Method and system for producing epitaxial wafers

Abstract

The invention relates to a method and a system for producing epitaxial wafers. The method for producing the epitaxial wafer comprises the following steps: acquiring a total score of a chamber according to data of a plurality of characteristics of the epitaxial wafer produced in the chamber of an epitaxial furnace and weights corresponding to the data; and performing production distribution on the chambers based on the total score. According to the method and system for producing the epitaxial wafer, the production distribution efficiency in epitaxial wafer production can be improved, and the reasonability of cavity distribution in epitaxial wafer production can be improved.

Description

Technical Field

[0001] The present disclosure relates to the field of semiconductor manufacturing technology, and in particular, to a method and system for producing epitaxial wafers. Background Art

[0002] Epitaxial wafer is a product that deposits a single crystal silicon layer by applying epitaxial growth technology on a substrate wafer. It has the advantages of few surface defects, adjustable thickness and controllable resistivity. The epitaxial growth process is carried out in a sealed chamber of a special epitaxial furnace. The state of this chamber has a decisive influence on the entire growth process and the quality of the final epitaxial wafer.

[0003] Since various types of epitaxial wafer products have different requirements for chamber status, in order to ensure the production of products that meet specific quality standards, it is necessary to arrange chambers that match the quality requirements for corresponding production. Therefore, before arranging production, it is necessary to evaluate the status of each chamber. At present, this evaluation work is usually completed manually. The staff uses their professional knowledge and experience to analyze the characteristic data of the epitaxial wafers produced from the chamber, and then form a personal judgment on the chamber status.

[0004] However, since the evaluation work involves comprehensive analysis of a large number of feature data, it is difficult for staff to come up with a comprehensive result in a short period of time, resulting in an inefficient evaluation process, which in turn limits the efficiency of production allocation. In addition, manual evaluation is highly subjective, and different staff may give different evaluation results, resulting in low reliability and accuracy of the evaluation results, which may lead to unreasonable chamber allocation, thus affecting production resource allocation and product quality. Summary of the invention

[0005] This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

[0006] The object of the present disclosure is to provide a method and system for producing epitaxial wafers that can improve production allocation efficiency.

[0007] Another object of the present disclosure is to provide a method and system for producing epitaxial wafers that can improve the rationality of chamber allocation.

[0008] In order to achieve the above object, according to one aspect of the present disclosure, a method for producing an epitaxial wafer is provided, comprising: Obtaining a total score of the chamber according to data of a plurality of features of epitaxial wafers produced in the chamber of the epitaxial furnace and weights corresponding to the data; Production is allocated to chambers based on the total score.

[0009] In some embodiments, obtaining a total score of a chamber based on data of multiple features of epitaxial wafers produced in a chamber of an epitaxial furnace and weights corresponding to the data may include: determining a score of the data based on the data and a target value corresponding to the data, and performing weighted summation of the score and the corresponding weight to obtain a total score.

[0010] In some embodiments, allocating production to chambers based on the total score may include: comparing the total score with a threshold, grading the chambers according to the degree of deviation between the total score and the threshold when the total score is greater than the threshold, and allocating the chambers for production according to the grading.

[0011] In some embodiments, allocating production to the chambers based on the total score may further include: shutting down the epitaxial furnace when the total score is less than or equal to a threshold.

[0012] In some embodiments, the method for producing an epitaxial wafer may further include: constructing weights for data of a plurality of features before obtaining a total score of the chamber.

[0013] In some embodiments, the method for producing an epitaxial wafer may further include: measuring a plurality of features of the epitaxial wafer to obtain data before obtaining the overall score of the chamber.

[0014] In some embodiments, the overall score of a chamber may be updated based on data of multiple characteristics of each epitaxial wafer produced in the chamber.

[0015] In some embodiments, the plurality of features may be selected from the group consisting of: resistivity, thickness, defects, flatness, grain levels, and metal levels of the epitaxial wafer.

[0016] In some implementations, each feature of the plurality of features may include at least one item of data.

[0017] According to another aspect of the present disclosure, there is provided a system for producing an epitaxial wafer, comprising: a calculation unit, which is used to obtain a total score of the chamber according to data of multiple features of epitaxial wafers produced in the chamber of the epitaxial furnace and weights corresponding to the data; An allocation unit is used to allocate production to chambers based on the total score.

[0018] According to the above technical solution, a scoring system based on data and weight is used to determine the total score of the chamber, so that each feature of the epitaxial wafer can be considered accordingly according to its importance, and the state of the chamber can be measured by specific numerical values, thereby realizing the objectivity and standardization of the evaluation process of the chamber state. As a result, the interference of personal subjective judgment is avoided, the reliability and accuracy of the evaluation results are improved, and the allocation of chambers is made more reasonable, which is conducive to optimizing resource allocation and improving product quality. In addition, the objectivity and standardization of the evaluation process are also conducive to shortening the evaluation time and improving the evaluation efficiency, thereby speeding up the production allocation and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The features and advantages of the embodiments of the present disclosure will become more easily understood through the following description with reference to the accompanying drawings. The drawings are not drawn to scale and some features may be enlarged or reduced to show details of specific components. In the drawings: Figure 1 It is a schematic diagram of a chamber of an epitaxial furnace according to the related art.

[0020] Figure 2 is a flow chart of a method for producing an epitaxial wafer according to an embodiment of the present disclosure.

[0021] Figure 3 The present invention is a flowchart of a method for producing an epitaxial wafer according to another embodiment of the present disclosure.

[0022] Figure 4 The data of multiple features of the epitaxial wafer and the weights corresponding to the data are exemplarily shown in a bar graph.

[0023] In the drawings, the same or corresponding technical features or components are represented by the same or corresponding reference numerals. DETAILED DESCRIPTION

[0024] The present disclosure is described in detail below with reference to the accompanying drawings by means of exemplary embodiments. It should be noted that the following detailed description of the present disclosure is only for illustrative purposes and is by no means a limitation of the present disclosure.

[0025] In order to facilitate the understanding of the present disclosure, it should be noted that the chamber of the epitaxial furnace referred to in the present disclosure refers to the reaction chamber of the epitaxial furnace used to produce epitaxial wafers, that is, the chamber in which the wafers are placed and epitaxial growth is performed. Figure 1 The chamber 10 of the epitaxial furnace 1 will be exemplarily described.

[0026] like Figure 1As shown in FIG, the epitaxial furnace 1 may include an upper quartz bell jar 11 and a lower quartz bell jar 12, an upper lamp group 13 and a lower lamp group 14, an air inlet 15 and an air outlet 16, a susceptor 17 and a susceptor support structure 18. The chamber 10 of the epitaxial furnace 1 is substantially defined by the upper quartz bell jar 11 and the lower quartz bell jar 12.

[0027] When performing the epitaxial growth process, the wafer to be epitaxially grown is transported to the chamber 10 via a conveying device and placed on the susceptor 17. The upper lamp group 13 and the lower lamp group 14 are used for heating to provide the high temperature conditions required for epitaxial growth. The raw material gas flows through the main surface of the wafer through the air inlet 15 and the air outlet 16 to perform a vapor deposition reaction at a high temperature. During the epitaxial growth process, the susceptor support structure 18 drives the susceptor 17 to rotate so that the vapor deposition reaction can be carried out evenly on the surface of the wafer. After the epitaxial growth is completed, the obtained epitaxial wafer is output to the outside of the chamber 10.

[0028] As mentioned above, in epitaxial production, the state of the chamber of the epitaxial furnace will have a direct impact on the quality of the epitaxial wafers. The epitaxial production site is usually equipped with multiple epitaxial furnaces and chambers according to specific production needs and process characteristics. Different chambers may have different states due to various factors such as age, maintenance, operating conditions, etc. Therefore, it is necessary to evaluate the state of the chamber before actual production arrangements are made, and to allocate production to the chamber based on the evaluation results.

[0029] When evaluating the state of a chamber, the staff can usually determine whether the state of the chamber can continue to be used for production by judging whether the epitaxial wafers produced in the chamber meet their quality standards. To this end, the staff usually analyzes the data of many characteristics related to the quality of the epitaxial wafers, specifically, for example, judging item by item whether the measured data of each characteristic of the epitaxial wafer meets the corresponding specifications.

[0030] However, the manual evaluation method can only preliminarily determine whether a chamber can be used for production. For the many different chambers that are determined to be able to be used for production and are waiting to be allocated for production, due to the reasons mentioned above, it is difficult for the staff to make an accurate and reliable judgment on the quality levels of different chamber states in a short period of time. This greatly limits the efficiency and rationality of production allocation, and thus has a negative impact on product quality and production efficiency.

[0031] In this regard, refer to Figure 2 According to an embodiment of the present disclosure, there is provided a method for producing an epitaxial wafer, comprising: S100: Obtaining a total score of the chamber according to data of multiple features of epitaxial wafers produced in the chamber of the epitaxial furnace and weights corresponding to the data; S200: Allocate production to the chambers based on the total score.

[0032] Specifically, the characteristics of an epitaxial wafer refer to a series of indicators used to measure the quality of an epitaxial wafer, such as indicators in terms of physical, chemical and electrical properties. The data of a characteristic refers to a numerical value used to describe and quantify the characteristic. Exemplarily, the characteristic of an epitaxial wafer is, for example, flatness, which is the main indicator for measuring the surface quality of an epitaxial wafer. The data used to quantify flatness may be, but is not limited to, warp or bow, etc.

[0033] In step S100, for example, the total score of the chamber can be obtained by a specific calculation method based on the data of each feature and the weight corresponding to the data. For example, the data of each feature can be processed to obtain an intermediate value, and the total score can be obtained based on the intermediate value and the corresponding weight, such as by weighted summation.

[0034] It should be understood that the weight corresponding to the data of each feature reflects the importance of the feature in evaluating the chamber state. By introducing weights, multiple features that reflect the quality of epitaxial wafers can be reasonably considered. Therefore, the total score of the chamber obtained based on the data and weights can measure the quality of the epitaxial wafer and thus represent the level of the chamber state.

[0035] In step S200, illustratively, whether the state of the chamber can continue to be used for production can be judged based on the total scores of different chambers, and the states of different chambers can be objectively sorted based on the total scores of different chambers, thereby facilitating the allocation of different chambers to matching production tasks.

[0036] Exemplarily, the status of different chambers can be evaluated based on the relative total scores of different chambers. For example, a chamber with a relatively high total score, that is, a relatively good status, can be allocated to produce products with higher quality requirements.

[0037] In addition, for example, if the total score of a chamber is significantly lower than the total score of other chambers or much lower than the average of the total scores of all chambers, it can be determined that the state of the chamber is not suitable for direct subsequent production. In this case, the corresponding epitaxial furnace can be shut down for troubleshooting or maintenance.

[0038] Through the above scheme, a scoring system based on data and weight is used to determine the total score of the chamber, so that each feature of the epitaxial wafer can be considered accordingly according to its importance, and the state of the chamber can be measured by specific numerical values, thereby realizing the objectivity and standardization of the evaluation process of the chamber state. In this way, the interference of personal subjective judgment is avoided, the reliability and accuracy of the evaluation results are improved, and the allocation of chambers is made more reasonable, which is conducive to optimizing resource allocation and improving product quality. In addition, the objectivity and standardization of the evaluation process are also conducive to shortening the evaluation time and improving the evaluation efficiency, thereby speeding up the speed of production allocation and improving production efficiency.

[0039] In addition, the above solution also facilitates the realization of automated data processing, which not only reduces the deviations and errors that may be caused by manual processing, but also effectively saves labor costs and improves production efficiency.

[0040] In some embodiments, the plurality of features of the epitaxial wafer may be selected from the group consisting of: resistivity, thickness, defects, flatness, particle level, and metal level of the epitaxial wafer. That is, at least three or all of the above features may be selected as considerations for evaluating the chamber state according to specific needs.

[0041] As key performance indicators that directly affect semiconductor devices, the above characteristics can reflect the quality level of epitaxial wafers from different aspects. Therefore, the use of the above types of characteristics can provide a relatively more comprehensive and reliable evaluation of the state of the chamber, which helps to further improve the rationality of production allocation.

[0042] In some embodiments, each of the multiple features of the epitaxial wafer may include at least one item of data. That is, each feature may be quantified or described by at least one type of data, which helps to achieve a more comprehensive and integrated consideration of the features, helps to further improve the accuracy of the evaluation results, and thus improves the rationality of the chamber allocation.

[0043] For example, Figure 4 As indicated by the abscissa in , the resistivity data may include a resistivity uniformity value. The thickness data may include a thickness uniformity value. The defect data may include a defect count, such as the number of defects determined by edge back front inspection (EBFIS). The particle level data may include LLS@200nm, i.e., the number of particles with a size of 200 nanometers determined by localized light scattering (LLS) on each epitaxial wafer.

[0044] In addition, the flatness data may include Site Front surface referenced least sQuares / Range (SFQR) and Edge Site Front surface referenced least sQuares / Range (ESFQR), etc. The metal level data may include Minority Carrier Life Time (MCLT), Bulk Metal content such as Bulk-Fe, Surface Metal content, and metal content detected by Poly-Si Ultra Trace Profile (PUTP), etc.

[0045] It should be understood that the types of features of the epitaxial wafer and the data of each feature are not limited to the above examples.

[0046] In some embodiments, step S100 of the method for producing epitaxial wafers may include: determining a score of the data according to the data and a target value corresponding to the data, and performing weighted summation of the score and the corresponding weight to obtain a total score.

[0047] By first scoring the data and then performing weighted summation, it is convenient to convert the original different types of data of each feature into a unified and comparable score, so that the total score obtained by weighted summation can more accurately measure the state of the chamber.

[0048] Exemplarily, the target value can be set as a single value. In this regard, the score of the data can be determined according to the degree of deviation between the data and the target value. For example, the closer the data is to the target value, the higher the score of the data.

[0049] Alternatively, the target value may be set as a numerical range, for example, a numerical range corresponding to a product quality standard. In this case, sub-intervals may be defined based on the target numerical range, and different sub-intervals may correspond to different scores. In this regard, the score of the data may be determined based on the sub-interval in which the data is located.

[0050] It should be understood that the specific manner of determining the score of the data and the specific manner of obtaining the total score of the chamber are not limited to the above examples.

[0051] In some embodiments, step S200 of the method for producing epitaxial wafers may include: a step of comparing the total score with a threshold value, and when the total score is greater than the threshold value, grading the chambers according to the degree of deviation between the total score and the threshold value, and allocating the chambers for production according to the grading.

[0052] For example, the threshold value may correspond to a value corresponding to the minimum acceptable state of the chamber, so as to determine whether the epitaxial wafers produced in the chamber can meet the minimum acceptable quality requirements. In this case, the threshold value is equivalent to a passing score of the state of the chamber, which is used to determine whether the chamber can at least be used to produce products that meet the minimum quality requirements.

[0053] The threshold value may be obtained, for example, based on a standard value of feature data and a weight corresponding to the data, but is not limited thereto. The threshold value may be determined, for example, based on production requirements and historical data.

[0054] When grading the chambers, illustratively, the greater the deviation between the total score and the threshold, the better the state of the chamber and the higher its grade. For example, the chambers can be divided into different grades such as excellent, good, and qualified to adapt to production activities with different product quality requirements.

[0055] In some embodiments, step S200 of the method for producing epitaxial wafers may further include: shutting down the epitaxial furnace when the total score is less than or equal to a threshold value.

[0056] When the threshold corresponds to the minimum acceptable state of the chamber, when the total score is less than or equal to the threshold, it indicates that the state of the chamber cannot reach the minimum acceptable level, that is, the quality of the epitaxial wafers produced in the chamber will not meet the minimum product quality requirements, and therefore the chamber is not suitable for continued production.

[0057] By accurately identifying chambers that are not up to standard and shutting down the epitaxial furnace in time, it is easy to recover the chamber to improve or restore its performance and status. This method helps reduce production risks, avoids wasting more raw materials and other resources in chambers with poor conditions, and avoids the production of large-scale substandard epitaxial wafers.

[0058] In some embodiments, the method for producing an epitaxial wafer may further include: constructing weights for the data of the plurality of features before obtaining the total score of the chamber.

[0059] Exemplarily, when the feature includes multiple data, a weight is constructed for each of the multiple data. Moreover, each of the multiple data can be set with the same or different weights according to its importance in describing the feature.

[0060] For example, Figure 4 The vertical axis represents the weight corresponding to the data. For the feature of the particle level of the epitaxial wafer, it can include four data, among which the weights of MCLT and Bulk Fe can both be 0.09, and the weights of PUTP and SurfaceMetal can both be 0.07.

[0061] It is understandable that the weights corresponding to the feature data can be dynamically adjusted according to product demand and historical data to adapt to production needs at different stages.

[0062] In some embodiments, the method for producing an epitaxial wafer may further include: measuring a plurality of features of the epitaxial wafer to obtain data before obtaining the overall score of the chamber.

[0063] The data of multiple characteristics of the epitaxial wafer can be obtained by corresponding measurement devices. For example, the SFQR and ESFQR of flatness can be obtained by using a topography tester.

[0064] Additionally, the data may be either measured in real time or may be previously measured and stored for easy recall and use in obtaining the total score for the chamber.

[0065] like Figure 3 As shown in , a method for producing an epitaxial wafer according to another embodiment of the present disclosure may include: S1: weights are constructed for data of multiple features of an epitaxial wafer produced in a chamber of an epitaxial furnace; S2: measuring multiple features of the epitaxial wafer to obtain data; S3: Obtaining a total score of the chamber according to data of multiple features and weights corresponding to the data; S4: compare the total score with a threshold; when the total score is greater than the threshold, execute S5: classify the chambers according to the degree of deviation between the total score and the threshold, and allocate the chambers for production according to the classification; when the total score is less than or equal to the threshold, execute S6: shut down the epitaxial furnace.

[0066] It can be understood that the order of step S1 and step S2 is not limited to this.

[0067] In some embodiments, the total score of a chamber can be updated based on data of multiple features of epitaxial wafers produced in the chamber each time. In other words, the total score of a chamber can be updated periodically with the latest data obtained each time the chamber is used to produce epitaxial wafers, thereby ensuring that the total score can reflect the latest status of the chamber. Here, "each time" refers to each production activity or each production cycle.

[0068] Exemplarily, the epitaxial wafers produced in the chamber each time may be a batch of epitaxial wafers. To this end, data of multiple features of one or each epitaxial wafer in the batch of epitaxial wafers may be collected, and the total score of the chamber may be re-obtained based on the collected data and the weights corresponding to the data.

[0069] During the production process, the current state of the chamber is fed back in a timely manner by continuously updating the total score, which allows the operator to monitor the chamber state in real time and respond to changes in the chamber state in a timely manner, thereby maintaining production stability and improving production efficiency. It is also beneficial to ensure product quality and reduce the risk of unqualified products.

[0070] According to an embodiment of the present disclosure, a system for producing an epitaxial wafer is also provided, comprising: a calculation unit, which is used to obtain a total score of the chamber according to data of multiple features of epitaxial wafers produced in the chamber of the epitaxial furnace and weights corresponding to the data; An allocation unit is used to allocate production to chambers based on the total score.

[0071] In some embodiments, the system for producing epitaxial wafers may further include a construction unit configured to construct weights for data of a plurality of features.

[0072] In some embodiments, the system for producing epitaxial wafers may further include an acquisition unit configured to measure a plurality of features of the epitaxial wafer to obtain data.

[0073] Although the present disclosure has been described with reference to exemplary embodiments, it should be understood that the present disclosure is not limited to the specific embodiments described and shown in detail herein. Various changes may be made to the exemplary embodiments by those skilled in the art without departing from the scope defined by the claims of the present disclosure.

[0074] The features mentioned and / or shown in the above description of the exemplary embodiments of the present disclosure may be combined in the same or similar manner into one or more other embodiments, combined with features in other embodiments or substituted for corresponding features in other embodiments. The technical solutions obtained by these combinations or substitutions shall also be deemed to be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. A method for producing an epitaxial wafer, It is characterized in that include: Obtaining a total score of the chamber according to data of a plurality of features of epitaxial wafers produced in the chamber of the epitaxial furnace and weights corresponding to the data; Production is allocated to the chambers based on the total score.

2. The method for producing an epitaxial wafer according to claim 1, It is characterized in that The method of obtaining the total score of the chamber based on data of multiple features of epitaxial wafers produced in the chamber of the epitaxial furnace and weights corresponding to the data includes: determining the score of the data based on the data and a target value corresponding to the data, and performing weighted summation of the score and the corresponding weight to obtain the total score.

3. The method for producing an epitaxial wafer according to claim 1, It is characterized in that The production allocation of the chamber based on the total score includes: comparing the total score with a threshold value, and when the total score is greater than the threshold value, grading the chamber according to the degree of deviation between the total score and the threshold value, and allocating the chamber for production according to the grading.

4. The method for producing an epitaxial wafer according to claim 3, It is characterized in that The allocating production to the chamber based on the total score further includes: shutting down the epitaxial furnace when the total score is less than or equal to the threshold.

5. The method for producing an epitaxial wafer according to claim 1, It is characterized in that Also includes: Before obtaining the total score of the chamber, the weights are constructed for the data of the plurality of features.

6. The method for producing an epitaxial wafer according to claim 1, It is characterized in that Also includes: Prior to obtaining the overall score of the chamber, the plurality of features of the epitaxial wafer are measured to obtain the data.

7. The method for producing an epitaxial wafer according to claim 1, It is characterized in that The total score of the chamber is updated based on the data of the plurality of features of each epitaxial wafer produced in the chamber.

8. The method for producing an epitaxial wafer according to claim 1, It is characterized in that The plurality of features are selected from the group consisting of: resistivity, thickness, defects, flatness, grain levels, and metal levels of the epitaxial wafer.

9. The method for producing an epitaxial wafer according to claim 1, It is characterized in that Each feature of the plurality of features includes at least one item of data.

10. A system for producing epitaxial wafers, It is characterized in that include: a calculation unit, configured to obtain a total score of the chamber according to data of a plurality of features of epitaxial wafers produced in the chamber of the epitaxial furnace and weights corresponding to the data; An allocating unit is used to allocate production to the chamber based on the total score.

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