Method and device for detecting pre-cleaning efficiency of wafer in cavity
By establishing a reaction time set and resistivity detection, combined with element content analysis, and selecting the shortest reaction time as the standard time, the problems of low efficiency and low accuracy of wafer pre-cleaning efficiency detection in the cavity are solved, and efficient and accurate cleaning detection is achieved.
Patent Information
- Application Number
- CN202510962046.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-11
- Publication Date
- 2025-09-26
AI Technical Summary
In the prior art, the detection of wafer pre-cleaning efficiency in a chamber has the problems of low detection efficiency and low precision, especially the measurement error caused by the change in roughness of the metal surface before and after reduction.
By establishing different reaction time sets, performing reduction reaction treatment on standard wafers, detecting resistivity, selecting the same resistance value to form a resistance value set, obtaining the reaction time, selecting the shortest reaction time as the standard time, combining element content detection to ensure cleaning completion, and using a four-probe tester to detect resistivity.
The efficiency and accuracy of wafer pre-cleaning detection in the chamber are improved, the waiting time is reduced, and the full progress of the reduction reaction is ensured.
Smart Images
Figure CN120709175A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of semiconductor detection technology, and in particular to a method and device for detecting wafer pre-cleaning efficiency in a cavity. Background Art
[0002] In semiconductor manufacturing, metals such as copper and aluminum are widely used in metal interconnection processes. Due to the active nature of metals, they are easily oxidized. The resistance of the oxidized metal will increase, thus affecting the electrical properties. Therefore, a pre-cleaning step is added before the barrier layer process to remove the oxidized surface.
[0003] In existing technologies, pre-cleaning systems employ reactive pre-cleaning, primarily utilizing plasma-activated hydrogen to react with oxidized metals to reduce them, achieving cleanliness standards. Reduction performance is monitored by measuring the reflectivity of the metal film on the wafer surface before and after the process. However, changes in the roughness of the metal surface before and after reduction can lead to measurement errors, reducing detection efficiency. Therefore, it is necessary to provide a new method and device for measuring wafer pre-cleaning efficiency within a chamber to address these issues. Summary of the Invention
[0004] The technical problem to be solved by the present application is to provide a detection method and a detection device for wafer pre-cleaning efficiency in a cavity that can improve detection efficiency and have high detection accuracy.
[0005] To solve the above technical problems, according to an embodiment of the present application, a method for detecting wafer pre-cleaning efficiency in a chamber is provided, comprising the following steps: Obtain several wafer standards; Select different reaction times to establish a first detection time set; Performing reduction reaction processing on a plurality of wafer standard sheets according to the reaction times in the first detection time set, respectively, to obtain wafer detection sheets with corresponding reaction times; Detecting the resistivity of each wafer detection piece respectively to obtain a resistance value corresponding to each wafer detection piece; Selecting multiple standard resistance values with the same value from the multiple resistance values to form a resistance value set; Obtaining the reaction time corresponding to each standard resistance value in the resistance value set to form a first reaction time set; The shortest reaction time is selected from the first reaction time set as the first standard time for performing the reduction reaction process.
[0006] A detection device for wafer pre-cleaning efficiency in a chamber, used to implement the above detection method, the detection device comprising a process chamber; an electrostatic chuck, disposed in the process chamber and used for carrying the wafer; a cleaning device, disposed in the process chamber, for ejecting gas, wherein the gas reacts with the wafer to perform a reduction reaction to clean the wafer; A detection device is arranged in the process chamber to detect the resistivity of the wafer.
[0007] By adopting the above technical solution, a first detection time set is established, and a plurality of wafer standard pieces are subjected to reduction reaction processing according to the reaction time in the first detection time set to obtain a plurality of wafer detection pieces; the corresponding resistance value is obtained by detecting the resistivity of the wafer detection piece, and the same resistance value is selected, and the resistance value with the smallest reaction time is selected from multiple identical resistance values, and the reaction time is used as the first standard time, and the wafer standard piece is subjected to reduction reaction processing based on the first standard time, and under the first standard time, the reduction reaction processing is fully carried out, thereby being able to detect the reduction ability of the cavity, reducing the waiting time for detection on the measuring machine, and the detection efficiency of this method is high, and the detection accuracy is improved.
[0008] According to an embodiment of the present application, obtaining a plurality of wafer standard sheets includes: Performing physical vapor deposition on a plurality of the wafers to obtain a plurality of wafer pre-processed sheets; Performing oxidation reaction treatment on a plurality of the wafer pre-processed sheets to obtain a plurality of the wafer standard sheets; wherein the oxidation reaction temperature is 300-400° C., the oxidation reaction gas flow rate is 2500-5000 sccm, and the oxidation reaction time is 10-100 s.
[0009] According to an embodiment of the present application, the resistivity of each wafer inspection piece is detected respectively to obtain the resistance value corresponding to each wafer inspection piece, including: Establishing a plurality of inspection points on each of the wafer inspection sheets; Respectively detecting the resistivity of a plurality of detection points to obtain a plurality of data values to be processed; An average value of the plurality of data values to be processed is calculated to obtain the resistance value corresponding to each wafer inspection piece.
[0010] According to an embodiment of the present application, establishing multiple inspection points on each wafer inspection sheet includes: Establishing a central inspection point at the center of the wafer inspection piece; A plurality of detection areas are established around the central detection point at even intervals, and a plurality of regional detection points are established in each detection area.
[0011] According to an embodiment of the present application, selecting the shortest reaction time from the first reaction time set as the first standard time for performing the reduction reaction process includes: Performing element content detection on the surface of the wafer inspection piece corresponding to the first standard time length to obtain element content data; When the element content data does not include oxygen, it is determined that the cleaning of the wafer is completed within the first standard time period; When the element content data includes oxygen, it is determined that the cleaning of the wafer is not completed within the first standard time period.
[0012] According to an embodiment of the present application, selecting the shortest reaction time from the first reaction time set as the first standard time for performing the reduction reaction process further includes: When the cleaning of the wafer is not completed, removing the first standard time from the first reaction time set to form a second reaction time set; Selecting the shortest reaction time from the second reaction time set as the second standard time for performing the reduction reaction process; Element content detection is performed on the surface of the wafer inspection piece corresponding to the second standard time length until oxygen is no longer included in the element content data.
[0013] According to an embodiment of the present application, it further includes: performing the reduction reaction process on the wafer for the second standard time; detecting the resistivity of each of the wafers to obtain a comparative resistance value; Comparing the comparison resistance value with the standard resistance value; When the comparison resistance value is the same as the standard resistance value, it is determined that the cleaning of the wafer is completed; When the comparative resistance value is greater than the standard resistance value, it is determined that the cleaning of the wafer is not completed and the interior of the cavity is contaminated; When the interior of the cavity is contaminated, a different reaction time is reselected to establish a second detection time set; The standard wafer is retested according to the reaction time in the second detection time set.
[0014] According to an embodiment of the present application, when it is determined that the cleaning of the wafer is not completed, reselecting a different reaction time to establish a second detection time set includes: Selecting a reaction time equal to the second standard time as the shortest reaction time; Selecting a plurality of second detection time periods, each of which is greater than the shortest reaction time period; A plurality of the second detection durations and the shortest reaction times are grouped into a second detection duration set.
[0015] According to an embodiment of the present application, the detection device is a four-probe tester having a detection probe. The detection probe is movably disposed in the process chamber and is used to contact the wafer to detect the resistivity of the wafer. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 A step diagram of a detection method according to an embodiment of the present invention; Figure 2 A diagram showing the steps of a method for detecting the resistance value of a wafer inspection sheet according to an embodiment of the present invention; Figure 3 This is a step diagram of another detection method according to an embodiment of the present invention. DETAILED DESCRIPTION
[0017] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the invention belongs. The words "including" and similar words used in this article mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects.
[0018] The following is combined with Figure 1-3 , the specific implementation methods of the present invention are further described in detail.
[0019] An embodiment of the present invention provides a method for detecting wafer pre-cleaning efficiency in a chamber, which is used to detect the shortest time for the reduction reaction to proceed when the wafer undergoes reduction reaction cleaning, while ensuring that the wafer cleaning is completed, thereby determining this time as the time when the wafer pre-cleaning efficiency is highest. Specifically, the detection method includes the following steps: Obtain several wafer standards; Select different reaction times to establish a first detection time set; Performing reduction reaction processing on a plurality of wafer standard sheets according to the reaction times in the first detection time set, to obtain wafer detection sheets with corresponding reaction times; Detect the resistivity of each wafer test piece separately to obtain the resistance value corresponding to each wafer test piece; Selecting multiple standard resistance values with the same value from multiple resistance values to form a resistance value set; Obtaining the reaction time corresponding to each standard resistance value in the resistance value set to form a first reaction time set; The shortest reaction time is selected from the first reaction time set as the first standard time for performing the reduction reaction process.
[0020] In some embodiments, prior to testing, a standard wafer sheet is obtained and tested using the tail of the standard wafer sheet as a reference. Specifically, multiple standard wafer sheets are prepared, tested sequentially, and the time required for the reduction reaction to complete the wafer pre-cleaning is determined. More specifically, the standard wafer sheet is an oxidized wafer, which will be described later.
[0021] In some embodiments, since multiple wafer standard sheets are selected and it is impossible to confirm that the reduction reaction treatment is fully reacted under that length of time, it is necessary to select multiple different reaction time lengths and perform reduction reaction treatments for different lengths on each wafer standard sheet, thereby obtaining wafer inspection sheets under corresponding reaction time lengths. For example, reaction time lengths of 1s, 1.5s, 2s, 2.5s, and 3s are selected. Reduction reaction treatments of different reaction lengths are performed on different wafer standard sheets respectively, to obtain wafer inspection sheets corresponding to a reaction time length of 1s; wafer inspection sheets corresponding to a reaction time length of 1.5s; wafer inspection sheets corresponding to a reaction time length of 2s; wafer inspection sheets corresponding to a reaction time length of 2.5s; and wafer inspection sheets corresponding to a reaction time length of 3s.
[0022] In some embodiments, after obtaining multiple wafer inspection pieces, resistivity testing is performed on each wafer inspection piece respectively, so as to obtain the resistance value corresponding to each wafer inspection piece. Specifically, the resistance value corresponding to the wafer inspection piece when the reaction time is 1s can be obtained; the resistance value corresponding to the wafer inspection piece when the reaction time is 1.5s; the resistance value corresponding to the wafer inspection piece when the reaction time is 2s; the resistance value corresponding to the wafer inspection piece when the reaction time is 2.5s; and the resistance value corresponding to the wafer inspection piece when the reaction time is 3s. When the reduction reaction of the wafer is fully carried out, the resistance value will not change. For example, when the reaction time is 2s, the reduction reaction of the wafer is sufficient, and the resistance values when the reaction time is 2.5s and 3s are the same. For ease of understanding, it is assumed here as an example that, specifically, the resistance value of the wafer detection piece corresponding to the reaction time of 1s is 10; the resistance value of the wafer detection piece corresponding to the reaction time of 1.5s is 15; the resistance value of the wafer detection piece corresponding to the reaction time of 2s is 20; the resistance value of the wafer detection piece corresponding to the reaction time of 2.5s is 20; and the resistance value of the wafer detection piece corresponding to the reaction time of 3s is 20.
[0023] In some embodiments, after obtaining resistance values corresponding to a plurality of wafer inspection sheets, a plurality of standard resistance values having the same value are selected from the plurality of resistance values, and the plurality of standard resistance values are formed into a resistance value set.
[0024] In some specific embodiments, the reaction time corresponding to each standard resistance value in the resistance value set can be obtained. For example, as described above, the resistance value set includes three standard resistance values of 20, and the reaction times corresponding to these three standard resistance values are 2s, 2.5s, and 3s, respectively. These three standard resistance values form a first reaction time set.
[0025] In some more specific embodiments, the shortest reaction time in the first reaction time set is selected as the first standard time. That is, among the three standard resistance values corresponding to reaction times of 2s, 2.5s, and 3s, the shortest reaction time, i.e., a reaction time of 2s, is selected and used as the first standard time. The first standard time is used as the duration for the reduction reaction. Under the first standard time, it can be assumed that the reduction reaction on the wafer surface has fully occurred.
[0026] Obtain several wafer standards including: Performing physical vapor deposition on a plurality of wafers to obtain a plurality of wafer pre-processed sheets; Perform oxidation reaction treatment on several wafer pre-processed sheets to obtain several wafer standard sheets; the oxidation reaction temperature is 300-400°C, the oxidation reaction gas flow rate is 2500-5000sccm, and the oxidation reaction time is 10-100s.
[0027] In some embodiments, before obtaining a plurality of wafer standard sheets, a plurality of wafers are prepared and physical vapor deposition is performed on the plurality of wafers to obtain a plurality of wafer pre-processed sheets.
[0028] In some embodiments, the pre-processed wafers are subjected to an oxidation reaction to obtain a plurality of standard wafers. Specifically, the oxidation reaction temperature is 300-400°C, the oxidation reaction gas flow rate is 2500-5000 sccm, and the oxidation reaction time is 10-100 seconds.
[0029] In some specific embodiments, a metal film wafer deposited by physical vapor deposition is placed in an oxidation reaction chamber for oxidation; the fully oxidized wafer is used as an oxidized metal film standard, that is, as a wafer standard, with a metal film thickness of 10 um to 100 um, and the metal film can be selected from copper or aluminum.
[0030] The resistivity of each wafer test piece is tested separately, and the resistance value corresponding to each wafer test piece is obtained, including: Establish multiple inspection points on each wafer inspection sheet; Resistivity of multiple detection points is detected respectively to obtain multiple data values to be processed; The average value of multiple data values to be processed is calculated to obtain the resistance value corresponding to each wafer inspection piece.
[0031] In some embodiments, when testing the resistivity of a wafer test sheet, it is necessary to establish multiple test points on the wafer surface and then calculate an average value among the multiple test points.
[0032] In some embodiments, during the inspection process, resistivity measurements are performed on multiple inspection points to obtain corresponding resistance values at the multiple inspection points, i.e., the data values to be processed. The multiple data values to be processed are then averaged to obtain the corresponding resistance value of the wafer inspection sheet. This average method allows for a more accurate determination of the resistance value of the wafer inspection sheet, improving the problem of large resistance value errors caused by selecting a single point for measurement.
[0033] Multiple inspection points are established on each wafer inspection sheet, including: Establish a central inspection point at the center of the wafer inspection piece; Multiple detection areas are evenly spaced around the central detection point, and multiple regional detection points are established in each detection area.
[0034] In some embodiments, it is necessary to evenly establish multiple detection points on the wafer detection sheet. Specifically, first establish a central detection point at the center of the wafer detection sheet, and the central detection point is concentric with the wafer. After the central detection point is established, multiple detection areas are evenly established around the central detection point, and multiple regional detection points are established in each detection area. Specifically, multiple detection areas are evenly distributed in the circular circumference around the central detection point. In this application, four detection areas are taken as an example. Multiple regional detection points are established in each detection area, and multiple regional detection points are distributed radially along the wafer within the detection area.
[0035] In some specific embodiments, during the inspection process, the resistivity of the wafer inspection sheet is measured at the central inspection point and the regional inspection points, and the multiple resistivities obtained are averaged to obtain the resistance value of each wafer inspection sheet. The calculation method is conventional and will not be described in detail here.
[0036] Selecting the shortest reaction time from the first reaction time set as the first standard time for performing the reduction reaction process includes: Performing element content detection on the surface of the wafer inspection piece corresponding to the first standard time length to obtain element content data; When the element content data does not include oxygen, it is determined that the wafer cleaning is completed within the first standard time period; When the element content data includes oxygen, it is determined that the wafer cleaning is not completed within the first standard time period.
[0037] In some embodiments, because the resistance value corresponding to each wafer inspection sheet is the average of the resistivity of multiple points on the wafer inspection sheet surface, it is possible that the resistivity at some points is high and that at other points is low. Although the average values calculated in this way are the same, in reality, only part of the wafer inspection sheet surface has undergone sufficient reduction reaction treatment, while the remaining part has not. To improve this problem, the element content of the wafer inspection sheet surface must also be tested.
[0038] In some specific embodiments, the surface of the wafer inspection piece corresponding to the first standard time period is tested for element content. Specifically, during the testing process, the proportion of metal elements in the thin film on the surface of the wafer inspection piece is mainly tested.
[0039] In some more specific embodiments, the coordinates of the detection point are exactly the same as the coordinates of the resistivity detection point. When the proportion of copper or aluminum elements is 100%, the proportion of oxygen elements is 0, indicating that there is no residual oxygen element at this time, indicating that the reduction reaction is complete; when the proportion of copper or aluminum elements is not 100%, it means that the reduction reaction at the detection point is not completed.
[0040] Selecting the shortest reaction time from the first reaction time set as the first standard time for performing the reduction reaction process also includes: When the cleaning of the wafer is not completed, the first standard time is removed from the first reaction time set to form a second reaction time set; Selecting the shortest reaction time from the second reaction time set as the second standard time for performing the reduction reaction process; The element content of the surface of the wafer inspection piece corresponding to the second standard time length is detected until the element content data does not contain oxygen.
[0041] In some embodiments, by detecting the element content on the surface of the wafer inspection piece, it can be determined whether the reduction reaction has been fully carried out at each point on the surface of each wafer inspection piece. When the reduction reaction has not been fully carried out, it means that the wafer is not yet completed.
[0042] In some embodiments, when wafer cleaning is incomplete, it indicates that the reduction reaction under the first standard time period is insufficient at certain points on the wafer inspection sheet. Therefore, the first standard time period needs to be removed from the first reaction time set. The remaining reaction times after removing the first standard time period from the first reaction time set form a second reaction time set. For example, the first standard time period of 2 seconds is removed from the first reaction time set; the remaining reaction times of 2.5 seconds and 3 seconds form the second reaction time set.
[0043] In some specific embodiments, the shortest reaction time is selected from the second reaction time set as the second standard time for performing the reduction reaction process. Since the second reaction time set is formed by the reaction time after the first standard time is proposed from the first reaction time set, the second standard time must be greater than the first standard time, that is, the reduction reaction process under the second standard time will be more fully performed than the reduction reaction process under the first standard time. For example, in the second reaction time set formed by reaction times of 2.5s and 3s, the reaction time of 2.5s is selected as the second standard time.
[0044] In some more specific embodiments, the surface of the wafer inspection piece corresponding to the second standard time length is tested for element content, and the metal element content on the surface of the wafer inspection piece is determined until the element content data does not contain oxygen. At this time, the reduction reaction has been fully carried out at the detection points on the surface of the wafer inspection piece. It can be further determined that under the second standard time length, each point on the surface of the wafer inspection piece has been fully reduced, that is, the pre-cleaning of the wafer is completed. That is, it can be determined that under the second standard time length, the efficiency of wafer pre-cleaning is the highest.
[0045] Also includes: performing a reduction reaction process on the wafer for a second standard time; Detect the resistivity of each wafer and obtain the comparative resistance value; Compare the comparison resistor value with the standard resistor value; When the comparison resistance value is the same as the standard resistance value, it is determined that the wafer is cleaned; When the comparison resistance value is greater than the standard resistance value, it is determined that the wafer cleaning is not complete and the interior of the chamber is contaminated; When the interior of the cavity is contaminated, a different reaction time is reselected to establish a second detection time set; The wafer standard piece is retested according to the response time in the second detection time set.
[0046] In some embodiments, it has been determined that the reduction reaction on the wafer inspection sheet is most fully processed during the second standard time. Therefore, in the subsequent wafer pretreatment process, the resistance value corresponding to the second standard time can be used as a benchmark for comparison, that is, the standard resistance value can be used as a benchmark for comparison to determine whether the chamber used to clean the wafer is contaminated. When the chamber used to clean the wafer is not contaminated, the resistance value of each wafer should be the same as the standard resistance value; when the chamber used to clean the wafer is contaminated, the resistance value of each wafer should be greater than the standard resistance value.
[0047] In some specific embodiments, after each wafer is cleaned, it is necessary to detect the resistivity of each wafer and obtain a comparative resistance value. Specifically, the method for detecting the resistivity is the same as described above and will not be described in detail here.
[0048] In some specific embodiments, after obtaining the comparative resistance value, the comparative resistance value is compared with the standard resistance value. Specifically, when the comparative resistance value is less than the standard resistance value or the comparative resistance value is the same as the standard resistance value, it is determined that the wafer cleaning is complete and the chamber is not contaminated, or it can be determined that the contamination in the chamber is within the error range. When the comparative resistance value is greater than the standard resistance value, it is determined that the wafer cleaning is incomplete and the chamber is contaminated, but the contamination is not within the error range.
[0049] In some more specific embodiments, when the interior of the chamber is contaminated, the comparative resistance value may be greater than the standard resistance value, indicating that the reduction reaction of the wafer is not fully carried out. Therefore, the duration of the reduction reaction needs to be reselected.
[0050] More specifically, when the interior of the cavity is contaminated, a different reaction time is reselected to establish a second detection time set; several wafer standard pieces are subjected to reduction reaction treatment according to the reaction time in the second detection time set to obtain wafer detection pieces under the corresponding reaction time; the resistivity of each wafer detection piece is detected respectively to obtain the resistance value corresponding to each wafer detection piece; the reaction time is reselected as the first standard time according to the resistance value, and the element content of the wafer detection piece is re-detected. The steps are the same as those mentioned above and will not be repeated here.
[0051] When it is determined that the wafer cleaning is not completed, a different reaction time is reselected to establish a second detection time set including: The reaction time equal to the second standard time is selected as the shortest reaction time; Selecting multiple second detection time lengths, each of which is greater than the shortest reaction time length; The plurality of second detection durations and the shortest reaction durations are grouped into a second detection duration set.
[0052] In some embodiments, when a different reaction time is reselected to establish a second detection time set, the reselected reaction time may be partially identical to the first detection time selected when establishing the first detection time set.
[0053] In some specific embodiments, a reaction time that is the same as the second standard time is selected as the shortest reaction time; more specifically, multiple second detection time lengths are selected, and the intervals between two adjacent second detection time lengths are the same. At the same time, each second detection time length is greater than the second standard time length. For example, the second standard time length of 2.5s is used as the shortest reaction time length, and multiple second detection time lengths are selected on this basis. The second detection time lengths of 3s, 3.5s, 4s, 4.5s and 5s can be selected. And the second standard time length of 2.5s, the second detection time length of 3s, the second detection time length of 3.5s, the second detection time length of 4s, the second detection time length of 4.5s and the second detection time length of 5s are used as the second detection time length set. During the detection process, the wafer standard piece is subjected to an oxidation-reduction reaction treatment with each second detection time length in the second detection time length set, and the wafer detection piece is obtained again, and the reduction reaction treatment on the wafer detection piece is re-detected to fully carry out the reaction time required. This part has been described above and will not be repeated here.
[0054] The embodiment of the present application further discloses a detection device for wafer pre-cleaning efficiency in a chamber, which is used to implement the above-mentioned detection method. The detection device includes a process chamber; An electrostatic chuck is located in the process chamber and is used to hold the wafer; A cleaning device is provided in the process chamber and is used to eject gas, which reacts with the wafer to perform a reduction reaction to clean the wafer; The detection device is arranged in the process chamber to detect the resistivity of the wafer.
[0055] In some embodiments, wafers are inspected within a process chamber, where an electrostatic chuck is positioned within the chamber. The placement of the chuck can be bolted, clipped, or integrally formed, without limitation. The key consideration is that the chuck maintains its position within the chamber and is able to support the wafer. A cleaning device is also positioned within the chamber, capable of dispensing a reducing gas, such as plasma-activated hydrogen, which reacts with metal oxides to reduce them, thereby cleaning the wafer.
[0056] The detection device is a four-probe tester, which has a detection probe. The detection probe is movably arranged in the process chamber and is used to contact the wafer to detect the resistivity of the wafer.
[0057] In some embodiments, the detection device is a four-probe tester, wherein the four-probe tester has a detection probe, and the detection probe is movably arranged in the process chamber. Specifically, the detection probe can be moved in the vertical direction in the process chamber, so that when the wafer needs to be tested, the detection probe moves toward the surface of the wafer and contacts the surface of the wafer to detect the resistivity of the surface of the wafer. That is, the detection probe is integrated inside the process chamber to detect the cavity reduction ability, thereby reducing the waiting time for the measurement machine to detect and the measurement accuracy of the detection performed by this method is high. In addition, the resistance value data under the second standard time length is used as the reduction ability threshold data. When the reduction ability test is performed subsequently, the detection is started directly from the standard piece at the threshold data, which can reduce the number of standard pieces and improve the detection efficiency.
[0058] The implementation principle of the present application's method and device for detecting the pre-cleaning efficiency of wafers in a chamber is as follows: several wafers produced by physical vapor deposition are placed in an oxidation reaction chamber for oxidation to obtain wafer standard sheets. Since there is a difference in resistivity between metal oxidation and reduction, the reduction ability can be detected by the change in resistivity, thereby judging the cleaning efficiency of the wafer. The shortest time for which the reduction reaction is fully carried out is the reaction time with the highest cleaning efficiency for the wafer.
[0059] While the embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations of these embodiments are possible. However, it should be understood that such modifications and variations are within the scope and spirit of the present invention as set forth in the claims. Furthermore, the invention described herein is susceptible to other embodiments and may be practiced or implemented in a variety of ways.
Claims
1. A method for detecting wafer pre-cleaning efficiency in a chamber, characterized in that: The following steps are involved: Obtain several wafer standards; Select different reaction times to establish a first detection time set; Performing reduction reaction processing on a plurality of wafer standard sheets according to the reaction times in the first detection time set, respectively, to obtain wafer detection sheets with corresponding reaction times; Detecting the resistivity of each wafer detection piece respectively to obtain a resistance value corresponding to each wafer detection piece; Selecting multiple standard resistance values with the same value from the multiple resistance values to form a resistance value set; Obtaining the reaction time corresponding to each standard resistance value in the resistance value set to form a first reaction time set; The shortest reaction time is selected from the first reaction time set as the first standard time for performing the reduction reaction process.
2. The detection method according to claim 1, wherein The step of obtaining a plurality of wafer standard sheets comprises: Performing physical vapor deposition on a plurality of the wafers to obtain a plurality of wafer pre-processed sheets; Performing oxidation reaction treatment on a plurality of the wafer pre-processed sheets to obtain a plurality of the wafer standard sheets; wherein the oxidation reaction temperature is 300-400° C., the oxidation reaction gas flow rate is 2500-5000 sccm, and the oxidation reaction time is 10-100 s.
3. The detection method according to claim 1, wherein The resistivity of each wafer detection piece is detected respectively to obtain the resistance value corresponding to each wafer detection piece, which includes: Establishing a plurality of inspection points on each of the wafer inspection sheets; Respectively detecting the resistivity of a plurality of detection points to obtain a plurality of data values to be processed; An average value of the plurality of data values to be processed is calculated to obtain the resistance value corresponding to each wafer inspection piece.
4. The detection method according to claim 3, characterized in that The establishing of multiple inspection points on each wafer inspection sheet includes: Establishing a central inspection point at the center of the wafer inspection piece; A plurality of detection areas are established around the central detection point at even intervals, and a plurality of regional detection points are established in each detection area.
5. The detection method according to claim 2, characterized in that The selecting the shortest reaction time from the first reaction time set as the first standard time for performing the reduction reaction process includes: Performing element content detection on the surface of the wafer inspection piece corresponding to the first standard time length to obtain element content data; When the element content data does not include oxygen, it is determined that the cleaning of the wafer is completed within the first standard time period; When the element content data includes oxygen, it is determined that the cleaning of the wafer is not completed within the first standard time period.
6. The detection method according to claim 5, characterized in that The step of selecting the shortest reaction time from the first reaction time set as the first standard time for performing the reduction reaction process further includes: When the cleaning of the wafer is not completed, removing the first standard time from the first reaction time set to form a second reaction time set; Selecting the shortest reaction time from the second reaction time set as the second standard time for performing the reduction reaction process; Element content detection is performed on the surface of the wafer inspection piece corresponding to the second standard time length until oxygen is no longer included in the element content data.
7. The detection method according to claim 6, characterized in that Also includes: performing the reduction reaction process on the wafer for the second standard time; detecting the resistivity of each of the wafers to obtain a comparative resistance value; Comparing the comparison resistance value with the standard resistance value; When the comparison resistance value is the same as the standard resistance value, it is determined that the cleaning of the wafer is completed; When the comparative resistance value is greater than the standard resistance value, it is determined that the cleaning of the wafer is not completed and the interior of the cavity is contaminated; When the interior of the cavity is contaminated, a different reaction time is reselected to establish a second detection time set; The standard wafer is retested according to the reaction time in the second detection time set.
8. The detection method according to claim 7, characterized in that When it is determined that the cleaning of the wafer is not completed, reselecting a different reaction time to establish a second detection time set includes: Selecting a reaction time equal to the second standard time as the shortest reaction time; Selecting a plurality of second detection time periods, each of which is greater than the shortest reaction time period; A plurality of the second detection durations and the shortest reaction times are grouped into a second detection duration set.
9. A device for detecting wafer pre-cleaning efficiency in a chamber, used to implement the detection method according to any one of claims 1 to 8, characterized in that: The detection device includes a process chamber; an electrostatic chuck, disposed in the process chamber and used for carrying the wafer; a cleaning device, disposed in the process chamber, for ejecting gas, wherein the gas reacts with the wafer to perform a reduction reaction to clean the wafer; A detection device is arranged in the process chamber to detect the resistivity of the wafer.
10. The detection device according to claim 9, characterized in that: The detection device is a four-probe tester having a detection probe. The detection probe is movably disposed in the process chamber and is used to contact the wafer to detect the resistivity of the wafer.