Wafer baking apparatus and baking method thereof

Abstract

The present application relates to the technical field of semiconductor manufacturing, and particularly relates to a wafer baking device and a baking method thereof. The wafer baking device comprises: a constant-temperature chamber, which is filled with a protective gas with a preset temperature; a conveying mechanism, which comprises at least two vertically arranged conveying belts that move synchronously, and a plurality of support arms are correspondingly arranged on adjacent two conveying belts in a circumferential direction, and two support arms correspondingly arranged on adjacent two conveying belts form a carrying platform for carrying wafers, and the carrying platform has a baking starting position and a baking ending position respectively located at two ends of the conveying belts; and a mechanical arm, which is configured to move a plurality of wafers entering the constant-temperature chamber in sequence to the carrying platform currently at the baking starting position, and move the wafers on the carrying platform reaching the baking ending position away. A plurality of movable carrying platforms are formed by the conveying mechanism, so that a plurality of wafers can be baked simultaneously, and the efficiency of conveying goods and the production capacity are greatly improved.

Description

Technical Field

[0001] This invention relates to the field of semiconductor manufacturing technology, and in particular to a wafer baking apparatus and a baking method thereof. Background Technology

[0002] Photolithography manufacturing equipment generally consists of a spin coater and a photolithography machine. The spin coater and developer performs functions such as silicon wafer pretreatment, photoresist coating, baking and shaping, and development. The baking device is used for silicon wafer preheating, photoresist shaping, and silicon wafer cooling before and after photoresist coating.

[0003] Existing baking equipment mainly consists of a robotic arm, a constant-temperature hot plate, and a chamber. After entering the chamber, the wafer is placed on the constant-temperature hot plate by the robotic arm. After a period of heating, it is then carried out of the chamber by the robotic arm. This working method means that each chamber can only process one wafer at a time. Generally speaking, the baking time commonly used for current photolithography processes is within 90 seconds. When the number of baking equipment reaches a certain level, the production capacity can be met. However, if new processes require longer baking times, such as guided self-assembly technology, a certain high-temperature annealing time is required after coating the polymer material. However, due to the long annealing time (commonly 3-6 minutes), if large-volume shipments are processed, the throughput efficiency of processes like guided self-assembly in existing baking equipment will be low. Summary of the Invention

[0004] The purpose of this invention is to provide a wafer baking apparatus and baking method, which solves the problem of low throughput of existing wafer baking apparatuses in certain processes with long baking times.

[0005] To achieve the above objectives, the present invention provides a wafer baking apparatus, comprising:

[0006] A temperature-controlled chamber filled with a protective gas at a preset temperature, the protective gas being configured to bake wafers entering the temperature-controlled chamber;

[0007] The conveying mechanism includes at least two vertically arranged and synchronously moving conveyor belts. Several support arms are arranged in a circumferential direction on adjacent two conveyor belts, and two support arms arranged in a corresponding manner on the adjacent two conveyor belts form a support platform for carrying the wafer. The support platform has a baking start position and a baking end position located at both ends of the conveyor belts, respectively.

[0008] A robotic arm is configured to move a number of wafers that sequentially enter the constant temperature chamber to a support platform currently at the baking start position, and to remove wafers from the support platform when they reach the baking end position.

[0009] Optionally, the support arm is further provided with a plurality of support columns, and the wafer is placed on the support columns.

[0010] Optionally, the support columns are three in number and arranged in a triangular pattern.

[0011] Optionally, a temperature sensor is also provided on the support arm, the temperature sensor being configured to monitor the temperature of the wafer located on the support arm.

[0012] Optionally, the wafer baking apparatus further includes a first buffer chamber filled with a protective gas at the preset temperature, and the outlet of the first buffer chamber is connected to the inlet of the constant temperature chamber to send the wafer into the constant temperature chamber for baking.

[0013] Optionally, the wafer baking apparatus further includes a second buffer chamber filled with a protective gas at the preset temperature, and the inlet of the second buffer chamber is connected to the outlet of the constant temperature chamber to receive the wafers baked in the constant temperature chamber.

[0014] Optionally, the moving speed of the conveyor belt is matched with the baking time of the wafer.

[0015] Based on this, the present invention also provides a wafer baking method, which uses the wafer baking apparatus described above to bake several wafers, including:

[0016] A protective gas at a preset temperature is filled into the constant temperature chamber to bring the temperature of the constant temperature chamber to the preset temperature.

[0017] The moving speed of two adjacent conveyor belts is preset according to the baking time of the wafer, and then the two adjacent conveyor belts are made to move synchronously at the preset moving speed.

[0018] Several wafers that have entered the constant temperature chamber are moved to the support platform at the current baking start position, while wafers that have reached the baking end position are removed.

[0019] Optionally, the wafer baking apparatus further includes a first buffer chamber filled with a protective gas at the preset temperature. The outlet of the first buffer chamber is connected to the inlet of the constant temperature chamber. Before the wafer is fed into the constant temperature chamber, the wafer baking method further includes:

[0020] The wafer is fed into the first buffer cavity;

[0021] After a preset time has elapsed, the wafer is transferred from the first buffer cavity to the constant temperature chamber for baking.

[0022] Optionally, the wafer baking apparatus further includes a second buffer chamber filled with a protective gas at the preset temperature. The inlet of the second buffer chamber is connected to the outlet of the constant temperature chamber. After the wafer reaches the baking termination position, the wafer baking method further includes:

[0023] The wafer is fed into the second buffer cavity.

[0024] The wafer baking apparatus and baking method provided by the present invention have at least one of the following beneficial effects:

[0025] 1) By filling the constant temperature chamber with a protective gas at a preset temperature, the constant temperature chamber is kept at a constant temperature. The temperature of the protective gas determines the temperature of the constant temperature chamber, which reduces the overall horizontal requirements of the wafer placement in the entire wafer baking device and improves the baking stability.

[0026] 2) By setting several support arms on two adjacent conveyor belts and forming a support platform for carrying the wafers with two corresponding support arms on two adjacent conveyor belts, multiple wafers can be baked at the same time, which greatly improves the throughput efficiency and capacity of the wafer baking device.

[0027] 3) Since the length of the conveyor belt is constant, the speed of the conveyor belt can determine the baking time of the wafer. That is, by matching the speed of the conveyor belt with the baking time of the wafer, the wafer can complete one baking process just when it reaches the baking end position from the baking start position.

[0028] 4) By setting a first buffer chamber and a second buffer chamber at the inlet and outlet of the constant temperature chamber respectively, the airflow disturbance caused when the wafer enters and exits the constant temperature chamber can be reduced. Attached Figure Description

[0029] Those skilled in the art will understand that the accompanying drawings are provided to better understand the invention and do not constitute any limitation on the scope of the invention. Wherein:

[0030] Figure 1 This is a schematic diagram of the structure of a wafer entering a constant temperature chamber according to an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram of the structure when a wafer is removed from the constant temperature chamber according to an embodiment of the present invention;

[0032] Figure 3 This is a schematic diagram showing the arrangement of the constant temperature chamber and the buffer chamber according to an embodiment of the present invention.

[0033] In the attached image:

[0034] 1-Constant temperature chamber; 2-Wafer; 3-Conveyor belt; 4-Support arm; 5-First buffer chamber; 6-Second buffer chamber. Detailed Implementation

[0035] To make the objectives, advantages, and features of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are in a very simplified form and use non-precise proportions, and are only used to facilitate and clearly illustrate the purpose of the embodiments of this invention. Please refer to the accompanying drawings to make the objectives, features, and advantages of this invention more apparent and understandable. It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are only used to complement the content disclosed in the specification, for those skilled in the art to understand and read, and are not intended to limit the implementation conditions of this invention. Any modifications to the structure, changes in proportions, or adjustments to the size, if they are the same as or similar to the effects and objectives achieved by this invention, should still fall within the scope of the technical content disclosed in this invention.

[0036] As used herein, the singular forms “a,” “an,” and “the” include plural objects unless otherwise expressly indicated. As used herein, the term “or” is generally used to include “and / or” unless otherwise expressly indicated. As used herein, the term “a number” is generally used to include “at least one” unless otherwise expressly indicated. As used herein, the term “at least two” is generally used to include “two or more” unless otherwise expressly indicated. Furthermore, the terms “first,” “second,” and “third” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as “first,” “second,” or “third” may explicitly or implicitly include one or at least two of that feature.

[0037] In the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0038] Please refer to Figures 1-2 , Figure 1 This is a schematic diagram of the structure of a wafer entering a constant temperature chamber according to an embodiment of the present invention; Figure 2This is a schematic diagram illustrating the structure of a wafer being removed from a constant-temperature chamber according to an embodiment of the present invention. This embodiment provides a wafer baking apparatus, including:

[0039] The constant temperature chamber 1 is filled with a protective gas at a preset temperature, and the protective gas is configured to bake the wafer 2 that enters the constant temperature chamber 1.

[0040] The conveying mechanism includes at least two vertically arranged and synchronously moving conveyor belts 3. Several support arms 4 are arranged in the circumferential direction on adjacent two conveyor belts 3, and two support arms 4 arranged in the circumferential direction on adjacent two conveyor belts 3 form a support platform for carrying wafer 2. The support platform has a baking start position and a baking end position located at both ends of the conveyor belts 3 respectively.

[0041] A robotic arm (not shown in the figure) is configured to move a number of wafers 2 that sequentially enter the constant temperature chamber 1 to a support platform currently at the baking start position, and to remove the wafers 2 from the support platform when they reach the baking end position.

[0042] By filling the chamber with a protective gas at a preset temperature to maintain a constant temperature, the temperature of the protective gas determines the temperature of the constant temperature chamber 1. This reduces the overall horizontal requirements for wafer 2 placement in the wafer baking apparatus and improves the baking stability. Furthermore, by utilizing a conveyor mechanism to form multiple movable support platforms, multiple wafers 2 can be baked simultaneously, greatly improving the throughput and capacity of the wafer baking apparatus.

[0043] Specifically, the protective gas includes, but is not limited to, nitrogen or helium, and its temperature can be set according to process parameters to create a constant temperature environment within the chamber.

[0044] Preferably, there are at least two conveyor belts 3, that is, there can be two, three or more conveyor belts 3. This application does not limit this. Any two adjacent conveyor belts 3 can form multiple carrier platforms for carrying wafers 2.

[0045] This embodiment uses two conveyor belts 3 as an example for explanation. The two support arms 4 set on the two conveyor belts 3 form a horizontal bearing platform, and the wafer 2 located on the bearing platform is also horizontal.

[0046] Alternatively, the baking start position and baking end position can be located at the top and bottom of the conveyor belt 3, respectively, but this application is not limited thereto. For example, the baking start position can be located at the top of the conveyor belt 3, and the baking end position can be located at the bottom of the conveyor belt 3, in which case the wafer 2 can move from top to bottom with the conveyor belt 3. Or, the baking start position can be located at the bottom of the conveyor belt 3, and the baking end position can be located at the top of the conveyor belt 3, in which case the wafer 2 can move from bottom to top with the conveyor belt 3.

[0047] In this embodiment, the conveyor belt 3 can be driven by a precision motor and gears. Its moving speed and working time can be set and controlled by a motor controller. Since the length of the conveyor belt 3 is constant, the moving speed of the conveyor belt 3 can determine the baking time of the wafer 2. That is, by matching the moving speed of the conveyor belt 3 with the baking time of the wafer 2, the wafer 2 completes one baking process exactly when it reaches the baking end position from the baking start position. In this embodiment, the baking start position is located at the top of the conveyor belt 3, such as... Figure 1 As shown, the baking termination position is located at the bottom end of the conveyor belt 3, as... Figure 2 As shown.

[0048] Meanwhile, since several support arms 4 are provided on the two conveyor belts 3 in the circumferential direction, the maximum number of wafers that the wafer baking device can carry at the same time can be determined by the number and length of the conveyor belts 3 and the number of support arms 4.

[0049] Preferably, the support arm 4 is further provided with several support pillars, and the wafer 2 is placed on the support pillars. By providing support pillars, the contact area between the support arm 4 and the wafer 2 is reduced, thereby reducing contamination on the back side of the wafer 2. The support pillars are preferably made of silicone.

[0050] More preferably, there are three support pillars arranged in a triangular pattern to ensure the stability of the support for wafer 2. Of course, there may be more than three support pillars, and this application does not limit this.

[0051] More preferably, a temperature sensor is also provided on the support arm 4. The temperature sensor is configured to monitor the temperature of the wafer 2 located on the support arm 4 in real time, so as to monitor the temperature change of the wafer 2 during the baking process, and thus facilitate the optimization of the baking process of the wafer 2.

[0052] In this embodiment, the baking time and temperature of wafer 2 are set to 10 minutes and 150°C, respectively. The conveyor belt 3 is controlled by a precision motor. Each conveyor belt 3 is 100cm long and has 16 robotic arms evenly distributed on it. Each robotic arm has three silicone supports and a temperature sensor arranged in a triangle to support wafer 2 and monitor the temperature change of wafer 2 during the baking process.

[0053] Please refer to Figure 3 The wafer baking apparatus also includes a first buffer chamber 5, which is filled with a protective gas at a preset temperature. The outlet of the first buffer chamber 5 is connected to the inlet of the constant temperature chamber 1 to feed the wafer 2 into the constant temperature chamber 1 for baking. By setting the first buffer chamber 5 before the wafer 2 enters the constant temperature chamber 1 and injecting a protective gas at the same temperature as that in the constant temperature chamber 1 into the first buffer chamber 5, the airflow disturbance caused when the wafer 2 enters the constant temperature chamber 1 can be reduced.

[0054] In this embodiment, the left door of the first buffer chamber 5 is the inlet, and the right door is the outlet and is connected to the inlet of the constant temperature chamber 1. The first buffer chamber 5 has three working stages. In the first stage, the robotic arm sends the wafer 2 into the first buffer chamber 5 through the left door, and the right door is closed. Then, in the second stage, both doors are closed at the same time, and a protective gas at the same temperature as that in the constant temperature chamber 1 is injected into the first buffer chamber 5. After waiting for a preset time, in the third stage, the left door is closed, the right door is opened, and the robotic arm sends the wafer 2 into the constant temperature chamber 1.

[0055] Preferably, the wafer baking apparatus further includes a second buffer chamber 6, which is filled with a protective gas at a preset temperature. The inlet of the second buffer chamber 6 is connected to the outlet of the constant temperature chamber 1 to receive the wafer 2 that has been baked in the constant temperature chamber 1. By providing the second buffer chamber 6 after the wafer 2 is removed from the constant temperature chamber 1, and injecting a protective gas at the same temperature as that in the constant temperature chamber 1 into the second buffer chamber 6, airflow disturbances caused when the wafer 2 is removed from the constant temperature chamber 1 can be reduced. Similarly, the design of the second buffer chamber 6 is similar to that of the first buffer chamber 5, and will not be described in detail here.

[0056] Based on this, embodiments of the present invention also provide a wafer baking method, which uses the wafer baking apparatus described above to bake several wafers, including:

[0057] S1. Fill the constant temperature chamber 1 with a protective gas at a preset temperature so that the temperature of the constant temperature chamber 1 reaches the preset temperature.

[0058] S2. Based on the baking time of wafer 2, the moving speed of the two adjacent conveyor belts 3 is preset, and then the two adjacent conveyor belts 3 are made to move synchronously according to the preset moving speed.

[0059] S3. Move the several wafers 2 that have entered the constant temperature chamber 1 in sequence to the support platform that is currently at the baking start position, and at the same time remove the wafers 2 that have reached the baking end position.

[0060] Preferably, the wafer baking apparatus further includes a first buffer chamber 5, which is filled with a protective gas at a preset temperature. The outlet of the first buffer chamber 5 is connected to the inlet of the constant temperature chamber 1. Before the wafer 2 is fed into the constant temperature chamber 1, the wafer baking method further includes:

[0061] Wafer 2 is fed into the first buffer cavity 5;

[0062] After waiting for a preset time, wafer 2 is transported from the first buffer cavity 5 to the constant temperature chamber 1 for baking.

[0063] Preferably, the wafer baking apparatus further includes a second buffer chamber 6, which is filled with a protective gas at a preset temperature. The inlet of the second buffer chamber 6 is connected to the outlet of the constant temperature chamber 1. After the wafer 2 that has reached the baking termination position is removed, the wafer baking method further includes:

[0064] Wafer 2 is fed into the second buffer cavity 6.

[0065] In summary, the embodiments of the present invention provide a wafer baking apparatus and a baking method thereof. By filling the chamber with a protective gas at a preset temperature to maintain the chamber at a constant temperature, the temperature of the protective gas determines the temperature of the constant temperature chamber 1. This reduces the overall horizontal requirements for the placement of the wafers 2 in the entire wafer baking apparatus and improves the stability of the baking process. Furthermore, by utilizing a conveying mechanism to form multiple movable support platforms, multiple wafers 2 can be baked simultaneously, greatly improving the throughput and capacity of the wafer baking apparatus.

[0066] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure are within the protection scope of the present invention. Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the present invention and its equivalents, the present invention also intends to include these modifications and variations.

Claims

1. A wafer baking apparatus, characterized in that, include: A temperature-controlled chamber filled with a protective gas at a preset temperature, the protective gas being configured to bake wafers entering the temperature-controlled chamber; The conveying mechanism includes at least two vertically arranged and synchronously moving conveyor belts. Several support arms are arranged in a circumferential direction on adjacent two conveyor belts, and two support arms arranged in a corresponding manner on the adjacent two conveyor belts form a support platform for carrying the wafer. The support platform has a baking start position and a baking end position located at both ends of the conveyor belts, respectively. A robotic arm is configured to move a number of wafers that sequentially enter the constant temperature chamber to a support platform currently at the baking start position, and to remove wafers from the support platform when they reach the baking end position. The moving speed of the conveyor belt is matched with the baking time of the wafer, so that the wafer completes one baking process exactly when it reaches the baking end position from the baking start position.

2. The wafer baking apparatus according to claim 1, characterized in that, The support arm is also provided with several support columns, and the wafer is placed on the support columns.

3. The wafer baking apparatus according to claim 2, characterized in that, The support columns consist of three columns arranged in a triangular pattern.

4. The wafer baking apparatus according to claim 2, characterized in that, The support arm is also equipped with a temperature sensor, which is configured to monitor the temperature of the wafer located on the support arm.

5. The wafer baking apparatus according to claim 1, characterized in that, The wafer baking apparatus further includes a first buffer chamber filled with a protective gas at the preset temperature. The outlet of the first buffer chamber is connected to the inlet of the constant temperature chamber to send the wafer into the constant temperature chamber for baking.

6. The wafer baking apparatus according to claim 1 or 5, characterized in that, The wafer baking apparatus further includes a second buffer chamber, which is filled with a protective gas at the preset temperature. The inlet of the second buffer chamber is connected to the outlet of the constant temperature chamber to receive the wafers that have been baked in the constant temperature chamber.

7. A wafer baking method, comprising baking a plurality of wafers using a wafer baking apparatus according to any one of claims 1-6, characterized in that, include: A protective gas at a preset temperature is filled into the constant temperature chamber to bring the temperature of the constant temperature chamber to the preset temperature. The moving speed of two adjacent conveyor belts is preset according to the baking time of the wafer, and then the two adjacent conveyor belts are made to move synchronously at the preset moving speed. Several wafers that have entered the constant temperature chamber are moved to the support platform at the current baking start position, while wafers that have reached the baking end position are removed.

8. The wafer baking method according to claim 7, wherein the wafer baking apparatus further comprises a first buffer chamber, the first buffer chamber being filled with a protective gas at the preset temperature, and the outlet of the first buffer chamber being connected to the inlet of the constant temperature chamber, characterized in that, Before the wafer is placed into the constant temperature chamber, the wafer baking method further includes: The wafer is fed into the first buffer cavity; After a preset time has elapsed, the wafer is transferred from the first buffer cavity to the constant temperature chamber for baking.

9. The wafer baking method according to claim 7, wherein the wafer baking apparatus further comprises a second buffer chamber, the second buffer chamber being filled with a protective gas at the preset temperature, and the inlet of the second buffer chamber being connected to the outlet of the constant temperature chamber, characterized in that, After removing the wafer that has reached the baking termination position, the wafer baking method further includes: The wafer is fed into the second buffer cavity.

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