structures of the spring leaf and the limiting piece and the fastening manner of the two shown in Figures 3 and 4 are only exemplary and not restrictive. In specific implementations, the spring leaf and the limiting member can be fastened using different mechanical structures and different methods.

Figure 5 illustrates an example method 500 for passive leveling utilizing the leveling aid of the present invention.

As shown, method 500 begins at step 505. In step 505, the mask plate is adsorbed on the mask plate adsorption stage.

For example, adsorption parts (such as adsorption grooves or adsorption holes) may be provided on the mask plate adsorption stage, and the mask plate may be adsorbed through these adsorption parts.

Next, in step 510, the silicon wafer is raised from below the mask plate adsorption platform through the through hole of the mask plate adsorption platform.

For example, the silicon wafer can be placed on a platform that can move up and down, and the size of the platform is smaller than the through hole, so that the platform can move up and down within the through hole. After the silicon wafer is placed on the platform, when the driving platform is raised, the silicon wafer will rise with the platform.

There is a certain gap between the platform and the through hole, so that the platform can move up and down in the through hole. At the same time, the gap should be small enough (e.g., smaller than the diameter of the ball) so that the ball does not fall into the gap.

In step 515, when the distance between the silicon wafer and the mask plate adsorption stage meets the preset condition, the control member of each leveling component controls the corresponding small ball to slide between the mask plate and the silicon wafer.

In specific implementation, different preset conditions can be set according to the actual situation.

For example, in some examples, when the distance between the silicon wafer and the mask adsorption stage is equal to a preset value, the distance can be considered to meet the preset condition. The preset value can be a specific value larger than the diameter of the ball.

In other examples, when the distance between the silicon wafer and the mask adsorption stage is within a certain preset range, the distance can be considered to meet the preset conditions. The lower limit of the preset range can be a specific value greater than the diameter of the ball, and the upper limit of the preset range can be the lower limit plus a certain increment value.

In embodiments of the present disclosure, when the distance between the silicon wafer and the mask adsorption platform meets the preset condition, the upward movement of the platform can be suspended, and the cylinder in the control part can be activated to move, and the ball can be pushed away from the spring through the cylinder movement. fixing holes on the chip and slide between the mask and the silicon wafer. At this time, the bottom of the ball is in contact with the upper surface of the silicon wafer, while the top of the ball is not in contact with the mask.

In step 520, the silicon wafer continues to rise until the top of each ball contacts the mask and the bottom contacts the silicon wafer.

After the ball slides between the mask and the silicon wafer, the upward movement of the platform can be resumed, so that the silicon wafer continues to rise with the platform. When the silicon wafer rises until the tops of the three balls touch the mask and the bottoms touch the silicon wafer, the platform and the silicon wafer are stopped from continuing to rise.

At this time, since the diameter of the small balls is the same, the distance between the mask and the silicon wafer is equal to the diameter of the small balls. At the same time, since the three non-collinear points determine a plane, the silicon wafer and the mask can be made parallel to each other through the three non-collinear balls, thereby achieving passive leveling between the two.

In the specific implementation, due to factors such as the difference in cylinder driving force, the unlevelled state (non-parallel) between the mask plate and the silicon wafer, the initial position of the balls, the interaction of each ball during the sliding process (such as collision), etc. Influence, the possibility that the final positions of the three small balls will be collinear after sliding on the silicon wafer is extremely low. Therefore, when the requirements for leveling accuracy are not too high, it can always be considered that the final positions of the three balls are not collinear.

In other implementations, in order to improve the leveling accuracy, three small balls can be initially used for leveling. When the final positions of the three small balls are detected to be collinear, another additional small ball can be added and slid to Participate in leveling between the silicon wafer and the mask.

In some implementations, when it is detected that the final positions of the three balls are collinear, certain external mechanical disturbances (such as tilt, vibration, collision, etc.) can be added to destroy the collinear relationship between the ball positions, thereby Make sure that the final positions of the three balls are not collinear.

In order to better understand the present invention, an exemplary process of ball sliding during passive leveling using the leveling auxiliary device of the present invention is further explained below with reference to FIGS. 6-8 .

For the convenience of explanation, assume that three chutes and three small balls (denoted as small ball A, small ball B and small ball C respectively) evenly distributed along the circular through hole are used. The three small balls are not collinear, and The diameter of each ball is d.

In some implementations, the diameter d of the ball may be 2 mm.

In some implementations, the balls may be ceramic balls.

In some implementations, the balls may be metal balls.

Figure 6 shows a schematic diagram after the ball slides out of the chute and slides between the mask plate and the silicon wafer during the leveling process.

As shown in the figure, ball A, ball B and ball C are all located on the silicon wafer inside the circular through hole. At this time, the bottom of each small ball is in contact with the upper surface of the silicon wafer, while the top of each small ball is not in contact with the mask (not shown in Figure 6).

In various embodiments of the present invention, there are no strict requirements on the specific position of each small ball on the silicon wafer. That is, the ball does not need to be located at a specific location on the silicon wafer.

As shown in Figure 6, ball A, ball B and ball C are located at three different positions on the silicon wafer, and these three positions are not collinear. Since three non-collinear points determine a plane, the silicon wafer and mask can be made parallel to each other through three small balls, thereby achieving passive leveling between the two.

As an example, FIG. 7 shows a side view of the system after the ball slides between the mask and the silicon wafer during the leveling process.

Assume that at some point during the leveling process, the silicon wafer and mask have not yet been leveled. At this time, the gap between the silicon wafer and the mask plate is different at different positions. As shown in Figure 7, the maximum gap between the silicon wafer and the mask is H1 (shown on the left side of the figure), and the minimum gap between the silicon wafer and the mask is H2 (shown on the right side of the figure).

In the example of Figure 7, H1 is larger than H2, and H2 is larger than the diameter d of the ball. It can be seen that the silicon wafer and the mask are not parallel at this time. In Figure 7, the distance between each ball and the mask is different. Specifically, the distance between ball A and the mask plate is the largest, and the distance between ball C and the mask plate is the smallest.

Figure 8 shows a side view of the system after the leveling process.

When the silicon wafer continues to rise as shown in Figure 7, the bottom of the stage carrying the silicon wafer is a flexible mechanism with degrees of freedom in the Z direction and pitch. When the first small ball first contacts the mask and the silicon wafer and receives force Afterwards, the stage carrying the silicon wafer continues to rise. Since the first ball, the mask plate, and the stage are in contact, the stage will perform a pitching motion, and the distance between the remaining balls, the mask plate, and the silicon wafer will decrease. Eventually, the tops of all the balls will be in contact with the mask and the bottoms will be in contact with the silicon wafer, as shown in Figure 8. Specifically, the tops of small balls A, small balls B and small balls C all contact the lower surface of the mask, and the bottoms of small balls A, small balls B and small balls C all contact the upper surface of the silicon wafer.

At this time, since the diameters of small ball A, small ball B and small ball C are equal (all equal to d), when each small ball contacts the mask plate and the silicon wafer, the distance between the mask plate and the silicon wafer will are equal at all positions and equal to the diameter of the ball d.

As mentioned earlier, three non-collinear points define a plane. Therefore, when the non-collinear balls A, B and C are in contact between the mask plate and the silicon wafer, the silicon wafer and the mask plate can be made parallel to each other, thereby achieving passive leveling between them. .

It should be noted that although FIGS. 6-8 illustrate that the leveling assembly includes three small balls, the present invention is not limited thereto. In actual implementation, more than three small balls (such as four small balls, five small balls, etc.) can be used, thereby increasing the possibility that the positions of the small balls are not collinear. In addition, in order to improve the reliability of leveling, the diameter of the balls can be checked regularly to ensure that the diameter of each ball remains the same. If it is found that the diameter of the ball has decreased (for example, due to wear), the ball can be replaced in time.

The leveling auxiliary device of the present invention arranges at least three small balls with the same diameter between the silicon wafer and the mask plate. When the silicon wafer rises to a certain height, the tops of the small balls contact the mask plate and the bottoms contact the silicon wafer, thereby achieving Passive leveling between wafer and mask. The technical solution of the present invention can quickly realize passive leveling between the silicon wafer and the mask plate, and has a simple structure and low cost.

The detailed description set forth above in connection with the appended drawings describes examples and does not represent all examples that may be implemented or that fall within the scope of the claims. The terms "example" and "exemplary" when used in this specification mean "serving as an example, instance, or illustration" and do not mean "better or superior to other examples."

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. Therefore, use of these phrases may refer to more than one embodiment. Furthermore, the described features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Accordingly, the claims are not intended to be limited to the aspects shown herein, but are to be accorded the full scope consistent with the language of the claims, wherein reference to the singular form of an element is not intended to be limited unless expressly stated otherwise. It means "there is and only one", but "one or more". Unless specifically stated otherwise, the term "some" refers to one or more. All structural and functional equivalents to the elements of the various aspects described throughout this invention that are now or hereafter known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be covered by the claims.

It should also be noted that these embodiments may be described as processes depicted as flowcharts, flowcharts, structural diagrams, or block diagrams. Although a flowchart may describe operations as a sequential process, many of these operations can be performed in parallel or concurrently. Additionally, the order of these operations can be rearranged.

While various embodiments have been illustrated and described, it is to be understood that the embodiments are not limited to the precise configurations and components described above. Various modifications, substitutions and improvements apparent to those skilled in the art may be made in the arrangement, operation and details of the apparatus disclosed herein without departing from the scope of the claims.

Claims (10)

1. A leveling assistance device comprising:

a mask plate adsorption table for adsorbing a mask plate, the center of the mask plate adsorption table being provided with a through hole and a plurality of sliding grooves being arranged along the circumference of the through hole, wherein a silicon wafer can rise from below the mask plate adsorption table through the through hole, and the number of the plurality of sliding grooves is 3 or more; and

a plurality of leveling assemblies, each leveling assembly disposed in one of the plurality of runners, wherein each leveling assembly includes a ball and a control member, and the diameters of the balls in each leveling assembly are the same,

the control piece of each leveling assembly can control the corresponding small ball to slide between the mask plate and the silicon wafer.

2. The leveling assistance apparatus of claim 1, wherein the through hole is a circular through hole, and a diameter of the circular through hole is larger than the silicon wafer.

3. The leveling aid of claim 1, wherein the control member of each leveling assembly comprises a reed, a stop, and a cylinder.

4. A leveling aid as claimed in claim 3, wherein one end of the reed of each leveling assembly is provided with a fixing hole, a ball is adhered in the fixing hole, the other end of the reed is provided with a connecting hole, and the reed is fixed to a stopper by a screw and the connecting hole, the stopper is provided with a cylinder fixing groove and a cylinder fixing hole, and a connecting rod of a cylinder is fixed in the cylinder fixing groove and locked by the screw and the cylinder fixing hole.

5. The leveling aid as recited in claim 4 wherein the control member of each leveling assembly pushes the ball out of the fixed aperture to slide between the mask plate and the silicon wafer by movement of the air cylinder.

6. A levelling assistance device according to claim 3 wherein the reed has a thickness of between 0.09mm and 0.12mm.

7. The leveling aid of claim 1, wherein the material of the ball comprises ceramic or metal.

8. The leveling assistance apparatus of claim 1, wherein the plurality of runners are evenly distributed along the through hole.

9. The leveling assistance apparatus as set forth in claim 1, wherein the mask plate suction table sucks the mask plate through a suction groove or suction hole.

10. A method of passive levelling using a levelling assistance device as claimed in any one of claims 1 to 9, comprising:

adsorbing the mask plate on a mask plate adsorption table;

enabling the silicon wafer to rise from the lower part of the mask plate adsorption table through the through hole of the mask plate adsorption table;

when the distance between the silicon wafer and the mask plate adsorption table reaches a preset condition, controlling the corresponding pellets to slide between the mask plate and the silicon wafer through the control piece of each leveling assembly; and

the silicon wafer is continuously lifted until the top of each small ball is abutted against the mask plate and the bottom is abutted against the silicon wafer.