CN117913022A - Wafer stress detection and holding device and wafer stress detection equipment - Google Patents

Abstract

The present disclosure relates to a wafer stress detection holding device and a wafer stress detection apparatus, which includes a peripheral holding mechanism configured to switch between a first state in which the peripheral holding mechanism is in contact with a peripheral edge of a wafer to hold the wafer, and a second state in which the peripheral holding mechanism is away from the peripheral edge so as not to affect detection of the peripheral edge; and a center holding mechanism configured to switch between a first mode in which the center holding mechanism is in contact with the center of the wafer to hold the wafer and a second mode in which the center holding mechanism is away from the center so as not to affect detection of the center, wherein when the peripheral edge is subjected to detection, the peripheral edge holding mechanism is in the second state and the center holding mechanism is in the first mode, and when the center is subjected to detection, the peripheral edge holding mechanism is in the first state and the center holding mechanism is in the second mode. The technical scheme of the disclosure can minimize the influence of the wafer holding component on wafer stress detection.

Description

Wafer stress detection and holding device and wafer stress detection equipment

Technical Field

The present disclosure relates to the field of semiconductor wafer testing technologies, and in particular, to a wafer stress detection and holding device and a wafer stress detection apparatus.

Background

With the increasing demands on wafer quality in the semiconductor manufacturing industry, higher demands are being placed on the detection of internal defects and internal stresses in wafers that affect wafer performance and stability. The infrared depolarization technology is used as a common method for detecting the stress in the wafer, and can be used for detecting the stress distribution in the wafer, identifying the stress change in the wafer after each process and analyzing the defects in the wafer.

When the stress detection is performed by adopting the infrared depolarization technology, the supporting piece is used for supporting the periphery of the wafer and driving the wafer to rotate. Upon inspection, the stress detection unit moves from the center to the periphery of the wafer and emits and receives polarized light perpendicular to the wafer. And when the stress detection unit moves for a certain distance, collecting polarization information of the radius circle corresponding to the distance, and continuously moving to the periphery in the mode so as to collect the polarization information of each radius circle of the wafer, thereby obtaining the stress detection result of the whole wafer.

However, since the periphery of the wafer is supported by the support member, when the stress detection unit moves to the periphery position, the support member may appear in the optical path of the vertically emitted polarized light, resulting in that the polarized light is not received or the polarization state information of the received polarized light is abnormal at the corresponding position of the support member, so that the stress detection result of the wafer is affected, which causes inconvenience to the subsequent stress numerical analysis and easily causes errors in the stress analysis result of the wafer.

Disclosure of Invention

To solve the above-described technical problems, it is desirable for embodiments of the present disclosure to provide a wafer stress detection holding device that minimizes an influence of a wafer holding member on wafer stress detection.

The technical scheme of the present disclosure is realized as follows:

According to a first aspect of the present disclosure, there is provided a wafer stress detection holding device including:

A peripheral edge holding mechanism configured to switch between a first state in which the peripheral edge holding mechanism is in contact with the peripheral edge of the wafer to hold the wafer and a second state in which the peripheral edge holding mechanism is away from the peripheral edge so as not to affect detection of the peripheral edge; and

A center holding mechanism configured to switch between a first mode in which the center holding mechanism is in contact with the center of the wafer to hold the wafer, and a second mode in which the center holding mechanism is away from the center so as not to affect detection of the center,

Wherein the peripheral edge holding mechanism is in the second state and the center holding mechanism is in the first mode when the peripheral edge is subjected to the detection, and the peripheral edge holding mechanism is in the first state and the center holding mechanism is in the second mode when the center is subjected to the detection.

In some embodiments, the peripheral edge holding mechanism may include at least three support pins configured to move relative to the wafer between a first radial position in which the at least three support pins contact the bottom of the wafer to support the wafer so that the peripheral edge holding mechanism is in a first state and a second radial position in which the at least three support pins are away from the bottom so that the peripheral edge holding mechanism is in a second state.

In some embodiments, the peripheral retaining mechanism may further comprise a ring on which the at least three support pins are disposed.

In some embodiments, the at least three support pins may be three in number and uniformly distributed in the circumferential direction of the ring.

In some embodiments, the center hold mechanism may include a vertical rod configured to move relative to the wafer between a first vertical position in which the vertical rod contacts the bottom of the wafer to support the wafer to place the center hold mechanism in the first mode and a second vertical position in which the vertical rod is away from the bottom to place the center hold mechanism in the second mode.

In some embodiments, the wafer stress detection holding apparatus may further include a first driver for driving the peripheral holding mechanism to rotate so as to rotate the wafer together with the peripheral holding mechanism when the peripheral holding mechanism is in the first state.

In some embodiments, the wafer stress detection holding apparatus may further include a second driver for driving the center holding mechanism to rotate so as to rotate the wafer together with the center holding mechanism when the center holding mechanism is in the first state.

In some embodiments, the vertical rod may be hollow to provide vacuum suction to the supported wafer.

According to a second aspect of the present disclosure, a wafer stress detection apparatus is provided, which may comprise a wafer stress detection holding device according to the first aspect of the present disclosure.

In some embodiments, the wafer stress detection apparatus may further include:

a polarized laser detection module configured to emit a polarized laser beam perpendicular to the wafer to detect stress of the wafer;

And the driving module is used for driving the polarized laser detection module to move relative to the held wafer so that the polarized laser beam can be emitted to any position on the whole radius of the wafer.

According to the above technical scheme, a 'peripheral holding mode' for providing peripheral holding action at the periphery by the peripheral holding mechanism is adopted when the center of the wafer is detected; and switching to a "center hold mode" in which the center holding mechanism provides a center holding action at the center when the peripheral edge is detected. Thus, the optical path of the polarized laser beam is ensured not to be affected by the wafer stress detection and holding device no matter when the center or the periphery is detected. Compared with the scheme of adopting a fixed and unchanged peripheral support mode in the prior art, the wafer holding mode capable of switching between the peripheral holding mode and the central holding mode avoids or reduces the interference of the wafer holding mode on the stress detection process to the greatest extent, minimizes the influence of the wafer holding component on the stress detection, and improves the accuracy and the reliability of the stress detection result of the whole wafer.

Drawings

FIG. 1 is a schematic diagram of a wafer stress detection apparatus according to the related art;

FIG. 2 is a schematic top view of a wafer stress test holding device of the wafer stress test apparatus of FIG. 1;

FIG. 3 is an exemplary graphical representation of stress detection results obtained using the wafer stress detection apparatus of FIG. 1;

FIG. 4 is a schematic diagram of a wafer stress detection holding device according to an embodiment of the present disclosure;

FIG. 5 is a schematic view of a first state and a second state of a peripheral edge retaining mechanism according to an embodiment of the present disclosure;

FIG. 6 is a schematic view of a peripheral retention mechanism according to an embodiment of the present disclosure;

FIG. 7 is a schematic illustration of a first mode and a second mode of a center hold mechanism according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram of another wafer stress detection retaining device according to an embodiment of the present disclosure;

FIG. 9 is a schematic diagram of a wafer stress detection apparatus according to an embodiment of the present disclosure;

Fig. 10 is an exemplary illustration of stress detection results obtained using the wafer stress detection apparatus of fig. 9.

Detailed Description

The technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure.

In order to more clearly understand the problems mentioned in the background art, a conventional wafer stress inspection process will be described with reference to fig. 1 in conjunction with a related art wafer stress inspection apparatus.

First, the principle of stress detection by the infrared depolarization technique will be briefly described. In the case where a stress field exists in the wafer, polarized light emitted to the wafer is birefringent due to the stress when passing through the wafer, and the polarization state of the polarized light is changed, so that polarized light in two directions is formed. And analyzing the polarization states of the received two polarized lights to obtain the stress information of the wafer.

As shown in fig. 1 and 2, in a conventional wafer stress inspection process using an infrared depolarization technique, a wafer W is placed on a load-bearing base located outside a peripheral edge WE of the wafer W, and the wafer W is supported at the peripheral edge WE by a support 10' and rotated. The stress detection unit 20' includes an emitter 21' and a receiver 23' of polarized light, which are disposed perpendicular to the wafer W on both sides thereof such that laser light from the emitter 21' passes vertically through the wafer W to be received by the receiver 23 '.

At the time of inspection, the stress detecting means moves from the center WC of the wafer W toward the peripheral edge WE in the radial direction. For example, the stress detection unit 20 'is first moved to a position 2mm from the center of the wafer, at which distance the stress detection unit 20' detects the polarization state of polarized light transmitted through the wafer W during one rotation (360 °) of the wafer W, thereby collecting polarization state information of a circle having a radius of 2 mm. Subsequently, the stress detection unit 20' continues to move in unit steps of X mm and collects polarization state information, for example, when moving to 2+x mm in the radial direction, collects polarization state information of a circle having a radius of 2+x mm. In this way, the stress detection unit 20' continuously moves towards the peripheral edge WE of the wafer W until the polarization information of the circles with different radii within the whole radius range is collected, and finally, the stress detection result of the whole wafer W is obtained.

However, as previously mentioned, when the stress detecting unit 20' moves to the position of the peripheral edge WE of the wafer W, the support 10' providing support at the peripheral edge WE may appear in the optical path of the polarized light, resulting in that the position corresponding to the support 10' does not receive the polarized light or the polarization state information of the received polarized light is abnormal. As shown in fig. 3, the effect of the support 10 'is shown in the stress test result of the wafer W as an abnormally high stress region on the peripheral edge WE of the wafer W, that is, a considerable stress value (even a stress maximum value in the result of fig. 3) appears at a position corresponding to the three supports 10' in fig. 2.

In the case of analysis based on the stress detection results, on the one hand, for example, in the case of performing related data processing to analyze stress distribution, for example, in the case of determining parameters such as stress mean value, median value, etc., it is inevitably necessary to select a stress maximum value and/or a high stress value, and thus, the data processing may be inaccurate for the stress detection results similar to those of fig. 3. On the other hand, in terms of internal defect discrimination, the stress maximum value and/or the high stress value is generally used as a main basis for identifying a large defect in the wafer W, such as a pit, a bump, or the like, and thus, when identifying a defect of the peripheral edge WE, an abnormally high stress area similar to that in fig. 3 affects the actual discrimination.

In a word, the local high stress value caused by the existing wafer supporting mode can cause interference and inconvenience to the analysis process of the stress detection result, and easily cause errors of the wafer stress analysis result, so that the method is unfavorable for obtaining a real and reliable stress result and defect situation.

In this regard, the present disclosure will address the above-described problems by improving the manner in which wafers are supported during stress testing.

As shown in fig. 4 to 9, according to an embodiment of the present disclosure, a wafer stress detection holding apparatus 10 is proposed, the wafer stress detection holding apparatus 10 including a peripheral holding mechanism 100 and a center holding mechanism 200, wherein the peripheral holding mechanism 100 is configured to switch between a first state and a second state, and the center holding mechanism 200 is configured to switch between a first mode and a second mode.

In the first state of the peripheral edge holding mechanism 100, the peripheral edge holding mechanism 100 contacts the peripheral edge WE of the wafer W to hold the wafer W. For example, the peripheral holding mechanism 100 may contact the bottom of the peripheral WE and hold the wafer W with upward supporting force. Or the peripheral edge holding mechanism 100 may contact the side of the peripheral edge WE and hold the wafer W with a radially inward clamping force. Or the peripheral edge holding mechanism 100 may contact with the upper portion of the peripheral edge WE and hold the wafer W with an upward suction force. It should be appreciated that the peripheral edge holding mechanism 100 may also contact and hold the wafer W in other ways with the peripheral edge WE.

In the second state of the peripheral edge holding mechanism 100, the peripheral edge holding mechanism 100 is away from the peripheral edge WE so as not to affect the detection of the peripheral edge WE. In other words, the peripheral edge holding mechanism 100 is away from the peripheral edge WE and in a state of being out of contact with the peripheral edge WE, is in a range that does not affect detection of the peripheral edge WE. In view of the fact that the polarized laser beam for inspection will pass perpendicularly through the periphery WE of the wafer W, the periphery holding mechanism 100 in the second state is at least in the radial direction beyond the wafer W, i.e. outside the sides of the wafer W, in order to avoid affecting the optical path of the polarized laser beam. Or the peripheral edge holding mechanism 100 is located radially outward of the side surface of the wafer W at a distance from the side surface.

In the first mode of the center holding mechanism 200, the center holding mechanism 200 is in contact with the center WC of the wafer W to hold the wafer W. For example, the center holding mechanism 200 may contact the bottom of the center WC and hold the wafer W with upward supporting force. Or the center holding mechanism 200 may contact the top of the center WC and hold the wafer W with an upward suction force. It should be appreciated that the center hold mechanism 200 may also contact and hold the wafer W with the center WC in other ways.

In the second mode of the center hold mechanism 200, the center hold mechanism 200 is remote from the center WC so as not to affect detection of the center WC. Specifically, the center holding mechanism 200 is located away from the center WC and in a state of being out of contact with the center WC in a range that does not affect detection of the center WC. To avoid affecting the optical path of the polarized laser beam, the center holding mechanism 200 may extend beyond the outer side of the wafer W in the radial direction, for example. Or the center holding mechanism 200 may be out of the optical path range of the polarized laser beam in the axial direction of the wafer W.

When the center WC receives the test, the peripheral holding mechanism 100 is in the first state and the center holding mechanism 200 is in the second mode. Specifically, when the center WC receives the inspection, the wafer W is held by the peripheral edge holding mechanism 100 in contact with the peripheral edge WE, and the center holding mechanism 200 is away from the center WC and in a range that does not affect the inspection of the center WC. At this time, the center holding mechanism 200 does not appear in the optical path of the polarized laser beam, and thus does not interfere or affect the detection of the center WC.

When the peripheral edge WE receives the detection, the peripheral edge holding mechanism 100 is in the second state and the center holding mechanism 200 is in the first mode. Specifically, when the peripheral edge WE receives the inspection, the wafer W is held by the center holding mechanism 200 while being contacted at the center WC, and the peripheral edge holding mechanism 100 is away from the peripheral edge WE and in a range that does not affect the inspection of the peripheral edge WE. At this time, the peripheral edge holding mechanism 100 does not appear in the optical path of the polarized laser beam, and thus does not interfere or affect the detection of the peripheral edge WE.

By the wafer stress detection holding device 10 of the present disclosure, the manner of holding the wafer W during the stress detection process is improved. Since the peripheral edge holding mechanism 100 is switchable between the first state and the second state, the center holding mechanism 200 is switchable between the first mode and the second mode, and thus the "peripheral edge holding mode" in which the peripheral edge holding mechanism 100 provides the peripheral edge holding action at the peripheral edge WE is adopted when the center WC receives the detection; and switches to a "center hold mode" in which the center hold mechanism 200 provides a center hold action at the center WC when the peripheral edge WE receives a detection. Thus, the optical path of the polarized laser beam is ensured not to be affected by the wafer stress detection holding device 10, regardless of whether the center WC or the peripheral edge WE is detected. Compared with the scheme of adopting a fixed and unchanged peripheral support mode in the prior art, the wafer holding mode capable of switching between the peripheral holding mode and the central holding mode avoids or reduces the interference of the holding mode of the wafer W on the stress detection process to the greatest extent, minimizes the influence of the wafer holding component on the wafer stress detection, and improves the accuracy and reliability of the stress detection result of the whole wafer W.

The wafer W is disk-shaped, and thus has two circular main surfaces and an annular side surface between the two circular main surfaces. In addition, the two circular main surfaces will generally be distinguished between a front surface and a back surface, in which case the above-mentioned "peripheral edge" refers to a radial edge region in the front or back surface, which region is, as will be readily appreciated, annular. In addition, the "center" mentioned above refers to a radially central region in the front or back face.

Furthermore, it is noted that the present disclosure is applicable to wafers having diameters of 300mm, 200mm, 150mm, and other sizes. The material of the wafer may be silicon, germanium, gallium nitride, silicon carbide, or other materials.

In some embodiments of the present disclosure, the peripheral edge holding mechanism 100 includes at least three support pins 110, the at least three support pins 110 configured to move relative to the wafer W between a first radial position in which the at least three support pins 110 contact the bottom WB of the wafer W to support the wafer W such that the peripheral edge holding mechanism 100 is in the first state, and a second radial position in which the at least three support pins 110 are away from the bottom WB such that the peripheral edge holding mechanism 100 is in the second state.

Specifically, when the center WC is inspected, the at least three support pins 110 are in a first radial position, at which time the at least three support pins 110 are in contact with the bottom WB of the wafer W to provide an upward supporting force to the wafer W to hold the wafer W, thereby avoiding the optical path of the polarized laser beam passing through the center WC from being affected by the center holding mechanism 200.

When the peripheral edge WE is subjected to detection, the at least three support pins 110 are in the second radial position, in which the at least three support pins 11 are distanced from the bottom WB and are in a range that does not affect the detection of the peripheral edge WE. At this time, the wafer W is supported by the center holding mechanism 200, thereby avoiding the influence of the peripheral holding mechanism 100 on the optical path of the polarized laser beam passing from the peripheral edge WE.

By the movement of the at least three support pins 110 between the first radial position and the second radial position, the switching of the peripheral edge holding mechanism 100 between the first state and the second state is completed, and the stress detection of the center WC and the peripheral edge WE of the wafer W is minimized with the corresponding cooperation of the center holding mechanism 200.

It is contemplated that the at least three support pins 110 may be moved between the first radial position and the second radial position by telescoping, rotating, flipping, or other means of movement.

In some embodiments of the present disclosure, the peripheral holding mechanism 100 further includes a ring 120, and the at least three support pins 110 are disposed on the ring 120.

As shown in fig. 4 to 6, the ring 120 is disposed concentrically with the wafer W radially outside the wafer W and surrounds the wafer W. In this case, the ring 120 and the at least three support pins 110 provided thereon as a whole constitute a holder for supporting the peripheral edge WE at the time of detection of the center WC, so as to provide a more stable supporting action and also to bring the wafer W into rotation.

In addition, the ring 120 can serve as a base to provide a stable installation position for the at least three support pins 110 and to make the arrangement heights of the at least three support pins 110 uniform with each other, thereby facilitating the formation of a horizontal state when the wafer W is supported.

It is contemplated that the at least three support pins 110 may be arranged on the ring 120 to be slidable in a radial direction relative to the ring 120 such that the support pins 110 each switch between a first radial position and a second radial position.

It is also contemplated that the at least three support pins 110 may be removably disposed on the collar 120 for adjustment and replacement.

In some embodiments of the present disclosure, as shown in fig. 4 to 6, the at least three support pins 110 are three in number and uniformly distributed in the circumferential direction of the ring 120.

Specifically, the three support pins 110 are disposed at equal intervals in the circumferential direction of the ring 120 such that the support pins 110 have equal support intervals. The three support pins 110 are arranged at intervals of 120 ° with reference to the center WC of the wafer W.

With this arrangement, when the three support pins 110 are moved to the first radial position to contact the bottom of the wafer W, more effective and uniform support can be provided for the bottom WB of the wafer W.

In some embodiments of the present disclosure, as shown in fig. 7, the center hold mechanism 200 includes a vertical rod 210, the vertical rod 210 being configured to move between a first vertical position and a second vertical position relative to the wafer W. In the first vertical position, the vertical rod 210 is in contact with the bottom WB of the wafer W to support the wafer W such that the center hold mechanism 200 is in the first mode, and in the second vertical position, the vertical rod 210 is away from the bottom WB such that the center hold mechanism 200 is in the second mode.

Specifically, the vertical rod 210 is in a second vertical position away from the bottom WB when the center WC is under inspection, at which time the wafer W is supported by the peripheral holding mechanism 100 such that stress detection of the center WC is not affected by the vertical rod 210. The vertical rod 210 is in a first vertical position in contact with the bottom WB when the peripheral edge WE is under inspection, at which time the wafer W is supported by the vertical rod 210 such that stress detection of the peripheral edge WE is not affected by the peripheral edge holding mechanism 100.

By moving the vertical rod 210 between the first vertical position and the second vertical position, the switching of the center holding mechanism 200 between the first mode and the second mode is completed, and the stress detection of the center WC and the peripheral edge WE of the wafer W is minimized under the corresponding cooperation of the peripheral edge holding mechanism 100.

It is contemplated that the vertical rod 210 may be a telescoping rod to move between the first and second vertical positions in a telescoping manner. Or the vertical rod 210 can be driven by other power components to move between the first vertical position and the second vertical position.

In some embodiments of the present disclosure, as shown in fig. 8, the wafer stress detection holding apparatus 10 further includes a first driver 300, the first driver 300 being configured to drive the peripheral holding mechanism 100 to rotate so as to rotate the wafer W with the peripheral holding mechanism 100 when the peripheral holding mechanism 100 is in the first state.

Specifically, the first driver 300 is in power connection with the peripheral holding mechanism 100. For example, the first driver 300 may be a device generating a rotational motion, such as a motor (e.g., a servo motor, a stepper motor, etc.).

The first driver 300 may transmit the rotational power to the ring 120 of the peripheral holding mechanism 100, and the ring 120 in turn transmits the rotational power to each of the support pins 110. When the peripheral edge holding mechanism 100 contacts with the peripheral edge WE of the wafer W and supports the wafer W, the wafer W is driven by the ring 120 and the supporting pins 110 to rotate together so as to cooperate with the polarization laser detection module to perform the stress detection operation.

In some embodiments of the present disclosure, as shown in fig. 8, the wafer stress detection holding apparatus 10 further includes a second driver 400 for driving the center holding mechanism 200 to rotate so as to rotate the wafer W together with the center holding mechanism 200 when the center holding mechanism 200 is in the first mode.

Specifically, the second driver 400 forms a power connection with the center hold mechanism 200. The second driver 400 may be a device for generating a rotational motion, such as a motor (e.g., a servo motor, a stepper motor, etc.). The second driver 400 may transmit a rotation power to the center holding mechanism 200 to drive the wafer W to rotate together when the center holding mechanism 200 contacts the center WC of the wafer W, so as to perform a stress detection operation in cooperation with the polarized laser detection module.

In the case where the center hold mechanism 200 includes the vertical rod 210, it is contemplated that the second driver 400 may be a device that can produce both rotational and linear motion, such that the same device can be used to achieve both rotation of the vertical rod 210 and the wafer W and movement of the vertical rod 210 between the first and second vertical positions to facilitate mode switching of the center hold mechanism 200.

In some embodiments of the present disclosure, the vertical rod 210 is hollow to provide vacuum suction to the supported wafer W.

Specifically, the vertical rod 210 is hollow, and thus has a passage allowing an air flow to pass therethrough. In this case, the vertical rod 210 can provide vacuum suction to the center WC of the wafer W by forming negative pressure at one end thereof contacting the wafer W to suction-hold the wafer W.

By vacuum suction, the vertical rod 210 can more closely contact the center WC of the wafer W in the first vertical position, thereby providing a more secure support for the wafer W, which is advantageous for the wafer W to remain stable and not easily fall off during rotation.

It is contemplated that the vertical rod 210 may be connected with a negative pressure generating means, such as a vacuum pump, and a negative pressure controlling means, such as a control valve, for controlling the establishment and release of the vacuum to facilitate the switching of the vertical rod 210 between the first mode and the second mode.

According to an embodiment of the present disclosure, a wafer stress detection apparatus 1 is proposed, the wafer stress detection apparatus 1 comprising a wafer stress detection holding device 10 according to the foregoing embodiment of the present disclosure.

In some embodiments of the present disclosure, as shown in fig. 9, the wafer stress detection apparatus 1 further includes:

A polarized laser light detection module 20, the polarized laser light detection module 20 being configured to emit a polarized laser beam PL perpendicular to the wafer W to detect stress of the wafer W;

The driving module 30, as schematically shown by the open arrow in fig. 9, the driving module 30 is for driving the polarized laser detection module 20 to move relative to the wafer W to be held so that the polarized laser beam PL can be emitted at least to any position over the entire radius of the wafer W.

It is also contemplated that the polarized laser detection module 20 may include:

A laser generator 21 for emitting an original laser beam OL;

a polarizer 22 for converting the original laser beam OL into a polarized laser beam PL;

a laser receiver 23 for receiving a polarized laser beam PL propagating through the wafer W.

Finally, taking a wafer W having a diameter of 300mm as an example, the entire wafer stress detection process will be exemplarily described in connection with the wafer stress detection apparatus 1 of the present disclosure.

It is assumed that the stress detection process is performed stepwise from the center WC of the wafer W to be measured and radially outward toward the peripheral edge WE. In this case, before the start of the inspection, as shown in fig. 9, the laser generator 21 and the polarizer 22 of the polarized laser inspection module 20 are disposed on one side (lower side in fig. 9) of the main surface of the wafer W to be inspected, and the laser receiver 23 is disposed on the other side (upper side in fig. 9) of the wafer W to be inspected. The connecting line of the laser generator 21, the polarizer 22 and the laser receiver 23 is perpendicular to the center of the main surface of the wafer W to be measured.

At the time of inspection, the laser generator 21 emits an original laser beam OL perpendicular to the wafer W to be inspected. The polarizer 22 receives the original laser beam OL and converts the original laser beam OL into a polarized laser beam PL. The polarized laser beam PL propagates through the wafer W to be measured until received by the laser receiver 23, whereby polarization information of the polarized laser beam PL is collected.

First, the polarized laser detection module 20 will detect the center WC first. Before starting the inspection, the wafer W to be inspected is held by the peripheral holding mechanism 100 of the wafer stress inspection holding device 10. After the wafer W to be measured is held stable and starts to rotate, the polarized laser detection module 20 starts to move from the center toward the periphery WE in the radial direction by the driving module 30.

Assume that the polarized laser light detecting module 20 first reaches a position 2mm from the center of the wafer W, and at this distance, collects polarization state information of the circle having a radius of 2mm during 360 ° rotation of the wafer W. In the case of using a circle having a radius of 2mm as the initial detection circle, the polarized laser detection module 20 continues to move toward the peripheral edge WE of the wafer W in unit steps X.

When the polarized laser light detection module 20 is moved close to the peripheral edge WE, for example, before the polarized laser light detection module 20 is moved to a position spaced apart from the center of the wafer by 148mm, preferably to a position spaced apart from the center of the wafer by 145mm, the polarized laser light detection is suspended and the wafer W is stopped from rotating. At this time, the center holding mechanism 200 is lifted up and supports the center WC of the wafer W in a vacuum suction manner. At the same time, the peripheral edge holding mechanism 100 moves outward away from the peripheral edge WE to the outside of the wafer W. After the vacuum is stabilized, the center holding mechanism 200 drives the wafer W to continue rotating, the polarization detection is restarted, and the polarized laser detection module 20 continues to move towards the periphery WE until the stress detection of the whole wafer W is completed.

Through the above process, the polarization laser detection module 20 collects the polarization information of the plurality of circles with different radii, and finally integrates the polarization information of the circles with all radii to obtain the polarization information of the whole wafer W, so that the stress detection result of the wafer W can be obtained through analysis.

Illustratively, the stress detection result obtained by using the wafer stress detection apparatus 1 of the present disclosure is shown in fig. 10, and as shown in the figure, the peripheral WE area has no stress abnormality area caused by the support, so the stress abnormality occurring at the peripheral WE can be used as a reliable basis for judging the damage or defect of the wafer W itself.

It should be noted that: the embodiments of the present disclosure may be arbitrarily combined without any collision.

The foregoing is merely specific embodiments of the disclosure, but the protection scope of the disclosure is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the disclosure, and it is intended to cover the scope of the disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims (10)

1. A wafer stress detection holding device, characterized in that the wafer stress detection holding device comprises:

a peripheral edge holding mechanism configured to switch between a first state in which the peripheral edge holding mechanism is in contact with a peripheral edge of a wafer to hold the wafer and a second state in which the peripheral edge holding mechanism is away from the peripheral edge so as not to affect detection of the peripheral edge; and

A center holding mechanism configured to switch between a first mode in which the center holding mechanism is in contact with a center of the wafer to hold the wafer and a second mode in which the center holding mechanism is away from the center so as not to affect detection of the center,

Wherein the peripheral edge holding mechanism is in the second state and the center holding mechanism is in the first mode when the peripheral edge is detected, and wherein the peripheral edge holding mechanism is in the first state and the center holding mechanism is in the second mode when the center is detected.

2. The wafer stress detection holding device of claim 1, wherein the peripheral holding mechanism comprises at least three support pins configured to move relative to the wafer between a first radial position in which the at least three support pins contact a bottom of the wafer to support the wafer to place the peripheral holding mechanism in the first state and a second radial position in which the at least three support pins are away from the bottom to place the peripheral holding mechanism in the second state.

3. The wafer stress detection holding device of claim 2, wherein the peripheral holding mechanism further comprises a ring on which the at least three support pins are disposed.

4. The wafer stress detection holding apparatus according to claim 3, wherein the number of the at least three support pins is three and is uniformly distributed in the circumferential direction of the ring.

5. The wafer stress detection holding apparatus of claim 1, wherein the center holding mechanism comprises a vertical rod configured to move relative to the wafer between a first vertical position in which the vertical rod is in contact with a bottom of the wafer to support the wafer to place the center holding mechanism in the first mode and a second vertical position in which the vertical rod is away from the bottom to place the center holding mechanism in the second mode.

6. The wafer stress detection holding apparatus of claim 1, further comprising a first driver for driving the peripheral holding mechanism in rotation so as to rotate the wafer with the peripheral holding mechanism when the peripheral holding mechanism is in the first state.

7. The wafer stress detection holding apparatus of claim 2, further comprising a second driver for driving the center holding mechanism in rotation so as to rotate the wafer with the center holding mechanism when the center holding mechanism is in the first mode.

8. The wafer stress detection holding device of claim 5, wherein the vertical rod is hollow to provide vacuum suction to the supported wafer.

9. A wafer stress inspection apparatus, characterized in that it comprises the wafer stress inspection holding device according to any one of claims 1 to 8.

10. The apparatus of claim 9, wherein the wafer stress detection apparatus further comprises:

A polarized laser detection module configured to emit a polarized laser beam perpendicular to the wafer to detect stress of the wafer;

And the driving module is used for driving the polarized laser detection module to move relative to the held wafer, so that the polarized laser beam can be emitted to any position on the whole radius of the wafer at least.