Semiconductor wafer detection method
By attaching the mold extraction material to the detection site of the semiconductor wafer and curing and shaping, the problem of the failure to accurately detect the wafer edge in the prior art is solved, and non-destructive detection and high-precision morphological information acquisition are achieved.
Patent Information
- Application Number
- CN202411525230.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-29
- Publication Date
- 2025-02-14
AI Technical Summary
Existing semiconductor wafer detection methods cannot accurately detect wafer edge areas, there are blind spots, and traditional methods often require damage to wafers to obtain cross-sections for detection.
The mold extraction material is used to attach it to the detection site of the semiconductor wafer to be tested, so that it is cured and set, and then the morphological information of the setting surface is detected under a microscope after being demolded, thereby obtaining the morphological information of the wafer edge.
Accurate detection of the edge area of the semiconductor wafer is achieved, and it is non-destructive detection, reducing waste caused by testing and achieving micron-scale plasticization accuracy.
Smart Images
Figure CN119438251A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductor technology, and in particular to a method for detecting a semiconductor wafer. Background Art
[0002] Semiconductor wafers are the basic raw materials for manufacturing semiconductor devices. High-purity semiconductors are prepared into wafers through processes such as crystal pulling and slicing. Wafers undergo a series of semiconductor manufacturing processes to form extremely small circuit structures, and then they are cut, packaged, and tested to become chips, which are widely used in various electronic devices. The edges of wafers are thin and easy to break, so the quality control of the edge fillet of incoming wafers is very important. During the inspection of incoming semiconductor wafers, they need to be inspected according to sampling standards.
[0003] At present, the inspection method for wafer inspection is that the inspectors use microscopes and naked eyes to inspect the surface of silicon wafers. However, this inspection method does not cover the edge area of the wafer, resulting in blind spots in the inspection, and the size and shape of the edge area of the wafer cannot be accurately inspected. Alternatively, the silicon wafer is broken to obtain a cross section, and the cross section is observed and measured under a microscope. Summary of the invention
[0004] The embodiment of the present application provides a method for detecting a semiconductor wafer, which is capable of detecting an edge area and realizing non-destructive detection.
[0005] The semiconductor wafer detection method provided in the embodiment of the present application includes the following steps: selecting a detection site on the semiconductor wafer to be tested; attaching a molding material to the detection site and solidifying the molding material to obtain a solidified body, the solidified body having a molding surface that fits the detection site; after demolding the solidified body, detecting the morphological information of the molding surface under a microscope to obtain the morphological information of the detection site.
[0006] According to an embodiment of the present application, the curing temperature of the molding material satisfies 0°C to 50°C.
[0007] According to an embodiment of the present application, the pH of the molding material satisfies pH=6-8.
[0008] According to an embodiment of the present application, the molding material includes at least one of AB molding soil, colloid, and clay.
[0009] According to an embodiment of the present application, the molding material contains Si element.
[0010] According to an embodiment of the present application, the step of selecting a detection site on the semiconductor wafer to be tested includes: selecting a detection site on the semiconductor wafer to be tested at a depth of 1 cm 2 / pc~5cm 2 The detection sites are arranged at a density of / .
[0011] According to an embodiment of the present application, the step of performing microscope inspection after demoulding the cured shaped body comprises:
[0012] The solidified body is sliced along a direction perpendicular to the forming surface to obtain a cross section and detect the morphological information of the cross section.
[0013] According to an embodiment of the present application, the same solidified body is sliced multiple times to obtain multiple cross sections, and the multiple cross sections are parallel.
[0014] According to an embodiment of the present application, the shaping surface includes a first shaping surface and a second shaping surface, and the first shaping surface and the second shaping surface are adjacent to each other at an edge of the semiconductor wafer to be tested;
[0015] The first shaping surface and the cross section have a first intersection line, the second shaping surface and the cross section have a second intersection line, and the first intersection line is connected to the second intersection line.
[0016] According to an embodiment of the present application, the first intersection line includes a first parallel portion and a first bordering portion connected to each other; the second intersection line includes a second parallel portion and a second bordering portion connected to each other; the first parallel portion is parallel to the second parallel portion, and the first bordering portion and the second bordering portion are connected at an edge;
[0017] The topographic information of the shaping surface includes the length of the first bordering portion and the length of the second bordering portion.
[0018] Compared with the prior art, this application has at least the following technical effects:
[0019] The semiconductor wafer detection method provided in the embodiment of the present application is to attach the molding material to the detection site of the semiconductor wafer to be tested, so that the molding material is solidified to obtain a solidified body, the molding material has a plastic effect, and does not deform after solidification, and the solidified body records the morphological information of the detection site of the semiconductor wafer to be tested. The morphological information of the solidified body is obtained under a microscope to obtain the morphological information of the detection site of the semiconductor wafer to be tested, especially the edge morphological information. The use of molding materials can achieve molding accuracy to the micron level; and non-destructive testing can be achieved to reduce the waste caused by testing. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Features, advantages, and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings.
[0021] Figure 1 A schematic diagram of a process flow of a semiconductor wafer detection method according to an embodiment of the present application;
[0022] Figure 2 This is the process of using AB molding soil to perform molding and testing experiments in the embodiments of this application;
[0023] Figure 3It is a schematic diagram of detecting surface particles before and after molding using AB molding soil in the embodiment of the present application;
[0024] Figure 4 It is a schematic diagram of multiple slicing after taking a mold using AB molding soil in an embodiment of the present application;
[0025] Figure 5 It is a structural schematic diagram of the intersection line of the shaping surface and the cross section of an embodiment of the present invention;
[0026] Reference numerals:
[0027] 10-first intersection line; 11-first parallel portion; 12-first bordering portion;
[0028] 20- second intersection line; 21- second parallel portion; 22- second bordering portion;
[0029] In the drawings, the same reference numerals are used for the same components. The drawings are not drawn to scale. DETAILED DESCRIPTION
[0030] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the detailed description below, many specific details are proposed in order to provide a comprehensive understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by illustrating examples of the present invention. In the drawings and the following description, at least part of the known structures and technologies are not shown in order to avoid unnecessary ambiguity of the present invention; and, for clarity, the size of some structures may be exaggerated. In addition, the features, structures or characteristics described below may be combined in one or more embodiments in any suitable manner.
[0031] The directional words appearing in the following description are all directions shown in the figures, and do not limit the detection device of the present invention and the detection method of position accuracy. In the description of the present invention, it should also be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.
[0032] At present, the inspection method for wafer inspection is that the inspector inspects the surface of the silicon wafer with the naked eye using a microscope, but such inspection method does not cover the edge area of the wafer, resulting in a blind spot in the inspection, and the size and shape of the edge area of the wafer cannot be accurately inspected, or the silicon wafer is destroyed to obtain a cross section, and the cross section is observed and measured under a microscope. Therefore, after research, the inventor of this application provides a semiconductor wafer inspection method that can detect the edge area and realize non-destructive inspection.
[0033] Figure 1 The flow chart of the semiconductor wafer inspection method is shown in FIG. Figure 1 The semiconductor wafer detection method provided in the present application comprises the following steps:
[0034] S100: selecting a detection site on the semiconductor wafer to be tested;
[0035] S200: attaching the molding material to the detection site and solidifying the molding material to obtain a solidified body, wherein the solidified body has a molding surface that fits the detection site;
[0036] S300: After demoulding the solidified body, the morphology information of the molding surface is detected under a microscope to obtain the morphology information of the detection site.
[0037] According to the semiconductor wafer detection method of the embodiment of the present application, the molding material is attached to the detection site of the semiconductor wafer to be tested, and the molding material is solidified to obtain a solidified body. The molding material has a plastic effect and does not deform after solidification. The solidified body records the morphological information of the detection site of the semiconductor wafer to be tested. The morphological information of the solidified body is obtained under a microscope to obtain the morphological information of the detection site of the semiconductor wafer to be tested, especially the edge morphological information. The use of molding materials can achieve molding accuracy to the micron level; and non-destructive testing can be achieved to reduce the waste caused by testing.
[0038] [S100]
[0039] In S100, positions that need to be inspected are selected on the semiconductor wafer to be inspected as inspection sites; the positions that need to be inspected can be selected specifically or randomly.
[0040] In some embodiments, the detection site may be located on the surface of the semiconductor wafer to be tested, or may be located on the peripheral edge of the semiconductor wafer to be tested.
[0041] In some embodiments, the number of detection sites on each semiconductor wafer to be tested may be one or more, and a point may be selected on the semiconductor wafer to be tested as the detection site, or an area may be selected as the detection site, and the embodiments of the present application are not limited thereto. The more points are selected, the richer the morphological information obtained, and the morphological information of the semiconductor wafer to be tested can be more comprehensively understood.
[0042] In some embodiments, the step of selecting a detection site on the semiconductor wafer to be tested includes: selecting a detection site on the semiconductor wafer to be tested at a depth of 1 cm 2 / pc~5cm 2 The detection sites are arranged at a density of / .
[0043] For example, the density of the detection sites arranged on the semiconductor wafer to be tested is 1 cm 2 / pcs, 2cm 2 / pcs, 3cm 2 / pcs, 4cm 2 / pcs, 5cm 2 / or a value between any two of the above ranges.
[0044] When inspecting the peripheral side of the semiconductor wafer to be inspected, the same density can be used for arrangement.
[0045] [S200]
[0046] In S200, the surface information of the detection site is extracted using the molding material, and after solidification and shaping, a solidified body is obtained to obtain a shaping surface that fits the detection site, and the shaping surface can reproduce the fine structure of the detection site.
[0047] The molding material is in a soft state before solidification and shaping, and can be attached to the detection site without dead angles to reproduce the morphological information of the detection site. After solidification and shaping, it can be removed for detection. The molding surface of the solidified body is attached to the detection site without dead angles, recording the morphological information of the detection site of the semiconductor wafer to be tested. By testing the molding surface, the molding material can replace the direct detection of the semiconductor wafer. When the edge area of the semiconductor wafer needs to be detected, it can be detected without destroying the semiconductor wafer.
[0048] In order to reduce the contamination of the semiconductor wafer to be tested, so that the semiconductor wafer to be tested can continue to be used after the molding material is attached and sampled, in some embodiments, the curing temperature of the molding material satisfies 0°C to 50°C. The curing temperature of the molding material within the above temperature range can reduce the contamination and damage to the semiconductor wafer to be tested. Exemplarily, the curing temperature of the molding material is 5°C, 10°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C or a range between any two of the above values.
[0049] Similarly, different pH values of the molding materials may also cause contamination to the semiconductor wafer to be tested. During the research process, the inventor of the present application tried to use soap as a molding material for experiments. The soap was also able to extract the morphological information of the semiconductor wafer to be tested. However, after the experiment, when the semiconductor wafer to be tested was inspected, it was found that the semiconductor wafer to be tested was contaminated.
[0050] In order to reduce the contamination of the semiconductor wafer to be tested, in some embodiments, the pH of the molding material satisfies pH=6-8. The pH of the molding material within the above range can reduce the contamination of the semiconductor wafer to be tested, so that the semiconductor wafer to be tested can continue to be used after the molding material is attached and sampled. Exemplarily, the pH of the molding material is 6, 6.1, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, 7, 7.1, 7.2, 7.3, 7.4, 7.5, 7.6, 7.7, 7.8, 7.9, 8 or a range between any two of the above values.
[0051] In some embodiments, the molding material includes at least one of AB molding soil, colloid, and clay.
[0052] When testing the same semiconductor wafer to be tested, the same test site can be cured and shaped with different molding materials, which can improve the accuracy of the test. Different test sites can be cured and shaped with the same or different molding materials. AB molding soil, colloid, and clay all have good molding effects and can be attached to the test site without dead angles to reproduce the morphological information of the test site.
[0053] In the present application, the molding material can achieve the shaping effect, and other molding materials that can achieve the shaping effect can also be used, and the present application is not limited to this.
[0054] In some embodiments, the molding material contains Si element.
[0055] The inventors of the present application have discovered through experiments that when the mold material contains Si element, especially when it contains a large amount of silicon element, the contamination of the semiconductor wafer to be tested can be reduced because the semiconductor wafer to be tested is also made of high-purity silicon.
[0056] See also Figure 3 In the embodiment of the present application, AB mold soil with a pH of about 7 is used to mold the semiconductor wafer to be tested. After the mold is completed, the semiconductor wafer to be tested is cleaned and then tested. It is found that the AB mold soil causes almost no contamination to the semiconductor wafer to be tested. Please refer to Figure 4The inventors of the present application conducted surface particle detection on the semiconductor wafer to be tested before and after using AB molding soil for molding. The number of surface particles on the semiconductor wafer to be tested was 58 before molding, and the number of surface particles on the semiconductor wafer to be tested was 12 after molding. The change in the number of surface particles was within the allowable error range. It can be considered that the AB molding soil did not cause contamination to the semiconductor wafer to be tested, and the semiconductor wafer to be tested can still be used subsequently.
[0057] [S300]
[0058] In S300, the shaped surface of the solidified body is inspected under a microscope. For example, the microscope can be a scanning electron microscope or a transmission electron microscope. The above microscope has a higher magnification and can obtain more accurate morphological information.
[0059] In some embodiments, the step of performing microscopic inspection after demoulding the cured shaped body comprises:
[0060] The solidified body is sliced along a direction perpendicular to the forming surface to obtain a cross section and detect the morphological information of the cross section.
[0061] The lines of the cross section provide morphological information at a certain strip position on the semiconductor wafer to be tested. By detecting the morphological information of the cross section, the morphological information at a certain strip position on the semiconductor wafer to be tested can be obtained.
[0062] In some embodiments, the same solidified body is sliced multiple times to obtain multiple cross sections, and the multiple cross sections are parallel.
[0063] Multiple cross sections can be obtained by slicing multiple times, and detecting the morphological information of multiple cross sections can obtain more comprehensive morphological information on the semiconductor wafer to be tested.
[0064] When multiple cross sections are parallel, the topographic information of the interval positions can be obtained to determine whether the semiconductor wafer to be tested is uniform. Figure 3 As shown, in the embodiment of the present application, the solidified body is sliced multiple times, and each cross section is tested to obtain multiple sets of information to determine whether the semiconductor wafer to be tested is uniform. At the same time, the semiconductor wafer to be tested is destroyed and then the fragments of the test site are extracted for testing. After comparing the test results, it is found that the cross section completely reflects the morphological information of the semiconductor wafer to be tested.
[0065] Of course, multiple cross sections may also be non-parallel to obtain diverse morphological information at different positions, but the present application is not limited thereto.
[0066] See also Figure 5 (only the intersection line is shown in the figure). In some embodiments, the shaping surface includes a first shaping surface and a second shaping surface, and the first shaping surface and the second shaping surface are bordered at the edge of the semiconductor wafer to be tested;
[0067] The first shaping surface and the cross section have a first intersection line 10 , the second shaping surface and the cross section have a second intersection line 20 , and the first intersection line 10 is connected to the second intersection line 20 .
[0068] When the first shaping surface and the second shaping surface are adjacent to each other at the edge of the semiconductor wafer to be tested, it indicates that the shaping surface not only records the morphological information of the surface of the semiconductor wafer to be tested, but also records the morphological information at the edge of the semiconductor wafer.
[0069] At this time, the solidified shaped body is sliced along a direction perpendicular to the shaping surface, and the obtained cross section includes the morphology information at the edge of the semiconductor wafer to be tested.
[0070] The cross section is observed under a microscope, wherein the morphological information of the surface of the semiconductor wafer to be tested can be obtained by detecting the first intersection line 10 and the second intersection line 20, and the morphological information of the edge of the semiconductor wafer to be tested can be obtained by detecting the vicinity of the connection point between the first intersection line 10 and the second intersection line 20.
[0071] In some embodiments, please combine Figure 4 And continue to read Figure 5 The first intersection line 10 includes a first parallel portion 11 and a first bordering portion 12 connected to each other; the second intersection line 20 includes a second parallel portion 21 and a second bordering portion 22 connected to each other; the first parallel portion 11 is parallel to the second parallel portion 21, and the first bordering portion 12 and the second bordering portion 22 are connected at the edge;
[0072] The topographic information of the shaping surface includes the lengths of the first bordering portion 12 and the second bordering portion 22 .
[0073] Where the edge of the semiconductor wafer to be tested begins to narrow reflects the sharpness of the edge of the semiconductor wafer to be tested, which is very important for whether the semiconductor wafer to be tested can be used normally and is one of the conditions for judging whether the semiconductor wafer to be tested is qualified. The length of the first border portion 12 and the second border portion 22 reflects the morphological information of where the edge of the semiconductor wafer to be tested begins to narrow. In the embodiment of the present application, by detecting the length of the first border portion 12 and the second border portion 22, the morphological information of where the edge of the semiconductor wafer to be tested begins to narrow can be obtained.
[0074] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced by equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A method for detecting a semiconductor wafer, characterized in that: The steps include: Selecting a detection site on a semiconductor wafer to be tested; Attaching a molding material to the detection site and solidifying the molding material to obtain a solidified body, wherein the solidified body has a molding surface that fits the detection site; After the solidified body is demoulded, the morphology information of the molding surface is detected under a microscope to obtain the morphology information of the detection site.
2. The method for detecting a semiconductor wafer according to claim 1, characterized in that: The curing temperature of the molding material meets 0°C to 50°C.
3. The method for detecting a semiconductor wafer according to claim 1, wherein: The pH of the molding material satisfies pH=6-8.
4. The method for detecting a semiconductor wafer according to any one of claims 1 to 3, characterized in that: The molding material includes at least one of AB molding soil, colloid, and clay.
5. The method for detecting a semiconductor wafer according to claim 4, characterized in that: The molding material contains Si element.
6. The method for detecting a semiconductor wafer according to claim 1, wherein: The step of selecting a detection site on the semiconductor wafer to be tested comprises: selecting a detection site on the semiconductor wafer to be tested at a depth of 1 cm 2 / pc~5cm 2 The detection sites are arranged at a density of / .
7. The method for detecting a semiconductor wafer according to claim 1, characterized in that: The step of performing microscope inspection after demoulding the solidified body comprises: The solidified shaped body is sliced along a direction perpendicular to the shaping surface to obtain a cross section, and the morphological information of the cross section is detected.
8. The method for detecting a semiconductor wafer according to claim 7, characterized in that: The same solidified body is sliced multiple times to obtain multiple cross sections, and the multiple cross sections are parallel.
9. The method for detecting a semiconductor wafer according to claim 7, characterized in that: The shaping surface comprises a first shaping surface and a second shaping surface, wherein the first shaping surface and the second shaping surface are adjacent to each other at the edge of the semiconductor wafer to be tested; The first shaping surface and the cross section have a first intersection line, the second shaping surface and the cross section have a second intersection line, and the first intersection line is connected to the second intersection line.
10. The method for detecting a semiconductor wafer according to claim 9, characterized in that: The first intersection line includes a first parallel portion and a first bordering portion connected to each other; the second intersection line includes a second parallel portion and a second bordering portion connected to each other; the first parallel portion is parallel to the second parallel portion, and the first bordering portion and the second bordering portion are connected at an edge; The topographic information of the shaping surface includes the lengths of the first bordering portion and the second bordering portion.