CN217902248U - Edge finding device for flat edge of wafer and photoetching system - Google Patents

Abstract

The utility model discloses a limit device and photoetching system are sought to wafer plain edge. The edge searching device comprises a carrying platform for carrying the wafer; the optical fiber sensor comprises a first optical fiber sensor, a second optical fiber sensor and a third optical fiber sensor, wherein the first optical fiber sensor comprises a first optical fiber bundle port, and the second optical fiber sensor comprises a second optical fiber bundle port; a connecting line of vertical projections of the first optical fiber bundle port and the second optical fiber bundle port on a plane where the wafer is located forms a first connecting line, and a perpendicular line of the first connecting line passes through the center of the wafer; the distance between the first connecting line and the circle center is greater than or equal to the first distance and smaller than the radius of the wafer; the third optical fiber sensor comprises a third optical fiber bundle port, and a connecting line of the vertical projection of the third optical fiber bundle port on the plane where the wafer is located and the circle center forms a preset included angle with a perpendicular line of the first connecting line passing through the circle center. By the scheme, the flat edges of the wafers of different types can be accurately positioned, so that the photoetching system meets the positioning requirements of the wafers of different types.

Description

Edge finding device for flat edge of wafer and photoetching system

Technical Field

The embodiment of the utility model provides a relate to the lithography technology field, especially relate to a limit device and photoetching system are sought to wafer plain edge.

Background

With the rapid development of the third-generation semiconductor industry, the types of wafers are more and more, the requirements on testing are higher and higher, and the requirements on the positioning accuracy of the wafers are higher and higher.

The conventional chip is opaque and round, and a pattern needs to be cut on the chip to confirm the coordinate system of the chip, which can be divided into Flat edge (Flat) and Notch (Notch) according to the shape of the pattern. The current positioning of the wafer coordinate is mainly based on the sensing of the light signal by the correlation sensor. The correlation sensor is suitable for edge searching of a wafer with good shading performance, but a typical representative of a third-generation semiconductor is a silicon carbide wafer which is a semitransparent or pure transparent wafer, the light transmittance of the semitransparent or pure transparent wafer is high, light cannot be effectively shielded, optical signal detection failure can be caused, and therefore edge searching of the transparent wafer cannot be achieved.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides an edge device and lithography system are sought to wafer plain noodles to the position of accurate positioning wafer plain noodles makes edge device and lithography system are sought to wafer plain noodles satisfy the location demand of different grade type wafer.

In a first aspect, an embodiment of the present invention provides an edge finding device for a flat edge of a wafer, for finding the edge of the wafer with the flat edge, the flat edge of the wafer with a first distance is provided between the circle centers of the wafer, the edge finding device includes:

the carrying platform is used for carrying the wafer;

the optical fiber sensors are arranged on one side, close to the carrying platform, of the wafer; the optical fiber sensor comprises an optical fiber bundle port, and the vertical projection of the optical fiber bundle port on the plane of the wafer is positioned in the edge area of the wafer;

wherein the plurality of fiber optic sensors includes a first fiber optic sensor including a first fiber optic bundle port, a second fiber optic sensor including a second fiber optic bundle port, and a third fiber optic sensor; a connecting line of vertical projections of the first optical fiber bundle port and the second optical fiber bundle port on a plane where the wafer is located forms a first connecting line, and a perpendicular line of the first connecting line passes through the center of the wafer;

the distance between the first connecting line and the circle center is greater than or equal to the first distance and smaller than the radius of the wafer; the length of the first connecting line is less than or equal to that of the flat edge;

the third optical fiber sensor comprises a third optical fiber bundle port, and the distance between the vertical projection of the third optical fiber bundle port on the plane where the wafer is located and the circle center is greater than or equal to the first distance; and is less than or equal to the radius of the wafer;

and a connecting line of the vertical projection of the third optical fiber bundle port on the plane where the wafer is located and the circle center forms a preset included angle with a perpendicular line of the first connecting line passing through the circle center.

In a second aspect, an embodiment of the present invention further provides a lithography system, including the first aspect of the present invention, a wafer flat edge finding device.

The wafer flat edge searching device provided by the embodiment of the utility model comprises a carrying platform used for bearing a wafer; the optical fiber sensors are arranged on one side of the wafer close to the carrying platform; the optical fiber sensor comprises an optical fiber bundle port, and the vertical projection of the optical fiber bundle port on the plane of the wafer is positioned in the edge area of the wafer; the optical fiber sensors comprise a first optical fiber sensor, a second optical fiber sensor and a third optical fiber sensor, wherein the first optical fiber sensor comprises a first optical fiber bundle port, and the second optical fiber sensor comprises a second optical fiber bundle port; a connecting line of vertical projections of the first optical fiber bundle port and the second optical fiber bundle port on a plane where the wafer is located forms a first connecting line, and a perpendicular line of the first connecting line passes through the center of the wafer; the distance between the first connecting line and the circle center is greater than or equal to the first distance and smaller than the radius of the wafer; the length of the first connecting line is less than or equal to that of the flat edge; the third optical fiber sensor comprises a third optical fiber bundle port, and the distance between the vertical projection of the third optical fiber bundle port on the plane where the wafer is located and the circle center is greater than or equal to the first distance; and is less than or equal to the radius of the wafer; and a connecting line of the vertical projection of the third optical fiber bundle port on the plane where the wafer is located and the circle center forms a preset included angle with a perpendicular line of the first connecting line passing through the circle center. In the embodiment of the utility model, the edge of the wafer is detected by using a plurality of optical fiber sensors, so that the accuracy of positioning the flat edge of the wafer is improved; and the edge-finding device for the flat edge of the chip can be used for carrying out edge-finding positioning on various types of wafers, so that the photoetching system can meet the positioning requirements of different types of wafers.

Drawings

Fig. 1 is a schematic structural diagram of a wafer flat edge finding device according to an embodiment of the present invention;

FIG. 2 is a top view of the edge finder for wafer edge trimming shown in FIG. 1;

fig. 3 is a top view of another wafer flat edge finder according to an embodiment of the present invention;

fig. 4 is a schematic circuit diagram of a wafer edge-finding device according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the invention and are not limiting of the invention. It should be further noted that, for the convenience of description, only some of the structures related to the present invention are shown in the drawings, not all of the structures.

The embodiment of the utility model provides a limit device is sought to wafer flush edge for seek the limit to the wafer that has the flush edge, have first distance between the centre of a circle of the flush edge of wafer and wafer. Fig. 1 is a schematic structural diagram of an edge finding device for a wafer flat edge according to an embodiment of the present invention, fig. 2 is a top view of the edge finding device for the wafer flat edge shown in fig. 1, refer to fig. 1 and fig. 2, an embodiment of the present invention provides an edge finding device for a wafer flat edge, including: a carrier 1 for carrying a wafer 2; the optical fiber sensors 3 are arranged on one side, close to the carrier platform 1, of the wafer 2; the optical fiber sensor 3 comprises an optical fiber bundle port 4, and the vertical projection of the optical fiber bundle port 4 on the plane of the wafer 2 is positioned in the edge area of the wafer 2;

wherein the plurality of fiber sensors 3 includes a first fiber sensor 31, a second fiber sensor 32 and a third fiber sensor 33, the first fiber sensor 31 includes a first fiber bundle port 41, and the second fiber sensor 32 includes a second fiber bundle port 42; a connecting line of vertical projections of the first optical fiber bundle port 41 and the second optical fiber bundle port 42 on the plane of the wafer 2 forms a first connecting line 5, and a perpendicular line b of the first connecting line 5 passes through a circle center O of the wafer 2;

the distance d1 between the first connecting line 5 and the circle center O is greater than or equal to the first distance d and smaller than the radius r of the wafer 2; the length h1 of the first connecting line 5 is less than or equal to the length h of the flat edge 21;

the third optical fiber sensor 33 comprises a third optical fiber bundle port 43, and a distance d2 between a vertical projection of the third optical fiber bundle port 43 on the plane where the wafer 2 is located and the circle center O is greater than or equal to the first distance d; and is less than or equal to the radius r of the wafer 2;

a connecting line a between a vertical projection of the third fiber bundle port 43 on the plane of the wafer 2 and the center O forms a predetermined included angle θ with a perpendicular line b of the first connecting line 5 passing through the center O.

Specifically, as shown in fig. 1 and fig. 2, the edge finder includes a stage 1 for bearing a wafer 2, and a shape of a bearing surface of the stage 1 may be any shape, which is not limited in the embodiments of the present invention.

Wherein optionally, wafer 2 can be the different chips of transparence such as sapphire piece, silicon chip or carborundum piece, the embodiment of the utility model provides a this unreinforced and do not also not restrict. The shape of the wafer 2 is as shown in fig. 2, the edge of the wafer 2 being composed of a flat edge 21 and a round edge. The embodiment of the utility model provides an edge finding device, the position of the plain edge 21 of mainly used definite wafer 2. For clarity of explaining the arrangement position of the optical fiber sensor 3, only a part of the structure of the wafer flat edge finding device is shown in fig. 2, and the whole structure is not shown; fig. 2 illustrates an example of the structure of the edge finding device when the wafer 2 is not placed, and the wafer 2 is indicated by a dashed circle.

The edge searching device further comprises a plurality of optical fiber sensors 3, the optical fiber sensors 3 are arranged on one side of the wafer 2 close to the carrying platform 1, namely, the optical fiber sensors and the carrying platform 1 are arranged on the same side relative to the wafer 2. Each optical fiber sensor 3 comprises an optical fiber bundle port 4, the vertical projection of the optical fiber bundle port 4 on the plane of the wafer 2 is located in the edge area of the wafer 2, and then the edge of the wafer 2 is detected by using the detection optical signal sent by the optical fiber sensor 3. It should be noted that fig. 1 and 2 only show a partial structure of the optical fiber sensor 3, and do not show the entire structure of the optical fiber sensor 3.

Optionally, the edge finder may further include a rotating shaft 6 and an OF workbench 7, the rotating shaft 6 is connected to the carrier 1, the rotating shaft 6 rotates to enable the carrier 1 to drive the wafer 2 to rotate, the rotating shaft 6 is connected to the OF workbench 7, and the OF workbench 7 is used to fix the rotating shaft 6. The optical fiber sensor 3 is fixed to the OF table 7.

The fiber bundle port 3 may include a light beam emitting end (not shown) for emitting the probe light signal and a light beam receiving end (not shown) for receiving the reflected light signal reflected by the wafer 2. It can be understood that the reflected light signal received by the light beam receiving end is different between the probe light signal passing through the wafer 2 and the probe light signal not passing through the wafer 2. When the detection optical signal does not pass through the wafer 2, the light beam reflection end cannot receive the reflection optical signal, and at the moment, the condition that the upper part of the optical fiber beam port 4 is not shielded by the wafer 2 can be judged; when the detection light signal passes through the wafer 2, the light beam reflection end can receive the reflected light signal, and when the detection light signal passes through different positions of the wafer 2, the reflected light signal has different intensities, if the detection light signal hits the inside of the wafer 2, the reflected light signal is stronger, if the detection light signal hits the edge of the wafer 2, the reflected light signal exists but is weaker, if the detection light signal does not hit the wafer 2, the reflected light signal cannot be received, that is, the reflected light signal received by the optical fiber sensor 3 is minimum close to zero, and the detection light signal can be considered to hit the edge of the wafer 2. Therefore, whether the upper part of the optical fiber beam port 4 corresponds to the edge of the wafer 2 can be judged according to the intensity of the reflected light signal received by the light beam receiving end, and the edge searching process of the wafer 2 is further completed.

The optical fiber sensor can not only sense the reflected light signals passing through the opaque wafer, but also sense the reflected light signals passing through the transparent wafer, and the application range of the wafer flat edge searching device is expanded. And the intensity of the reflected light signal detected based on the optical fiber sensor is more accurate, and the positioning accuracy of the wafer can be improved.

Optionally, the optical fiber sensor may be an optical fiber reflective digital identification sensor, and when the detection light signal passes through the wafer, the light beam receiving end may receive the diffuse reflection light signal and generate a digital signal, and then the signal board may determine whether to detect the edge of the wafer according to the digital signal.

With continued reference to fig. 1 and 2, in the present embodiment, the plurality of optical fiber sensors 3 includes a first optical fiber sensor 31 and a second optical fiber sensor 32. Wherein the first optical fiber sensor 31 comprises a first optical fiber bundle port 41 and the second optical fiber sensor 32 comprises a second optical fiber bundle port 42. Since fig. 2 is a top view, the structures in fig. 2 can also be considered as vertical projections of the structures in the plane of the wafer.

Furthermore, a connection line of vertical projections of the first optical fiber bundle port 41 and the second optical fiber bundle port 42 on the plane of the wafer 2 forms a first connection line 5, the first connection line 5 is a straight line, and a perpendicular line b of the first connection line 5 passes through a circle center O of the wafer 2; in addition, the distance d1 between the first connection line 5 and the center O is greater than or equal to the distance between the flat edge 21 of the wafer 2 and the center O, that is, greater than or equal to the first distance d, and less than or equal to the radius r of the wafer 2; meanwhile, the length h1 of the first connecting line 5 is less than or equal to the length h of the flat edge of the wafer 2. In this arrangement, the first connection line 5 can correspond to the flat edge 21 of the wafer 2 more accurately, and the first optical fiber bundle port 41 and the second optical fiber bundle port 42 can be used for detecting the flat edge 21 of the wafer 2. It can be understood that, after the wafer 2 is placed on the carrier 1 of the edge finder, the carrier 1 will drive the wafer 2 to rotate to complete the edge finder. During the rotation of the wafer 2, the optical fiber sensor 3 will continuously send out a detection light signal, which defines the position of the wafer 2 as the first position when the symmetry axis of the flat edge 21 of the wafer 2 rotates to coincide with the perpendicular b of the first connection line 5. Under the first position, the flat edge 21 approaches the first connecting line 5, the position of the flat edge 21 can be determined according to the intensity of the reflected light signals received by the first optical fiber sensor 31 and the second optical fiber sensor 32, and when the first optical fiber sensor 31 and the second optical fiber sensor 32 judge that the edge of the flat edge 21 is detected, the flat edge 21 is considered to reach the designated position, and the edge searching operation is finished. In fig. 2, the flat edge 21 reaches the designated position, and the position of the wafer 2 is at the end of the edge finding operation.

Wherein, the length h1 of first line 5 is the distance between first fiber bundle port 41 and the second fiber bundle port 42, the embodiment of the utility model provides a do not inject the concrete length that sets up of first line 5, and the skilled person in the art can set for according to actual demand, only needs to guarantee that the length h1 of first line 5 is less than or equal to the length h of the plain edge 21 of wafer 2 to guarantee the accuracy of first optical fiber sensor 31 and second optical fiber sensor 32 to the plain edge location. It should be noted that, the distance between the projections of the two structures or the two structures indicated in the above embodiments is the distance between the centers of the projections of the two structures or the two structures.

Optionally, in a possible embodiment, the length h1 of the first connection line 5 may be set to the length h of the flat edge 21, so as to ensure that the first optical fiber bundle port 41 and the second optical fiber bundle port 42 correspond to two ends of the flat edge 21, respectively, and further ensure that the entire flat edge is accurately positioned.

Further, still referring to fig. 1 and 2, in the embodiment of the present invention, a third optical fiber sensor 33 is further provided, and the third optical fiber sensor 33 includes a third optical fiber bundle port 43. The distance d2 between the vertical projection of the third optical fiber bundle port 43 on the plane of the wafer 2 and the center O of the wafer 2 is greater than or equal to the first distance d, and is less than or equal to the radius r of the wafer 2. Furthermore, a connection line a between a vertical projection of the third fiber bundle port 43 on the plane of the wafer 2 and the center O forms a predetermined included angle θ with a perpendicular line b passing through the first connection line 5 of the center O, where the predetermined included angle θ is an included angle between the connection line a and the perpendicular line b along the rotation direction of the wafer 2, and may also be referred to as a predetermined included angle θ hereinafter.

In this configuration, the third optical fiber sensor 33 can assist in determining the position of the flat edge 21 of the wafer 2. Specifically, when the third optical fiber sensor 33 does not receive the reflected light signal or the received reflected light signal is very small and close to zero, it indicates that the flat edge 21 of the wafer 2 is located at the position corresponding to the third optical fiber bundle port 43, at this time, since the connection line a between the vertical projection of the third optical fiber bundle port 43 on the plane where the wafer 2 is located and the circle center O and the perpendicular line b of the first connection line 5 passing through the circle center O form the preset included angle θ, after the wafer 2 rotates by the angle corresponding to the preset included angle θ, the flat edge 21 can rotate to the vicinity of the first connection line 5, and the first optical fiber sensor 31 and the second optical fiber sensor 32 can be further used for detecting the flat edge 21.

That is, in this embodiment, if the wafer 2 is not located at the first position, the third optical fiber sensor 33 may be first utilized to detect whether the flat edge 21 of the wafer 2 is located at the position corresponding to the third optical fiber bundle port 43, when it is determined that the flat edge 21 reaches the position corresponding to the third optical fiber bundle port 43, the wafer 2 may be controlled to rotate by the preset included angle θ, after the preset included angle θ is rotated, the wafer 2 is located at the first position, and then the position of the flat edge 21 is accurately located according to the detection results of the first optical fiber sensor 31 and the second optical fiber sensor 32, and when the first optical fiber sensor 31 and the second optical fiber sensor 32 receive the minimum approximate zero of the reflected light signals, it may be determined that the flat edge 21 reaches the designated position (i.e., the position shown in fig. 2), and the edge finding operation is completed. In addition, since the distance d2 between the vertical projection of the third optical fiber bundle port 43 on the plane where the wafer 2 is located and the center O of the wafer 2 is greater than or equal to the first distance d and less than or equal to the radius r of the wafer 2, when the wafer 2 is located at the first position, the third optical fiber bundle port 43 should correspond to the edge of the circular edge of the wafer 2, and at this time, the third optical fiber sensor 33 should receive a weak reflected light signal, and therefore, it can be further determined whether the flat edge 21 reaches the specified position by combining the reflected light signal detected by the third optical fiber sensor 33, and the detection accuracy of the flat edge position of the wafer 2 is improved.

The embodiment of the utility model provides an edge device is sought to wafer plain edge need not to destroy the original hardware of photoetching system, and the convenience is reformed transform the edge device of seeking of current photoetching system, reduces and reforms transform the cost, sparingly reforms transform the time.

The wafer flat edge searching device provided by the embodiment of the utility model comprises a carrying platform used for bearing a wafer; the optical fiber sensors are arranged on one side of the wafer close to the carrying platform; the optical fiber sensor comprises an optical fiber bundle port, and the vertical projection of the optical fiber bundle port on the plane of the wafer is positioned in the edge area of the wafer; the optical fiber sensors comprise a first optical fiber sensor, a second optical fiber sensor and a third optical fiber sensor, wherein the first optical fiber sensor comprises a first optical fiber bundle port, and the second optical fiber sensor comprises a second optical fiber bundle port; a connecting line of vertical projections of the first optical fiber bundle port and the second optical fiber bundle port on a plane where the wafer is located forms a first connecting line, and a perpendicular line of the first connecting line passes through the center of a circle of the wafer; the distance between the first connecting line and the circle center is greater than or equal to the first distance and smaller than the radius of the wafer; the length of the first connecting line is less than or equal to that of the flat edge; the third optical fiber sensor comprises a third optical fiber bundle port, and the distance between the vertical projection of the third optical fiber bundle port on the plane where the wafer is located and the circle center is greater than or equal to the first distance; and is less than or equal to the radius of the wafer; and a connecting line of the vertical projection of the third optical fiber bundle port on the plane where the wafer is located and the circle center forms a preset included angle with a perpendicular line of the first connecting line passing through the circle center. In the embodiment of the utility model, the edge of the wafer is detected by using a plurality of optical fiber sensors, so that the accuracy of positioning the flat edge of the wafer is improved; and the edge-finding device for the flat edge of the chip can be used for carrying out edge-finding positioning on various types of wafers, so that the photoetching system can meet the positioning requirements of different types of wafers.

Alternatively, referring still to fig. 2, in a possible embodiment, the first optical fiber bundle port 41 may be elongated, and an extension line of the first optical fiber bundle port 41 passes through the center O.

As shown in fig. 2, the first optical fiber bundle port 41 is elongated, and the extension line of the first optical fiber bundle port 41 passes through the center O, that is, the extension direction of the first optical fiber bundle port 41 passes through the connection line a between the center O and the first optical fiber bundle port, and for convenience of description, it is defined that the extension line of the first optical fiber bundle port 41 extends in a first direction X and the extension direction of the first connection line 5 extends in a second direction Y. The first optical fiber bundle port 41 may include a plurality of beam emitting ends and beam receiving ends arranged along the first direction X, so that the first optical fiber bundle port 41 is overall in a strip shape.

The advantage that setting up first optical fiber bundle port 41 and being rectangular form lies in, if all reflected light signal intensity that first optical fiber sensor 31 received is all very little, then the plain end 21 of explaining wafer 2 just with first optical fiber bundle port 41 in the planar vertical projection of wafer 2 place perpendicular, wafer 2 rotatory predetermines contained angle theta this moment after, the plain end 21 of wafer 2 can arrive near first line 5 more accurately, promote plain end positioning efficiency from this, under the accurate prerequisite of assurance plain end positioning, the work efficiency of the edge device is sought in the plain end of chip has been promoted.

Optionally, to the line of the vertical projection of the third optical fiber bundle port on the plane where the wafer is located and the circle center, and the size of the preset included angle between the perpendicular lines passing through the first line of the circle center, the embodiment of the present invention does not limit, for example, the preset included angle may be set to 45 °, 90 ° or 180 °, but is not limited thereto.

Illustratively, in the embodiment shown in FIG. 2, the predetermined included angle θ is 180. At this time, in the first direction X, the third optical fiber bundle port 43, the first optical fiber bundle port 41, and the second optical fiber bundle port 42 are respectively disposed at two sides of the wafer 2, so that the first optical fiber sensor 31, the second optical fiber sensor 32, and the third optical fiber sensor 33 can detect a wafer 2 profile in a large range, and it is ensured that the wafer 2 is accurately positioned as a whole.

When the preset included angle θ is 180 °, the operation of the edge finder can be generally described as follows: firstly, a wafer 2 is fixed on a carrier 1, then the carrier 1 rotates to drive the wafer 2 to rotate, in the process of rotating the wafer 2, each optical fiber sensor 3 sends out a detection light signal, when a flat edge 21 of the wafer 2 passes through the corresponding position of the third optical fiber beam port 43, the third optical fiber sensor 33 can detect a small reflection light signal, then the wafer 2 is controlled to rotate for 180 degrees and stop, at the moment, the wafer 2 is in a first position, then the carrier 1 can move in the first direction X and the second direction Y, and in the moving process, whether the flat edge 21 of the wafer 2 reaches a specified position is detected through the first optical fiber sensor 31 and the second optical fiber sensor 32. When the minimum of the reflected light signals is detected to be close to zero, the flat edge 21 is in place, the flat edge 21 of the wafer 2 can be judged to be found, and the edge finding work is finished.

Optionally, fig. 3 is a top view of another wafer flat edge finding device provided in the embodiment of the present invention, as shown in fig. 3, in a possible embodiment, the plurality of optical fiber sensors may further include a fourth optical fiber sensor 34, and the fourth optical fiber sensor 34 includes a fourth optical fiber bundle port 44; the distance d3 between the vertical projection of the fourth optical fiber bundle port 44 on the plane of the wafer 2 and the circle center O is equal to the radius r of the wafer 2; an included angle between a connecting line c of a vertical projection of the fourth optical fiber bundle port 44 on the plane where the wafer 2 is located and the circle center O and a perpendicular line b of the first connecting line 5 passing through the circle center O is a first included angle θ 1; an included angle between a connecting line e between the end point of the flat edge 21 and the center O and a perpendicular line b of the first connecting line 5 passing through the center O is a second included angle θ 2, and the first included angle θ 1 is greater than the second included angle θ 2.

Specifically, as shown in fig. 3, in this embodiment, a fourth optical fiber sensor 34 may be further provided, where the fourth optical fiber sensor 34 includes a fourth optical fiber bundle port 44, a distance d3 between a vertical projection of the fourth optical fiber bundle port 44 on the plane of the wafer 2 and the center O of the wafer 2 is equal to the radius r of the wafer 2, and the fourth optical fiber sensor 34 may be configured to detect the round edge of the wafer 2.

In this embodiment, a first included angle θ 1 is formed between a line c connecting a vertical projection of the fourth optical fiber bundle port 44 on the plane where the wafer 2 is located and the center O and a perpendicular line b of the first line 5 passing through the center O, and a second included angle θ 2 is formed between a line e connecting an end point of the flat edge 21 and the center O and a perpendicular line b of the first line 5 passing through the center O, where the first included angle θ 1 is set to be greater than the second included angle θ 2, so that the fourth optical fiber bundle port 44 can accurately position the edge of the circular edge of the wafer 2.

When the first optical fiber bundle port 41, the second optical fiber bundle port 42 and the fourth optical fiber bundle port 44 are arranged according to the above positional relationship, the center O of the wafer 2 can be determined according to the reflected light signals detected by the first optical fiber sensor 31, the second optical fiber sensor 32 and the fourth optical fiber sensor 34, and then the position of the flat edge 21 of the wafer 2 can be determined.

Specifically, when the wafer 2 rotates to the first position, if the reflected light signals received by the first optical fiber sensor 31, the second optical fiber sensor 32, and the fourth optical fiber sensor 34 are all very small and close to zero, it can be considered that the first optical fiber bundle port 41 and the second optical fiber bundle port 42 exactly correspond to the edge of the flat edge 21 of the wafer 2, and the fourth optical fiber bundle port 44 exactly corresponds to the edge of the circular edge of the wafer 2, and at this time, it is determined that the flat edge 21 of the wafer 2 is found.

Optionally, for the specific setting position of the fourth optical fiber bundle port 44, the embodiment of the present invention is not limited, and those skilled in the art can set the setting according to actual situations.

In a possible embodiment, as shown in fig. 3, a line c connecting a vertical projection of the fourth fiber bundle port 44 on the plane of the wafer 2 and the center O is parallel to the first line 5. That is, a connection line c between a vertical projection of the fourth fiber bundle port 44 on the plane of the wafer 2 and the center O of the wafer 2 is perpendicular to the first direction X and parallel to the second direction Y. In this way, when the wafer 2 slightly moves in the second direction Y, the fourth optical fiber sensor 34 can detect the intensity change of the reflected optical signal more sensitively, which is beneficial to accurately positioning the edge of the wafer 2.

Optionally, in a possible embodiment, the plurality of optical fiber sensors may further include at least two flat edge position verification optical fiber sensors; the fiber bundle ports of the at least two flat edge position verification fiber sensors are positioned on the same straight line with the first fiber bundle port and the second fiber bundle port, and the fiber bundle ports of the at least two flat edge position verification fiber sensors are positioned between the first fiber bundle port and the second fiber bundle port.

Specifically, in this embodiment, at least two flat-edge verification optical fiber sensors may be further provided, and the following description will take the case where two flat-edge verification optical fiber sensors are provided as an example, and the actual number of the flat-edge verification optical fiber sensors is not limited thereto. Still referring to fig. 3, a plurality of fiber optic sensors may be provided including a first edge verification fiber optic sensor 35 and a second edge verification fiber optic sensor 36, the first edge verification fiber optic sensor 35 including a fifth fiber optic bundle port 45, the second edge verification fiber optic sensor 36 including a sixth fiber optic bundle port 46.

Wherein the fifth optical fiber bundle port 45 and the sixth optical fiber bundle port 46 are located on the same straight line as the first optical fiber bundle port 41 and the second optical fiber bundle port 42, and the fifth optical fiber bundle port 45 and the sixth optical fiber bundle port 46 are located between the first optical fiber bundle port 41 and the second optical fiber bundle port 42, it can also be understood that the vertical projection of the fifth optical fiber bundle port 45 and the sixth optical fiber bundle port 46 on the plane of the wafer 2 is located on the first connecting line 5.

The presence of the optical fiber sensors is verified by at least two flat edges, which can further determine whether to accurately position the flat edge 21 of the wafer 2. If the flat edge 21 of the wafer 2 reaches the designated position, the intensity of the reflected light signal detected by the flat edge verification optical fiber sensor is the same as that of the reflected light signal detected by the first optical fiber sensor 31 and the second optical fiber sensor 32, and the reflected light signals are both very small and close to zero; if the intensity of the reflected light signals detected by the flat edge verification optical fiber sensor and the first optical fiber sensor 31 and the second optical fiber sensor 32 is very different, it indicates that there is a false detection situation, and at this time, the edge searching device rotates again, and the edge searching step in the above embodiment is executed again.

Optionally, in a possible embodiment, the edge finder further includes a driving rotation mechanism, and the driving rotation mechanism is connected to the carrier and configured to drive the carrier to rotate the wafer.

Specifically, in the embodiment of the present invention, a driving rotation mechanism can be provided, the driving rotation mechanism can be a rotating shaft, when the driving rotation mechanism is the rotating shaft, the driving rotation mechanism is directly connected to the stage, and the driving rotation mechanism drives the stage to drive the wafer to rotate, so that the flat edge of the wafer rotates around the center of the wafer.

Optionally, the driving rotation mechanism may also be a unit connected to the rotating shaft, and the driving rotation mechanism may drive the rotating shaft to rotate, so that the rotating shaft drives the carrier and the wafer on the carrier to rotate. Of course, the specific setting mode of the driving rotation mechanism can be set by a person skilled in the art according to actual needs, and the embodiment of the present invention is not described nor limited to this.

Fig. 4 is a schematic circuit structure diagram of a wafer flat edge searching device according to an embodiment of the present invention, referring to fig. 4, in a possible embodiment, the edge searching device further includes a signal board 8; the signal board 8 is electrically connected with the plurality of optical fiber sensors 3, and the signal board 8 comprises a detection light signal output end (not shown in the figure), a reflected light signal receiving end (not shown in the figure) and a reflected light signal analysis unit (not shown in the figure); the optical fiber beam port (not shown in the figure) of the optical fiber sensor 3 comprises a light beam transmitting end (not shown in the figure) and a light beam receiving end (not shown in the figure), wherein the light beam transmitting end is electrically connected with the detection light signal output end and is used for emitting a detection light signal; the light beam receiving end is electrically connected with the reflected light signal receiving end and is used for receiving the reflected light signal and transmitting the reflected light signal to the reflected light signal receiving end; the reflected light signal analysis unit is electrically connected with the reflected light signal receiving end, and the reflected light signal analysis unit determines the position of the wafer according to the reflected light signal received by the reflected light signal receiving end.

Specifically, as shown in fig. 4, the wafer flat edge searching apparatus further includes a signal board 8, the signal board 8 is electrically connected to the plurality of optical fiber sensors 3, the signal board 8 can control each optical fiber sensor 3 to emit a detection light signal and receive a reflection light signal, and the signal board 8 includes a detection light signal output end (not shown), a reflection light signal receiving end (not shown), and a reflection light signal analyzing unit (not shown). The detection light signal output end is electrically connected with a light beam emitting end (not shown in the figure) of each optical fiber beam port (not shown in the figure), and the signal plate 8 controls the light beam emitting end to emit a detection light signal through the detection light signal output end; the reflected light signal receiving end is electrically connected with a light beam receiving end (not shown in the figure) of each optical fiber beam port, and the reflected light signal received by the light beam receiving end is transmitted to the reflected light signal receiving end; the reflected light signal receiving end is electrically connected with the reflected light signal analysis unit, and the reflected light signal analysis unit determines the position of the wafer according to the reflected light signal received by the reflected light signal receiving end.

Optionally, the driving rotation mechanism may be electrically connected to the signal board, and when the signal board determines that the flat edge of the wafer is located at the position corresponding to the third optical fiber bundle port, the driving rotation mechanism may be controlled to drive the wafer to rotate by a preset angle, so that the flat edge of the wafer rotates to a position near the first connection line.

Optionally, still referring to fig. 4, the edge finder may further include a signal processing board 9, where the signal processing board 9 is electrically connected to the plurality of optical fiber sensors 3 and the signal board 8, respectively, and the signal processing board 9 processes the reflected light signal received by the beam receiving end (not shown in the figure) and transmits the processed reflected light signal to the reflected light signal receiving end (not shown in the figure) of the signal board 8.

Specifically, when the optical fiber sensor 3 is an optical fiber reflective digital sensor, the optical fiber sensor 3 generates a corresponding digital signal according to the reflected light signal received by the light beam receiving end. Therefore, in this embodiment, a signal processing board 9 may be disposed between the signal board 8 and each optical fiber sensor 3, the signal processing board 9 is electrically connected to the plurality of optical fiber sensors 3 and the signal board 8, respectively, and the signal processing board 9 may process the reflected light signal received by the light beam receiving end and transmit the processed reflected light signal to the reflected light signal receiving end of the signal board 8, so as to allow the signal board 8 to determine the reflected light signal.

The specific setting mode of the signal board and the signal processing board may be set by a person skilled in the art according to actual requirements, which is not described or limited in this embodiment.

Optionally, referring still to fig. 4, in a possible embodiment, the edge finder may further include a plurality of fiber amplifiers 10; one end of the optical fiber amplifier 10 is connected to the optical fiber sensor 3, and the other end of the optical fiber amplifier 10 is connected to the signal processing board 9.

Specifically, as shown in fig. 4, in the embodiment of the present invention, optical fiber amplifiers 10 may be further disposed on the connection path between the optical fiber sensor 3 and the signal processing board 9, and the number of the optical fiber amplifiers 10 is the same as that of the optical fiber sensors 3. As will be understood by those skilled in the art, the optical fiber amplifier 10 is an optical amplifier using an optical fiber as a gain medium, and generally, its internal structure is an optical fiber, and optical pumping is performed by doping a special element in the optical fiber, so as to amplify an optical signal. One end of the optical fiber amplifier 10 is connected with the optical fiber sensor 3, and the other end of the optical fiber amplifier 10 is connected with the signal processing board 9, so as to simultaneously amplify the detection light signal emitted from the light beam emitting end and the reflected light signal received by the light beam receiving end.

In other embodiments, the edge finder may further include other structural components known to those skilled in the art, and the embodiments of the present invention are not described or limited herein.

Based on the same conception, the embodiment of the present invention further provides a lithography system, which includes any one of the wafer edge-finding devices provided by the above embodiments, and therefore, the lithography system also has the technical effects of the above wafer edge-finding device, and the same parts can be understood with reference to the above description, which is not repeated herein.

In other embodiments, the lithography system may further include other structural components known to those skilled in the art, which are not described or limited herein.

It should be noted that the foregoing is only a preferred embodiment of the present invention and the technical principles applied. It will be understood by those skilled in the art that the present invention is not limited to the particular embodiments illustrated herein, but is capable of various obvious modifications, rearrangements, combinations and substitutions without departing from the scope of the invention. Therefore, although the present invention has been described in greater detail with reference to the above embodiments, the present invention is not limited to the above embodiments, and may include other equivalent embodiments without departing from the scope of the present invention.

Claims (11)

1. The utility model provides a wafer plain edge seeks limit device, is used for seeking limit to the wafer that has the plain edge, has first distance between the centre of a circle of the plain edge of wafer and the wafer, seek the limit device and include:

the carrying platform is used for carrying the wafer;

the optical fiber sensors are arranged on one side, close to the carrying platform, of the wafer; the optical fiber sensor comprises an optical fiber bundle port, and the vertical projection of the optical fiber bundle port on the plane of the wafer is positioned in the edge area of the wafer;

wherein the plurality of fiber optic sensors includes a first fiber optic sensor including a first fiber optic bundle port, a second fiber optic sensor including a second fiber optic bundle port, and a third fiber optic sensor; a connecting line of vertical projections of the first optical fiber bundle port and the second optical fiber bundle port on a plane where the wafer is located forms a first connecting line, and a perpendicular line of the first connecting line passes through the center of the wafer;

the distance between the first connecting line and the circle center is greater than or equal to the first distance and smaller than the radius of the wafer; the length of the first connecting line is less than or equal to that of the flat edge;

the third optical fiber sensor comprises a third optical fiber bundle port, and the distance between the vertical projection of the third optical fiber bundle port on the plane where the wafer is located and the circle center is greater than or equal to the first distance; and is less than or equal to the radius of the wafer;

and a connecting line of the vertical projection of the third optical fiber bundle port on the plane where the wafer is located and the circle center forms a preset included angle with a perpendicular line of the first connecting line passing through the circle center.

2. The wafer flat edge finder according to claim 1, wherein the first fiber bundle port is elongated, and an extension line of the first fiber bundle port passes through the center of the circle.

3. The wafer flat edge finder device according to claim 1, wherein the predetermined included angle is 180 °.

4. The wafer flat edge finder device according to claim 1, wherein the plurality of fiber sensors further includes a fourth fiber sensor including a fourth fiber bundle port; the distance between the vertical projection of the fourth optical fiber bundle port on the plane where the wafer is located and the circle center is equal to the radius of the wafer;

the included angle between the vertical projection of the fourth optical fiber bundle port on the plane where the wafer is located and the connecting line of the circle center and the perpendicular line of the first connecting line passing through the circle center is a first included angle; and the included angle between the connecting line of the end point of the flat edge and the circle center and the perpendicular line passing through the first connecting line of the circle center is a second included angle, and the first included angle is larger than the second included angle.

5. The apparatus as claimed in claim 4, wherein a line connecting a vertical projection of the fourth fiber bundle port on the plane of the wafer and the center of the circle is parallel to the first line.

6. The wafer flat edge finder device according to claim 1, wherein said plurality of optical fiber sensors further comprises at least two flat edge position verification optical fiber sensors; the fiber bundle ports of the at least two flat edge position verification fiber sensors are positioned on the same straight line with the first fiber bundle port and the second fiber bundle port, and the fiber bundle ports of the at least two flat edge position verification fiber sensors are positioned between the first fiber bundle port and the second fiber bundle port.

7. The wafer flat edge finding device according to claim 1, further comprising a driving rotation mechanism, connected to the stage, for driving the stage to rotate the wafer.

8. The wafer flat edge finding device according to claim 1, further comprising a signal plate; the signal board is electrically connected with the optical fiber sensors and comprises a detection light signal output end, a reflected light signal receiving end and a reflected light signal analysis unit;

the optical fiber beam port of the optical fiber sensor comprises a light beam transmitting end and a light beam receiving end, and the light beam transmitting end is electrically connected with the detection light signal output end and is used for emitting a detection light signal; the light beam receiving end is electrically connected with the reflected light signal receiving end and is used for receiving the reflected light signal and transmitting the reflected light signal to the reflected light signal receiving end;

the reflected light signal analysis unit is electrically connected with the reflected light signal receiving end, and the reflected light signal analysis unit determines the position of the wafer according to the reflected light signal received by the reflected light signal receiving end.

9. The wafer edge-flattening searching device according to claim 8, further comprising a signal processing board electrically connected to the plurality of optical fiber sensors and the signal board, respectively, the signal processing board processing the reflected light signals received by the light beam receiving end and transmitting the processed reflected light signals to the reflected light signal receiving end of the signal board.

10. The wafer flat edge finder according to claim 9, further comprising a plurality of fiber amplifiers; one end of the optical fiber amplifier is connected with the optical fiber sensor, and the other end of the optical fiber amplifier is connected with the signal processing board.

11. A lithography system comprising the wafer edge finder according to any one of claims 1 to 10.

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