TWI842400B - Wafer hidden crack detection device and wafer hidden crack detection method - Google Patents

Abstract

The present invention provides a wafer latent crack detection device and a wafer latent crack detection method. The device comprises: a stage unit for carrying a wafer to be tested; a pressing unit for pressing the wafer to be tested on the stage unit, the pressing unit being located above the stage unit, the pressing unit comprising a pressing rod and a driving member, the pressing rod being axially perpendicular to the stage unit and moving along its own axis. The pressing unit is movable in one direction, a pressing head is provided at one end of the pressing unit in the axial direction close to the carrier unit, a driving member is connected to one end of the pressing unit in the axial direction far away from the carrier unit; and a control unit is used to control the working state of the pressing unit according to preset pressing parameters, and the preset pressing parameters include at least one of the following: pressing force, pressing times, pressing position and pressing time.

Description

Wafer hidden crack detection device and wafer hidden crack detection method

The present invention relates to the field of semiconductor manufacturing technology, and in particular to a wafer hidden crack detection device and a wafer hidden crack detection method.

In the field of semiconductor wafer manufacturing, wafer hidden cracks are relatively hidden and non-penetrating crack defects inside the wafer. It is generally speculated that they are caused by uneven internal thermal stress during crystal growth or stress damage during mechanical processing. Minor hidden crack defects affect product quality and cannot be used for high-end chip processing and manufacturing; more serious hidden crack defects generally cause fragmentation problems during the molding or polishing process, often leading to failures of related process equipment and the need to replace related grinding discs and other spare parts, resulting in a huge waste of production capacity and production costs.

Among the related technologies, the following two methods are generally used to detect wafer crack defects: 1) Automatic detection method: Use a penetrating crack camera to detect crack defects inside the wafer. This method has poor detection accuracy, and the related technical conditions are not yet fully mature. It is still in the stage of gradual improvement and verification. In addition, the detection effect on heavily doped products is obviously poor, and the equipment investment cost is relatively high. 2) Manual detection method: Use a penetrating crack camera to detect crack defects inside the wafer. Touch, press, knock, etc. to magnify the hidden crack damage inside the wafer, and use manual visual inspection to observe abnormalities on the wafer surface such as bulges, cracks, surface roughness, etc., so as to determine whether there are hidden crack defects inside the wafer. The operation of this method is difficult to quantify, especially the pressure value of the wafer during pressing and knocking cannot be quantified. The overall detection result has no data support, poor credibility, and low detection rate.

The embodiment of the present invention provides a wafer hidden crack detection device and a wafer hidden crack detection method, which can solve the problem that the manual wafer detection method in the related technology cannot quantitatively amplify the wafer hidden crack damage, improve the detection accuracy, and have a high detection rate.

The technical solutions provided by the embodiments of the present invention are as follows:

In a first aspect, an embodiment of the present invention provides a wafer crack detection device, comprising: a stage unit for carrying a wafer to be tested; a pressing unit for pressing the wafer to be tested on the stage unit, the pressing unit being located above the stage unit, the pressing unit comprising a pressing rod and a driving member, the pressing rod being axially perpendicular to the stage unit and being movable along its own axis. Movement, the pressing unit is provided with a pressing head at one end of the pressing unit in the axial direction close to the carrier unit, the driving member is connected to the end of the pressing unit in the axial direction far away from the carrier unit; and a control unit for controlling the working state of the pressing unit according to a preset pressing parameter, the preset pressing parameter includes at least one of the following: pressing force, pressing times, pressing position and pressing time.

Illustratively, the default press parameters include press parameters input by a user and/or pre-stored press parameters.

Exemplarily, the actuator includes a servo cylinder.

Exemplarily, the control unit includes: a pressure sensor, which is arranged on the pressing head and used to detect the instantaneous pressure value of the pressing head pressing on the wafer to be tested; and a controller, which is electrically connected to the pressure sensor and used to control the working state of the driving part according to the instantaneous pressure value fed back by the pressure sensor and the pressure value in the preset pressing parameter.

Exemplarily, the carrier unit includes: a carrier body for holding the wafer to be tested; and a rotating mechanism, which is connected to the carrier body and can drive the carrier body to perform circular motion around an axis perpendicular to the carrier body.

Exemplarily, the control unit is also connected to the rotating mechanism to control the working state of the rotating mechanism according to preset pressing parameters.

Exemplarily, the driving part includes a high-frequency pulse vibration motor capable of driving the pressing rod to perform high-frequency pulse vibration; the pressing head is also provided with a sonar probe, which is used to detect the real-time vibration sound wave data on the surface of the wafer to be tested; the control unit also includes: a memory for pre-storing normal sound wave data; an acoustic wave analyzer connected to the sonar probe and the memory, which is used to compare the real-time vibration sound wave data with the normal sound wave data to determine the hidden crack result of the wafer to be tested.

In the second aspect, the embodiment of the present invention also provides a wafer crack detection method, which is applied to the wafer crack detection device as described above, and the method includes the following steps: placing the wafer to be tested on the carrier unit; the control unit controls the working state of the pressing unit according to the preset pressing parameters to perform a pressing action on the wafer to be tested on the carrier unit, wherein the preset pressing parameters include at least one of the following: pressing force value, pressing times, pressing position and pressing time.

Exemplarily, the control unit controls the working state of the pressing unit according to the preset pressing parameters to perform a pressing action on the wafer to be tested on the stage unit, specifically including: the user inputs the pressing parameters into the controller, or the pressing parameters are pre-stored in the controller; the position of the wafer to be tested is adjusted so that the first position to be tested of the wafer to be tested is located directly below the pressing head; the controller controls the driving part to start so that the pressing rod descends and press the first position to be tested; the pressure sensor feeds back the instantaneous pressure value of the pressing head to the controller, and when the instantaneous pressure value reaches the pressing force value in the preset pressing parameter, the pressing rod is controlled to stop descending, and after staying for the pressing time in the preset pressing parameter, the pressing rod is controlled to rise to complete a pressing action; the above pressing action is repeated to complete multiple pressing actions for the first position to be tested according to the number of pressing times.

Exemplarily, the control unit controls the working state of the pressing unit according to the preset pressing parameters to perform a pressing action on the wafer to be tested on the stage unit, specifically including: after completing multiple pressing actions on the first position to be tested, rotating the stage body through the rotating mechanism to adjust the position of the wafer to be tested so that the second position to be tested of the wafer to be tested is located directly below the pressing head; repeating the above pressing action to complete multiple pressing actions for the second position to be tested.

Exemplarily, when the control unit controls the working state of the pressing unit according to the preset pressing parameters to perform a pressing action on the wafer to be tested on the stage unit, the driving component is controlled to drive the pressing component to perform high-frequency pulse vibration on the surface of the wafer to be tested; the real-time vibration sound wave data on the surface of the wafer to be tested is detected by the sonar probe; and the real-time vibration sound wave data and the normal sound wave data are compared by the sound wave analyzer to determine the hidden crack result of the wafer to be tested.

The advantages brought by the embodiments of the present invention are as follows:

The wafer crack detection device and wafer crack detection method provided by the embodiment of the present invention can perform quantified pressing actions such as pressing force, pressing times and pressing time on the designated position of the wafer to be tested, solving the problem that the pressure cannot be quantified in the manual tapping detection method in the prior art.

S01~S02: Steps

10: Wafer to be tested

20: Carrier unit

21: Carrier body

22: Rotating mechanism

30: Pressing unit

31: Press the lever

311: Press the head

32:Driver

33:Sonar probe

41: Pressure sensor

42: Controller

50: Base

60: Body

61: Transparent protective cover

70: Display screen

FIG1 is a schematic diagram showing the structure of a wafer latent crack detection device provided in an embodiment of the present invention; FIG2 is a flow chart showing a wafer latent crack detection method provided in an embodiment of the present invention.

In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described below in conjunction with the attached drawings of the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without progressive labor are within the scope of protection of the present invention.

Unless otherwise defined, the technical or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. "First", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, "one", "an" or "the" and similar words do not indicate quantity restrictions, but indicate the existence of at least one. "Including" or "including" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, but do not exclude other elements or objects. "Connected" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right", etc. are only used to express relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

As shown in FIG. 1 , the wafer crack detection device provided by the embodiment of the present invention includes: a stage unit 20 for carrying a wafer 10 to be tested; a pressing unit 30 for pressing the wafer 10 to be tested on the stage unit 20, the pressing unit 30 being located above the stage unit 20, the pressing unit 30 including a pressing rod 31 and a driving member 32, the pressing rod 31 being axially perpendicular to the stage unit 20 and extending along its axis. The pressing unit 30 is movable in the axial direction, and a pressing head 311 is provided at one end of the pressing unit 30 close to the carrier unit 20 in the axial direction, and the driving member 32 is connected to one end of the pressing unit 30 far away from the carrier unit 20 in the axial direction; and a control unit for controlling the working state of the pressing unit 30 according to a preset pressing parameter, and the preset pressing parameter includes at least one of the following: pressing force, pressing times, pressing position and pressing time.

In the above scheme, when the wafer crack detection device performs wafer crack detection, the wafer to be tested 10 can be placed on the stage unit 20, and the control unit can control the pressing unit 30 to press the wafer to be tested 10 by preset pressing parameters, so that the pressing force, pressing times and pressing time of the designated position of the wafer to be tested 10 can be quantified, solving the problem that the pressure cannot be quantified in the manual knocking detection method in the related technology, and compared with the problem of poor detection accuracy of the camera used in the related technology, the detection accuracy can be improved and the detection rate is high.

As shown in the figure, in some exemplary embodiments, the preset pressing parameters include pressing parameters input by the user and/or pre-stored pressing parameters. That is, the preset pressing parameters can be pressing parameters input by the operator according to actual detection requirements each time the wafer crack detection is performed (for example, a display screen 70 can be set on the device to display the pressing parameters input by the user), or they can be pre-stored pressing parameters.

In some embodiments, the driving member 32 includes a servo cylinder. The servo cylinder is used to drive the pressing rod 31 to move, so that the pressing rod 31 can slowly press the wafer 10 to be tested, so as to minimize the damage to the wafer surface. Of course, it can be understood that the driving member 32 is not limited to the servo cylinder. For example, the driving member 32 can also be a hydraulic cylinder, etc.

Exemplarily, as shown in FIG1 , the control unit includes: a pressure sensor 41, which is arranged on the pressing head 311 and is used to detect the real-time pressure value of the pressing head 311 pressing on the wafer 10 to be tested; and a controller 42, which is electrically connected to the pressure sensor 41 and is used to control the working state of the driving part according to the real-time pressure value fed back by the pressure sensor 41 and the pressure value in the preset pressing parameter.

By adopting the above solution, by setting the pressure sensor 41 on the pressing head 311, the pressing force of the pressing head 311 can be detected in real time, so that the pressing force can be accurately controlled for different types of silicon wafers. In addition, an elastic pad can also be set on the pressing head 311 to avoid damage to the wafer surface.

In addition, as shown in FIG. 1 , the carrier unit 20 includes: a carrier body 21 for holding the wafer 10 to be tested; and a rotating mechanism 22, which is connected to the carrier body 21 and can drive the carrier body 21 to perform circular motion around an axis perpendicular to the carrier body 21.

By adopting the above scheme, the carrier body 21 can perform circular motion under the drive of the rotating mechanism 22. In this way, when the wafer 10 to be tested is placed on the carrier body 21, by rotating the carrier body 21, a certain position of the wafer 10 to be tested can be located directly below the pressing head 311 as the current position to be tested; after the pressing action of the current position to be tested is completed, the carrier body 21 can be rotated by a predetermined angle so that the next position to be tested of the wafer 10 to be tested is located directly below the pressing head 311 to perform the pressing detection of the next position to be tested, until all positions to be tested have completed the pressing detection.

The control unit is also connected to the rotating mechanism 22 and is used to control the working state of the rotating mechanism 22 according to the preset pressing parameters.

In addition, in an exemplary embodiment, the driving member 32 includes a high-frequency pulse vibration motor capable of driving the pressing rod 31 to perform high-frequency pulse vibration; as shown in FIG1 , the pressing head 311 is also provided with a sonar probe 33, and the sonar probe 33 is used to detect the real-time vibration sound wave data on the surface of the wafer 10 to be tested; the control unit also includes: a memory for pre-storing normal sound wave data; and a sound wave analyzer connected to the sonar probe 33 and the memory, for comparing the real-time vibration sound wave data with the normal sound wave data to determine the hidden crack result of the wafer to be tested.

By adopting the above scheme, the control unit sends a high-frequency pulse command to the driving element 32 to control the pressing rod 31 to vibrate the surface of the wafer 10 to be tested at a high frequency. Since normal wafers and cracked wafers have different degrees of absorption of sound waves, the crack condition of the wafer can be identified by analyzing the difference in sound waves, and the automatic detection function can be realized to solve the problem of low efficiency of manual detection.

In addition, as a specific embodiment, as shown in FIG1 , the overall structure of the wafer crack detection device may also include: a base 50 and a body 60, wherein the carrier unit 20 may be disposed on the base 50, and the body 60 may be fixed on the base 50. As shown in the figure, the pressing rod 31 and the driving member 32 may be installed on the body 60, and the body 60 may include a transparent protective cover 61 to facilitate maintenance of the pressing unit 30, etc.

In the second aspect, the embodiment of the present invention also provides a wafer crack detection method, which is applied to the wafer crack detection device provided by the embodiment of the present invention, as shown in FIG2, the method includes the following steps: step S01, the wafer 10 to be tested is placed on the stage unit 20; step S02, the control unit controls the working state of the pressing unit 30 according to the preset pressing parameter to perform a pressing action on the wafer 10 to be tested on the stage unit 20, wherein the preset pressing parameter includes at least one of the following: pressing force value, pressing times, pressing position and pressing time.

Exemplarily, the above step S02 specifically includes: step S021, the user inputs a pressing parameter into the controller 42, or the controller 42 stores the pressing parameter in advance; step S022, adjusting the position of the wafer 10 to be tested so that the first position to be tested of the wafer 10 to be tested is located directly below the pressing head 311; step S023, the controller 42 controls the driving member 32 to start, so that the pressing rod 31 descends and presses the first position to be tested; step S024, the pressure The sensor 41 feeds back the instantaneous pressure value of the pressing head 311 to the controller 42. When the instantaneous pressure value reaches the pressing force value in the preset pressing parameter, the pressing rod 31 is controlled to stop descending, and after staying for the pressing time in the preset pressing parameter, the pressing rod 31 is controlled to rise to complete a pressing action; Step S025, repeat the above pressing action (i.e., step S023 to step S024), so as to complete multiple pressing actions for the first position to be tested according to the number of pressing times.

Exemplarily, the above step S01 specifically further includes: step S026, after completing multiple pressing actions on the first position to be tested, rotating the stage body 21 through the rotating mechanism 22 to adjust the position of the wafer 10 to be tested so that the second position to be tested of the wafer 10 to be tested is located directly below the pressing head 311; step S027, repeating the above pressing actions (i.e., step S023 to step S024) to complete multiple pressing actions for the second position to be tested.

Exemplarily, step S02 specifically includes: when the control unit controls the working state of the pressing unit 30 according to the preset pressing parameters to perform a pressing action on the wafer 10 to be tested on the stage unit 20, the driving component 32 is controlled to drive the pressing component to perform high-frequency pulse vibration on the surface of the wafer 10 to be tested; the sonar probe 33 is used to detect the real-time vibration sound wave data on the surface of the wafer 10 to be tested; and the sound wave analyzer 44 is used to compare the real-time vibration sound wave data with the normal sound wave data to determine the hidden crack result of the wafer to be tested.

The following points need to be explained: (1) The drawings of the embodiments of the present invention only involve structures related to the embodiments of the present invention, and other structures can refer to the general design; (2) For the sake of clarity, the thickness of the layer or region in the drawings used to describe the embodiments of the present invention is enlarged or reduced, that is, these drawings are not drawn according to the actual scale. It can be understood that when an element such as a layer, film, region or substrate is said to be located "on" or "under" another element, the element can be "directly" located "on" or "under" another element or there can be an intermediate element; (3) In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other to obtain new embodiments.

The above is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. The protection scope of the present invention shall be based on the protection scope of the patent application.

10: Wafer to be tested

20: Carrier unit

21: Carrier body

22: Rotating mechanism

30: Pressing unit

31: Press the lever

311: Press the head

32:Driver

33:Sonar probe

41: Pressure sensor

42: Controller

50: Base

60: Body

61: Transparent protective cover

70: Display screen

Claims (8)

A wafer crack detection device includes: a stage unit for carrying a wafer to be tested; a pressing unit for performing a pressing action on the wafer to be tested on the stage unit, the pressing unit is located above the stage unit, the pressing unit includes a pressing rod and a driving member, the pressing rod is axially perpendicular to the stage unit and can move along its own axis, the pressing unit is provided with a pressing head at one end close to the stage unit in its axial direction, the driving member is connected to one end of the pressing unit in its axial direction away from the stage unit; and a control unit for controlling the working state of the pressing unit according to a preset pressing parameter. The preset pressing parameters include at least one of the following: pressing force, pressing times, pressing position and pressing time; the driving part includes a high-frequency pulse vibration motor capable of driving the pressing rod to perform high-frequency pulse vibration; the pressing head is also provided with a sonar probe, which is used to detect the real-time vibration sound wave data on the surface of the wafer to be tested; the control unit also includes: a memory, which is used to pre-store normal sound wave data; an acoustic wave analyzer, which is respectively connected to the sonar probe and the memory, and is used to compare the real-time vibration sound wave data with the normal sound wave data to determine the hidden crack result of the wafer to be tested. A wafer crack detection device as described in claim 1, wherein the preset pressing parameters include pressing parameters input by the user and/or pre-stored pressing parameters. The wafer crack detection device as described in claim 1, wherein the control unit includes: a pressure sensor, the pressure sensor is arranged on the pressing head, and is used to detect the real-time pressure value of the pressing head pressing on the wafer to be tested; and a controller, the controller is electrically connected to the pressure sensor, and is used to control the working state of the driving part according to the real-time pressure value fed back by the pressure sensor and the pressure value in the preset pressing parameter. The wafer hidden crack detection device as described in claim 1, wherein the carrier unit includes: a carrier body for holding the wafer to be tested; and a rotating mechanism, the rotating mechanism is connected to the carrier body and can drive the carrier body to perform circular motion around an axis perpendicular to the carrier body; the control unit is also connected to the rotating mechanism and is used to control the working state of the rotating mechanism according to a preset pressing parameter. A wafer crack detection method is applied to a wafer crack detection device as described in any one of claims 1 to 4, the method comprising the following steps: placing a wafer to be tested on the carrier unit; the control unit controls the working state of the pressing unit according to a preset pressing parameter to perform a pressing action on the wafer to be tested on the carrier unit, wherein the preset pressing parameter includes at least one of the following: pressing force value, pressing times, pressing position and pressing time. The wafer crack detection method as described in claim 5, wherein, when applied to the wafer crack detection device as described in claim 3, the control unit controls the working state of the pressing unit according to the preset pressing parameters to perform a pressing action on the wafer to be tested on the stage unit, specifically including: the user inputs the pressing parameters into the controller, or the pressing parameters are pre-stored in the controller; the position of the wafer to be tested is adjusted so that the first position to be tested of the wafer to be tested is located directly below the pressing head; the controller The driving part is controlled to start so that the pressing rod descends and presses on the first position to be tested; The pressure sensor feeds back the instantaneous pressure value of the pressing head to the controller. When the instantaneous pressure value reaches the pressing force value in the preset pressing parameter, the pressing rod is controlled to stop descending, and after staying for the pressing time in the preset pressing parameter, the pressing rod is controlled to rise to complete a pressing action; the above pressing action is repeated to complete multiple pressing actions for the first position to be tested according to the number of pressing times. The wafer crack detection method as described in claim 5, wherein when applied to the wafer crack detection device as described in claim 4, the control unit controls the working state of the pressing unit according to the preset pressing parameters to perform a pressing action on the wafer to be tested on the stage unit, specifically including: after completing multiple pressing actions on the first position to be tested, rotating the stage body through the rotating mechanism to adjust the position of the wafer to be tested so that the second position to be tested of the wafer to be tested is located directly below the pressing head; repeating the above pressing action to complete multiple pressing actions for the second position to be tested. The wafer hidden crack detection method as described in claim 5, wherein, when applied to the wafer hidden crack detection device as described in claim 1, the method further comprises the following steps: when the control unit controls the working state of the pressing unit according to the preset pressing parameters to perform a pressing action on the wafer to be tested on the stage unit, the driving component is controlled to drive the pressing component to perform high-frequency pulse vibration on the surface of the wafer to be tested; the real-time vibration sound wave data of the surface of the wafer to be tested is detected by a sonar probe; and the real-time vibration sound wave data is compared with normal sound wave data by a sound wave analyzer to determine the hidden crack result of the wafer to be tested.