Method for detecting large particles on surfaces of wafer

Abstract

The present invention belongs to the field of integrated circuit manufacturing. Provided is a method for detecting large particles on the surfaces of a wafer. The method comprises: a first water vapor removal step, involving: putting a first test wafer into a first chamber, and removing water vapor on the surfaces of the first test wafer; a deposition step, involving: putting the first test wafer into a second chamber, and forming a thin film layer on an upper surface of the first test wafer; a first detection step, involving: confirming whether large particles are present on the surfaces of the first test wafer, and if large particles are present, analyzing chemical components of the large particles; a second water vapor removal step, involving: putting a second test wafer into the first chamber, and removing water vapor on the surfaces of the second test wafer; a second detection step, involving: confirming whether large particles are present on the surfaces of the second test wafer; and a determination step, involving: determining the reason for the presence of the large particles. By means of the method for detecting large particles on the surfaces of a wafer in the present invention, it can be accurately and efficiently determined which chamber of a machine is abnormal, such that an abnormal chamber can be processed in a timely manner.

Description

A method for detecting large particles on wafer surface Technical Field

[0001] The present invention relates to the field of semiconductor integrated circuit manufacturing, and in particular to a method for detecting large particles on a wafer surface. Background Art

[0002] During the semiconductor integrated circuit manufacturing process, if a chamber in a machine experiences an anomaly, surface defects, such as large particles, may appear when processing wafers in that chamber. This can cause the chip in the area containing the large particles to be scrapped, resulting in a decrease in yield. Furthermore, in some processes, such as PVD (physical vapor deposition) processes, the machine used includes multiple chambers, and during the PVD process, the wafer needs to enter multiple chambers in sequence. When large particle defects occur, it is often difficult to determine which chamber has the anomaly. Therefore, a method for detecting large particles on the wafer surface is needed that can accurately and efficiently determine which chamber of the machine has the anomaly, so that the anomaly can be promptly addressed. Technical issues

[0003] The present invention aims to provide a method for detecting large particles on a wafer surface. Technical Solutions

[0004] The equipment used in the method includes: a physical vapor deposition machine and a large particle detector. The physical vapor deposition machine includes: a first chamber for removing moisture from the wafer surface and a second chamber for forming a thin film layer. The large particle detection method for the wafer surface includes:

[0005] a first moisture removal step of placing a first test wafer into a first chamber of the physical vapor deposition tool, irradiating the first test wafer with a light bulb in the first chamber, thereby removing moisture from a surface of the first test wafer, and then extracting the moisture from the first chamber;

[0006] Deposition step: placing the first test machine wafer into the second chamber of the physical vapor deposition machine, and forming a thin film layer on the upper surface of the first test machine wafer;

[0007] A first detection step: detecting the first test machine wafer by the large particle detector to confirm whether there are large particles on the surface of the first test machine wafer, and if large particles are present, analyzing the chemical composition of the large particles;

[0008] a second moisture removal step of placing a second test wafer into the first chamber of the physical vapor deposition tool, irradiating the second test wafer with a light bulb in the first chamber, thereby removing moisture from a surface of the second test wafer, and then extracting the moisture from the first chamber;

[0009] A second detection step: detecting the second test machine wafer by the large particle detector to confirm whether there are large particles on the surface of the second test machine wafer, and if there are large particles, analyzing the chemical composition of the large particles; and

[0010] Determining step: determining the reason for the presence of the large particles based on the results of the first detecting step and the second detecting step. Beneficial effects

[0011] The method for detecting large particles on the wafer surface of the present invention can accurately and efficiently determine which chamber of the machine has an abnormality, so that the chamber with the abnormality can be processed in a timely manner. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] FIG1 is a schematic diagram of a PVD machine used in the method for detecting large particles on a wafer surface of the present invention; and

[0013] FIG2 is a flow chart of the method for detecting large particles on a wafer surface according to the present invention.

[0014] Explanation of symbols

[0015] 100 PVD machines

[0016] F2 first chamber

[0017] R3 Second chamber

[0018] F3 spare first chamber Modes for Carrying Out the Invention

[0019] The method for detecting large particles on a wafer surface according to the present invention will be described below with reference to FIG. 1 and FIG. 2 .

[0020] The apparatus used in the wafer surface large particle detection method of the present invention includes a PVD (physical vapor deposition) tool 100 and a PMD (large particle detector) (not shown). As shown in Figure 1 , the PVD tool 100 includes a first chamber F2 for removing moisture from the wafer surface and a second chamber R3 for forming a thin film layer.

[0021] In this embodiment, the PMD is a KLA 8920 manufactured by KLA Corporation (USA). In other embodiments, the PMD may be another type of machine. The PVD machine 100 may be any type of machine commonly used in the art.

[0022] As shown in FIG2 , the wafer surface large particle detection method of the present invention includes: a first moisture removal step S001 , a deposition step S002 , a first detection step S003 , a second moisture removal step S004 , a second detection step S005 , and a determination step S006 . Each step will be described in detail below.

[0023] First moisture removal step S001: Place the first test wafer into the first chamber F2 of the PVD machine 100, illuminate the first test wafer with the light bulb of the first chamber F2, thereby removing moisture on the surface of the first test wafer, and extracting the moisture from the first chamber F2.

[0024] Deposition step S002: A first test wafer is placed in the second chamber R3 of the PVD tool 100, and a thin film layer is formed on the upper surface of the first test wafer. In this embodiment, a phase change material thin film layer is formed on the upper surface of the first test wafer. In other embodiments, other thin film layers may also be formed. The thin film layer can be formed using methods commonly used in the art and will not be further described here.

[0025] First detection step S003: detecting the first test wafer through PMD to confirm whether there are large particles on the surface of the first test wafer; if there are large particles, analyzing the chemical composition of the large particles.

[0026] In this example, large particles are defined as particles larger than 5 microns. Inspection revealed the presence of large particles on the surface of the wafer from the first tester. Analysis revealed that the primary component of these large particles was titanium (Titanium). However, Ti should not be present in either chambers F2 or R3, indicating that an abnormality has occurred in either chamber F2 or R3.

[0027] In order to further determine whether the abnormality occurs in the first chamber F2 or the second chamber R3, another test is required. In this test, the test wafer only enters the first chamber F2.

[0028] Second moisture removal step S004: Place the second test wafer into the first chamber F2 of the PVD machine 100, illuminate the second test wafer with the light bulb of the first chamber F2, thereby removing moisture on the surface of the second test wafer and extracting the moisture from the first chamber F2.

[0029] Second detection step S005: Detect the second test machine wafer through PMD to confirm whether there are large particles on the surface of the second test machine wafer. If large particles are present, analyze the chemical composition of the large particles.

[0030] In this embodiment, large particles were also detected on the surface of the wafer from the second test machine. Analysis also revealed that the main component of these large particles was Ti. The results of the two PMD tests are shown in the following table:

[0031] Number of large particles on wafer F2R3: √√1 on the first test machine; √1 on the second test machine

[0032] Determination step S006: Determine the reason for the presence of large particles based on the results of the first detection step S003 and the second detection step S005.

[0033] Because the second tester wafer only entered the first chamber F2, large particles were also detected on the surface of the second tester wafer. The main component of these large particles was Ti, which should not be present in the first chamber F2. Therefore, it was determined that there was an abnormality in the first chamber F2. Therefore, maintenance of the first chamber F2 was required.

[0034] Alternatively, the backup first chamber F3 can be used for further testing. Specifically, the third test wafer is first placed in the backup first chamber F3 to remove moisture from its surface. The third test wafer is then placed in the second chamber R3 to form a thin film layer on its upper surface. The third test wafer is then tested using the PMD tool. If no large particles are detected, it indicates that the problem lies with the first chamber F2.

[0035] As shown in FIG2 , the method for detecting large particles on a wafer surface of the present invention further includes:

[0036] Maintenance step S007: If the first chamber F2 is determined to be abnormal in the determination step S006, the first chamber F2 is maintained. The first chamber F2 can be maintained by a commonly used method in the art, which will not be described in detail here.

[0037] The large particle detection method on the wafer surface of the present invention can accurately and efficiently determine which chamber of the machine has an abnormality, so that the abnormal chamber can be processed in a timely manner.

[0038] Although the present invention has been disclosed in the form of embodiments as described above, they are not intended to limit the present invention. Any professional and technical personnel in this field may make various necessary changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope defined by the attached claims.

Claims

1. A method for detecting large particles on a wafer surface, the device used in the method comprising: A physical vapor deposition machine (100) and a large particle detector, wherein the physical vapor deposition machine (100) comprises: a first chamber for removing moisture from a wafer surface, and a second chamber for forming a thin film layer, and a method for detecting large particles on a wafer surface comprises: First moisture removal step S001: placing a first test machine wafer into a first chamber of the physical vapor deposition machine (100), irradiating the first test machine wafer with a light bulb in the first chamber, thereby removing moisture from the surface of the first test machine wafer, and extracting the moisture from the first chamber; Deposition step S002: placing the first test machine wafer into the second chamber of the physical vapor deposition machine (100), and forming a thin film layer on the upper surface of the first test machine wafer; First detection step S003: detecting the first test machine wafer by the large particle detector to confirm whether there are large particles on the surface of the first test machine wafer, and if there are large particles, analyzing the chemical composition of the large particles; Second water vapor removal step S004: placing a second test machine wafer into the first chamber of the physical vapor deposition machine (100), irradiating the second test machine wafer with a light bulb in the first chamber, thereby removing water vapor on the surface of the second test machine wafer, and extracting the water vapor from the first chamber; Second detection step S005: detecting the second test machine wafer by the large particle detector to confirm whether there are large particles on the surface of the second test machine wafer, and if there are large particles, analyzing the chemical composition of the large particles; and Determination step S006: according to the results of the first detection step S003 and the second detection step S005, determine the reason for the existence of the large particles.

2. The method for detecting large particles on a wafer surface as claimed in claim 1, further comprising: Maintenance step S007: If in the determination step S006, it is determined that the first chamber is abnormal, maintenance is performed on the first chamber.

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