Development of wafer back surface inspection system of grinding machine

Abstract

The invention provides development of a grinding machine wafer back face inspection system. The development comprises the steps that a light source module projects light to a film pasting area on the back face of a wafer in a stepping type triggering mode in the wafer moving process; the optical imaging module is used for collecting image data of a film pasting area on the back face of the wafer in real time. The image acquisition card is connected to the optical imaging module and is used for converting the image data into digital signals; the industrial personal computer receives the digital signal, carries out defect analysis on the image data, and recognizes a wafer film pasting bubble or foreign matter defect; the monitoring system PC is in communication connection with the industrial personal computer, displays an analysis result and triggers an abnormal alarm mechanism; the system is linked with the wafer transportation device through an abnormity alarm mechanism to suspend movement, and starts a reinspection process to confirm a defect position, so that the wafer is inspected after a wafer cutting and grinding process, the wafer with an abnormal inspection result is subjected to wafer alarm through system management, then reinspection is carried out, and defective parts after reinspection are removed. Through development and application of the function, continuous occurrence of defects is avoided.

Description

Technical Field

[0001] The present invention relates to the field of semiconductors, in particular to the field of wafer processing and detection technology, and specifically to the development of a wafer backside inspection system for a grinding machine. Background Art

[0002] During the wafer cutting and thinning process, wafer defects caused by various reasons cannot be discovered after the grinding process, resulting in defective parts entering the subsequent production and processing flow and leaking out. It is necessary to develop a grinding machine wafer back side inspection system after the wafer is cut. Summary of the Invention

[0003] In view of the above-mentioned shortcomings of the prior art, the purpose of the present invention is to provide a development of a grinding machine wafer backside inspection system to solve the difficulties of the prior art.

[0004] To achieve the above objectives and other related objectives, the present invention provides a development of a grinding machine wafer backside inspection system, comprising:

[0005] A wafer transport device, wherein the wafer transport device is used to carry and move wafers;

[0006] The light source module includes: a light source module that projects light toward the film-attaching area on the back of the wafer in a step-by-step triggering manner during the movement of the wafer;

[0007] An optical imaging module, comprising a high-resolution industrial camera for collecting real-time image data of the film-attached area on the back of the wafer;

[0008] An image acquisition card, connected to the optical imaging module, for converting image data into digital signals;

[0009] An industrial computer configured to receive the digital signal and perform defect analysis on the image data based on a preset algorithm to identify wafer film bubbles or foreign matter defects;

[0010] A monitoring system PC, which is in communication with the industrial computer and is used to display analysis results and trigger an abnormality alarm mechanism;

[0011] The system uses an abnormal alarm mechanism to link the wafer transport device to suspend movement and initiate a re-inspection process to confirm the defect location.

[0012] According to the preferred solution, the light source module adopts a multi-band tunable light source, and adaptively adjusts the wavelength range according to the characteristics of the wafer film material to enhance the imaging contrast between bubbles and foreign matter.

[0013] According to the preferred solution, the image processing algorithm built into the industrial computer includes grayscale threshold segmentation, morphological filtering and edge contour extraction, which are used to distinguish bubble defects from scratches on the wafer surface.

[0014] According to the preferred solution, the re-inspection process includes a secondary focus scanning mode, which uses local magnification imaging and dynamic exposure compensation technology to perform high-precision re-inspection of the alarm area and generate a defect coordinate mapping diagram.

[0015] According to the preferred solution, the monitoring system PC controls the wafer transport device to move to the next process or defective product collection location and integrates a defect statistics module to record the number, size distribution and position density of bubbles by batch.

[0016] The present invention adopts a wafer transport device, a light source module, an optical imaging module, an image acquisition card, an industrial computer, and a monitoring system PC to realize the inspection of wafer defects and bubble defects after the wafer cutting and grinding process. Through system management, wafers with abnormal inspection results will be alarmed and re-inspected, and the defective parts after re-inspection will be removed. Through the development and application of this function, the incidence rate of quality defective parts in the later process is reduced, and the continuous occurrence of defects is avoided.

[0017] Hereinafter, the best embodiment for carrying out the present invention will be described in more detail with reference to the accompanying drawings so that the features and advantages of the present invention can be easily understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Shown is a schematic diagram of the relationship between the steps of the present invention;

[0019] Figure 2 The left side shows a schematic diagram of the industrial computer of the present invention performing defect analysis on image data and displaying it on the monitoring system PC, and the right side shows a schematic diagram of the re-inspection process confirming the defect location and displaying it on the monitoring system PC7; DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the technical solution 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 drawings of specific embodiments of the present invention. The same figure marks in the drawings represent the same components. It should be noted that the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] Compared to the embodiments shown in the drawings, feasible embodiments within the scope of protection of the present invention may have fewer components, additional components not shown in the drawings, different components, differently arranged components, or differently connected components, etc. In addition, two or more components in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.

[0022] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by persons of ordinary skill in the field to which the invention belongs. The words "first", "second" and similar terms used in the patent application specification and claims of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "a" or "an" do not necessarily indicate a quantity limitation. Words such as "include" or "comprising" mean that the elements or objects preceding the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0023] The present invention proposes the development of a grinding machine wafer back side inspection system for use in wafer processing technology. The present invention does not limit the thickness specifications of the wafers to be processed, but the wafer transport device, light source module, optical imaging module, image acquisition card, industrial computer, and monitoring system PC structure are particularly suitable for wafer detection technology.

[0024] In general, the development of the grinding machine wafer back side inspection system proposed in the present invention mainly includes a wafer transport device, a light source module, an optical imaging module, an image acquisition card, an industrial computer, and a monitoring system PC.

[0025] The specific development and use process of a grinding machine wafer backside inspection system includes:

[0026] S1: The wafer processing device carries the wafer and moves it to the inspection station. The light source module projects light onto the film-attaching area on the back of the wafer in a step-by-step trigger mode.

[0027] S2: The high-resolution industrial camera in the optical imaging module captures the optical image of the back of the wafer in real time, converts the analog signal into a digital signal through the image acquisition card, and transmits it to the industrial computer;

[0028] S3: The industrial computer calls preset algorithms, such as grayscale threshold segmentation and morphological filtering, to process image data and distinguish defect types such as bubbles, foreign matter, and surface scratches.

[0029] S4: The monitoring system PC displays the defect distribution map and statistical results. If an abnormality is detected, an alarm mechanism is triggered, the wafer movement is suspended, and the re-inspection process is started;

[0030] S5: The re-inspection process uses local magnification imaging and dynamic exposure compensation technology to scan the alarm area again and generate a defect coordinate map to ensure the accuracy of the inspection results;

[0031] S6: The monitoring system PC controls the wafer transport device to move to the defective product collection area and records the number, size, and location density of defects;

[0032] S7: The technicians inspect the wafer cutting equipment and adjust the processing technology by referring to the defective position density in the monitoring system PC.

[0033] The wafer transport device is used to carry and move wafers.

[0034] The above-mentioned light source module includes: projecting light to the film-pasting area on the back of the wafer in a step-by-step triggering manner during the movement of the wafer. The light source module adopts a multi-band tunable light source and adaptively adjusts the wavelength range according to the characteristics of the wafer film material to enhance the imaging contrast of bubbles and foreign objects.

[0035] The above-mentioned industrial computer is configured to receive digital signals and perform defect analysis on the image data based on a preset algorithm to identify wafer film bubbles or foreign matter defects. The image processing algorithm built into the industrial computer includes grayscale threshold segmentation, morphological filtering and edge contour extraction, which are used to distinguish bubble defects from scratches on the wafer surface.

[0036] The above-mentioned monitoring system PC is communicatively connected to the industrial computer to display the analysis results and trigger the abnormal alarm mechanism. The system uses the abnormal alarm mechanism to link the wafer transport device to suspend movement and start the re-inspection process to confirm the defect location. The re-inspection process includes a secondary focus scanning mode, which uses local magnification imaging and dynamic exposure compensation technology to perform high-precision re-inspection of the alarm area to generate a defect coordinate mapping map.

[0037] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. Development of a grinding machine wafer backside inspection system, characterized in that: include: A wafer transport device, wherein the wafer transport device is used to carry and move wafers; The light source module includes: a light source module that projects light toward the film-attaching area on the back of the wafer in a step-by-step triggering manner during the movement of the wafer; An optical imaging module, comprising a high-resolution industrial camera for collecting real-time image data of the film-attached area on the back of the wafer; An image acquisition card, connected to the optical imaging module, for converting image data into digital signals; An industrial computer configured to receive the digital signal and perform defect analysis on the image data based on a preset algorithm to identify wafer film bubbles or foreign matter defects; A monitoring system PC, which is in communication with the industrial computer and is used to display analysis results and trigger an abnormality alarm mechanism; The system uses an abnormal alarm mechanism to link the wafer transport device to suspend movement and initiate a re-inspection process to confirm the defect location.

2. The development of the grinding machine wafer backside inspection system according to claim 1 is characterized in that, The light source module adopts a multi-band tunable light source and adaptively adjusts the wavelength range according to the characteristics of the wafer film material to enhance the imaging contrast between bubbles and foreign matter.

3. The development of the grinding machine wafer backside inspection system according to claim 2, characterized in that, The image processing algorithm built into the industrial computer includes grayscale threshold segmentation, morphological filtering and edge contour extraction, which are used to distinguish bubble defects from scratches on the wafer surface.

4. The development of the grinding machine wafer backside inspection system according to claim 3 is characterized in that, The re-inspection process includes a secondary focus scanning mode, which uses local magnification imaging and dynamic exposure compensation technology to perform high-precision re-inspection of the alarm area and generate a defect coordinate mapping diagram.

5. The development of the grinding machine wafer backside inspection system according to claim 4, characterized in that, The monitoring system PC controls the wafer transport device to move to the next process or defective product collection location and integrates a defect statistics module to record the number, size distribution and position density of bubbles by batch.

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