Wafer boat, batch processing device and low-pressure vapor deposition method

Abstract

The invention provides a wafer boat, a batch processing device and a low-pressure vapor deposition method, the wafer boat is used for depositing a product film layer on the front side of a product wafer and comprises a first area and a second area which are adjacent, the first area comprises a plurality of product wafer grooves, the second area comprises a monitoring wafer groove, and the second area is located on the bearing side of the product wafer groove; wherein the product wafer grooves are used for bearing the product wafer and exposing the back surface of the product wafer, and a first distance is formed between the product wafer grooves; the monitoring wafer groove is used for bearing a monitoring wafer and exposing the back surface of the monitoring wafer, a second interval is arranged between the first area and the second area, and the proportion of the first interval and the second interval is in positive correlation with the proportion of the thermal radiation rate of the product wafer back surface film layer and the thermal radiation rate of the monitoring wafer back surface film layer. According to the wafer boat, the uniformity of the thickness of a product film layer between product wafers at different positions on the wafer boat can be improved.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a wafer boat, a batch processing device and a low-pressure vapor deposition method. Background Art

[0002] Semiconductor chips are usually made from wafers through multiple processes. In the manufacturing process of semiconductor chips, furnace tubes are an indispensable device. Furnace tubes can be used in processes such as deposition, diffusion, oxidation and annealing on wafers. Among them, the process of using furnace tubes to form different types of thin films on wafers is the basic process of semiconductor chips. In this process, multiple product wafers (Product Wafer, which is a wafer used for production and processing, and the finished product will be sold to customers) are first placed on a wafer boat, and then the wafer boat is placed in the furnace tube.

[0003] In the prior art, a wafer boat generally has a first area and a second area, wherein the first area includes a plurality of product wafer slots for carrying product wafers, and the second area includes monitoring wafer slots for carrying monitor wafers (Monitor Wafer, which is a wafer used for testing to monitor the process of product wafers, such as for testing deposition or etching rate, film uniformity, particle contamination, etc.). The slot spacing in the wafer boat is generally uniform, that is, the spacing between adjacent product wafer slots is generally consistent with the spacing between adjacent product wafer slots and monitoring wafer slots.

[0004] However, when the wafer boat with uniform groove spacing is used in a deposition process in which heat conduction is mainly based on heat radiation (such as low pressure chemical vapor deposition), the problem of uneven deposition of product wafers will occur.

[0005] In view of the existence of the above technical problems, the present application provides a new wafer boat, a batch processing device and a low-pressure vapor deposition method to at least partially solve the above problems. Summary of the invention

[0006] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further described in detail in the Detailed Description of the Invention section. The Summary of the Invention section of this application does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the scope of protection of the claimed technical solution.

[0007] In response to the current problems, the present application provides a wafer boat for depositing a product film layer on the front side of a product wafer, comprising an adjacent first zone and a second zone, wherein the first zone comprises a plurality of product wafer slots, the second zone comprises a monitoring wafer slot, and the second zone is located on the carrying side of the product wafer slots; wherein the product wafer slots are used to carry the product wafers and expose the back sides of the product wafers, and the product wafer slots have a first spacing therebetween; the monitoring wafer slots are used to carry the monitoring wafers and expose the back sides of the monitoring wafers, and the first zone has a second spacing therebetween, and the ratio of the first spacing to the second spacing is positively correlated to the ratio of the thermal emissivity of the film layer on the back side of the product wafer and the film layer on the back side of the monitoring wafer.

[0008] In some embodiments of the present application, when the thermal emissivity of the film layer on the back side of the monitoring wafer is greater than that of the film layer on the back side of the product wafer, the second spacing dimension is greater than the first spacing; when the thermal emissivity of the film layer on the back side of the monitoring wafer is equal to that of the film layer on the back side of the product wafer, the second spacing dimension is equal to the first spacing; when the thermal emissivity of the film layer on the back side of the monitoring wafer is less than that of the film layer on the back side of the product wafer, the second spacing dimension is less than the first spacing.

[0009] In some embodiments of the present application, the product film layer includes silicon nitride and / or polysilicon.

[0010] In some embodiments of the present application, the monitoring wafer backside film layer includes silicon nitride, silicon oxide or silicon.

[0011] In some embodiments of the present application, the monitoring wafer back side film layer includes silicon, the product wafer back side film layer includes silicon nitride, the product film layer includes silicon nitride, and the ratio of the first spacing to the second spacing is 2-3.

[0012] In some embodiments of the present application, the second zone includes a plurality of the monitoring wafer slots, and a fourth spacing is provided between the monitoring wafer slots, and the fourth spacing is the same as the second spacing.

[0013] In some embodiments of the present application, the wafer boat also includes a third zone adjacent to the first zone, the third zone is located on a side of the first zone away from the second zone, the third zone includes a monitoring wafer slot, and there is a third distance between the third zone and the first zone, and the third distance is the same as the first distance.

[0014] In some embodiments of the present application, the wafer boat further includes a fourth area, the fourth area is located on a side of the monitoring wafer slot away from the first area, the fourth area includes a dummy wafer slot, and the dummy wafer slot is used to carry a dummy wafer.

[0015] According to another aspect of the present application, a batch processing apparatus is provided for low-pressure vapor deposition, comprising a chamber and any one of the above-mentioned wafer boats that can be disposed in the chamber.

[0016] According to another aspect of the present application, a low-pressure vapor deposition method is provided, which is performed using the batch processing apparatus, wherein the monitoring wafer is carried on each of the monitoring wafer slots, the product wafer is carried on each of the product wafer slots, and the product film layer is deposited on the product wafers.

[0017] According to the wafer boat, batch processing device and low-pressure vapor deposition method of the embodiments of the present application, the ratio of the first spacing and the second spacing is adjusted based on the ratio of the thermal emissivity of the film layer on the back side of the product wafer and the film layer on the back side of the monitoring wafer. This can reduce the influence of the difference in thermal emissivity of the film layer on the back side of the product wafer and the film layer on the back side of the monitoring wafer on the thickness of the product film layer deposited on the front side of the product wafer, and improve the uniformity of the product film layer thickness between product wafers at different positions on the wafer boat. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The following drawings of the present application are used as a part of the present application for understanding the present application. The drawings show the embodiments of the present application and their descriptions, which are used to explain the principle of the present application.

[0019] Figure 1A A partial structural schematic diagram of a wafer boat according to an embodiment of the present application is shown.

[0020] Figure 1B A schematic structural diagram of a wafer boat provided with dummy wafers, product wafers and monitoring wafers according to an embodiment of the present application is shown.

[0021] Figure 2A A partial structural schematic diagram of a wafer boat according to another embodiment of the present application is shown.

[0022] Figure 2B A schematic structural diagram of a wafer boat provided with dummy wafers, product wafers and monitoring wafers according to another embodiment of the present application is shown.

[0023] In the attached figure:

[0024] 101 first spacing;

[0025] 102 second spacing;

[0026] 103 third spacing;

[0027] 104 4th pitch;

[0028] 110 District 1;

[0029] 111 product wafer slot;

[0030] 112 product wafers;

[0031] 120 2nd District;

[0032] 121 monitoring wafer slot;

[0033] 122 monitoring wafer;

[0034] 130 3rd District;

[0035] 140 4th District;

[0036] 141 dummy wafer slot;

[0037] 142 dummy wafer. DETAILED DESCRIPTION

[0038] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present application. However, it is apparent to those skilled in the art that the present application can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present application, some technical features well known in the art are not described.

[0039] It should be understood that the present application can be implemented in different forms and should not be construed as being limited to the embodiments presented herein. On the contrary, providing these embodiments will make the disclosure thorough and complete and fully convey the scope of the present application to those skilled in the art. In the accompanying drawings, the sizes and relative sizes of layers and regions may be exaggerated for clarity. The same reference numerals throughout represent the same elements.

[0040] It should be understood that when an element or layer is referred to as "on ...", "adjacent to ...", "connected to" or "coupled to" other elements or layers, it can be directly on, adjacent to, connected to or coupled to other elements or layers, or there can be intervening elements or layers. On the contrary, when an element is referred to as "directly on ...", "directly adjacent to ...", "directly connected to" or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc. can be used to describe various elements, components, regions, layers and / or parts, these elements, components, regions, layers and / or parts should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or part from another element, component, region, layer or part. Therefore, without departing from the teachings of the present application, the first element, component, region, layer or part discussed below can be represented as a second element, component, region, layer or part.

[0041] Spatially relative terms such as "under," "below," "below," "under," "above," "above," etc., may be used herein for ease of description to describe the relationship of an element or feature shown in the figures to other elements or features. It should be understood that in addition to the orientations shown in the figures, the spatially relative terms are intended to include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, then the elements or features described as "under other elements" or "under" or "under" will be oriented as "on" the other elements or features. Therefore, the exemplary terms "under" and "under" may include both upper and lower orientations. The device may be oriented otherwise (rotated 90 degrees or other orientations) and the spatial descriptors used herein are interpreted accordingly.

[0042] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present application. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0043] In the prior art, a wafer boat generally has a first area and a second area, wherein the first area includes a plurality of product wafer slots for carrying product wafers, and the second area includes a monitoring wafer slot for carrying monitoring wafers, and the second area is located on the carrying side of the first area. The slot spacing in the wafer boat is generally uniform, that is, the spacing between adjacent product wafer slots is generally consistent with the spacing between adjacent product wafer slots and monitoring wafer slots.

[0044] However, when the wafer boat with uniform groove spacing is used in a deposition process where heat conduction is mainly based on heat radiation, such as LPCVD (Low Pressure Chemical Vapor Deposition), the problem of uneven deposition of product wafers may occur.

[0045] Taking the deposition of polysilicon on product wafers by LPCVD as an example, in the semiconductor production process, for the purpose of cost saving, dummy wafers (also called fake wafers, used to fill the blank areas in the reaction chamber) and monitoring wafers with some specific surface materials are used. The air pressure in the reaction chamber is very low, and heat propagation is mainly based on heat radiation between wafers. However, different materials have different thermal emissivity, and some film deposition processes are sensitive to temperature. For example, when polysilicon is deposited on the front of the product wafer, the material on the back of the product wafer is silicon, and the material on the back of the monitoring wafer is silicon nitride, the product wafer closest to the monitoring wafer in the first zone is wafer A, and the wafer below wafer A is wafer B. The material facing the front of wafer A is silicon nitride, and the material facing the front of wafer B is the bottom of wafer A, which is silicon. The thermal radiation efficiency of silicon nitride is higher than that of silicon. The polysilicon deposition process is sensitive to temperature. Under the condition of the same groove spacing, the front side of wafer A is heated more than wafer B. The surface temperature of wafer A is higher and the deposited film layer is thicker. Therefore, the film deposition thickness between wafer A and wafer B is uneven, affecting the product yield.

[0046] In order to solve at least one of the above-mentioned technical problems, the present application provides a wafer boat for depositing a product film layer on the front side of a product wafer, comprising an adjacent first zone and a second zone, wherein the first zone comprises a plurality of product wafer slots, the second zone comprises a monitoring wafer slot, and the second zone is located on the carrying side of the product wafer slot; wherein the product wafer slot is used to carry the product wafer and expose the back side of the product wafer, and a first spacing is provided between the product wafer slots; the monitoring wafer slot is used to carry the monitoring wafer and expose the back side of the monitoring wafer, and a second spacing is provided between the first zone and the second zone, and a ratio of the first spacing to the second spacing is positively correlated with a ratio of the thermal emissivity of the film layer on the back side of the product wafer and the film layer on the back side of the monitoring wafer.

[0047] According to the wafer boat of the present application, the ratio of the first spacing and the second spacing is adjusted based on the ratio of the thermal emissivity of the film layer on the back side of the product wafer and the film layer on the back side of the monitoring wafer. This can reduce the influence of the difference in thermal emissivity of the film layer on the back side of the product wafer and the film layer on the back side of the monitoring wafer on the thickness of the product film layer deposited on the front side of the product wafer, and improve the uniformity of the product film layer thickness of different product wafers.

[0048] In order to thoroughly understand the present application, detailed steps and structures will be presented in the following description to illustrate the technical solution proposed by the present application. The preferred embodiments of the present application are described in detail below, but in addition to these detailed descriptions, the present application may also have other implementation methods.

[0049] Reference below Figure 1A to Figure 1B and Figure 2A to Figure 2BA wafer boat according to multiple embodiments of the present application is described. The wafer boat is used to deposit a product film layer on the front of a product wafer 112, and includes adjacent first and second areas 110 and 120, wherein the first area 110 includes multiple product wafer slots 111, and the second area 120 includes a monitoring wafer slot 121, and the second area 120 is located on the carrying side of the product wafer slot 111; wherein the product wafer slot 111 is used to carry the product wafer 112 and expose the back of the product wafer 112, and there is a first spacing 101 between the product wafer slots 111; the monitoring wafer slot 121 is used to carry the monitoring wafer 122 and expose the back of the monitoring wafer 122, and there is a second spacing 102 between the first area 110 and the second area 120, and the ratio of the first spacing 101 to the second spacing 102 is positively correlated with the ratio of the thermal emissivity of the film layer on the back of the product wafer 112 and the film layer on the back of the monitoring wafer 122.

[0050] In actual production, the ratio of the first spacing 101 and the second spacing 102 can be adjusted according to the ratio of the thermal emissivity of the film layer on the back of the product wafer 112 and the film layer on the back of the monitoring wafer 122. The larger the ratio of the thermal emissivity of the film layer on the back of the product wafer 112 and the film layer on the back of the monitoring wafer 122, the larger the ratio of the first spacing 101 and the second spacing 102, and vice versa. By adjusting the ratio of the first spacing 101 and the second spacing 102 by the ratio of the thermal emissivity of the film layer on the back of the product wafer 112 and the film layer on the back of the monitoring wafer 122, the influence of the difference in the thermal emissivity of the film layer on the back of the wafer on the thickness of the product film layer deposited on the front of the product wafer 112 can be reduced, and the uniformity of the thickness of the product film layer between the product wafers 112 at different locations of the wafer boat can be improved.

[0051] In some embodiments, the wafer boat can be placed in the furnace tube. When the product film layer is deposited on the front of the product wafer 112, the product film layer is affected not only by the thermal radiation of the film layer on the back of the wafer, but also by the gas flow distribution. It can be understood that when the gas flow in the furnace tube is evenly distributed, the ratio of the first spacing 101 to the second spacing 102 can be determined based on the difference in thermal radiation rate between the film layer on the back of the product wafer 112 and the film layer on the back of the monitoring wafer 122. Figure 1A and Figure 1B As shown, when the thermal emissivity of the film layer on the back side of the monitoring wafer 122 is greater than that of the film layer on the back side of the product wafer 112, the size of the second spacing 102 can be greater than the first spacing 101, that is, the ratio of the first spacing 101 to the second spacing 102 is less than 1; when the thermal emissivity of the film layer on the back side of the monitoring wafer 122 is equal to that of the film layer on the back side of the product wafer 112, the size of the second spacing 102 can be equal to the first spacing 101, that is, the ratio of the first spacing 101 to the second spacing 102 is equal to 1; as shown Figure 2A and Figure 2BAs shown, when the thermal emissivity of the film layer on the back side of the monitoring wafer 122 is less than that of the film layer on the back side of the product wafer 112, the size of the second spacing 102 can be smaller than the first spacing 101, that is, the ratio of the first spacing 101 to the second spacing 102 is greater than 1. Of course, the size between the second spacing 102 and the first spacing 101 is not limited to the above situation. In view of the fact that the deposition rate of the product film layer is also related to the gas flow distribution, the gas flow distribution needs to be considered when adjusting the size of the second spacing 102 and / or the first spacing 101, and then adjusted according to the actual situation.

[0052] In some embodiments, the product film layer deposited on the front side of the product wafer 112 by the wafer boat of this embodiment may be a low-pressure deposited film layer whose deposition process is sensitive to heat. For example, the product film layer may include silicon nitride and / or polycrystalline silicon, or may also include other types of low-pressure deposited film layers whose deposition process is sensitive to heat, without limitation.

[0053] In some embodiments, the backside film layer of the monitoring wafer 122 carried in the wafer boat of this embodiment may include silicon nitride, silicon oxide or silicon, etc., which is not limited thereto.

[0054] In some embodiments, the backside film layer of the product wafer 112 carried in the wafer boat of this embodiment may also be silicon nitride, silicon oxide or silicon, etc., which is not limited to this.

[0055] Among them, the reference values ​​of thermal emissivity (emissivity) of silicon nitride, silicon oxide and silicon are usually within 0.1μm to 1μm. For example, at 500℃ to 800℃, the reference value of thermal emissivity (emissivity) of silicon nitride is 0.9μm, the reference value of thermal emissivity (emissivity) of silicon oxide is 0.6μm to 0.7μm, and the reference value of thermal emissivity (emissivity) of silicon / polysilicon is 0.6μm to 0.7μm. In this embodiment, by first determining the material of the back film layer of the monitoring wafer 122 and the product wafer 112, and then determining the thermal emissivity of the back film layer, the ratio of the first spacing 101 to the second spacing 102 can be adjusted according to the ratio of the thermal emissivity of the back film layer of the product wafer 112 and the back film layer of the monitoring wafer 122, so as to reduce the influence of the difference in thermal emissivity of the back film layer of the wafer on the thickness of the product film layer deposited on the front of the product wafer 112, and improve the uniformity of the thickness of the product film layer between the product wafers 112 at different locations of the wafer boat.

[0056] In some embodiments, the specific ratio and / or specific spacing size of the first spacing 101 and the second spacing 102 can be obtained through experiments or simulations, and the specific method is not limited. It should be noted that when obtaining the specific ratio and / or specific spacing size of the first spacing 101 and the second spacing 102, in addition to considering the influence of the thermal emissivity of the different materials of the back film layer of the product wafer 112 and the back film layer of the monitoring wafer 122, the influence of the gas flow distribution on the deposition can also be considered, so as to obtain the best specific ratio and / or the best specific spacing size. Under the best specific ratio and / or the best specific spacing size, the uniformity of the product film thickness of different product wafers 112 can be significantly improved.

[0057] For example, taking the case where the back film layer of the monitoring wafer 122 includes silicon, the back film layer of the product wafer 112 includes silicon nitride, and the product film layer includes silicon nitride as an example, the thermal emissivity of the back film layer of the product wafer 112 is greater than the thermal emissivity of the back film layer of the monitoring wafer 122, and the ratio of the first spacing 101 to the second spacing 102 can be 2 to 3, such as 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, etc. Within this ratio range, the problem of uneven product film layer thickness of different product wafers 112 caused by the difference in thermal emissivity of the back film layer of the product wafer 112 and the back film layer of the monitoring wafer 122 can be significantly reduced. It should be noted that the optimal value of the above ratio range can be obtained through experiments or simulations.

[0058] In some embodiments, the second zone 120 may include one or more monitoring wafer slots 121, which is not limited. When the second zone 120 includes multiple monitoring wafer slots 121, there is a fourth spacing 104 between the monitoring wafer slots 121, and the fourth spacing 104 is the same as the second spacing 102. The monitoring wafer 122 in the second zone 120 that is closest to the first zone 110 is wafer C, and the product wafer 112 in the first zone 110 that is closest to the second zone is wafer D. The front sides of wafers C and D are facing the back film layer of the monitoring wafer 122. By making the fourth spacing 104 the same as the second spacing 102, it can be achieved that at least wafer C in the monitoring wafer 122 accurately reflects the product film layer condition on the surface of the product wafer 112. Among them, Figure 1A As shown, when the second spacing 102 is larger than the first spacing 101, the fourth spacing 104 is the same as the second spacing 102 and is also larger than the first spacing 101; Figure 2A As shown, when the second spacing 102 is smaller than the first spacing 101 , the fourth spacing 104 is the same as the second spacing 102 and is also smaller than the first spacing 101 .

[0059] In some embodiments, Figure 1A to Figure 1B or Figure 2A to Figure 2BAs shown, the wafer boat may further include a third area 130 adjacent to the first area 110, the third area 130 is located on a side of the first area 110 away from the second area 120, the third area 130 includes a monitoring wafer slot 121, and a third spacing 103 is provided between the third area 130 and the first area 110, and the third spacing 103 is the same as the first spacing 101. Among them, the monitoring wafer 122 carried on the monitoring wafer slot 121 of the third area 130 and the front side of the product wafer 112 are both facing the back side film layer of the product wafer 112, by making the third spacing 103 the same as the first spacing 101, the heat radiation received by the front side of the monitoring wafer 122 is the same as the heat radiation received by the front side of the product wafer 112, and the thickness of the product film layer deposited on the front side of the product wafer 112 can be reflected by the monitoring wafer 122.

[0060] In some embodiments, Figure 1A to Figure 1B or Figure 2A to Figure 2B As shown, the wafer boat may further include a fourth area 140, and the fourth area 140 is located on the side of the monitoring wafer slot 121 away from the first area 110, for example, the fourth area 140 is located on the side of the second area 120 away from the first area 110, or the fourth area 140 is located on the side of the third area 130 away from the first area 110. The fourth area 140 includes a dummy wafer slot 141, and the dummy wafer slot 141 is used to carry a dummy wafer 142. Usually, the thermal emissivity of the surface film layer of the dummy wafer 142 is greatly different from that of the product wafer 112. By setting the fourth area 140 on the side of the monitoring wafer slot 121 away from the first area 110, the dummy wafer 142 is located between the monitoring wafer 122 and the product wafer 112, and the monitoring wafer 122 is also spaced therebetween, so that the difference in thermal emissivity between the surface film layer of the dummy wafer 142 and the back film layer of the product wafer 112 can be avoided to have a deterioration effect on the preparation of the product film layer.

[0061] It should be noted that, in some embodiments not shown in the figure, the wafer boat includes a plurality of combination areas, and the combination area includes adjacent first areas 110 and second areas 120. For example, the wafer boat includes two adjacent combination areas, namely, a first combination area and a second combination area, the first combination area is located on the bearing side of the second combination area, and the second area 120 in the second combination area is multiplexed as the third area 130 of the first combination area.

[0062] According to another aspect of the present application, a batch processing device is provided. The batch processing device is used for low-pressure vapor deposition and includes a chamber and a wafer boat that can be disposed in the chamber.

[0063] The wafer boat can be implemented as the wafer boat mentioned above, and the above description can be referred to, and no further description is given here. It can be understood that the wafer boat can be arranged in the chamber, that is, when the batch processing device is in use, the wafer boat is placed in the chamber.

[0064] In some embodiments, the batch processing device may be implemented as a vertical hot furnace tube or other suitable devices, which are not limited thereto.

[0065] According to another aspect of the present application, a low-pressure vapor deposition method is provided, which is performed using a batch processing device, wherein a monitoring wafer 122 is carried on each monitoring wafer slot 121, a product wafer 112 is carried on each product wafer slot 111, and a product film layer is deposited on the product wafer 112.

[0066] For example, the low-pressure vapor deposition method may be LPCVD, or THALD (Thermal Atomic Layer Deposition), etc., which is not limited here.

[0067] Among them, the batch processing device can be implemented as the batch processing device mentioned above, and reference can be made to the introduction above, which will not be repeated here.

[0068] In summary, according to the wafer boat, batch processing device and low-pressure vapor deposition method of the embodiments of the present application, the ratio of the first spacing and the second spacing is adjusted based on the ratio of the thermal emissivity of the film layer on the back side of the product wafer and the film layer on the back side of the monitoring wafer, which can reduce the influence of the difference in thermal emissivity of the film layer on the back side of the product wafer and the film layer on the back side of the monitoring wafer on the thickness of the product film layer deposited on the front side of the product wafer, and improve the uniformity of the product film layer thickness of different product wafers.

[0069] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application to this. Those of ordinary skill in the art may make various changes and modifications therein without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0070] Similarly, it should be understood that in order to streamline the present application and help understand one or more of the various application aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, the method of the present application should not be interpreted as reflecting the following intention: the claimed application requires more features than the features clearly stated in each claim. More specifically, as reflected in the corresponding claims, the application point is that the corresponding technical problem can be solved with less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0071] In addition, those skilled in the art will appreciate that, although some embodiments described herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the claims, any one of the claimed embodiments can be used in any combination.

[0072] It should be noted that the above embodiments illustrate rather than limit the present application, and that those skilled in the art may devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference symbol between brackets should not be construed as a limitation to the claims. The use of the words first, second, and third, etc. does not indicate any order. These words may be interpreted as names.

Claims

1. A wafer boat, used for depositing a product film layer on the front side of a product wafer, characterized in that: It comprises a first area and a second area adjacent to each other, wherein the first area comprises a plurality of product wafer slots, the second area comprises a monitoring wafer slot, and the second area is located at a carrying side of the product wafer slot; Among them, the product wafer slot is used to carry the product wafer and expose the back side of the product wafer, and there is a first spacing between the product wafer slots; the monitoring wafer slot is used to carry the monitoring wafer and expose the back side of the monitoring wafer, and there is a second spacing between the first area and the second area, and the ratio of the first spacing to the second spacing is positively correlated with the ratio of the thermal emissivity of the back side film layer of the product wafer and the back side film layer of the monitoring wafer.

2. The wafer boat according to claim 1, characterized in that: When the thermal emissivity of the film layer on the back side of the monitoring wafer is greater than that of the film layer on the back side of the product wafer, the second spacing dimension is greater than the first spacing dimension; when the thermal emissivity of the film layer on the back side of the monitoring wafer is equal to that of the film layer on the back side of the product wafer, the second spacing dimension is equal to the first spacing dimension; when the thermal emissivity of the film layer on the back side of the monitoring wafer is less than that of the film layer on the back side of the product wafer, the second spacing dimension is less than the first spacing dimension.

3. The wafer boat according to claim 1, characterized in that: The product film layer includes silicon nitride and / or polysilicon.

4. The wafer boat according to claim 1, characterized in that: The film layer on the back side of the monitoring wafer includes silicon nitride, silicon oxide or silicon.

5. The wafer boat according to claim 1, characterized in that: The monitoring wafer backside film layer comprises silicon, the product wafer backside film layer comprises silicon nitride, the product film layer comprises silicon nitride, and the ratio of the first spacing to the second spacing is 2-3.

6. The wafer boat according to claim 1, characterized in that: The second area includes a plurality of the monitoring wafer slots, and a fourth spacing is provided between the monitoring wafer slots, and the fourth spacing is the same as the second spacing.

7. The wafer boat according to claim 1, characterized in that: The wafer boat also includes a third area adjacent to the first area, the third area is located on a side of the first area away from the second area, the third area includes a monitoring wafer slot, and there is a third distance between the third area and the first area, and the third distance is the same as the first distance.

8. The wafer boat according to claim 1 or 7, characterized in that: The wafer boat further includes a fourth area, the fourth area is located at a side of the monitoring wafer slot away from the first area, the fourth area includes a dummy wafer slot, and the dummy wafer slot is used to carry a dummy wafer.

9. A batch processing apparatus for low pressure vapor deposition, characterized in that: The invention comprises a chamber and a wafer boat according to any one of claims 1 to 8 which can be disposed in the chamber.

10. A low-pressure vapor deposition method, characterized in that: The process is carried out using a batch processing apparatus as described in claim 9, wherein the monitoring wafer is carried on each of the monitoring wafer slots, the product wafer is carried on each of the product wafer slots, and the product film layer is deposited on the product wafers.

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