Load lock device with cooling function and wafer cooling control method

Abstract

A load lock device with a cooling function and a wafer cooling control method. The load lock device includes a load lock chamber, an air intake device, an exhaust device, a pressure protection device, and a temperature detection device. When the internal air pressure of the load lock chamber is lower than atmospheric pressure, the air intake device is opened to backfill the chamber with intake air. When the internal air pressure of the load lock chamber is backfilled to the same pressure as atmospheric pressure, the exhaust device is opened to exhaust excess air from the load lock chamber. When the temperature detection device detects that the wafer temperature meets a set temperature or the exhaust time of the exhaust device meets a preset time, the exhaust device and the air intake device are closed. When the internal air pressure of the load lock chamber exceeds a set value, the pressure protection device is automatically opened to control the internal air pressure of the load lock chamber within the set value.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor equipment manufacturing, and in particular to a wafer cooling method and device. Background Art

[0002] In the prior art, wafer cooling methods for cooling wafers generally include: setting some flow channels on the wafer support to allow the coolant to flow; or providing a cooling plate and setting gas channels at specific positions on the cooling plate to allow the cooling gas to flow in a manner that transversely crosses the upper and lower surfaces of the wafer (substrate).

[0003] The wafer cooling device in the prior art has the following technical problems:

[0004] First, the structure of the wafer cooling device is usually designed to be complex, resulting in high equipment manufacturing costs and inconvenience in implementation.

[0005] Secondly, if the pressure of the cooling gas entering the chamber is too high, it may cause damage to equipment or personnel. Therefore, the safety performance of the system needs to be further improved.

[0006] Therefore, there is an urgent need for a low-cost wafer cooling solution with simple structure, easy implementation, flexible control method and high system safety. Summary of the Invention

[0007] In order to solve the above technical problems, the present invention provides a load lock device with cooling function and a wafer cooling control method. The load lock device is simple and easy to use, low in cost, flexible in control mode and high in system security.

[0008] In one embodiment, the load lock device with cooling function provided by the present invention includes:

[0009] a load lock chamber having a top portion and a bottom portion;

[0010] an air inlet device, an exhaust device, and a pressure protection device, disposed on the top portion and in fluid communication with the interior of the load lock chamber;

[0011] a temperature detection device, arranged at the bottom;

[0012] When the internal pressure of the load lock chamber is lower than atmospheric pressure, the air intake device is opened to backfill the intake air. When the internal pressure of the load lock chamber is backfilled to the same as atmospheric pressure, the exhaust device is opened to exhaust excess gas from the load lock chamber. When the temperature detection device detects that the wafer temperature meets a set temperature or the exhaust time of the exhaust device meets a preset time, the exhaust device and the air intake device are closed. When the internal pressure of the load lock chamber is higher than a set value, the pressure protection device is automatically opened to control the pressure in the load lock chamber within the set value.

[0013] In one embodiment, the load lock device with cooling function further includes wafer supports located on opposite sides of the load lock chamber for supporting wafers. The wafer supports include upper supports and lower supports, with the upper supports specifically designed for supporting wafers that are not cooled but are only transferred, and the lower supports specifically designed for supporting wafers that require cooling.

[0014] In one embodiment, the upper support and the lower support are not used at the same time.

[0015] In one embodiment, the pressure protection device includes a pressure relief support base, a pressure spring sleeved on the outside of the pressure relief support base, a sealing cover sleeved on the outside of the pressure spring, a spring limiter arranged below the pressure spring, and an anti-falling ring arranged below the spring limiter.

[0016] In one embodiment, a sealing ring is further provided between the pressure relief support base and the sealing cover for further sealing.

[0017] In one embodiment, the length of the compression spring in its natural state and the base length of the pressure relief support base are determined by the expected internal and external pressure difference of the load lock chamber.

[0018] In one embodiment, the backfill gas of the air intake device is cooling gas.

[0019] In one embodiment, the cooling gas is nitrogen.

[0020] In one embodiment, the load lock device with cooling function further includes a pressure detector located at the top for detecting the internal air pressure of the load lock chamber.

[0021] The present invention also provides a wafer cooling control method, which includes but is not limited to the following steps:

[0022] a: Place the high-temperature wafer into the load lock chamber through the wafer inlet of the load lock chamber;

[0023] b: introducing cooling gas into the load lock cavity through an air inlet device to backfill the cavity;

[0024] c. Determine whether the internal pressure of the load lock chamber reaches atmospheric pressure; if so, proceed to step d; if not, return to step b;

[0025] d. Open the exhaust device located at the top of the load lock chamber;

[0026] e: Detect whether the temperature of the wafer reaches a set temperature or whether the opening time of the exhaust device reaches a preset time; if so, execute step f; if not, return to execute step d.

[0027] f: closing the exhaust device and the air intake device;

[0028] g: Open the atmospheric valve and start film transmission.

[0029] In one embodiment, the wafer cooling control method further includes: when the internal air pressure of the load lock chamber exceeds a set value, automatically opening a pressure protection device located at the top of the load lock chamber to control the pressure in the load lock chamber within the set value.

[0030] The load lock device with cooling function of the present invention has a simple structure, is easy to implement, and has low implementation costs. It also has a pressure protection function, significantly improving safety. The load lock device of the present invention is mainly used in semiconductor equipment, can be industrialized, and has production economic value. Preferably, it can be used in existing PECVD, ALD and other product lines. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above summary of the invention and the following detailed description of the present invention will be better understood when read in conjunction with the accompanying drawings. It should be noted that the drawings are only examples of the invention claimed. In the drawings, the same reference numerals represent the same or similar elements.

[0032] Figure 1 A load lock device with a cooling function according to an embodiment of the present invention is shown;

[0033] Figure 2 A schematic structural diagram of a pressure protection device according to an embodiment of the present invention is shown;

[0034] Figure 3 A flow chart of a wafer cooling method according to an embodiment of the present invention is shown; and

[0035] Figure 4 A flow chart of a wafer cooling method according to an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0036] The following specific embodiments illustrate the embodiments of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will include many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description.

[0037] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0038] Furthermore, the terms "upper," "lower," "left," "right," "top," "bottom," "horizontal," and "vertical" used in the following description should be understood to refer to the orientations depicted in that section and the accompanying drawings. These relative terms are used solely for convenience of description and do not necessarily imply that the devices described herein must be manufactured or operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0039] It will be understood that although the terms "first", "second", "third", etc. may be used herein to describe various pipes, channels, components, areas, layers and / or parts, these components, areas, layers and / or parts should not be limited by these terms, and these terms are only used to distinguish different pipes, channels, components, areas, layers and / or parts.

[0040] In the prior art, wafer cooling methods for cooling wafers generally include: setting some flow channels on the wafer support to allow the coolant to flow; or providing a cooling plate and setting gas channels at specific positions on the cooling plate to allow the coolant to flow in a manner that transversely crosses the upper and lower surfaces of the wafer (substrate).

[0041] The wafer cooling device in the prior art has the following technical problems:

[0042] For example, the structure of a wafer cooling device is usually designed to be complex, resulting in high equipment manufacturing costs and inconvenient implementation.

[0043] For another example, if the pressure of the cooling gas introduced into the chamber is too high, it may cause damage to equipment or personnel. Therefore, the safety performance of the system needs to be further improved.

[0044] Therefore, there is an urgent need for a low-cost wafer cooling solution with simple structure, easy implementation, flexible control method and high system safety.

[0045] In order to solve the above technical problems, the present invention provides a load lock device with a cooling function. The load lock device with a cooling function is simple and easy to operate, low in cost, flexible in control mode and high in system safety.

[0046] The load lock device with cooling function is mainly used in semiconductor equipment, can be industrialized, has production economic value, and can preferably be used in existing PECVD, ALD and other product lines.

[0047] Figure 1 A load lock device with a cooling function according to an embodiment of the present invention is shown.

[0048] In one embodiment, the load lock apparatus of the present invention includes, but is not limited to, an air inlet device 101, a wafer holder 102, a temperature detection device 103, an exhaust device 104, a load lock chamber, and a pressure protection device 106. The load lock chamber includes a load lock body 105 and a load lock chamber 107 formed by the load lock body 105.

[0049] The wafer holders 102 are distributed on opposite sides of the load lock chamber 105, and are used to carry and support wafers. In one embodiment, in order to solve the problem of particle size, the wafer holder can be a double-layer holder, including an upper holder and a lower holder. The upper holder and the lower holder are not used at the same time. The upper holder can be used exclusively for carrying wafers that are not cooled but only transferred, and the lower holder can be used exclusively for carrying wafers that need to be cooled. Since wafers that need to be cooled are usually wafers that have undergone process processing, their surfaces will carry more particles, and their cleanliness is worse than that of wafers that have not undergone process processing (that is, wafers that do not need to be cooled but only transferred). Therefore, if these two wafers with different requirements are placed on the same holder, cross contamination will occur. The present invention adopts a double-layer holder, and different layers carry wafers with different requirements, which can avoid cross contamination and solve the particle size problem.

[0050] The load lock chamber 105 has a top and a bottom. The air inlet device 101, the exhaust device 104, and the pressure protection device 106 are disposed at the top of the load lock chamber 105 and are in fluid communication with the load lock chamber 107. The temperature detection device 103 is disposed at the bottom of the load lock chamber 105 for detecting wafer temperature.

[0051] The load lock chamber 105 has a wafer entrance at its side. After the processing, the high-temperature wafer enters the chamber through the wafer entrance at its side and is placed on the wafer holder 102 .

[0052] The gas inlet device 101 is used to introduce cooling gas, such as nitrogen, into the load lock chamber 107. Preferably, nitrogen gas with a temperature below 20° can be used.

[0053] When the pressure inside the load lock chamber 107 falls below atmospheric pressure, the inlet device 101 begins backfilling the chamber to equal the external atmospheric pressure. Then, the exhaust device 104 opens to exhaust excess gas from the chamber. Because the backfill gas is at a lower temperature, the low-temperature backfill gas circulates within the chamber to cool the wafers.

[0054] When the pressure inside the load lock chamber 107 exceeds a set value (i.e., the trigger pressure), the pressure protection device 105 automatically opens to control the internal pressure of the load lock chamber within the set value to prevent the internal pressure of the chamber from being too high due to unexpected circumstances, thereby causing damage to equipment or personal injury. In one embodiment, the set value is greater than atmospheric pressure, for example, 1.1×10 5 Pa.

[0055] In one embodiment, a pressure gauge (e.g., Figure 1 (not shown) for detecting the air pressure of the load lock chamber 107. The pressure detector can be any type of device for detecting air pressure well known to those skilled in the art.

[0056] Figure 2 The following is a schematic diagram of the structure of a pressure protection device according to one embodiment of the present invention. The pressure protection device 106 includes a pressure relief support base 221, a pressure spring 222 sleeved on the outside of the pressure relief support base 221, a sealing cover 223 sleeved on the outside of the pressure spring 222, a spring stop 224 disposed below the pressure spring 222, and an anti-drop ring 225 disposed below the spring stop 224. A sealing ring 226 is also included between the pressure relief support base 221 and the sealing cover 223 for further sealing.

[0057] When the pressure protection device 106 is in the closed position, the fixed spring limiter 224 within it causes the pressure spring 222 to deform and be stressed. The greater the deformation and stress on the pressure spring 222, the greater the pressure difference between the interior of the load lock chamber 107 and the external environment required to open the pressure protection device, that is, to achieve automatic gas discharge, and the higher the pressure inside the load lock chamber 107.

[0058] When the pressure in the load lock chamber 107 does not reach the trigger pressure, the pressure protection device 106 is in a closed state, that is, the pressure relief support base 221 and the sealing cover 223 are in sealed contact. The trigger pressure is the upper limit of the pressure at which the pressure protection device maintains a sealed state and is greater than the external ambient pressure. For example, the trigger pressure can be 1.1×10 5 Pa.

[0059] When the air pressure in the load lock chamber 107 reaches the trigger pressure, that is, the pressure protection device 106 connected to the load lock chamber 107 reaches the trigger pressure, the pressure protection device 106 is triggered to perform mechanical pressure relief and exhaust.

[0060] Specifically, the spring limiter 224 in the pressure protection device 106 is pushed upward by the pressure in the load lock chamber 107, which increases the elastic deformation of the pressure spring 222 located above it, causing the pressure spring 222 to be elastically released upward to open the sealing contact between the pressure relief support base 221 and the sealing cover 223 of the pressure protection device 106, thereby realizing automatic pressure relief and exhaust of the pressure protection device 106, so as to limit the air pressure in the load lock chamber 107 to the target air pressure (i.e., the triggering air pressure).

[0061] When the air pressure in the load lock chamber 107 does not reach the preset upper pressure limit, the force applied to the spring limiter 224 in the pressure protection device 106 is insufficient to support the pressure spring 222 above it to push open the pressure relief support base 221 .

[0062] Because the opening and closing of the pressure protection device 106 depends on the atmospheric pressure differential between the load lock chamber 107 and the external environment, the natural length of the pressure spring 222 and the base length of the pressure relief support base 221 in the pressure protection device 106 can be determined based on the expected pressure differential between the inside and outside of the load lock chamber 107. Specifically, if the pressure differential between the inside and outside of the load lock chamber 107 is to be reduced, the base length of the pressure relief support base 221 can be increased to reduce the force on the pressure spring 222.

[0063] An anti-falling ring 225 is provided below the spring limiter 224 of the pressure protection device 106. The anti-falling ring 225 contacts and connects the spring limiter 224 and the load locking chamber 107 to effectively prevent the pressure protection device 106 from failing to relieve pressure due to abnormal falling of the spring limiter 224 caused by external disturbances such as vibration.

[0064] Figure 3 A flow chart of a wafer cooling method according to an embodiment of the present invention is shown. The method includes but is not limited to the following steps.

[0065] Step 301: A high-temperature wafer is placed into the load lock chamber through a wafer inlet of the load lock chamber.

[0066] Step 302: Cooling gas is introduced into the load lock cavity through the air inlet device to backfill the cavity.

[0067] Step 303: Determine whether the internal pressure of the load lock chamber has reached atmospheric pressure. If so, proceed to step 304; if not, return to step 302 to continue introducing cooling gas to backfill the chamber.

[0068] Step 304: Open the exhaust device.

[0069] Step 305: Detect whether the wafer temperature reaches a set temperature. If so, execute step 306; if not, return to step 304.

[0070] Step 306: Close the exhaust device and the air intake device.

[0071] Step 307: Open the atmospheric valve and start film transmission.

[0072] Figure 4 A flow chart of a wafer cooling method according to another embodiment of the present invention is shown. The method includes but is not limited to the following steps.

[0073] Step 401: A high-temperature wafer is placed into the load lock chamber through a wafer inlet of the load lock chamber.

[0074] Step 402: Cooling gas is introduced into the load lock chamber through the air inlet device to backfill the chamber.

[0075] Step 403: Determine whether the internal pressure of the load lock chamber has reached atmospheric pressure. If so, proceed to step 404; if not, return to step 402 to continue introducing cooling gas to backfill the chamber.

[0076] Step 404: Open the exhaust device.

[0077] Step 405: Determine whether the opening time of the exhaust device reaches a preset time. If so, execute step 406; if not, return to step 404.

[0078] Step 406: Close the exhaust device and the air intake device.

[0079] Step 407: Open the atmospheric valve and start film transmission.

[0080] It should be noted that, while steps 301 to 307 or steps 401 to 407 are being performed, if the pressure inside the load lock chamber is higher than a set value, the pressure protection device is automatically activated.

[0081] The present invention provides a load lock chamber with a cooling function. The load lock chamber is simple and easy to operate, has low cost, flexible control mode and high system safety.

[0082] In one embodiment, the load lock device with cooling function provided by the present invention includes:

[0083] a load lock chamber having a top portion and a bottom portion;

[0084] an air inlet device, an exhaust device, and a pressure protection device, disposed on the top portion and in fluid communication with the interior of the load lock chamber;

[0085] a temperature detection device, arranged at the bottom;

[0086] When the internal pressure of the load lock chamber is lower than atmospheric pressure, the air intake device is opened to backfill the intake air. When the internal pressure of the load lock chamber is backfilled to the same as atmospheric pressure, the exhaust device is opened to exhaust excess gas from the load lock chamber. When the temperature detection device detects that the wafer temperature meets a set temperature or the exhaust time of the exhaust device meets a preset time, the exhaust device and the air intake device are closed. When the internal pressure of the load lock chamber is higher than a set value, the pressure protection device is automatically opened to control the internal pressure of the load lock chamber within the set value.

[0087] In one embodiment, the load lock device with cooling function further includes wafer supports located on opposite sides of the load lock chamber for supporting wafers. The wafer supports include upper supports and lower supports, with the upper supports specifically designed for supporting wafers that are not cooled but are only transferred, and the lower supports specifically designed for supporting wafers that require cooling.

[0088] In one embodiment, the upper support and the lower support are not used at the same time.

[0089] In one embodiment, the pressure protection device includes a pressure relief support base, a pressure spring sleeved on the outside of the pressure relief support base, a sealing cover sleeved on the outside of the pressure spring, a spring limiter arranged below the pressure spring, and an anti-falling ring arranged below the spring limiter.

[0090] In one embodiment, a sealing ring is further provided between the pressure relief support base and the sealing cover for further sealing.

[0091] In one embodiment, the length of the compression spring in its natural state and the base length of the pressure relief support base are determined by the expected internal and external pressure difference of the load lock chamber.

[0092] In one embodiment, the backfill gas of the air intake device is cooling gas.

[0093] In one embodiment, the cooling gas is nitrogen.

[0094] In one embodiment, the nitrogen gas is below 20 degrees Celsius.

[0095] In one embodiment, the load lock device with cooling function further includes a pressure detector located at the top for detecting the internal air pressure of the load lock chamber.

[0096] The present invention also provides a wafer cooling control method, which includes but is not limited to the following steps:

[0097] a: Place the high-temperature wafer into the load lock chamber through the wafer inlet of the load lock chamber;

[0098] b: introducing cooling gas into the load lock cavity through an air inlet device to backfill the cavity;

[0099] c. Determine whether the internal pressure of the load lock chamber reaches atmospheric pressure; if so, proceed to step d; if not, return to step b;

[0100] d. Open the exhaust device located at the top of the load lock chamber;

[0101] e: Detect whether the temperature of the wafer reaches a set temperature or whether the opening time of the exhaust device reaches a preset time; if so, execute step f; if not, return to execute step d.

[0102] f: closing the exhaust device and the air intake device;

[0103] g: Open the atmospheric valve and start film transmission.

[0104] In one embodiment, the wafer cooling control method further includes: when the internal air pressure of the load lock chamber exceeds a set value, automatically opening a pressure protection device located at the top of the load lock chamber to control the pressure in the load lock chamber within the set value.

[0105] The load lock device with cooling function of the present invention has a simple structure, is easy to implement, and has low implementation cost. It also has a pressure protection function, significantly improving safety. The load lock chamber of the present invention is applicable to semiconductor equipment and can be industrialized, with production economic value. Preferably, it can be used in existing PECVD, ALD and other product lines.

[0106] The terms and expressions used herein are for descriptive purposes only, and the present invention is not limited to these terms and expressions. The use of these terms and expressions is not intended to exclude any equivalent features shown and described (or portions thereof), and it should be recognized that various modifications that may exist are also intended to be included within the scope of the claims. Other modifications, variations, and substitutions are also possible. Accordingly, the claims should be deemed to cover all such equivalents.

[0107] Similarly, it should be pointed out that although the present invention has been described with reference to the current specific embodiments, ordinary technicians in this technical field should realize that the above embodiments are only used to illustrate the present invention, and various equivalent changes or substitutions can be made without departing from the spirit of the present invention. Therefore, as long as the changes and modifications to the above embodiments are within the scope of the essential spirit of the present invention, they will fall within the scope of the claims of this application.

Claims

1. A load lock device with cooling function, characterized in that: The load lock device comprises: a load lock chamber having a top portion and a bottom portion; an air inlet device, an exhaust device, and a pressure protection device, disposed on the top portion and in fluid communication with the interior of the load lock chamber; a temperature detection device, arranged at the bottom; When the internal pressure of the load lock chamber is lower than atmospheric pressure, the air intake device is opened to backfill the intake air. When the internal pressure of the load lock chamber is backfilled to the same as atmospheric pressure, the exhaust device is opened to exhaust excess gas from the load lock chamber. When the temperature detection device detects that the wafer temperature meets a set temperature or the exhaust time of the exhaust device meets a preset time, the exhaust device and the air intake device are closed. When the internal pressure of the load lock chamber is higher than a set value, the pressure protection device is automatically opened to control the internal pressure of the load lock chamber within the set value. The pressure protection device includes a pressure relief support base, a pressure spring sleeved on the outside of the pressure relief support base, a sealing cover sleeved on the outside of the pressure spring, a spring limiter arranged below the pressure spring, and an anti-falling ring arranged below the spring limiter, wherein the anti-falling ring contacts and connects the spring limiter and the load lock chamber; When the internal air pressure of the load lock chamber is higher than the set value, the spring limiter is pushed upward by the pressure in the load lock chamber, increasing the elastic deformation of the pressure spring located above it, causing the pressure spring to elastically release upward to open the sealing contact between the pressure relief support base and the sealing cover.

2. The load lock device with cooling function according to claim 1, wherein: Also includes: Wafer supports are distributed on opposite sides of the load lock chamber and are used to carry wafers; The wafer support includes an upper support and a lower support. The upper support is specifically used to carry wafers that are not cooled but only transferred, and the lower support is specifically used to carry wafers that need to be cooled.

3. The load lock device with cooling function according to claim 2, wherein: The upper support and the lower support are not used at the same time.

4. The load lock device with cooling function according to claim 1, wherein: A sealing ring is also included between the pressure relief support base and the sealing cover for further sealing.

5. The load lock device with cooling function according to claim 1, wherein: The length of the compression spring in its natural state and the base length of the pressure relief support base are determined by the expected internal and external pressure difference of the load lock chamber.

6. The load lock device with cooling function according to claim 1, wherein: The backfill gas of the air intake device is cooling gas.

7. The load lock device with cooling function according to claim 1, wherein: A pressure detector is also included, located at the top, for detecting the internal air pressure of the load lock chamber.

8. A wafer cooling control method for a load lock apparatus according to any one of claims 1 to 7, characterized in that: The method comprises: a: Place the high-temperature wafer into the load lock chamber through the wafer inlet of the load lock chamber; b: introducing cooling gas into the load lock cavity through an air inlet device to backfill the cavity; c. Determine whether the internal pressure of the load lock chamber reaches atmospheric pressure; if so, proceed to step d; if not, return to step b; d. Open the exhaust device located at the top of the load lock chamber; e: Detecting whether the temperature of the wafer reaches a set temperature or whether the opening time of the exhaust device reaches a preset time; if so, executing step f; if not, returning to executing step d; f: closing the exhaust device and the air intake device; g: Open the atmospheric valve and start film transmission.

9. The wafer cooling control method according to claim 8, wherein: Also includes: When the internal air pressure of the load lock chamber exceeds a set value, the pressure protection device located at the top of the load lock chamber is automatically opened to control the pressure in the load lock chamber within the set value.

Images