Wafer boat structure
By designing support pillars and heating components for the crystal boat structure, uniform temperature on the wafer surface was achieved, solving the problem of uneven thin film deposition and improving product yield.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- GTA SEMICON CO LTD
- Filing Date
- 2025-03-27
- Publication Date
- 2026-04-17
AI Technical Summary
The existing furnace tubes have uneven film deposition on the wafer surface, especially the uneven film thickness caused by temperature differences between the wafer edge and center, which affects product yield.
A crystal boat structure was designed, including a support pillar and a heating component. The support pillar is hollow inside, and a heating wire passes through the boss and is connected to an external circuit through the hollow support pillar. The heating component is used to uniformly heat the surface of the wafer.
It improves the uniformity of thin film deposition on the wafer surface and increases product yield.
Smart Images
Figure CN224139424U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of semiconductor manufacturing, and in particular to a crystal boat structure. Background Technology
[0002] In the semiconductor field, thin films such as silicon dioxide (SiO2), silicon nitride (Si3N4), and polycrystalline silicon (Poly) are widely used in integrated circuit devices. The quality of processes such as the preparation of silicon dioxide thin films by reacting tetraethyl orthosilicate (TEOS) with oxygen (O2), the preparation of silicon nitride by reacting dichlorosilane (DCS) with ammonia (NH3), and the preparation of polycrystalline silicon by silane decomposition are receiving increasing attention. As processes become more advanced and feature sizes become smaller, the requirements for the dimensionality and uniformity of thin films deposited in low-pressure furnace tubes are also becoming increasingly stringent.
[0003] Because the heating wires in existing furnace tubes are located on the inner wall of the furnace cavity, closer to the edge of the wafer on the wafer boat, the temperature at the wafer edge is slightly higher than that at the wafer center. Silicon dioxide, polysilicon, and silicon nitride deposited using existing furnace tubes all exhibit a phenomenon where the film layer on the wafer surface is thinner in the center and thicker at the edges. Taking silicon dioxide as an example, there is also a phenomenon where the uniformity of the film layer on the wafer surface at the top of the wafer boat is poor, while the uniformity is good at the bottom of the wafer boat. Poor uniformity of the silicon dioxide film layer at the top of the wafer boat has a significant impact on the gate sidewall (spacer), thus affecting product yield. Summary of the Invention
[0004] The technical problem to be solved by this utility model is to provide a crystal boat structure for improving the uniformity of thin film deposition on the surface of wafers inside a low-pressure furnace tube.
[0005] To address the aforementioned issues, this invention provides a wafer boat structure, comprising: a support pillar with multiple slots formed on one side and a boss formed between adjacent slots; the slots are used to place wafers, and the support pillar is hollow; and multiple heating components, one of which is connected to a boss, each heating component including a heating wire that passes through the boss and is connected to an external circuit via the hollow support pillar. When the wafer is placed in a slot, the heating wire can be subjected to an electric current to heat the wafer.
[0006] In some embodiments, the heating assembly includes at least one linear hollow pipe and at least one annular hollow pipe that are interconnected, the linear hollow pipe being connected to the boss, and the heating wire being housed in the linear hollow pipe and the annular hollow pipe.
[0007] In some embodiments, the diameter of the annular hollow channel is smaller than the diameter of the wafer, and when the wafer is placed in the slot, the center of the wafer corresponds to the center of the annular hollow channel.
[0008] In some embodiments, each of the heating components includes two concentric annular hollow pipes, both of which are connected to the strip hollow pipe.
[0009] In some embodiments, a plurality of support columns are included, and the plurality of support columns connected to the heating assembly are distributed along a circumference.
[0010] In some embodiments, the heating wires in different annular hollow tubes of the same heating assembly are not connected, and the boat structure is capable of applying current to the heating wires in different annular hollow tubes respectively.
[0011] In some embodiments, the heating wires of the same heating assembly are connected, while the heating wires of different heating assemblies are not connected, and the crystal boat structure is capable of applying current to the heating wires of different heating assemblies respectively.
[0012] In some embodiments, the crystal boat structure includes multiple different regions, each region being provided with at least one heating component, the heating wires of the heating components in the same region being connected, and the heating wires of the heating components in different regions being disconnected, the crystal boat structure being able to apply current to the heating wires in different regions respectively.
[0013] In some embodiments, a temperature measuring instrument is also included, which is used to detect the temperature in different regions of the crystal boat structure.
[0014] The above technical solution, by setting a heating assembly including a heating wire, connects the heating assembly to a boss between two adjacent slots on one side of a support column. By making the support column hollow, a channel is provided for the heating wire, allowing it to pass through the boss and communicate with an external circuit through the hollow support column. Using this wafer boat structure, when the wafer is placed in the slot, the wafer surface can be heated as needed, improving the uniformity of the wafer surface temperature, thereby improving the uniformity of the thin film deposited on the wafer surface, and ultimately improving the product yield.
[0015] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit the present invention. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the crystal boat structure provided in the first embodiment of this utility model;
[0018] Figure 2 This is a front view of the crystal boat structure provided in the first embodiment of this utility model;
[0019] Figure 3 This is a top view of the heating assembly of the crystal boat structure provided in the first embodiment of this utility model;
[0020] Figure 4 This is a front view of the crystal boat structure provided in the second embodiment of this utility model.
[0021] List of reference numerals in the attached diagram:
[0022] 10 circumference
[0023] 11, 21 Support columns
[0024] Card slots 111 and 211
[0025] 112, 212 convex platforms
[0026] 12, 22 Heating Components
[0027] 121 Annular Hollow Pipe
[0028] 122 strip hollow pipes
[0029] 13, 23 heating wires
[0030] 41 First District
[0031] 42 Second Region Detailed Implementation
[0032] The technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
[0033] Please refer to this as well. Figures 1-3 , Figure 1This is a schematic diagram of the crystal boat structure provided in the first embodiment of this utility model; Figure 2 This is a front view of the crystal boat structure provided in the first embodiment of this utility model; Figure 3 This is a top view of the heating assembly of the crystal boat structure provided in the first embodiment of this utility model. For ease of description of the inventive points, only a portion of the crystal boat structure is shown in the figure.
[0034] like Figure 1 As shown, the crystal boat structure includes: a support column 11 and a heating assembly 12.
[0035] The support column 11 has a plurality of slots 111 formed on one side, and a boss 112 is formed between two adjacent slots 111. The slots 111 are used to place wafers, and the support column 11 is hollow inside.
[0036] In this embodiment, the support column 11 is a tubular structure. Specifically, the support column 11 is hollow inside as a cavity, and the boss 112 has a channel inside that connects to the cavity of the support column 11.
[0037] In some embodiments, the boat structure includes a plurality of support pillars 11, with slots 111 correspondingly arranged on all the support pillars 11 to allow a wafer to be fixed in the plane formed by the slots 111. The support pillars 11 connected to the heating assembly 12 are distributed along a circumference 10, and when the wafer is placed in the slots 111, the center of the wafer corresponds to the center of the circumference 10. In this embodiment, there are three support pillars 11, each connected to the heating assembly 12. In another embodiment, there are five support pillars 11, with three of them connected to the heating assembly 12.
[0038] refer to Figure 2 A heating assembly 12 is connected to a boss 112. The heating assembly 12 includes a heating wire 13, which passes through the boss 112 and is connected to an external circuit via a hollow support post 11. When the wafer is placed in the slot 111, an electric current can be applied to the heating wire 13 to heat the wafer. In this embodiment, the heating assembly 12 and the lower sidewall of the slot 111 are substantially in the same plane, so that the heating assembly 12 is close to the wafer, thereby ensuring that the heating assembly 12 can heat the wafer in the slot 111.
[0039] In some embodiments, the heating wire 13 is exposed; in other embodiments, the surface of the heating wire 13 is covered with a specific film layer.
[0040] In this embodiment, the wafer placed in the crystal boat structure needs to undergo a thin film deposition process on the wafer surface. The heating wire 13 is housed in the pipe, which can both heat the wafer and avoid mutual interference between the heating wire 13 and the thin film deposition process.
[0041] like Figure 3 As shown, the heating assembly 12 includes at least one linear hollow pipe 122 and at least one annular hollow pipe 121 that are interconnected. The linear hollow pipe 122 is connected to the boss 112, and the annular hollow pipe 121 is connected to the linear hollow pipe 122. The heating wire 13 is housed in the linear hollow pipe 122 and the annular hollow pipe 121.
[0042] Specifically, the heating wire 13, which is disposed in the strip hollow pipe 122 and the annular hollow pipe 121, passes through the internal channel of the boss 112 and the cavity of the support column 11, and is connected to the external circuit.
[0043] The resistance values of the heating wire 13 in the strip-shaped hollow pipe 122 and the annular hollow pipe 121 are different. In this embodiment, the resistance value of the heating wire 13 in the strip-shaped hollow pipe 122 is less than the resistance value of the heating wire 13 in the annular hollow pipe 121. Accordingly, the wafer surface is mainly heated by the heating wire 13 in the annular hollow pipe 121.
[0044] The diameter of the annular hollow pipe 121 is smaller than the diameter of the wafer. When the wafer is placed in the slot 111, the center of the wafer corresponds to the center of the annular hollow pipe 121 to uniformly heat the surface of the wafer.
[0045] In this embodiment, in order to adjust the temperature of the circular wafer surface, each heating component 12 includes two concentric annular hollow pipes 121, both of which are connected to the strip hollow pipe 122, thereby enabling better adjustment of the temperature of the wafer surface near the center.
[0046] The original heating wires inside the furnace tube are located on the inner wall of the furnace cavity, and the furnace cavity heating wires are closer to the edge of the wafer. Therefore, the heating of the wafer surface by the furnace cavity heating wires is not uniform. This application heats the heating wires 13 in the annular hollow pipe 121, additionally heating the wafer surface near the center, which can balance the temperature difference between the edge and the center of the wafer and avoid the temperature at the edge of the wafer being higher than the temperature at the center of the wafer.
[0047] like Figure 3As shown, in addition to the annular hollow pipe 121, the heating assembly 12 also includes three strip-shaped hollow pipes 122, and the heating wire 13 is disposed inside the strip-shaped hollow pipes 122. In this embodiment, the three strip-shaped hollow pipes 122 are not uniformly distributed relative to the annular hollow pipe 121, for example, Figure 3 The angle between the two strip-shaped hollow channels 122 on the left and right sides and the central strip-shaped hollow channel 122 is 102.5 degrees, while the angle between the two strip-shaped hollow channels 122 on the left and right sides is 155 degrees. Each strip-shaped hollow channel 122 is connected to both concentric annular hollow channels 121 and to the protrusion 112 of the support pillar 11, increasing the support area on the back side of the wafer. Correspondingly, the heating wire 13 in the annular hollow channel 121 is connected to the heating wire 13 in the strip-shaped hollow channel 122, and passes through the channel inside the protrusion 112 and the cavity of the support pillar 11, connecting to an external circuit.
[0048] This application also provides a second embodiment. The difference between the second embodiment and the first embodiment is that the crystal boat structure is divided into different regions, and different regions can be heated separately.
[0049] Figure 4 This is a front view of the crystal boat structure provided in the second embodiment of this utility model. For the convenience of describing the inventive points, only a part of the crystal boat structure is shown in the figure.
[0050] like Figure 4 As shown, the wafer boat structure includes a support pillar 21 and a heating assembly 22. Multiple slots 211 are formed on one side of the support pillar 21, and a boss 212 is formed between adjacent slots 211. The slots 211 are used to place the wafer, and the support pillar 21 is hollow. Multiple heating assemblies 22 are provided, with each heating assembly 22 connected to a boss 212. Each heating assembly 22 includes a heating wire 23, which passes through the boss 212 and is connected to an external circuit through the hollow support pillar 21. When the wafer is placed in the slot 211, an electric current can be applied to the heating wire 23 to heat the wafer.
[0051] The crystal boat structure is divided into different regions, including a first region 41 and a second region 42. Each region is provided with at least one heating component 22. The heating wires 23 of the heating components 22 within the same region are connected, while the heating wires 23 of the heating components 22 in different regions are not connected. Current is applied to the heating wires 23 in different regions to heat the different regions separately. For example, the first region 41 includes two heating components 22, and the second region 42 includes three heating components 22. The heating wires 23 between the heating components 22 in the first region 41 are connected, and the heating wires 23 between the heating components 22 in the second region 42 are connected. The heating wires 23 in the first region 41 and the heating wires 23 in the second region 42 are not connected within the support column 21, but pass through the support column 21 respectively. Thus, the crystal boat structure can apply current to the heating wires 23 in different regions to heat the different regions separately.
[0052] In this embodiment, a temperature measuring instrument (not shown) is also included, which is used to detect the temperature of different regions of the crystal boat structure. Specifically, the temperature measuring instrument is used to measure the temperature in different regions separately, for example, simultaneously monitoring and measuring the temperatures of the first region 41 and the second region 42. The current applied to the heating wire 23 in the corresponding region is adjusted based on the difference between the measurement result of the temperature measuring instrument and the target temperature.
[0053] In some embodiments, the crystal boat structure is longitudinally divided into an upper region, an upper-middle region, a middle region, a lower-middle region, and a lower region. The temperature of each of the five regions is measured using the temperature measuring instrument, and the temperature of each region is adjusted based on the collected temperatures.
[0054] In the prior art, during the deposition of silicon dioxide, the uniformity of the film layer on the wafer surface at the top of the crystal boat is poor, while the uniformity of the film layer on the wafer surface at the bottom of the crystal boat is good. The second embodiment of this application divides the crystal boat structure into different regions along its longitudinal direction, enabling the temperature of the wafer surfaces at different points along the longitudinal direction of the crystal boat structure to be adjusted separately, thereby improving the problem of poor film uniformity deposited on the wafer surface at the top of the existing crystal boat.
[0055] In some embodiments, the heating wires 23 of the same heating component 22 are connected, while the heating wires 23 of different heating components 22 are not connected. The crystal boat structure can apply current to the heating wires 23 of different heating components 22 respectively to heat the different heating components 23 respectively.
[0056] In some embodiments, the heating assembly 22 includes at least one linear hollow pipe and at least one annular hollow pipe that are interconnected. The linear hollow pipe is connected to the boss 212. The heating wire 23 is housed in the linear hollow pipe and the annular hollow pipe. The diameter of the annular hollow pipe is smaller than the diameter of the wafer. When the wafer is placed in the slot 211, the center of the wafer corresponds to the center of the annular hollow pipe.
[0057] The heating component 22 includes two or more annular hollow pipes. The heating wires in different annular hollow pipes of the same heating component 22 are not connected. The crystal boat structure can apply current to the heating wires 23 in different annular hollow pipes to heat the different annular hollow pipes respectively.
[0058] In existing technologies, the furnace heating wires are closer to the edge of the wafer, where the temperature is slightly higher than at the center. By heating different annular hollow tubes separately, the temperature of the wafer surface can be adjusted more evenly.
[0059] The above technical solution, by setting a heating assembly including a heating wire, connects the heating assembly to a boss between two adjacent slots on one side of a support column. By making the support column hollow, a channel is provided for the heating wire, allowing it to pass through the boss and communicate with an external circuit through the hollow support column. Using this wafer boat structure, when the wafer is placed in the slot, the wafer surface can be heated as needed, improving the uniformity of the wafer surface temperature, thereby improving the uniformity of the thin film deposited on the wafer surface, and ultimately improving the product yield.
[0060] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion. The various embodiments in this specification are described in a related manner, and similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments.
[0061] The above description is merely a preferred embodiment of this utility model and is not intended to limit the scope of protection of this utility model. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this utility model, and these improvements and modifications should also be considered within the scope of protection of this utility model.
Claims
1. A crystal boat structure, characterized by, The application relates to a wafer boat structure. The support column is internally hollow. The heating assembly comprises at least one strip-shaped hollow pipe and at least one ring-shaped hollow pipe which are in communication with each other.
2. The wafer boat structure of claim 1, wherein, The ring-shaped hollow pipe has a diameter smaller than that of the wafer.
3. The wafer boat structure of claim 2, wherein, Each heating assembly comprises two concentric ring-shaped hollow pipes which are in communication with the strip-shaped hollow pipe.
4. The wafer boat structure of claim 2, wherein, The wafer boat structure comprises a plurality of support columns which are in communication with the heating assemblies and are distributed along the circumference.
5. The wafer boat structure of claim 1, wherein, The heating wires in different ring-shaped hollow pipes of the same heating assembly are not in communication.
6. The wafer boat structure of claim 4, wherein, The heating wires in different heating assemblies are not in communication.
7. The wafer boat structure of claim 1, wherein, The wafer boat structure comprises a plurality of different regions, each region is provided with at least one heating assembly.
8. The wafer boat structure of claim 1, wherein, The wafer boat structure further comprises a temperature measuring instrument for detecting the temperature of different regions of the wafer boat structure.
9. The wafer boat structure of claim 8, wherein,