Heat treatment device

Abstract

The utility model provides a heat treatment device. The heat treatment device comprises a thermostatic chamber, a purifier and a high-temperature annealing furnace, the interior of the constant-temperature chamber is configured to have a stable target temperature; the high-temperature annealing furnace is arranged in the constant-temperature chamber and is configured to perform thermal annealing treatment on a target wafer; the purifier is arranged in the constant-temperature chamber and is configured to purify a gas atmosphere for high-temperature annealing and introduce the purified gas atmosphere into the high-temperature annealing furnace, and the distance between the purifier and the high-temperature annealing furnace is smaller than a set distance. The purification effect of the purifier can be improved by controlling the working temperature of the purifier through the constant-temperature chamber, and the problems of temperature difference, gas purity reduction and the like possibly caused by a long mounting distance can be avoided by controlling the distance between the purifier and the high-temperature annealing furnace, so that the water oxygen content in the annealing process can be effectively removed or controlled, and the service life of the high-temperature annealing furnace is prolonged. And the quality and the performance of the wafer are prevented from being influenced.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and in particular to a heat treatment device. Background Technology

[0002] High-temperature annealing is a common wafer planarization process used to improve crystal structure, repair defects, and activate doped atoms. During the fabrication process, careful attention must be paid to temperature, time, gas atmosphere, and flow rate. Besides these controllable parameters, the water vapor and oxygen content in the inlet gas (referred to as water-oxygen content) also affects the high-temperature annealing process. Water-oxygen content changes with the external environment, thus affecting the annealing effect and leading to uncontrollable process control. When the water-oxygen content in the inlet gas is too high, the water in the gas reacts with the silicon surface: 2H₂O (water vapor) + Si → SiO₂ + 2H₂. The generated SiO₂ continues to react with the surface silicon: SiO₂ + Si → 2SiO(g), thus leaving pores on the wafer surface, manifested as particle aggregation at the wafer surface edges. These particles may contaminate the wafer surface, affecting its performance and stability. Simultaneously, high water-oxygen content may also cause changes in the internal crystal structure of the wafer, generating unnecessary defects and stress.

[0003] Existing high-temperature annealing equipment has shortcomings in water and oxygen control, which affects the quality and performance of wafers. Utility Model Content

[0004] The purpose of this invention is to provide a heat treatment device to solve the problem that high-temperature annealing equipment has deficiencies in water and oxygen control, which affects the quality and performance of wafers.

[0005] To address the aforementioned problems, this utility model provides a heat treatment apparatus for non-contact planarization, the heat treatment apparatus comprising: a constant temperature chamber, a purifier, and a high-temperature annealing furnace;

[0006] The constant temperature chamber is configured to have a stable target temperature.

[0007] The high-temperature annealing furnace is located inside the constant temperature chamber and is configured to perform thermal annealing on the target wafer.

[0008] The purifier is located inside the constant temperature chamber and is configured to purify the gaseous atmosphere used for high-temperature annealing, and to introduce the purified gaseous atmosphere into the high-temperature annealing furnace. The distance between the purifier and the high-temperature annealing furnace is less than a set distance.

[0009] Optionally, in the heat treatment apparatus, the connecting pipe between the purifier and the high-temperature annealing furnace is a thermostatic pipe.

[0010] Optionally, in the heat treatment apparatus, the outer periphery of the connecting pipe is wrapped with a constant temperature belt to keep the connecting pipe at a constant temperature.

[0011] Optionally, in the heat treatment apparatus, the set distance is less than or equal to 50m.

[0012] Optionally, in the heat treatment apparatus, the purifier is configured to purify the argon atmosphere so that the water and oxygen content in the purified argon atmosphere is less than 0.1 ppb.

[0013] Optionally, in the heat treatment apparatus, the target temperature is 20°C to 25°C.

[0014] Optionally, the heat treatment apparatus further includes a temperature sensing unit disposed inside the constant temperature chamber and configured to provide feedback on the real-time temperature inside the constant temperature chamber.

[0015] Optionally, in the heat treatment apparatus, the heat treatment apparatus further includes a temperature control system configured to receive the sensed temperature from the temperature sensing unit and adjust the temperature inside the constant temperature chamber according to the sensed temperature, so as to maintain the temperature inside the constant temperature chamber within the target temperature.

[0016] Optionally, in the heat treatment apparatus, the temperature control system has an air inlet channel and an air return channel respectively connected to the constant temperature chamber, and the purifier is located in the constant temperature chamber closer to the air inlet channel.

[0017] Optionally, in the heat treatment apparatus, the heat treatment apparatus further includes an orifice plate installed inside the constant temperature chamber and located between the air inlet channel and the purifier, so that the air flowing into the constant temperature chamber through the air inlet channel is blown towards the purifier through the orifice plate.

[0018] In summary, the heat treatment apparatus provided by this utility model includes: a constant temperature chamber, a purifier, and a high-temperature annealing furnace; the constant temperature chamber is configured to have a stable target temperature; the high-temperature annealing furnace is located within the constant temperature chamber and configured to perform thermal annealing treatment on the target wafer; the purifier is located within the constant temperature chamber and configured to purify the gaseous atmosphere used for high-temperature annealing, and the purified gaseous atmosphere is introduced into the high-temperature annealing furnace, with the distance between the purifier and the high-temperature annealing furnace being less than a set distance. By controlling the operating temperature of the purifier through the constant temperature chamber, the purification effect of the purifier can be improved, and by controlling the distance between the purifier and the high-temperature annealing furnace, problems such as temperature difference and gas purity reduction that may occur due to a large installation distance can be avoided, thereby effectively removing or controlling the water and oxygen content during the annealing process and avoiding affecting the quality and performance of the wafer. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of the heat treatment apparatus provided in an embodiment of the present utility model;

[0020] The labels in the accompanying drawings are explained as follows:

[0021] 11-Constant temperature chamber; 12-Purifier; 13-High temperature annealing furnace; 14-Connecting pipe; 15-Temperature sensing unit; 16-Temperature control system; 161-Air inlet channel; 162-Air return channel; 17-Orifice plate. Detailed Implementation

[0022] The heat treatment apparatus proposed in this utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, used only to facilitate and clarify the explanation of the embodiments of this utility model. Furthermore, the structures shown in the drawings are often part of the actual structure. In particular, different proportions are sometimes used because different drawings need to show different emphases. It should be understood that relative terms such as "above," "below," "top," and "bottom" shown in the drawings can be used to describe the relationships between various elements. These relative terms are intended to cover different orientations of elements other than those depicted in the drawings. For example, if the apparatus is inverted relative to the view in the drawings, an element described as "above" another element will now be below that element. It should also be understood that, unless specifically stated or indicated, the terms "first," "second," "third," etc., in the specification are only used to distinguish the various components, elements, steps, etc., in the specification, and are not used to indicate logical or sequential relationships between the various components, elements, steps, etc.

[0023] This utility model embodiment provides a heat treatment device for non-contact planarization, such as... Figure 1 As shown, the heat treatment apparatus includes: a constant temperature chamber 11, a purifier 12, and a high-temperature annealing furnace 13. The constant temperature chamber 11 is configured to have a stable target temperature; the high-temperature annealing furnace 13 is disposed within the constant temperature chamber 11 and configured to perform thermal annealing on the target wafer; the purifier 12 is disposed within the constant temperature chamber 11 and configured to purify the gaseous atmosphere used for high-temperature annealing, and then introduce the purified gaseous atmosphere into the high-temperature annealing furnace 13. The distance between the purifier 12 and the high-temperature annealing furnace 13 is less than a predetermined distance.

[0024] In the existing technology, there will be a temperature difference between the gas from the outdoor gas supply station and the furnace tube entering the high-temperature annealing furnace 13, and there are certain problems with the pipeline layout. When the purifier 12 is installed too close to the high-temperature annealing furnace 13, it will easily affect the layout of the machine or cannot be installed due to wiring problems. When the installation distance is far, the pipeline layout cost will increase, and the purifier 12 cannot effectively remove or control the water and oxygen content during the annealing process.

[0025] The heat treatment apparatus provided in this embodiment can improve the purification effect of the purifier 12 by controlling the working temperature of the purifier 12 through the constant temperature chamber 11, and avoid problems such as temperature difference and gas purity reduction that may be caused by a large installation distance by controlling the distance between the purifier 12 and the high temperature annealing furnace 13. This effectively removes or controls the water and oxygen content during the annealing process and avoids affecting the quality and performance of the wafer.

[0026] The purified gas is fed into the high-temperature annealing furnace through a connecting pipe, and then discharged outside the constant temperature chamber through the exhaust pipe of the high-temperature annealing furnace.

[0027] Furthermore, the heat treatment apparatus provided in this embodiment further includes: a temperature sensing unit 15, which is disposed within the constant temperature chamber 11 and configured to provide feedback on the real-time temperature within the constant temperature chamber 11. Even further, the heat treatment apparatus provided in this embodiment further includes: a temperature control system 16, which is configured to receive the sensed temperature from the temperature sensing unit 15 and adjust the temperature within the constant temperature chamber 11 according to the sensed temperature, so as to maintain the temperature within the constant temperature chamber 11 within the target temperature.

[0028] The temperature sensing unit 15 can be a temperature sensor. The constant temperature chamber 11 can be equipped with multiple temperature sensors, which are distributed in different positions of the constant temperature chamber 11. For example, the constant temperature chamber 11 can be equipped with four temperature sensors, which are arranged vertically and horizontally, that is, two are set on the two sides near the purifier, and the other two can be set on the two sides near the high temperature annealing furnace.

[0029] The temperature control system 16 is located outside the constant temperature chamber 11, specifically communicating with the constant temperature chamber 11 via an air inlet channel 161 and a return air channel 162. The air inlet channel 161 can be located near the top wall of the constant temperature chamber 11, and the return air channel 162 can be located near the bottom wall of the constant temperature chamber 11, to form a circulating airflow to control the temperature inside the constant temperature chamber 11. Preferably, the target temperature is 20℃~25℃. Within this temperature range, the purifier 12 can achieve better purification results. That is, when the temperature sensor reports a temperature below 20℃, the temperature control system 16 raises the temperature inside the constant temperature chamber 11; when the temperature sensor reports a temperature above 25℃, the temperature control system 16 lowers the temperature inside the constant temperature chamber 11. In this embodiment, the temperature control system 16 can employ a common temperature control system, and this application does not describe or limit its further structural features.

[0030] Although the temperature control system 16 can control the actual temperature inside the constant temperature chamber 11 to a certain extent, there may be some temperature deviations at different locations within the constant temperature chamber 11. In particular, the area near the high-temperature annealing furnace 13 may experience higher temperatures due to the operating temperature of the furnace. Therefore, in this embodiment, it is preferable to design the connecting pipe 14 between the purifier 12 and the high-temperature annealing furnace 13 as a thermostatic pipe to reduce the impact of temperature changes within the constant temperature chamber 11 on the purity of the gas atmosphere and the performance of the purifier 12.

[0031] In one specific embodiment, the outer periphery of the connecting pipe 14 is wrapped with a temperature-controlled band to maintain a constant temperature for the connecting pipe 14. The material of the temperature-controlled band may be polyurethane, etc.

[0032] Preferably, in the heat treatment apparatus provided in this embodiment, the high-temperature annealing furnace 13 is disposed within the constant temperature chamber 11 to improve the effect of maintaining a constant temperature within the connecting pipe 14. Furthermore, the distance between the purifier 12 and the high-temperature annealing furnace 13 is less than or equal to 50m. This avoids the purifier 12 being installed too close to the high-temperature annealing furnace 13, which could easily affect the machine layout or prevent installation due to wiring issues. It also avoids the increased cost of pipe layout due to a long installation distance. In addition, a long connecting pipe can cause temperature differences, resulting in an increase in the water and oxygen content in the gas within the connecting pipe. Strictly controlling the length of the connecting pipe can prevent a decrease in gas purity, ensure that the water and oxygen content in the gas does not change, and thus guarantee wafer quality.

[0033] Furthermore, the purifier 12 is positioned within the constant temperature chamber 11 closer to the air inlet duct 161. It should be understood that "closer to the air inlet duct 161" here refers to its location relative to the return air duct 162. For example, as... Figure 1 As shown, the air inlet channel 161 of the temperature control system 16 supplies air near the top wall of the constant temperature chamber 11. The purifier 12 is located in the height direction between the air outlet of the air inlet channel 161 and the high temperature annealing furnace 13. In this way, the operating temperature of the purifier 12 and the temperature in the connecting pipe 14 can be closer to the target temperature.

[0034] Furthermore, the heat treatment apparatus also includes an orifice plate 17 installed inside the constant temperature chamber 11 and located between the air inlet channel 161 and the purifier 12, so that the air flowing into the constant temperature chamber 11 through the air inlet channel 161 is blown onto the purifier 12 through the orifice plate 17. The orifice plate 17 allows the air entering through the air inlet channel 161 to be blown onto the purifier 12 more evenly, improving the temperature uniformity of the purifier 12.

[0035] Since argon is typically used in thermal annealing, the purifier 12 in this embodiment is configured to purify the argon atmosphere so that the water and oxygen content in the purified argon atmosphere is less than 0.1 ppb. When other gases are used in the annealing process, the purifier 12 can also adaptably purify those gases.

[0036] In addition, preferably, the side wall of the constant temperature chamber 11 is provided with a heat insulation layer 111 to further ensure the stability of the temperature inside the constant temperature chamber 11.

[0037] Several comparative examples are provided below to further illustrate the heat treatment apparatus provided in this embodiment.

[0038] Comparative Example 1

[0039] A high-temperature annealing furnace is provided. The purifier is located outside the constant temperature chamber, 50m away from the high-temperature annealing furnace, and the two are connected by a connecting pipe. The temperature and water-oxygen content of the purified gas at the purifier end are tested.

[0040] SOI wafers are provided. The SOI wafers are loaded into a high-temperature annealing furnace at 550°C. Purified argon gas is introduced and the gas temperature and water and oxygen content are tested at the end of the high-temperature annealing furnace. The wafers are then heat-treated in an argon atmosphere at 1150°C for 2 hours at a flow rate of 18 SLM, and then cooled to 550°C.

[0041] Comparative Example 2

[0042] A high-temperature annealing furnace is provided, and the purifier is located in a constant temperature chamber. The water oxygen content at the purifier end is controlled at 0.1 ppb, and the distances from the high-temperature annealing furnace are 35m, 45m, 50m, 55m, and 65m respectively.

[0043] SOI wafers are provided. The SOI wafers are loaded into a high-temperature annealing furnace at 550°C. Purified argon gas is introduced and the gas temperature and water and oxygen content are tested at the end of the high-temperature annealing furnace. The wafers are then heat-treated in an argon atmosphere at 1150°C for 2 hours at a flow rate of 18 SLM, and then cooled to 550°C.

[0044] Comparative Example 3

[0045] A high-temperature annealing furnace is provided, and the purifier is located in a constant temperature chamber, 50m away from the high-temperature annealing furnace; the water oxygen content at the purifier end is adjusted to 0.06ppb, 0.08ppb, 0.1ppb, 0.15ppb, and 0.2ppb respectively.

[0046] SOI wafers are provided. The SOI wafers are loaded into a high-temperature annealing furnace at 550°C. Purified argon gas is introduced and the gas temperature and water and oxygen content are tested at the end of the high-temperature annealing furnace. The wafers are then heat-treated in an argon atmosphere at 1150°C for 2 hours at a flow rate of 18 SLM, and then cooled to 550°C.

[0047] The particle detection results for the three comparative examples are shown in Table 1:

[0048] Table 1

[0049]

[0050]

[0051] As can be seen from Table 1:

[0052] (1) When the room temperature changes significantly, the actual operating temperature of the purifier will be affected by the external temperature, and the water and oxygen content in the purified gas will increase, resulting in the problem of edge particle aggregation on the wafer surface.

[0053] (2) When the room temperature is constant, the wafer is not abnormal when the purifier is less than 50m away from the high temperature annealing furnace, but when the distance is greater than 50m, the water and oxygen concentration at the machine end will be affected by the distance, and the wafer surface will have abnormal edge particle aggregation problem.

[0054] (3) When the room temperature is constant and the distance between the purifier and the high-temperature annealing furnace is also constant, when the water and oxygen content in the high-temperature annealing furnace is greater than 0.1 ppb, the water and oxygen in the atmosphere will react significantly with the silicon surface, and the wafer surface edge will have particle aggregation problems after heat treatment.

[0055] Therefore, the heat treatment apparatus provided in this embodiment can effectively remove or control the water and oxygen content during the annealing process, thus avoiding any impact on the quality and performance of the wafer.

[0056] The three comparative examples above use SOI wafers as examples for verification. Those skilled in the art should know that an SOI wafer includes a supporting substrate, a buried oxide layer, and a device layer, with the supporting substrate and device layer separated by the buried oxide layer. Although the three comparative examples above use SOI wafers as examples for verification, SOI wafers do not constitute a limitation of this application, and other wafers can also be used for verification, such as silicon wafers.

[0057] In summary, the heat treatment apparatus provided in this embodiment includes: a constant temperature chamber, a purifier, and a high-temperature annealing furnace; the constant temperature chamber is configured to have a stable target temperature; the high-temperature annealing furnace is located within the constant temperature chamber and configured to perform thermal annealing treatment on the target wafer; the purifier is located within the constant temperature chamber and configured to purify the gaseous atmosphere used for high-temperature annealing, and to introduce the purified gaseous atmosphere into the high-temperature annealing furnace, wherein the distance between the purifier and the high-temperature annealing furnace is less than a set distance. By controlling the operating temperature of the purifier through the constant temperature chamber, the purification effect of the purifier can be improved, and by controlling the distance between the purifier and the high-temperature annealing furnace, problems such as temperature difference and gas purity reduction that may occur due to a large installation distance can be avoided, thereby effectively removing or controlling the water and oxygen content during the annealing process and avoiding affecting the quality and performance of the wafer.

[0058] It should be noted that although the present invention has been disclosed above with reference to preferred embodiments, any person skilled in the art can make many possible variations and modifications to the present invention without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention, without departing from the scope of the present invention, shall still fall within the protection scope of the present invention.

Claims

1. A heat treatment apparatus for non-contact planarization, characterized in that, The heat treatment apparatus includes: a constant temperature chamber, a purifier, and a high-temperature annealing furnace; The constant temperature chamber is configured to have a stable target temperature. The high-temperature annealing furnace is located inside the constant temperature chamber and is configured to perform thermal annealing on the target wafer. The purifier is located inside the constant temperature chamber and is configured to purify the gaseous atmosphere used for high-temperature annealing, and to introduce the purified gaseous atmosphere into the high-temperature annealing furnace. The distance between the purifier and the high-temperature annealing furnace is less than a set distance.

2. The heat treatment apparatus as described in claim 1, characterized in that, The connecting pipe between the purifier and the high-temperature annealing furnace is a thermostatic pipe.

3. The heat treatment apparatus as described in claim 2, characterized in that, The outer circumference of the connecting pipe is wrapped with a constant temperature band to keep the connecting pipe at a constant temperature.

4. The heat treatment apparatus as described in claim 1, characterized in that, The set distance is less than or equal to 50m.

5. The heat treatment apparatus as described in claim 1, characterized in that, The purifier is configured to purify an argon atmosphere such that the water and oxygen content in the purified argon atmosphere is less than 0.1 ppb.

6. The heat treatment apparatus as described in claim 1, characterized in that, The target temperature is 20℃~25℃.

7. The heat treatment apparatus as described in claim 1, characterized in that, The heat treatment apparatus further includes a temperature sensing unit, which is disposed inside the constant temperature chamber and configured to provide feedback on the real-time temperature inside the constant temperature chamber.

8. The heat treatment apparatus as described in claim 7, characterized in that, The heat treatment apparatus further includes a temperature control system configured to receive the sensed temperature from the temperature sensing unit and adjust the temperature inside the constant temperature chamber according to the sensed temperature, so as to maintain the temperature inside the constant temperature chamber within the target temperature.

9. The heat treatment apparatus as described in claim 8, characterized in that, The temperature control system has an air inlet channel and an air return channel that are respectively connected to the constant temperature chamber, and the purifier is located in the constant temperature chamber closer to the air inlet channel.

10. The heat treatment apparatus as described in claim 9, characterized in that, The heat treatment apparatus further includes an orifice plate installed inside the constant temperature chamber and located between the air inlet channel and the purifier, so that the air flowing into the constant temperature chamber through the air inlet channel is blown toward the purifier through the orifice plate.

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