CN111640686A

CN111640686A - Wafer detection method and wafer detection module

Info

Publication number: CN111640686A
Application number: CN202010510195.XA
Authority: CN
Inventors: 刘昊岩
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-06-08
Filing date: 2020-06-08
Publication date: 2020-09-08

Abstract

The invention discloses a wafer detection method, which comprises the steps of providing a wafer to be detected, wherein the wafer to be detected is provided with a plurality of optical microstructures; illuminating a plurality of selected areas one by one on the back of the wafer to be tested; detecting an image of the light transmitted through the selected area on the front side of the wafer to be detected; the images are analyzed to determine whether the wafer to be tested meets the specification. The wafer detection module comprises a wafer to be detected, a plurality of optical microstructures and a plurality of optical microstructures, wherein the wafer to be detected is provided with the optical microstructures; the light source device is arranged on the back surface of the wafer to be detected and used for providing a light source or illumination for the wafer to be detected; and the sensing mechanism is arranged on the front side of the wafer to be detected and is used for shooting images of the area illuminated by the light source device. Therefore, the wafer detection module and the wafer detection method can be used for detecting the compliance of the wafer before packaging, and are convenient and quick.

Description

Wafer detection method and wafer detection module

Technical Field

The present invention relates to a detection technology in the field of optoelectronic semiconductors, and in particular, to a detection method for detecting wafer characteristics and a wafer detection mechanism for detecting wafer characteristics.

Background

The common "depth of field sensing" method for visual information by the AI information acquisition function includes 1. binocular method (using phase difference) 2.DOE Diffractive Optical Elements (also called structured light) 3.TOF time-of-flight mass spectrometry (time-of-flight). The DOE principle is to project a pattern of spots (dots), which can be tens of thousands of dots. For example, when the DOE light irradiates, 3 thousands of round dots are projected on the face, a flat forehead has a light spot with a certain area size of an undeformed right circle, and a side face has a light spot with a certain area size of a deformed ellipse, and the depth of field of an object can be judged by utilizing the information, so that the three-dimensional appearance structure of the object is deduced. The DOE method has the defects that the distance is far, dots are distorted due to excessive divergence, and the judgment accuracy is reduced. TOF uses optical path difference, when light is projected onto a three-dimensional structure object, it is reflected, and the reflected optical path amount at each position is different, so that the depth of field can be calculated by reflecting the received information.

A typical DOE element or TOF element is fabricated using a Vertical Cavity Surface Emitting Laser (VCSEL). VCSEL is a Laser Diode (Laser Diode) manufactured by semiconductor process based on gallium arsenide semiconductor material, and its light beam is emitted from the front Surface, rather than the conventional side Surface, so it is called Surface-Emitting Laser (Surface-Emitting Laser). The VCSEL array can meet the wide measurement requirement of structured light projection in three-dimensional face digitization, and can be conveniently integrated in miniaturized equipment such as mobile phones.

By packaging the die with the optical structure and the VCSEL together, the desired DOE or TOF element can be fabricated. Wherein the die can be obtained by fabricating an optical structure on a wafer and cutting the wafer. As is well known, a wafer refers to a substrate (also called a wafer or a baseboard) from which semiconductor transistors or integrated circuits are fabricated. Since it is a crystalline material, it is called a wafer because it is circular in shape. Wafers are named and classified differently according to the substrate material. The wafer or the chip can be processed into various circuit element structures or optical structures, so that the wafer or the chip becomes a product with a specific photoelectric function.

Generally, after the wafer is diced into dies, the dies are packaged, and then the manufactured DOE element or TOF element is subjected to structural and optical or electrical function detection and identification after the packaging is completed, so as to ensure that the relevant elements meet the requirements of the system. When the photoelectric performance is found to be out of specification in the packaging test, the packaging is carried out again after the decapsulation and adjustment. This additionally increases the overall manufacturing cost of the associated components due to the higher packaging cost.

Therefore, if the die on the wafer can be optically inspected before packaging, the manufacturing cost can be greatly reduced and the defects and problems found can be immediately improved compared with the inspection after packaging.

Therefore, the present invention is directed to a wafer inspection method and a wafer inspection module for wafer inspection, so as to solve the above-mentioned problems.

Disclosure of Invention

The present invention provides a wafer inspection method, which can inspect the wafer and the dies thereon after the wafer is processed into an optical structure and before the wafer is cut and packaged, so as to reduce the overall cost in semiconductor manufacturing and improve the manufacturing efficiency of the semiconductor.

To achieve at least one of the advantages or other advantages, an embodiment of the invention provides a wafer inspection method, which includes providing a wafer to be inspected, the wafer having a plurality of optical microstructures; illuminating the selected areas one by one on the back of the wafer to be tested; detecting an image of the light after transmitting the selected area on the front side of the wafer to be detected; and analyzing the images to determine whether the wafer to be tested meets the specification.

Further, each of the aforementioned selected regions includes at least one die.

The plurality of optical microstructures are diffractive optical microstructures, lens structures or diffusion structures. The optical microstructure refers to a micro surface shape with a specific optical function, such as a groove, a bulge, a spherical bulge and the like of the same microstructure array. The optical properties of the optical microstructure are changed under the action of an external field of light, so that the optical microstructure is switched on, modulated, cut off, polarized, converged, brightened, increased in FOV, diffused and diffracted.

The wafer to be tested is a silicon wafer, and the optical microstructure is made of resin.

The detected image is an irradiation energy distribution image of the region.

Further, the selected areas include an area located at the center of the wafer to be tested and an area located at the edge of the wafer to be tested.

The step of analyzing the image to determine whether the wafer to be tested meets the specification further comprises setting a floating range value, which can be a preset upper and lower floating range value, by using a standard irradiation energy distribution map or a standard irradiation energy value sampling point value; and comparing the image of the area at the central position of the wafer to be detected and the image of the area at the edge position of the wafer to be detected with the set floating range value, if the image contrast value of each area is within the set range value, judging that the image contrast value meets the specification, and if the image contrast value of each area exceeds the set floating range value, judging that the image contrast value does not meet the specification.

To achieve at least one of the advantages or other advantages, an embodiment of the invention provides a wafer inspection module for a wafer inspection method, the wafer inspection module including a wafer to be inspected having a plurality of optical microstructures; the light source device is arranged on the back surface of the wafer to be tested and used for providing a light source or illumination for the wafer to be tested; and the sensing mechanism is arranged on the front side of the wafer to be detected and is used for shooting images of the wafer to be detected after being illuminated by the light source device.

The light source device is a Vertical Cavity Surface Emitting Laser (VCSEL) or an Edge Emitting Laser (EEL), and the wavelength range at least covers 760-1100 nm.

The sensing mechanism may include a camera device, and the camera device captures an image of the wafer to be measured after being illuminated.

The sensing mechanism can comprise a camera device and a screen, the light emitted by the light source device irradiates the wafer to be detected and then is projected on the screen, and the camera device shoots and stores the image on the screen.

Therefore, the wafer detection method and the wafer detection module for wafer detection provided by the invention can be used for detecting the compliance of the wafer before packaging, and are convenient and quick, so that the production and manufacturing cost of the photoelectric element is reduced.

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described below in detail with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are included to provide a further understanding of the embodiments of the application, are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the principles of the application. It should be apparent that the drawings in the following description are only examples of the present application and are not intended to limit the embodiments of the present invention, and that other drawings may be derived from the drawings by those skilled in the art without inventive faculty.

The drawings comprise:

FIG. 1 is a flow chart of one embodiment of a wafer inspection method of the present invention;

FIG. 2 is a schematic diagram of a selected inspection area in the wafer inspection method of the present invention;

FIG. 3 is a flow chart of another embodiment of a wafer inspection method of the present invention;

FIG. 4 is a schematic diagram of a selected die for inspection according to the wafer inspection method of the present invention;

FIGS. 5A, 5B and 5C are schematic views of different structures of the wafer inspection module according to the present invention;

FIG. 5 is a schematic diagram of a wafer under test according to the present invention; and

fig. 7 is a partially enlarged view of fig. 6.

The attached drawings are marked as follows: S01-S04, S11-S12-step 10-wafer inspection module 12-region 12B at center position of wafer 12A-region at edge position A-center point die a-peripheral die 1202-die 1204-optical microstructure 14-light source device 16-

sensing mechanism

1602, 1606, 1608-camera 1604-screen

Detailed Description

Specific structural and functional details disclosed herein are merely representative and are provided for purposes of describing example embodiments of the present invention. The present invention may, however, be embodied in many alternate forms and should not be construed as limited to only the embodiments set forth herein.

In the description of the present invention, it is to be understood that the terms "center", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations and positional relationships based on those shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or component in question must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be taken as limiting the present invention. Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless otherwise specified. In addition, the term "comprises" and any variations thereof mean "including at least".

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integrally formed connection; can be mechanically or electrically connected; the two components can be directly connected or indirectly connected through an intermediate medium, and the two components can be communicated with each other. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Referring to fig. 1, fig. 1 is a flowchart illustrating a wafer inspection method according to an embodiment of the invention. To achieve at least one of the above advantages or other advantages, an embodiment of the present invention provides a wafer inspection method, including:

in step one (S01), a wafer (wafer) to be tested is provided, the wafer having a plurality of optical microstructures. The optical microstructure on the wafer to be tested can be arranged in a plurality of ways. For example, a plurality of optical microstructures are directly formed on the wafer to be tested. Or, the wafer to be tested has a plurality of crystal grains, and each crystal grain has a plurality of optical microstructures. Or, the crystal grains on the wafer to be tested are crystal grains (die) obtained by cutting the wafer, and each crystal grain has a plurality of optical microstructures. The number of the crystal grains on the wafer is tens of thousands, and each crystal grain is imprinted with a plurality of optical microstructures.

Optical microstructures are defined as non-planar, including spherical protrusions, pillars, or asymmetric solid structures. Individual optical microstructures or a region have the same structural properties or optical output characteristics. The external dimension is 50nm-2mm, and the length, width and height are within 50nm-2 mm.

In the second step (S02), a plurality of selected areas are irradiated one by one on the back surface of the wafer to be tested. In this step, the operation method for selecting the area is as follows: selecting a region of a wafer to be tested close to the center (or the center), drawing a circle on the wafer by taking the region of the center as the center of the circle and taking a preset range as the radius, and selecting regions on the drawn circle, which correspond to different edge positions on the wafer to be tested, at equal angles. In general, the optical microstructure characteristics of the central region of the wafer during the fabrication process are more desirable, and the optical microstructure characteristics of the peripheral region of the wafer are more prone to be deviated. Therefore, when the wafer is detected, the area of the central position of the wafer and the optical microstructures manufactured on the periphery of the wafer can be selected for detection so as to confirm that the characteristics of each optical microstructure on the wafer to be detected are consistent and meet the established specifications or requirements.

Specifically, referring to fig. 2, fig. 2 is a schematic view illustrating a selected inspection area in the wafer inspection method according to the present invention. In the illustration, a central region 12A to be detected is first selected on a wafer 12 to be detected, a circle (virtual circle) is drawn on the wafer 12 to be detected with the selected central region 12A as a center and a preset range as a radius, and regions 12B corresponding to different edge positions on the wafer 12 to be detected on the circumference are selected at equal angles on the drawn circle. In addition to the virtual circle drawing method, other feasible methods or rules may be used to select the central region 12A and the edge region 12B to be detected on the wafer 12 to be detected. As shown in fig. 2, in this example, a region 12A of the central position to be detected is selected at the central position on the wafer 12 to be detected, and a region 12B of the edge position to be detected is selected at the upper, lower, left, right, and diagonal positions on the wafer 12 to be detected in a certain manner with the region 12A of the central position as the central coordinate position. The number of the selected central regions 12A is one, and the number of the selected edge regions 12B is eight.

And a third step (S03) of detecting the image of the light transmitted through the selected area on the front surface of the wafer to be tested. The image detected in this step is the irradiation energy distribution image of the selected region in the previous step. Referring to fig. 2, in this step, the front surface of the wafer 12 to be tested is individually detected for the effect of light transmitted through the selected central region 12A and the eight selected edge regions 12B.

Step four (S04), the images are analyzed to determine whether the wafer to be tested meets the specification. For example, the irradiation energy distribution image of the central point and the peripheral area of the wafer after irradiation is compared and analyzed by using the standard irradiation energy distribution map or the standard irradiation energy distribution sampling point value corresponding to the area as the judgment standard.

Referring to fig. 3, fig. 3 is a flowchart illustrating another embodiment of a wafer inspection method according to the present invention. Further, the method for detecting a wafer according to the present invention comprises the steps of:

step one (S11): setting a floating range value which can be a preset upper and lower floating range value according to the standard irradiation energy distribution diagram or the standard irradiation energy value sampling point value;

step two (S12): and comparing the image of the area at the central position of the wafer to be detected and the image of the area at the edge position of the wafer to be detected with the standard irradiation energy distribution diagram or the standard irradiation energy value sampling point value, judging that the contrast value of each selected area image meets the regulation if the contrast value is within the set floating range value, and judging that the contrast value does not meet the regulation if the contrast value exceeds the set floating range value.

The plurality of optical microstructures in the exemplary wafer inspection method may be diffractive optical microstructures, lens structures, or diffusive structures. The crystal grains with the diffractive optical microstructure can be applied to manufacturing of DOE elements, and the crystal grains with the diffusive optical microstructure can be applied to manufacturing of TOF elements. The optical microstructure refers to a micro surface shape with a specific optical function, such as a groove, a bulge, a spherical bulge and the like of the same microstructure array. The optical properties of the optical microstructure are changed under the action of an external field of light, so that the optical microstructure is switched on, modulated, cut off, polarized, converged, brightened, increased in FOV, diffused and diffracted.

It is noted that, in the present invention, a plurality of dies can be divided on the wafer to be tested, and each die has a plurality of optical microstructures. When the wafer is subjected to the illumination test, the plurality of dies may be in an uncut or cut state. The die after cutting is a plurality of particles separated from each other, however, since the whole wafer is adhered to the whole pasting film paper during cutting, the cut die does not fall off or separate from the whole wafer, and the detection method of the present invention can be used. The selected area may be irradiated one by one in accordance with a predetermined number of detections and detection positions when irradiated. That is, the relative positions of the wafer and the selected area after dicing are not changed, but the individual dies in the selected area after dicing are relatively independent.

Furthermore, when the wafer to be tested is divided into a plurality of dies, each of the selected areas includes at least one die. Specifically, referring to fig. 4, fig. 4 is a schematic diagram of selecting a die to be tested in the wafer testing method of the present invention, wherein each of the selected regions is composed of a number of dies. When the light irradiation test is performed, the crystal grains are in a state after being cut or in a state without being cut. In this example, the selected areas on the wafer 12 to be tested are the dies on the wafer, which have optical microstructures. When the wafer 12 to be tested selects the detection crystal grain, the central crystal grain a on the wafer 12 to be tested is selected in advance, a circle is virtually drawn by taking the central crystal grain a as the center of the circle and a certain radius, and then a plurality of peripheral crystal grains (crystal grains on the peripheral area of the wafer) are selected on the drawn virtual circumference. Eight peripheral dies a selected on the wafer 12 to be tested are shown in fig. 4, i.e., the selected peripheral dies a shown in fig. 4 are selected at 45 ° intervals on the circumference of the circle with the selected central die as the center of the circle a.

Examples of wafer (also referred to as "substrate" or "base") materials include silicon, germanium, GaAs, InP, GaN, and the like. In this example, the wafer (wafer) to be tested is a silicon wafer whose main component is SiO₂. The wafer to be tested can be made of glass, and in practice, schottky glass is mostly adopted. The wafer to be tested may also be a resin substrate that can conform to predetermined optical characteristics. The optical microstructure of the wafer can be made of resin. The resin material may be epoxy resin, Polycarbonate (PC), Polydimethylsiloxane (PDMS), etc. The resin materials have optical characteristics required by the wafer to be tested.

Referring to fig. 5A, 5B and 5C in conjunction with fig. 6 and 7, fig. 5A, 5B and 5C are schematic diagrams illustrating different structures of the wafer inspection module according to the present invention. To achieve at least one of the advantages or other advantages, an embodiment of the invention provides a wafer inspection module 10, which can be used for the wafer inspection, the wafer inspection module 10 includes a wafer 12 to be inspected, the wafer 12 having a plurality of optical microstructures 1204 thereon; a light source device 14, which is disposed on the back side of the wafer 12 to be tested and is used for providing a light source or illumination for the wafer 12 to be tested; and a sensing mechanism 16 disposed on the front surface of the wafer 12 to be tested for capturing images of the die 1202 illuminated by the light source device 14. The wafer 12 to be tested includes a plurality of dies 1202 thereon, and each die has a plurality of optical microstructures 1204.

The light source device 14 is a Vertical Cavity Surface Emitting Laser (VCSEL) or an Edge Emitting Laser (EEL). The light source device 14 may emit laser light (laser light), infrared light, or the like. The light source device 14 can emit light in a wavelength range of ultraviolet band at the minimum and far infrared band at the maximum. In the present invention, the wavelength range of the light emitted from the light source device 14 at least covers 760 and 1100 nm.

The plurality of optical microstructures 1204 in this example may be diffractive optical microstructures, lens structures, or diffusive structures. Wherein, the crystal grain with the diffraction optical microstructure can be applied to DOE, and the crystal grain with the diffusion optical microstructure can be applied to TOF. The optical microstructure refers to a micro surface shape with a specific optical function, such as a groove, a bulge, a spherical bulge and the like of the same microstructure array. The optical properties of the optical microstructure are changed under the action of an external field of light, so that the optical microstructure is switched on, modulated, cut off, polarized, converged, brightened, increased in FOV, diffused and diffracted.

As shown in fig. 5A, the sensing mechanism 16 further includes a camera 1602 and a screen 1604, the light emitted from the light source 14 illuminates the die and then projects the die on the screen 1604, and the camera 1602 captures and stores the image on the screen 1604. The screen 1604 may be a projection screen, and the die 1202 illuminated by the light source device 14 projects an image on the screen 1604, and the image capturing device 1602 captures the projected image. When the optical microstructure of the die 1202 on the wafer 12 to be tested is a diffusion structure, such as a TOF device, the die 1202 illuminated by the light source 14 is reflected by the screen 1604, projected to the camera 1602, and the image projected by the camera 1602 is captured and stored.

As shown in fig. 5B, the sensing mechanism 16 further includes a camera 1606, and the camera 1606 captures an image of the die after illumination. The light of the die 1202 illuminated by the light source device 14 is directly projected and imaged on the camera device 1606, and the image is captured and stored by the camera device 1606.

As shown in fig. 5C, the sensing mechanism 16 further includes a camera 1608, and the camera 1608 captures an image of the die after illumination. The light of the die 1202 illuminated by the light source device 14 is directly projected and imaged on the imaging device 1608, and the image is captured and stored by the imaging device 1608. In contrast to fig. 5B, in the example shown in fig. 5C, the position of the wafer 12 to be tested is fixed, the light source device 14 moves a certain distance toward the end far away from the wafer 12 to be tested, and the sensing mechanism 16 moves a certain distance toward the end near the wafer 12 to be tested, so as to perform the testing on the wafer 12 to be tested at a short distance. However, when inspecting the optical structure of the die on the wafer 12 to be inspected, the light source device 14, the wafer 12 to be inspected and the sensing mechanism 16 are moved relatively, and the main purpose is to better ensure the accuracy of the inspection result.

The image pickup device is one of a thermal imaging camera, an infrared camera, a CCD camera, a micro projector, or other image pickup devices capable of performing energy distribution shooting. The

image pickup devices

1602, 1606, and 1608 shown in fig. 5A, 5B, and 5C may be the same type or different types, depending on the actual situation.

With the above description in mind, the wafer inspection module 10 of the present invention is used to perform the following operations when inspecting the wafer 12 to be inspected: a wafer 12 to be tested is provided, which includes several to several ten thousand different crystal grains 1202, each of which has a different number of optical microstructures. In the present invention, a plurality of regions including at least one die are selected from the wafer 12 to be tested for detecting the optical structural characteristics thereof. In this example, the selected area includes at least one die at the center of the wafer to be tested, a virtual circle is made by taking the selected die as the center of the circle and a certain number as the radius, and dies in 4-6 areas (actually, the number may be more) with equal angles on the circumference are selected and the selected dies are located at the edge of the wafer 12 to be tested at the same time, as shown in fig. 2 or fig. 4.

In actual detection, when a region and grains to be detected are selected on a wafer to be detected by taking a central point as a circle center and by a certain radius and an equal angular distance, the set radius and the equal angular distance can be adaptively adjusted according to the size of the wafer to be detected, the number of the grains on the wafer to be detected and different sampling inspection standards so as to obtain an effective detection result with high detection sampling number and high accuracy.

After the wafer 12 is fixed in position, a light source 14 is disposed on the back side of the wafer 12 and a sensing mechanism 16 is disposed on the front side of the wafer 12. The light source device 14 is fixed by a carrying mechanism (not shown) and can move through the carrying mechanism. The light source device 14 illuminates the grains of the selected areas one by one, the selected areas are illuminated to form an image in the sensing mechanism 16, and the formed image is photographed by the sensing mechanism 16. The shot image is analyzed to judge whether the wafer to be tested meets the standard or not. The image taken is the irradiation energy distribution of the grains. In the process of testing the wafer, the wafer 12 to be tested, the light source device 14 and the sensing mechanism 16 can be moved relatively according to different situations or requirements to achieve better testing results.

Further description is made with reference to fig. 4, 5A, 5B, and 5C again. Referring to fig. 4, the number of dies to be tested selected in one example of the invention is nine, including a central die a and eight peripheral (peripheral) dies a. In the example shown in fig. 5A, the positions of the wafer 12 to be tested and the sensing mechanism 16 (which includes a camera device 1602 and a screen 1604) are kept still, the light source device 14 is moved by the supporting mechanism to illuminate the nine selected dies to be tested one by one and image on the screen 1604 or the camera device 1602, the image corresponding to the selected die is captured by the camera device 1602, and the captured image is analyzed to determine whether the wafer 12 to be tested meets the requirements.

In the example shown in fig. 5B, the sensing mechanism 16 is a camera device 1606, and the camera device 1606 is relatively far away from the wafer 12 to be tested, which does not affect the image capturing effect of the camera device on the selected die. The positions of the wafer 12 to be tested and the camera 1606 are kept still, the light source device 14 is moved through the carrying mechanism to illuminate the nine selected dies to be tested one by one and to form an image on the camera 1606, the image corresponding to the selected die is shot through the camera 1606, and the shot image is analyzed to confirm whether the wafer 12 to be tested meets the requirements.

In the example shown in fig. 5C, the sensing mechanism 16 is a camera 1608, and the camera 1608 is relatively close to the wafer 12 to be tested, which may affect the image capturing effect of the camera on the selected die. In this case, as compared with fig. 5B, the position of the wafer 12 to be tested is kept fixed, the light source device 14 is moved by the carrying mechanism to illuminate the nine selected dies to be tested one by one and to form an image on the camera device 1608, the position of the camera device 1608 can be moved simultaneously according to the actual shooting effect when the image corresponding to the selected die is shot by the camera device 1608, and then the shot image is analyzed to determine whether the wafer 12 to be tested meets the requirements.

In summary, the wafer inspection method and the wafer inspection module for wafer inspection provided by the invention can inspect the wafer compliance before packaging, and are convenient and fast, thereby reducing the production cost of integrated circuits.

Although the present invention has been described with reference to a preferred embodiment, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A wafer detection method is characterized by comprising the following steps:

providing a wafer to be tested, wherein the wafer to be tested is provided with a plurality of optical microstructures;

selecting a plurality of areas on the back of the wafer to be tested and illuminating one by one;

detecting an image of the region after light rays transmit on the front side of the wafer to be detected; and

and analyzing the image to judge whether the wafer to be detected meets the standard or not.

2. The wafer inspection method of claim 1, wherein each of said regions comprises at least one die.

3. The wafer inspection method of claim 1, wherein the plurality of optical microstructures are diffractive optical microstructures, lens structures, or diffusive structures.

4. The wafer inspection method as claimed in claim 1, wherein the wafer to be inspected is a silicon wafer, and the optical microstructure is made of resin.

5. The wafer inspection method of claim 1, wherein the image is an irradiation energy distribution image of the region.

6. The wafer inspection method as claimed in claim 5, wherein the selected areas include an area located at a center of the wafer to be inspected and an area located at an edge of the wafer to be inspected.

7. The method of claim 6, wherein the step of analyzing the image to determine whether the wafer under test meets the specification further comprises:

setting a floating range value according to a standard irradiation energy distribution diagram or a standard irradiation energy value sampling point value; and is

And comparing the image of the area at the central position of the wafer to be detected and the image of the area at the edge position of the wafer to be detected with the set floating range value, judging that the image contrast value of each area meets the specification if the image contrast value of each area is within the set floating range value, and judging that the image contrast value of each area does not meet the specification if the image contrast value of each area exceeds the set floating range value.

8. A wafer inspection module for use in a wafer inspection method, the wafer inspection module comprising:

a wafer to be tested, wherein the wafer to be tested is provided with a plurality of optical microstructures;

the light source device is arranged on the back surface of the wafer to be tested and used for providing a light source or illumination for the wafer to be tested; and

and the sensing mechanism is arranged on the front side of the wafer to be detected and is used for shooting images of the wafer to be detected after being illuminated by the light source device.

9. The wafer inspection module of claim 8 wherein the light source device is a Vertical Cavity Surface Emitting Laser (VCSEL) or an Edge Emitting Laser (EEL) having a wavelength range at least covering 760 and 1100 nm.

10. The wafer detection module as claimed in claim 8, wherein the sensing mechanism further comprises a camera device, and the camera device captures an image of the wafer to be detected after being illuminated.

11. The wafer detection module as claimed in claim 8, wherein the sensing mechanism further comprises a camera and a screen, the light emitted from the light source device irradiates the wafer to be detected and then projects on the screen, and the camera captures and stores the image on the screen.