Wafer internal and external defect detection discrimination apparatus

Abstract

The application discloses a wafer internal and external flaw detection distinguishing device, which comprises a parallel light source assembly, a wafer support, a vertical light source assembly and a detection assembly, the wafer is arranged on the wafer support, the parallel light source assembly is arranged on the side of the wafer support, the detection assembly is arranged on the central axis of the wafer, the light generated by the parallel light source assembly comprises upper parallel light and lower parallel light, the upper parallel light sweeps over the upper surface of the wafer, and the lower parallel light sweeps over the lower surface of the wafer. Compared with the prior art, the application has higher detection precision, higher detection efficiency and lower cost, and can effectively improve the quality control level in the wafer manufacturing process.

Description

Technical Field

[0001] This invention relates to the field of wafer fabrication, specifically to a device for detecting and distinguishing internal and external defects in a wafer. Background Technology

[0002] Wafer manufacturing is a crucial step in the semiconductor industry. It involves slicing single-crystal materials such as silicon, compound semiconductors, and glass into thin wafers, followed by multiple processing steps to ultimately create the basic materials used in integrated circuit manufacturing. The quality of the wafer directly impacts the performance and reliability of semiconductor chips.

[0003] Wafer inspection plays a crucial role in the wafer manufacturing process. By inspecting wafers, defects can be detected and eliminated in a timely manner, ensuring that the produced chips meet quality requirements. This is of great significance for improving chip yield, reducing production costs, and enhancing product competitiveness.

[0004] However, existing wafer inspection technologies also have some drawbacks. First, due to the light-transmitting characteristics of wafers, surface and internal defects can easily cause visual interference during inspection, making it difficult to determine whether a defect is on one side or internally. Second, existing technologies may lack sufficient sensitivity in detecting wafer defects, failing to accurately identify minute defects, and may also lack specificity, making it difficult to distinguish true defects from other surface features. Furthermore, traditional wafer inspection typically requires manual intervention and complex procedures, resulting in low efficiency and failing to meet the demands of large-scale production. Finally, existing wafer inspection equipment and technologies usually require expensive equipment and complex algorithms, leading to high costs and hindering their application in large-scale production.

[0005] Therefore, in order to improve the quality and efficiency of wafer manufacturing, it is necessary to continuously research and develop new wafer inspection technologies to overcome the shortcomings of existing technologies and achieve more accurate, efficient and low-cost wafer inspection. Summary of the Invention

[0006] To address the aforementioned technical problems, the present invention provides a wafer internal and external defect detection and differentiation device, comprising a parallel light source assembly, a wafer support, a vertical light source assembly, and a detection assembly. The wafer is placed on the wafer support, the parallel light source assembly is disposed to the side of the wafer support, and the detection assembly is disposed on the central axis of the wafer. The light generated by the parallel light source assembly includes upper parallel light and lower parallel light. The upper parallel light passes over the upper surface of the wafer, and the lower parallel light passes over the lower surface of the wafer.

[0007] Preferably, the parallel light source assembly includes an upper parallel light assembly and a lower parallel light assembly, wherein the upper parallel light assembly generates the upper parallel light and the lower parallel light assembly generates the lower parallel light.

[0008] Preferably, the parallel light source assembly includes a horizontal light source and a blocking object. The blocking object is disposed on the side of the wafer. The horizontal light source forms the upper parallel light on the upper surface of the wafer through the blocking object, while simultaneously forming the lower parallel light on the lower surface of the wafer.

[0009] Preferably, the parallel light source assembly includes a horizontal light source that conforms to the wafer absorption band.

[0010] Preferably, the beam of the horizontal light source is greater than the thickness of the wafer, and the height of the shield is the same as the thickness of the wafer.

[0011] Preferably, the detection component includes a charge-coupled device (CCD).

[0012] Preferably, the light emitted by the vertical light source component and the parallel light source component has different wavelengths.

[0013] Preferably, the detection component includes a color charge-coupled device (color CCD).

[0014] Preferably, the detection assembly includes a camera group consisting of a filter beam splitter.

[0015] Preferably, the vertical light source component and the horizontal light source component generate blue light or red light, respectively.

[0016] This invention employs light sources in two directions. A vertical light source component is used for initial defect localization, and a horizontal light source component is used for specific location analysis. Through two or one imaging processes, the precise location of the defect, both internal and external, is achieved. Compared with existing technologies, this invention offers higher detection accuracy, higher detection efficiency, and lower cost, effectively improving the quality control level in the wafer manufacturing process. Attached Figure Description

[0017] The invention will now be further described with reference to the accompanying drawings.

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is an illumination diagram of the vertical light source component in this invention;

[0020] Figure 3 This is an illumination diagram of the horizontal light source component in this invention;

[0021] Figure 4 This is a schematic diagram of Embodiment 2 of the present invention;

[0022] Figure 5 This is a schematic diagram of Embodiment 3 of the present invention.

[0023] The numbers in the image represent:

[0024] 1. Parallel light source assembly, 2. Vertical light source assembly, 3. Wafer, 4. Detection assembly, 5. Obstruction. Detailed Implementation

[0025] The various aspects of the present invention will be further described in detail below.

[0026] Unless otherwise defined or stated, all technical and scientific terms used herein have the same meaning as are familiar to those skilled in the art. Furthermore, any methods and materials similar to or equivalent to those described herein may be used in the methods of this invention.

[0027] like Figure 1 As shown, the present invention provides a device for detecting and distinguishing internal and external defects of a wafer 3, comprising: a parallel light source assembly 1, a wafer 3 support, a vertical light source assembly 2, and a detection assembly 4. The wafer 3 is placed on the wafer 3 support, the parallel light source assembly 1 is disposed to the side of the wafer 3 support, and the detection assembly 4 is disposed on the central axis of the wafer 3. The light generated by the parallel light source assembly 1 includes upper parallel light and lower parallel light. The upper parallel light passes over the upper surface of the wafer 3, and the lower parallel light passes over the lower surface of the wafer 3.

[0028] As an embodiment of the present invention, the parallel light source assembly 1 includes an upper parallel light assembly and a lower parallel light assembly. The upper parallel light assembly generates the upper parallel light, and the lower parallel light assembly generates the lower parallel light. The upper and lower parallel light assemblies each generate a set of light rays, forming the upper parallel light and the lower parallel light, respectively.

[0029] During the detection and differentiation process, a vertical light source is first generated by the vertical light source component 2 as incident light, which is directed onto the surface of the wafer 3. The direction of the incident light is opposite to that of the detection component 4. The light emitted from the vertical light source passes through the surface of the wafer 3 and is captured and imaged by the detection component 4. Taking three typical defects as examples, we can see that... Figure 1 The three types of defects shown are as follows: Figure 2 The three black dots represent defects A on the upper surface of wafer 3, C inside wafer 3, and B on the lower surface of wafer 3. At this point, the exact locations of these three defects cannot be clearly distinguished. Subsequently, the vertical light source component 2 is turned off, and the upper and lower parallel lights are turned on, passing over the upper and lower surfaces of wafer 3 respectively. The defects on the upper and lower surfaces cause light scattering, preventing the light from passing parallel. Instead, the light is captured and imaged by the detection component 4, forming bright spots on a black background. Figure 2-3As shown, by combining and comparing the two images, the location of each wafer 3 defect can be easily deduced. The defect C inside wafer 3 appears as a black dot when imaged by a vertical light source and has no bright spot when imaged by a horizontal light source. The defects A and B on the upper and lower surfaces of wafer 3 appear as black dots when imaged by a vertical light source and as bright spots when imaged by a horizontal light source.

[0030] In this embodiment, it is necessary to ensure that the upper and lower parallel lights are aligned with the upper and lower horizontal surfaces of the wafer 3, respectively. Since the light cannot be directed into the wafer 3 body, the alignment requirements of the upper and lower parallel lights with respect to the surface of the wafer 3 are relatively high.

[0031] As a second embodiment of the present invention, the parallel light source assembly 1 includes a horizontal light source and a blocking element 5. The blocking element 5 is disposed on the side of the wafer 3. The horizontal light source forms the upper parallel light on the upper surface of the wafer 3 through the blocking element 5, while simultaneously forming the lower parallel light on the lower surface of the wafer 3. The detection assembly 4 includes a charge-coupled device (CCD).

[0032] like Figure 4 As shown, in Embodiment 2, a shield 5 is used to cover the main thickness portion of the wafer 3 to ensure that light does not penetrate the wafer 3 body. The parallel light source assembly 1 uses only one horizontal light source, from which both the upper and lower parallel lights are generated. The beam of the horizontal light source is greater than the thickness of the wafer 3, and the height of the shield 5 is the same as the thickness of the wafer 3. The detection assembly 4 includes a charge-coupled device (CCD).

[0033] like Figure 5 As shown in Embodiment 3 of the present invention, the parallel light source assembly 1 includes a horizontal light source that conforms to the absorption band of the wafer 3. In this embodiment, since the horizontal light source is selected to be in a band that is easily absorbed by the wafer 3 body, the horizontal light source will be absorbed at a small depth when it shines on the wafer 3 and will not continue to propagate, which is similar to the function of the shield 5 in Embodiment 2.

[0034] In a fourth embodiment of the present invention, the light emitted by the vertical light source assembly 2 and the parallel light source assembly 1 is of different wavelengths. The detection assembly 4 includes a color charge-coupled device (color CCD).

[0035] As a fifth embodiment of the present invention, the light emitted by the vertical light source assembly 2 and the parallel light source assembly 1 is of different wavelengths. The detection assembly 4 includes a camera group composed of filter beam splitters.

[0036] Examples 4 and 5 employ simultaneous illumination of horizontal and vertical light sources and synchronous imaging. The camera group, composed of a color CCD and a filter beam splitter, can capture red, green, and blue light signals, thereby achieving color image capture. This allows for faster detection results and effectively improves detection efficiency.

[0037] Based on Embodiment 4 or 5, the present invention has Embodiment 6, in which the vertical light source component 2 and the parallel light source component 1 respectively generate blue light or red light. Red light and blue light are different wavelengths, so when imaging simultaneously, the color, brightness and clarity of the image are different, and defects in different locations can be clearly distinguished.

[0038] This invention employs light sources in two directions. The vertical light source component 2 is used for initial defect localization, and the horizontal light source component is used for specific location analysis. Through two or one imaging processes, the precise location of the defect, both internal and external, is achieved. Compared with existing technologies, this invention has higher detection accuracy, higher detection efficiency, and lower cost, and can effectively improve the quality control level in the wafer manufacturing process.

[0039] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A device for detecting and distinguishing internal and external defects in a wafer, characterized in that: The device includes a parallel light source assembly, a wafer support, a vertical light source assembly, and a detection assembly. The wafer is placed on the wafer support, the parallel light source assembly is located to the side of the wafer support, and the detection assembly is located on the central axis of the wafer. The light generated by the parallel light source assembly includes upper parallel light and lower parallel light. The upper parallel light passes over the upper surface of the wafer, and the lower parallel light passes over the lower surface of the wafer. The vertical light source component performs preliminary defect location, while the parallel light source component performs specific location analysis to achieve precise location of the defect, both internally and externally. The parallel light source assembly includes an upper parallel light assembly and a lower parallel light assembly, wherein the upper parallel light assembly generates the upper parallel light and the lower parallel light assembly generates the lower parallel light; Alternatively, the parallel light source assembly includes a horizontal light source and a shield. The shield is disposed on the side of the wafer. The horizontal light source forms the upper parallel light on the upper surface of the wafer and the lower parallel light on the lower surface of the wafer simultaneously through the shield. The beam of the horizontal light source is greater than the thickness of the wafer, and the height of the shield is the same as the thickness of the wafer. Alternatively, the parallel light source assembly may include a horizontal light source that conforms to the wafer absorption band.

2. The wafer internal and external defect detection and differentiation device as described in claim 1, characterized in that: The detection component includes a charge-coupled device.

3. The wafer internal and external defect detection and differentiation device as described in claim 1, characterized in that: The light emitted by the vertical light source component and the parallel light source component are of different wavelengths.

4. The wafer internal and external defect detection and differentiation device as described in claim 3, characterized in that: The detection component includes a color charge-coupled device.

5. The wafer internal and external defect detection and differentiation device as described in claim 3, characterized in that: The detection assembly includes a camera group consisting of filter beam splitters.

6. A wafer internal and external defect detection and differentiation device as described in any one of claims 3-5, characterized in that: The vertical light source component and the horizontal light source component respectively generate blue light or red light.

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