Semiconductor process apparatus and method for determining rotation speed of wafer boat thereof

Abstract

The present application belongs to the semiconductor process technology. Disclosed are a semiconductor process apparatus and a method for determining the rotation speed of a wafer boat thereof. The method comprises: acquiring first film thickness distribution data of a target wafer for a single film deposition at a preset wafer boat rotation speed; according to the first film thickness distribution data and a film deposition cycle, performing on the target wafer a film thickness distribution calculation for M times of film depositions at a plurality of different wafer boat rotation speeds, so as to obtain a plurality of pieces of second film thickness distribution data, M being a positive integer greater than or equal to a first preset threshold; calculating and comparing uniformity values of all the second film thickness distribution data, so as to find a wafer boat rotation speed corresponding to second film thickness distribution data having a minimum uniformity value and use same as a target wafer boat rotation speed. The present technical solution can greatly improve the experimental efficiency while greatly reducing the experiment time and experiment consumables, and ensures that wafer boats can rotate at an optimal rotation speed during film deposition, thus greatly improving the film deposition uniformity of products.

Description

Semiconductor process equipment and method for determining wafer boat rotation speed thereof Technical Field

[0001] The present application relates to the field of semiconductor process technology, and in particular to a semiconductor process equipment and a method for determining the rotation speed of a wafer boat thereof. Background Art

[0002] The vertical furnace atomic layer deposition equipment currently used on a large scale in the semiconductor industry is shown in Figure 1. By controlling the alternating introduction of the first reaction gas and the second reaction gas into the reaction chamber, a purge step is interspersed between the introduction of the two reaction gases into the reaction chamber to ensure that there is no residual reaction gas in the reaction chamber except for the reactants adsorbed on the surface, thereby realizing the atomic layer deposition process. Since the reaction gas mainly enters the reaction chamber from the gas injector 10 and is sprayed onto the wafer surface, it is inevitable that the supply of reaction gas is relatively more sufficient at one end near the gas injector 10, thereby causing the film thickness grown on the wafer surface near the gas injector 10 to be thicker. Therefore, in order to further improve the uniformity of the deposited film, the industry generally adopts the method of rotating the wafer boat, that is, setting a certain wafer boat rotation speed so that the wafer rotates with the wafer boat, thereby making the corresponding wafer position different each time the reaction gas is sprayed to offset the problem of uneven film thickness distribution.

[0003] In the prior art, although the industry has certain empirical values ​​for the setting of the wafer boat rotation speed: first, the wafer boat cannot rotate exactly one circle or an integer multiple of one circle after each atomic layer deposition cycle (for example, if the cycle time of the atomic layer deposition cycle is 30 seconds, the rotation speed cannot be set to 2 rpm), because this will cause the film thickness distribution of each deposition cycle to overlap, which is equivalent to the case of no rotation, resulting in poor film thickness uniformity. Secondly, the optimal wafer boat rotation speed can be found through a one-by-one experiment method to achieve the best film thickness uniformity. However, this method requires a lot of experimental time and experimental consumables. At the same time, the experimental efficiency is low, resulting in the fact that the optimal wafer boat rotation speed is rarely found in actual use, which in turn affects the uniformity of the product's thin film deposition.

[0004] Summary of the Invention

[0005] An embodiment of the present application provides a method for determining the rotation speed of a semiconductor process equipment and its wafer boat, aiming to solve the technical problem that the existing method for determining the rotation speed of a wafer boat consumes a large amount of experimental time and experimental consumables, and at the same time, the experimental efficiency is low, resulting in the optimal wafer boat rotation speed rarely being found in actual use, thereby affecting the uniformity of thin film deposition of the product.

[0006] In a first aspect, an embodiment of the present application provides a method for determining a rotation speed of a wafer boat, which is applied to semiconductor process equipment. The method includes:

[0007] Acquire first film thickness distribution data of a target wafer during a thin film deposition process at a preset wafer boat speed;

[0008] performing film thickness distribution calculations on the target wafer for M thin film depositions at multiple different wafer boat speeds based on the first film thickness distribution data and the film deposition cycle, to obtain multiple second film thickness distribution data, where M is a positive integer greater than or equal to a first preset threshold;

[0009] The uniformity values ​​of all the second film thickness distribution data are calculated and compared, and the wafer boat rotation speed corresponding to the second film thickness distribution data with the smallest uniformity value is used as the target wafer boat rotation speed.

[0010] In some embodiments, obtaining first film thickness distribution data of a thin film deposited on a target wafer at a preset wafer boat speed includes:

[0011] Setting a plurality of thickness detection points on the surface of the target wafer, and performing N thin film deposition on the target wafer at a preset wafer boat speed to obtain a deposited wafer, where N is a positive integer less than or equal to a second preset threshold, and the second preset threshold is less than the first preset threshold;

[0012] Detecting thickness data of the deposited wafer at each thickness detection point to obtain a plurality of wafer thickness values;

[0013] According to the multiple wafer thickness values, the initial thickness value of the target wafer and the value of N, the film thickness growth value of each thickness detection point of the target wafer after a thin film deposition is calculated to form the first film thickness distribution data.

[0014] In some embodiments, the plurality of thickness detection points are divided into a plurality of different thickness detection groups, and the plurality of thickness detection points in different thickness detection groups are evenly spaced and distributed on circumferences of different radii on the surface of the target wafer.

[0015] In some embodiments, setting a plurality of thickness detection points on the surface of the target wafer includes:

[0016] The center of the surface of the target wafer is used as the origin, and the coordinates of each thickness detection point are recorded in the form of polar coordinates.

[0017] In some embodiments, the film thickness growth value of each thickness detection point of the target wafer after a thin film deposition is calculated based on the multiple wafer thickness values, the initial thickness value of the target wafer, and the value of N, including:

[0018] When calculating the film thickness growth value at the current thickness detection point, the wafer thickness value corresponding to the current thickness detection point is subtracted from the initial thickness value of the target wafer, and then divided by the value of N to obtain the film thickness growth value at the current thickness detection point.

[0019] In some embodiments, the film thickness distribution calculation of M thin film depositions at multiple different wafer boat speeds is performed on the target wafer based on the first film thickness distribution data and the film deposition cycle to obtain multiple second film thickness distribution data includes:

[0020] When calculating the film thickness distribution of M thin film depositions on the target wafer at each wafer boat speed, the second film thickness distribution data corresponding to the current wafer boat speed is calculated based on the film thickness growth value of each thickness detection point, the film deposition cycle, the current wafer boat speed, and the value of M;

[0021] The second film thickness distribution data corresponding to each wafer boat speed is calculated one by one according to the film thickness growth value of each thickness detection point, the thin film deposition cycle, the value of each wafer boat speed and the value of M, thereby obtaining the plurality of second film thickness distribution data.

[0022] In some embodiments, the calculating of the second film thickness distribution data corresponding to the current wafer boat speed according to the film thickness growth value of each thickness detection point, the film deposition cycle, the current wafer boat speed value, and the value of M includes:

[0023] According to the film thickness growth value of each thickness detection point, the film deposition cycle, the current wafer boat speed value and the value of M, the film thickness growth distribution data formed by each film deposition in the process from the first film deposition to the Mth film deposition are calculated in sequence to obtain M film thickness growth distribution data;

[0024] The M film thickness growth distribution data are sequentially superimposed to obtain the second film thickness distribution data corresponding to the current wafer boat rotation speed.

[0025] In some embodiments, the film thickness growth distribution data formed by each thin film deposition process from the first thin film deposition to the Mth thin film deposition is calculated in sequence according to the film thickness growth value of each thickness detection point, the thin film deposition cycle, the current wafer boat speed value, and the value of M, including:

[0026] using the film thickness growth value of each thickness detection point in the first film thickness distribution data as the film thickness growth distribution data formed by the first thin film deposition;

[0027] Calculating the rotation angle of the target wafer during two adjacent thin film depositions according to the thin film deposition cycle and the current wafer boat speed;

[0028] After rotating the film thickness growth distribution data formed by the (i-1)th thin film deposition by the rotation angle, the film thickness growth distribution data formed by the (i)th thin film deposition is calculated, where i is a positive integer ranging from 2 to M.

[0029] In some embodiments, an absolute value of a difference between the wafer boat rotation speed and the preset wafer boat rotation speed is less than or equal to a preset threshold.

[0030] In a second aspect, an embodiment of the present application provides a semiconductor process device, including a controller, a thin film deposition process component, a reaction chamber, and a thickness detection component, wherein:

[0031] The thin film deposition process component is used to perform a thin film deposition process on the target wafer on the wafer boat in the reaction chamber;

[0032] The thickness detection component is used to detect the thickness of the target wafer on the wafer boat in the reaction chamber;

[0033] The controller is used to control the thin film deposition process component and the thickness detection component to work respectively, and execute the above-mentioned method for determining the rotation speed of the wafer boat during operation.

[0034] In the present application, when determining the rotation speed of the wafer boat, it is only necessary to first obtain the first film thickness distribution data of a thin film deposition on the target wafer at a preset wafer boat speed. Then, based on the first film thickness distribution data and the film deposition cycle, the film thickness distribution of the target wafer is calculated for M times of thin film deposition at different wafer boat speeds to obtain multiple second film thickness distribution data, where M is a positive integer greater than or equal to a first preset threshold. Finally, the uniformity values ​​of all the second film thickness distribution data are calculated and compared, and the wafer boat speed corresponding to the second film thickness distribution data with the smallest uniformity value is found as the target wafer boat speed. This target wafer boat speed is the optimal wafer boat rotation speed. As can be seen, the present technical solution can obtain the optimal wafer boat rotation speed through a single experimental data and computer simulation-assisted calculation method. This can greatly reduce experimental time and experimental consumables while greatly improving experimental efficiency, and ensure that the wafer boat can rotate at the optimal speed during the thin film deposition process, thereby greatly improving the uniformity of the thin film deposition of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The following detailed description of the specific embodiments of the present application in conjunction with the accompanying drawings will make the technical solutions and beneficial effects of the present application apparent.

[0036] FIG1 is a schematic diagram of the thin film deposition principle of an existing vertical furnace atomic layer deposition device.

[0037] FIG2 is a flowchart of a method for determining a rotation speed of a wafer boat of a semiconductor process equipment provided in an embodiment of the present application.

[0038] FIG. 3 is a flowchart of step S110 of the method for determining the rotation speed of the wafer boat shown in FIG. 2 .

[0039] FIG. 4 is a schematic diagram showing the distribution of thickness detection points of a target wafer in the method for determining the rotation speed of a wafer boat shown in FIG. 2 .

[0040] FIG. 5 is a flowchart of step S120 of the method for determining the rotation speed of the wafer boat shown in FIG. 2 .

[0041] FIG. 6 is a diagram showing the film thickness distribution effect of a thin film deposition on a target wafer in the method for determining the wafer boat rotation speed shown in FIG. 2 .

[0042] FIG. 7 is a diagram showing film thickness distribution effects of 120 thin film depositions calculated by simulation on a target wafer in the method for determining the wafer boat rotation speed shown in FIG. 2 .

[0043] FIG. 8 is a diagram showing the film thickness distribution of 120 actual thin film depositions on a target wafer in the method for determining the wafer boat rotation speed shown in FIG. 2 . DETAILED DESCRIPTION

[0044] The following, in conjunction with the accompanying drawings, clearly and completely describes the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of this application. In the absence of conflict, the following embodiments and their technical features can be combined with each other.

[0045] The vertical furnace atomic layer deposition equipment currently used on a large scale in the semiconductor industry is shown in Figure 1. By controlling the alternating introduction of the first reaction gas and the second reaction gas into the reaction chamber, a purge step is interspersed between the introduction of the two reaction gases into the reaction chamber to ensure that there is no residual reaction gas in the reaction chamber except for the reactants adsorbed on the surface, thereby realizing the atomic layer deposition process. Since the reaction gas mainly enters the reaction chamber from the gas injector 10 and is sprayed onto the wafer surface, it is inevitable that the supply of reaction gas is relatively more sufficient at one end near the gas injector 10, thereby causing the film thickness grown on the wafer surface near the gas injector 10 to be thicker. Therefore, in order to further improve the uniformity of the deposited film, the industry generally adopts the method of rotating the wafer boat, that is, setting a certain wafer boat rotation speed so that the wafer rotates with the wafer boat, thereby making the corresponding wafer position different each time the reaction gas is sprayed to offset the problem of uneven film thickness distribution.

[0046] In the prior art, although the industry has certain empirical values ​​for the setting of the wafer boat rotation speed: first, the wafer boat cannot rotate exactly one circle or an integer multiple of one circle after each atomic layer deposition cycle (for example, if the cycle time of the atomic layer deposition cycle is 30 seconds, the rotation speed cannot be set to 2 rpm), because this will cause the film thickness distribution of each deposition cycle to overlap, which is equivalent to the case of no rotation, resulting in poor film thickness uniformity. Secondly, the optimal wafer boat rotation speed can be found through a one-by-one experiment method to achieve the best film thickness uniformity. However, this method requires a lot of experimental time and experimental consumables. At the same time, the experimental efficiency is low, resulting in the fact that the optimal wafer boat rotation speed is rarely found in actual use, which in turn affects the uniformity of the product's thin film deposition.

[0047] Based on this, it is necessary to provide a new solution for determining the rotation speed of the wafer boat to solve the technical problem that the existing method for determining the rotation speed of the wafer boat consumes a lot of experimental time and experimental consumables. At the same time, the experimental efficiency is low, resulting in the optimal wafer boat rotation speed rarely being found in actual use, thereby affecting the uniformity of the thin film deposition of the product.

[0048] In one embodiment, as shown in FIG. 2 , the present invention provides a method for determining a wafer boat rotation speed, which is applied to semiconductor process equipment. The method for determining a wafer boat rotation speed may specifically include:

[0049] Step S110: obtaining first film thickness distribution data of a thin film deposition process on a target wafer at a preset wafer boat rotation speed.

[0050] It is understood that in order to obtain the first film thickness distribution data in the steps of this method, it is necessary to conduct a real thin film deposition experiment on the target wafer to obtain the corresponding experimental data. To this end, in addition to rotating the target wafer at a preset wafer boat speed, the wafer must also be placed under corresponding process conditions. The corresponding process conditions specifically refer to conditions that can achieve the corresponding thin film deposition process on the target wafer, including but not limited to controlling the reaction chamber where the target wafer is located to be within a suitable temperature range, maintaining a specific gas pressure in the reaction chamber, and introducing a specific gas into the reaction chamber. After the corresponding thin film deposition process is completed on the target wafer under the corresponding process conditions and the preset wafer boat speed, the corresponding thickness of each part of the target wafer can be further measured and simply calculated to obtain the first film thickness distribution data formed on the target wafer after a thin film deposition at the preset wafer boat speed.

[0051] Step S120 : performing film thickness distribution calculations on the target wafer for M times of thin film deposition at multiple different wafer boat rotation speeds based on the first film thickness distribution data and the film deposition cycle to obtain multiple second film thickness distribution data.

[0052] It is understandable that the thin film deposition cycle specifically refers to the time it takes for a target wafer to undergo a thin film deposition. In order to more accurately determine the film uniformity of the target wafer after thin film deposition at different wafer boat speeds, the prior art generally uses experimental data to perform a large number of thin film depositions (such as 100 times or 120 times) on the target wafer at multiple different wafer boat speeds before measuring the corresponding film uniformity, which consumes a lot of experimental time and experimental consumables. The method steps of the present application can be based on the first film thickness distribution data (i.e., the thickness distribution data of a thin film deposition) and the thin film deposition cycle, and the film thickness distribution of the target wafer can be calculated by computer simulation at multiple different wafer boat speeds for M thin film depositions to obtain multiple second film thickness distribution data, where M should be a positive integer greater than or equal to the first preset threshold, and the first preset threshold should be a positive integer with a large value, such as 100.

[0053] In addition, since the complete process of a thin film deposition (such as an Atomic Layer Deposition Cycle, referred to as an ALD cycle, i.e., an atomic layer deposition cycle) can specifically include a deposition process and a purge process, wherein the process time of the actual deposition process is generally only 2 seconds, relative to the rotation speed of the wafer boat, which is generally two or three revolutions per minute, the angle of the target wafer changed during the actual deposition process is almost negligible, and it can be considered that these changes have almost no effect on the film thickness distribution data. Therefore, the preset wafer boat speed mentioned above can be specifically 0, so that when the wafer boat is not rotating, after collecting the first film thickness distribution data of a thin film deposition of the target wafer, according to the first film thickness distribution data and the thin film deposition cycle, the film thickness distribution of the target wafer after M thin film depositions at multiple different wafer boat speeds is calculated to obtain multiple second film thickness distribution data. The above-mentioned multiple different wafer boat speeds can specifically include 1rpm, 1.1rpm, 1.2rpm, ..., 2.8rpm, 2.9rpm, etc. Generally speaking, to ensure more accurate data estimation, the absolute value of the difference between the wafer boat speed and the preset wafer boat speed should be less than or equal to a preset threshold. Since the smaller the absolute value of the difference between the wafer boat speed and the preset wafer boat speed, the closer the second film thickness distribution data obtained by calculating the film thickness distribution after performing M thin film depositions on the target wafer at that wafer boat speed is to the actual film thickness distribution data obtained in an actual thin film deposition experiment, thus, an appropriate preset threshold can be selected based on the actual calculation accuracy requirements. In this case, the preset wafer boat speed is not limited to 0. That is, multiple intermediate values ​​can be reasonably selected, and the first film thickness distribution data generated by each intermediate value can be used to simulate and calculate the corresponding multiple second film thickness distribution data. This ensures that the calculated second film thickness distribution data are closer to the actual film thickness distribution data obtained in an actual thin film deposition experiment. For example, if it is necessary to calculate the film thickness distribution data deposited at a speed between 0.5 rpm and 1.5 rpm, multiple intermediate values ​​can be selected from this range, such as 1 rpm.

[0054] Step S130 : calculating and comparing the uniformity values ​​of all the second film thickness distribution data, and finding the wafer boat speed corresponding to the second film thickness distribution data with the smallest uniformity value as the target wafer boat speed.

[0055] It can be understood that after obtaining multiple second film thickness distribution data through the above method steps, the uniformity value of each second film thickness distribution data can be calculated and compared, and the crystal boat speed corresponding to the second film thickness distribution data with the smallest uniformity value can be found as the target crystal boat speed, and the target crystal boat speed is the optimal speed for the crystal boat rotation.

[0056] In this way, in the embodiment of the present application, the optimal rotation speed of the wafer boat can be obtained through a single experimental data and computer simulation-assisted calculation method, which can greatly reduce the experimental time and experimental consumables while greatly improving the experimental efficiency, and ensuring that the wafer boat can rotate at the optimal speed during the thin film deposition process, thereby greatly improving the uniformity of the thin film deposition of the product.

[0057] In some examples, to obtain more accurate and reliable first film thickness distribution data, as shown in FIG3 , the process of executing the above method step of “obtaining first film thickness distribution data of a thin film deposition on a target wafer under preset process conditions” is as follows:

[0058] Step S111 : setting a plurality of thickness detection points on the surface of the target wafer, and performing N times of thin film deposition on the target wafer at a preset wafer boat speed to obtain a deposited wafer.

[0059] It can be understood that in order to avoid consuming a large amount of experimental time and experimental consumables, N should be a positive integer less than or equal to the second preset threshold, and the second preset threshold is smaller than the first preset threshold mentioned in the above method steps, that is, the second preset threshold should be a smaller positive integer, such as 10.

[0060] In order to ensure that the obtained first film thickness distribution data can better reflect the film thickness distribution of various parts of the target wafer surface, a plurality of thickness detection points can be set on the surface of the target wafer as shown in FIG4. Furthermore, the plurality of thickness detection points can be specifically divided into a plurality of different thickness detection groups, and the plurality of thickness detection points of different thickness detection groups are equally spaced on the circumference of different radii on the surface of the target wafer. At the same time, generally speaking, different thickness detection points can be marked with an X-coordinate-Y-coordinate coordinate system as shown in FIG4, but in order to reduce the difficulty of subsequent simulation calculations, the coordinates of the thickness detection points can also be recorded in the following manner, that is, the surface center of the target wafer is used as the origin, and the coordinates of each thickness detection point are recorded in the form of polar coordinates. Therefore, the X-coordinate-Y coordinates of the 49 thickness detection points shown in FIG4 can be converted into corresponding polar coordinates by the following Table 1:

[0061] Table 1

[0062] Step S112: Detecting thickness data of the deposited wafer at each thickness detection point to obtain a plurality of wafer thickness values.

[0063] It can be understood that after the deposited wafer is obtained through the above method steps, the thickness data of the deposited wafer at each thickness detection point can be detected to obtain multiple wafer thickness values. Specifically, at each thickness detection point, the deposited wafer is measured accordingly to obtain a wafer thickness value, and the corresponding value is recorded at the corresponding thickness detection point.

[0064] Step S113: Calculate the film thickness growth value of each thickness detection point of the target wafer after one thin film deposition based on multiple wafer thickness values, the initial thickness value of the target wafer, and the value of N to form first film thickness distribution data.

[0065] It can be understood that after obtaining multiple wafer thickness values ​​through the above method steps, the film thickness growth value of each thickness detection point of the target wafer after a thin film deposition can be calculated based on the multiple wafer thickness values, the initial thickness value of the target wafer and the value of N to form the first film thickness distribution data. The specific process is as follows: when calculating the film thickness growth value of the current thickness detection point, the corresponding measured wafer thickness value of the current thickness detection point is subtracted from the initial thickness value of the target wafer, and then divided by the value of N to obtain the film thickness growth value of the current thickness detection point.

[0066] Since the thickness changes of various parts of the target wafer after each thin film deposition are limited, this example obtains the film thickness growth value of each thickness detection point by taking the average value after performing N thin film depositions, which can ensure that the final first film thickness distribution data is more real and reliable.

[0067] In some examples, to better calculate and obtain more accurate multiple second film thickness distribution data, the above method step of "calculating the film thickness distribution of M thin film depositions at multiple different boat speeds on the target wafer based on the first film thickness distribution data and the film deposition cycle to obtain multiple second film thickness distribution data" is performed as follows: when calculating the film thickness distribution of M thin film depositions at each boat speed for the target wafer, the second film thickness distribution data corresponding to the current boat speed is calculated based on the film thickness growth value at each thickness detection point, the film deposition cycle, the current boat speed, and the value of M. In this way, the second film thickness distribution data corresponding to each boat speed is calculated based on the film thickness growth value at each thickness detection point, the film deposition cycle, the current boat speed, and the value of M, thereby obtaining multiple second film thickness distribution data. That is to say, the second film thickness distribution data corresponding to each crystal boat rotation speed is calculated one by one, and then a plurality of second film thickness distribution data are obtained, and the calculation method of the second film thickness distribution data corresponding to each crystal boat rotation speed is specifically as follows: according to the film thickness growth value of each thickness detection point, the thin film deposition cycle, the current crystal boat rotation speed value and the value of M, the second film thickness distribution data corresponding to the current crystal boat rotation speed is calculated.

[0068] Furthermore, as shown in FIG5 , the process of executing the above method step of “calculating the second film thickness distribution data corresponding to the current wafer boat speed according to the film thickness growth value at each thickness detection point, the film deposition cycle, the current wafer boat speed value, and the value of M” is as follows:

[0069] Step S121: Based on the film thickness growth value of each thickness detection point, the film deposition cycle, the current wafer boat speed value and the value of M, the film thickness growth distribution data formed by each thin film deposition from the first thin film deposition to the Mth thin film deposition are calculated in sequence to obtain M film thickness growth distribution data.

[0070] Step S122: superimposing the M film thickness growth distribution data in sequence to form second film thickness distribution data corresponding to the current wafer boat rotation speed.

[0071] It can be understood that in order to obtain the second film thickness distribution data corresponding to the current wafer boat speed, the preferred method is to first calculate the film thickness growth distribution data formed by each thin film deposition in the process from the first thin film deposition to the Mth thin film deposition, so as to obtain M film thickness growth distribution data, and then superimpose the M film thickness growth distribution data in sequence to form the second film thickness distribution data corresponding to the current wafer boat speed.

[0072] To better calculate the film thickness growth distribution data for each thin film deposition process from the first to the Mth thin film deposition, the following method can be used: First, the film thickness growth value at each thickness detection point in the first film thickness distribution data is used as the film thickness growth distribution data for the first thin film deposition process. Second, based on the film deposition cycle and the current wafer boat speed, the rotation angle of the target wafer between two adjacent thin film deposition processes is calculated. Finally, the film thickness growth distribution data for the i-1th thin film deposition process is rotated by this rotation angle to obtain the film thickness growth distribution data for the i-th thin film deposition process, where i is a positive integer from 2 to M.

[0073] Taking the current wafer boat speed of 1rpm and the film deposition cycle of 16s as an example, the wafer angle difference between each film deposition and the previous film deposition is 1×360×16 / 60=96°. Therefore, the film thickness growth distribution data of the current film deposition can be rotated 96° to obtain the film thickness growth distribution data of the next film deposition. However, since the two film thickness growth distribution data may not overlap, that is, they are not at the same position, in order to infer the film thickness of the next film deposition at the data point position of the current film deposition, linear calculation can be used. The specific calculation method is as follows:

[0074] 1. Based on the coordinate distribution of the thickness measurement points in Figure 4, the 49 thickness measurement points shown in Figure 4 are divided into four groups (point 1, points 2-9, points 10-25, and points 26-49) according to the size of the polar diameter. Since the wafer rotates circumferentially around the center of the circle, after the coordinates are converted to polar coordinates, the only difference between the points in each group is the polar angle coordinates. During the calculation process, only the relative rotation angle of each point in the group needs to be considered. This can greatly reduce the amount of calculation and the errors caused by the operation process.

[0075] 2. According to the above, the position of the first group (point 1) does not change during the rotation process, so the film thickness of each thin film deposition is the same; the second group (points 2-9) is rotated according to the angle of the wafer, such as 96°, so the polar coordinate of point 2 in the next thin film deposition becomes 186°, so the position of point 2 at this time falls between points 4 and 5 in this thin film deposition. According to the linear calculation, (film thickness at point 2 - film thickness at point 4) / (film thickness at point 5 - film thickness at point 4) = (polar angle at point 2 - polar angle at point 4) / (Point 5 polar angle - point 4 polar angle), substitute point 2 polar angle = 186° into the above formula, and the film thickness value of point 2 is {(point 5 film thickness - point 4 film thickness) × (186° - point 4 polar angle) / (point 5 polar angle - point 4 polar angle) + point 4 film thickness}. Similarly, the film thickness values ​​of all points in the second group in the next thin film deposition can be calculated. The corresponding film thickness values ​​of the third and fourth groups can also be calculated in the same way. Finally, the film thickness of the next thin film deposition at the data point position of this thin film deposition can be obtained.

[0076] After obtaining the film thickness growth distribution data formed by each thin film deposition in the above manner, that is, obtaining M film thickness growth distribution data, the M film thickness growth distribution data can be superimposed in sequence to form the second film thickness distribution data corresponding to the current wafer boat speed.

[0077] Still, taking the current wafer boat speed of 1rpm and the film deposition cycle of 16s as an example, on the basis of the first film thickness distribution data of the actual target wafer for one film deposition shown in Table 2 below and the film thickness distribution effect diagram of the target wafer for one film deposition shown in FIG6 , the above method is used to simulate and calculate to obtain the second film thickness distribution data of the target wafer for 120 film depositions as shown in Table 2 below and the film thickness distribution effect diagram of the target wafer for 120 film depositions as shown in FIG7 . At the same time, by comparing it with the actual film thickness distribution data of the target wafer after 120 film depositions in Table 2 below and the film thickness distribution effect diagram of the target wafer for 120 film depositions as shown in FIG8 , it can be seen that the calculated film thickness data is consistent with the actual film thickness distribution data. The calculated uniformity value (Unif%) of the second film thickness distribution data is consistent with the actual experimental data. The uniformity value (Unif%) of the film thickness distribution data of the target wafer after 120 thin film depositions is 1.05. It can be seen that the uniformity error between the two is very small, that is, the second film thickness distribution data obtained by simulation calculation in this application can truly reflect the film thickness distribution data of the target wafer after the corresponding thin film deposition at the corresponding wafer boat speed. Therefore, the example of this application calculates and compares the uniformity values ​​of multiple second film thickness distribution data calculated by it to find the wafer boat speed corresponding to the second film thickness distribution data with the smallest uniformity value as the target wafer boat speed, and the target wafer boat speed is the optimal speed for wafer boat rotation.

[0078] Table 2

[0079] In one embodiment, the present application further provides a semiconductor process device, which may include a controller, a thin film deposition process component, a reaction chamber, and a thickness detection component. The thin film deposition process component may be used to perform a thin film deposition process on a target wafer on a wafer boat within the reaction chamber. The thickness detection component may be used to detect the thickness of a target wafer on a wafer boat within the reaction chamber. The controller may be used to control the operation of the thin film deposition process component and the thickness detection component, respectively, and execute the method for determining the wafer boat rotation speed described in the above embodiment during operation, which will not be further described herein.

[0080] In some examples, taking the example of a thin film deposition process component that can be specifically used to perform an atomic layer deposition process on a target wafer on a wafer boat in the reaction chamber, the thin film deposition process component can specifically include a gas delivery component to deliver the reaction gas required for the atomic layer deposition process into the reaction chamber.

[0081] Although the present application has been shown and described with respect to one or more implementations, equivalent variations and modifications will occur to those skilled in the art based on reading and understanding this specification and the accompanying drawings. The present application includes all such modifications and variations and is limited only by the scope of the appended claims. In particular, with respect to the various functions performed by the above-mentioned components, the terms used to describe such components are intended to correspond to any component (unless otherwise indicated) that performs the specified function of the component (e.g., it is functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the function in the exemplary implementation of this specification shown herein.

[0082] That is, the above description is merely an embodiment of the present application and does not limit the patent scope of the present application. Any equivalent structural or equivalent process transformations made using the contents of the description and drawings of this application, such as the mutual combination of technical features between the various embodiments, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

[0083] In addition, in the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present application. In addition, for structural elements with the same or similar characteristics, the present application may use the same or different reference numerals to identify them. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0084] In this application, the word "exemplary" is used to mean "serving as an example, illustration or description". Any embodiment described in this application as "exemplary" is not necessarily to be construed as being more preferred or advantageous than other embodiments. In order to enable any person skilled in the art to implement and use the present application, the present application provides the above description. In the above description, various details are listed for the purpose of explanation. It should be understood that a person of ordinary skill in the art can recognize that the present application can be implemented without using these specific details. In other embodiments, well-known structures and processes will not be elaborated in detail to avoid obscuring the description of the present application with unnecessary details. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the widest scope consistent with the principles and features disclosed in this application.

Claims

1. A method for determining a rotation speed of a wafer boat, applied to semiconductor process equipment, characterized in that: The determination method comprises: Acquire first film thickness distribution data of a target wafer during a thin film deposition at a preset wafer boat speed; According to the first film thickness distribution data and the film deposition cycle, performing film thickness distribution calculation of M times of film deposition at multiple different wafer boat rotation speeds on the target wafer to obtain multiple second film thickness distribution data, where M is a positive integer greater than or equal to a first preset threshold value; The uniformity values ​​of all the second film thickness distribution data are calculated and compared, and the wafer boat rotation speed corresponding to the second film thickness distribution data with the smallest uniformity value is used as the target wafer boat rotation speed.

2. The determination method according to claim 1, characterized in that: The step of obtaining first film thickness distribution data of a thin film deposition on a target wafer at a preset wafer boat speed comprises: A plurality of thickness detection points are set on the surface of the target wafer, and N thin film depositions are performed on the target wafer at the preset wafer boat speed to obtain a deposited wafer, where N is a positive integer less than or equal to a second preset threshold value, and the second preset threshold value is less than the first preset threshold value; Detecting thickness data of the deposited wafer at each thickness detection point to obtain a plurality of wafer thickness values; According to the multiple wafer thickness values, the initial thickness value of the target wafer and the value of N, the film thickness growth value of each thickness detection point of the target wafer after a thin film deposition is calculated to form the first film thickness distribution data.

3. The determination method according to claim 2, characterized in that: The plurality of thickness detection points are divided into a plurality of different thickness detection groups, and the plurality of thickness detection points of different thickness detection groups are evenly spaced and distributed on circles of different radii on the surface of the target wafer.

4. The determination method according to claim 3, characterized in that: The step of setting a plurality of thickness detection points on the surface of the target wafer comprises: The center of the surface of the target wafer is taken as the origin, and the coordinates of each thickness detection point are recorded in the form of polar coordinates.

5. The determination method according to claim 2, characterized in that: The film thickness growth value of each thickness detection point of the target wafer after a thin film deposition is calculated based on the multiple wafer thickness values, the initial thickness value of the target wafer and the value of N, including: When calculating the film thickness growth value at the current thickness detection point, the corresponding measured wafer thickness value at the current thickness detection point is subtracted from the initial thickness value of the target wafer, and then divided by the value of N to obtain the film thickness growth value at the current thickness detection point.

6. The determination method according to claim 2, characterized in that: The film thickness distribution calculation of M times of thin film deposition at multiple different wafer boat speeds is performed on the target wafer according to the first film thickness distribution data and the film deposition cycle to obtain multiple second film thickness distribution data, including: When calculating the film thickness distribution of M thin film depositions at each wafer boat speed for the target wafer, the second film thickness distribution data corresponding to the current wafer boat speed is calculated based on the film thickness growth value at each thickness detection point, the film deposition cycle, the value of the current wafer boat speed, and the value of M; The second film thickness distribution data corresponding to each wafer boat speed is calculated one by one according to the film thickness growth value of each thickness detection point, the thin film deposition cycle, the value of each wafer boat speed and the value of M, so as to obtain the plurality of second film thickness distribution data.

7. The determination method according to claim 6, characterized in that: The second film thickness distribution data corresponding to the current wafer boat speed is calculated based on the film thickness growth value of each thickness detection point, the film deposition cycle, the value of the current wafer boat speed, and the value of M, including: According to the film thickness growth value of each thickness detection point, the film deposition cycle, the current wafer boat speed value and the value of M, the process from the first film deposition to the Mth film deposition is calculated in sequence. Film thickness growth distribution data formed by each thin film deposition to obtain M film thickness growth distribution data; The M film thickness growth distribution data are sequentially superimposed to obtain the second film thickness distribution data corresponding to the current wafer boat rotation speed.

8. The determination method according to claim 7, characterized in that: According to the film thickness growth value of each thickness detection point, the film deposition cycle, the value of the current wafer boat speed and the value of M, the film thickness growth distribution data formed by each film deposition during the first film deposition to the Mth film deposition are calculated in sequence, including: taking the film thickness growth value of each thickness detection point in the first film thickness distribution data as the film thickness growth distribution data formed by the first thin film deposition; According to the film deposition cycle and the current wafer boat rotation speed, a rotation angle of the target wafer during two adjacent film depositions is calculated; After rotating the film thickness growth distribution data formed by the i-1th thin film deposition by the rotation angle, the film thickness growth distribution data formed by the i-th thin film deposition is calculated, where i is a positive integer ranging from 2 to M.

9. The determination method according to any one of claims 1 to 8, characterized in that: An absolute value of a difference between the wafer boat rotation speed and the preset wafer boat rotation speed is less than or equal to a preset threshold.

10. A semiconductor process equipment, characterized in that: It includes a controller, a thin film deposition process component, a reaction chamber and a thickness detection component, wherein: The thin film deposition process component is used to perform a thin film deposition process on a target wafer on a wafer boat in the reaction chamber; The thickness detection component is used to detect the thickness of the target wafer on the wafer boat in the reaction chamber; The controller is used to control the thin film deposition process component and the thickness detection component to work respectively, and execute the method for determining the rotation speed of the wafer boat as described in any one of claims 1-9 when working.

Images