CN109285794B

CN109285794B - Visual inspection machine and method for wafer

Info

Publication number: CN109285794B
Application number: CN201710600948.4A
Authority: CN
Inventors: 孙瑞; 何昆哲; 赵厚莹
Original assignee: Zing Semiconductor Corp
Current assignee: Zing Semiconductor Corp
Priority date: 2017-07-21
Filing date: 2017-07-21
Publication date: 2020-11-20
Anticipated expiration: 2037-07-21
Also published as: CN109285794A

Abstract

The invention provides a visual inspection machine and a visual inspection method for a wafer. The visual inspection machine includes: the carrying platform is used for supporting the wafer to be tested; the mechanical arms are arranged on two sides of the carrying platform and used for grabbing the wafer to be detected; the mechanical arm is rotatably arranged around a first axial direction, a second axial direction and a third axial direction, the extending directions of the first axial direction and the second axial direction are two mutually perpendicular directions on a horizontal plane, and the extending direction of the third axial direction is a vertical direction perpendicular to the horizontal plane. According to the visual inspection machine and the inspection method, the mechanical arm can rotate around three different directions, such as an X axis, a Y axis and a Z axis, through different points and tracks. Through rotate to snatch different positions twice and realize that the wafer does not have the blind area, all regions can all be detected, have solved the problem that present visual inspection machine exists the unable comprehensive detection in dead angle, have further improved detection precision and degree of accuracy.

Description

Visual inspection machine and method for wafer

Technical Field

The invention relates to the technical field of semiconductors, in particular to a visual detection machine and a detection method for a wafer.

Background

In recent years, the technology of semiconductor manufacturing process has been dramatically advanced, and products are now required to be light, thin, short, small, with smaller IC size, stronger function and more pins. The high-level packaging method has high unit price, if the chip test can be carried out before the packaging, and the defective products are found to exist in the wafer, the marking is carried out, and the marked defective products are abandoned until the back-end packaging process, so that the unnecessary packaging cost can be saved.

Currently, in the semiconductor industry, a visual inspection machine (visual inspection machine) is mainly an instrument for observing wafer defects under a specific light source. Most of the traditional visual inspection machines have blind areas. Because the mechanical arm for grabbing the wafer shields the edge area of one part of the wafer, the shielded part cannot be inspected, and the visual inspection machine with a blind area cannot comprehensively inspect the defects of the wafer.

In addition, the visual inspection machine conveys the wafer to the wafer carrying frame through the mechanical arm, the wafer carrying frame clamps and clamps the wafer after sensing the wafer, and an operator can rotate the wafer by 360 degrees through the rocker so as to observe defects in the front surface, the back surface and the edge of the wafer from different angles. However, the current visual inspection machine carrier can shield partial edge of the wafer, and a blind area exists, so that an operator cannot comprehensively observe and detect the wafer.

Accordingly, there is a need for an improved visual inspection machine for inspecting wafers that eliminates the above-mentioned disadvantages.

Disclosure of Invention

In this summary, concepts in a simplified form are introduced that are further described in the detailed description. This summary of the invention is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

In view of the deficiencies of the prior art, the present invention provides a visual inspection machine for wafers, comprising:

the carrying platform is used for supporting the wafer to be tested;

the mechanical arms are arranged on two sides of the carrying platform and used for grabbing the wafer to be detected;

the mechanical arm is rotatably arranged around a first axial direction, a second axial direction and a third axial direction, the extending directions of the first axial direction and the second axial direction are two mutually perpendicular directions on a horizontal plane, and the extending direction of the third axial direction is a vertical direction perpendicular to the horizontal plane.

Optionally, the robot arm includes a first extending structure connected to the carrier, a second extending structure connected to the first extending structure, and a mechanical gripper connected to the second extending structure.

Optionally, the first extending structure extends outward from a side wall of the carrier, and the second extending structure rotates around the second axial direction around a joint of the first extending structure and the second extending structure.

Optionally, the mechanical grip rotates about the first axial direction about a junction of the second extending structure and the mechanical grip.

Optionally, the second extending structure comprises a vertical portion and a horizontal portion, wherein the vertical portion extends upward, and the horizontal portion extends in a direction close to the stage.

Optionally, a plurality of gripping and positioning pins are arranged on the mechanical gripper.

Optionally, the stage includes a stage main body and a wafer stage sleeved on the stage main body and rotatably disposed.

Optionally, a sliding rail is disposed between the stage main body and the wafer stage, and is used for rotating the robot arm around the third axis.

Optionally, the edge of the wafer carrier is provided with a plurality of wafer positioning pins.

Optionally, the wafer stage is sleeved on the stage main body in a vertically moving manner.

Optionally, the visual inspection machine further includes an inspection light source for inspecting whether the wafer to be inspected has defects.

The invention also provides a detection method using the visual detection machine, which is characterized by comprising the following steps:

grabbing the wafer to be detected from the carrying platform for the first time by using the mechanical arm, and rotating the mechanical arm around the first axial direction and the second axial direction to detect the wafer to be detected;

putting the wafer to be tested back to the carrying platform, and rotating the mechanical arm along the third axial direction;

and grabbing the wafer to be detected from the carrying platform for the second time by using the mechanical arm, wherein the positions of the wafer to be detected grabbed by the mechanical arm in the first grabbing and the second grabbing are different, and then rotating the mechanical arm around the first axial direction and the second axial direction so as to detect the wafer to be detected again.

Optionally, the method further comprises:

after the wafer to be detected is detected again, the wafer to be detected is placed back to the carrying platform;

and after aligning the notch mark of the wafer to be detected, sending the wafer to be detected back to the wafer box.

According to the visual inspection machine and the inspection method, the mechanical arm can rotate around three different directions, such as an X axis, a Y axis and a Z axis, through different points and tracks. Through rotate to snatch different positions twice and realize that the wafer does not have the blind area, all regions can all be detected, have solved the problem that present visual inspection machine exists the unable comprehensive detection in dead angle, have further improved detection precision and degree of accuracy.

Drawings

The following drawings of the invention are included to provide a further understanding of the invention. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

Reference numerals:

10. stage main body 11 and robot arm

12. Wafer stage 13 and wafer positioning pin

14. Sliding rail 111, first extension structure

112. Second extending structure 113, mechanical gripper

114. Grabbing positioning pin

FIG. 1 shows a schematic view of a visual inspection machine according to an embodiment of the present invention;

fig. 2 shows a flow chart of a method of inspection by a visual inspection machine according to an embodiment of the invention.

Detailed Description

In the following description, numerous specific details are set forth in order to provide a more thorough understanding of the present invention. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without one or more of these specific details. In other instances, well-known features have not been described in order to avoid obscuring the invention.

It is to be understood that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, the size and relative sizes of layers and regions may be exaggerated for clarity. Like reference numerals refer to like elements throughout.

It will be understood that when an element or layer is referred to as being "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it can be directly on, adjacent to, connected or coupled to the other elements or layers or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly adjacent to," "directly connected to" or "directly coupled to" other elements or layers, there are no intervening elements or layers present. It will be understood that, although the terms first, second, third, etc. may be used to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the present invention.

Spatial relational terms such as "under," "below," "under," "above," "over," and the like may be used herein for convenience in describing the relationship of one element or feature to another element or feature as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, then elements or features described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary terms "under" and "under" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial descriptors used herein interpreted accordingly.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. 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 in this specification, 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. As used herein, the term "and/or" includes any and all combinations of the associated listed items.

Embodiments of the invention are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of the invention. As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments of the invention should not be limited to the particular shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an implanted region shown as a rectangle will typically have rounded or curved features and/or implant concentration gradients at its edges rather than a binary change from implanted to non-implanted region. Also, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation is performed. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of the present invention.

In order to provide a thorough understanding of the present invention, detailed steps will be set forth in the following description in order to explain the technical solutions proposed by the present invention. The following detailed description of the preferred embodiments of the invention, however, the invention is capable of other embodiments in addition to those detailed.

Example one

In order to solve the foregoing technical problem, the present invention provides a visual inspection machine for a wafer, which is further described below with reference to the accompanying drawings, and fig. 1 shows a schematic structural diagram of the visual inspection machine according to an embodiment of the present invention.

Specifically, as shown in fig. 1, the visual inspection machine for wafers according to the present invention includes:

the carrying platform is used for supporting and fixing the wafer to be detected;

the mechanical arms 11 are arranged on two sides of the carrying platform and used for grabbing the wafer to be detected;

Specifically, the stage includes a stage main body 10 and a wafer stage 12, which are arranged vertically up and down. Wherein the vertical direction refers to the extension direction of the carrier.

Specifically, the wafer carrier is sleeved on the carrier main body, and the wafer carrier protrudes out of the surface of the carrier main body.

The wafer carrier 12 is used for supporting and fixing a wafer to be detected, transferring the wafer to the carrier in an actual detection process, and sending the wafer to a wafer box through the carrier after the detection is finished.

Optionally, in order to better fix the wafer to be tested, a wafer positioning pin 13 is disposed at the edge of the wafer stage 12.

Optionally, the wafer positioning pins 13 are uniformly distributed on the periphery of the wafer carrier 12, and are used for fixing the wafer within the area defined by the wafer positioning pins 13, so as to prevent the wafer to be measured from sliding off.

The number of the wafer positioning pins 13 is not limited to a certain range, for example, 3 wafer positioning pins 13 are uniformly arranged on the periphery of the wafer carrier 12.

A sliding rail 14 is disposed between the stage main body 10 and the wafer stage 12, and is used for rotating the robot arm around the third axis.

The third axial direction is the extending direction of the carrier and is defined as the Z-axis direction.

Optionally, the first axial direction may also be defined as an X-axis direction, and the second axial direction may also be defined as a Y-axis direction, where the X-axis direction and the Y-axis direction are on the same horizontal plane, and the Z-axis direction is a direction perpendicular to the horizontal plane, as shown in fig. 1.

Optionally, the robot 11 is disposed on the stage main body 10, and optionally, the robot 11 is distributed on two sides of the stage main body 10.

Further, the mechanical arms 11 are disposed oppositely, and the mechanical arms 11 are uniformly distributed on two sides of the stage main body 10.

Relative sliding between the stage main body 10 and the wafer stage 12 can be achieved by the slide rail 14, and rotation of the robot arm 11 about the Z axis is also achieved.

The rotation of the mechanical arm 11 around the Z axis can realize that different positions of the wafer to be tested are clamped in two grabbing processes through the rotation of the mechanical arm 11 in the detection process, so as to avoid the occurrence of blind areas in the detection process.

For example, in the first detection, the robot arm grasps the first position of the wafer to be detected, and then rotates a certain angle, for example, any angle between more than 0 ° and less than 180 °, so that in the second detection, the robot arm grasps the second position of the wafer to be detected, and the first position is detected again.

The robot arm may be driven by a driving mechanism, for example, the robot arm may be driven by a cylinder, a gear, a bobbin, etc., but the driving mechanism is not limited to the above-mentioned driving mechanism, and other driving mechanisms and structures commonly used in the art may be selected, and are not further limited herein.

Alternatively, the stage body 10 and the wafer stage 12 may slide up and down to adjust the height of the stage.

Optionally, the robot arm includes a first extending structure 111 connected to the stage, a second extending structure 112 connected to the first extending structure, and a mechanical hand 113 connected to the second extending structure.

The first extending structure 111 is fixedly connected to the stage main body 10, for example, by welding, and the robot arm 11 can rotate around the Z axis through the sliding rail 14, but the invention is not limited to this example.

The first extending structure 111 is rotatably connected to the second extending structure 112, and the first extending structure 111 is connected to the second extending structure 112 at a point B.

Optionally, the first extension structure 111 extends outward from the side wall of the stage body 10, as shown in fig. 1.

Further, a horizontal included angle between the extending direction of the first extending structure and the extending direction of the first axial direction is an acute angle.

Optionally, the second extending structure extends substantially along the Z-axis and may be at an angle to the Z-axis, as shown in fig. 1.

Optionally, the second extending structure rotates around the second axial direction by taking the joint of the first extending structure and the second extending structure as a center. For example, as shown in fig. 1, the second extending structure rotates around the Y axis around point B, for example, rotates around 360 ° around point B around the Y axis, so as to fully inspect the wafer.

The mechanical hand grip is rotatably connected with the second stretching structure, and the mechanical hand grip is connected with the second stretching structure at a point A.

The mechanical hand takes the joint of the second stretching structure and the mechanical hand as a center to rotate around the first axial direction. For example, as shown in fig. 1, the robot arm may rotate around the X axis around point a, for example, 360 ° around point a, to fully inspect the wafer.

Further, the second extending structure includes a vertical portion extending substantially along the Z-axis direction and a horizontal portion extending in a direction close to the stage (i.e., extending substantially along the X-axis direction).

Optionally, a plurality of gripping and positioning pins 114 are provided on the mechanical gripper to improve gripping efficiency and stability.

In the detection, after the mechanical arm grabs the wafer, the wafer can be rotated to inspect the defects on the wafer from different angles, after the observation, the wafer is placed on the carrying platform again, the carrying platform rotates by a certain angle, for example, 90 degrees, then the wafer is grabbed for the second time for visual inspection, and the key point is to inspect the first shielded part.

Example two

The invention also provides a detection method, which is used for detecting through the visual detection machine in the first embodiment.

As shown in fig. 2, the method includes:

Optionally, the method further comprises:

and after aligning the notch mark of the wafer to be detected, sending the wafer to the crystal box.

In one embodiment, after the robot arm picks up the wafer, the wafer may be rotated to inspect defects on the wafer from different angles, and after the inspection, the wafer is placed on the stage again, and the stage is rotated by a certain angle, for example, 90 °, and then the wafer is picked up again for visual inspection, with the emphasis on inspecting the first blocked portion.

The present invention has been illustrated by the above embodiments, but it should be understood that the above embodiments are for illustrative and descriptive purposes only and are not intended to limit the invention to the scope of the described embodiments. Furthermore, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and that many variations and modifications may be made in accordance with the teachings of the present invention, which variations and modifications are within the scope of the present invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims

1. A visual inspection machine for wafers, said visual inspection machine comprising:

the carrying platform is used for supporting the wafer to be tested;

wherein the mechanical arm is rotationally arranged around a first axial direction, a second axial direction and a third axial direction, the extension directions of the first axial direction and the second axial direction are two mutually perpendicular directions on a horizontal plane, the extension direction of the third axial direction is a vertical direction perpendicular to the horizontal plane, the mechanical arm comprises a first extension structure connected with the carrying platform, a second extension structure connected with the first extension structure and a mechanical hand connected with the second extension structure, the first extending structure extends outwards from the side wall of the carrying platform, the second extending structure rotates around the second axial direction by taking the joint of the first extending structure and the second extending structure as a center, the second extending structure comprises a vertical part and a horizontal part, wherein the vertical portion extends upwardly and the horizontal portion extends in a direction closer to the carrier; the carrying platform comprises a carrying platform main body and a wafer carrying platform which is sleeved on the carrying platform main body and is arranged in a rotating mode, and a sliding track is arranged between the carrying platform main body and the wafer carrying platform and used for enabling the mechanical arm to rotate around the third axial direction.

2. The visual inspection machine of claim 1, wherein the mechanical hand grip rotates about the first axial direction centered about a junction of the second extension and the mechanical hand grip.

3. The visual inspection machine of claim 1, wherein said mechanical gripper is provided with a plurality of gripper locating pins.

4. The visual inspection machine of claim 1, wherein an edge of said wafer stage is provided with wafer positioning pins.

5. The visual inspection machine of claim 1, wherein the wafer stage is vertically movably sleeved on the stage body.

6. The visual inspection machine of claim 1, further comprising an inspection light source for inspecting the wafer under test for defects.

7. An inspection method using the visual inspection machine of any of claims 1 to 6, the method comprising:

8. The method of claim 7, further comprising: