Clean wafer oven

Abstract

This invention provides a clean wafer oven, comprising: a housing and an air inlet; the housing has a baking cavity, and the housing is provided with an exhaust port communicating with the baking cavity; the air inlet, communicating with the baking cavity, can be used to introduce inert gas into the interior of the baking cavity, and the air inlet is configured such that the inert gas introduced into the interior of the baking cavity flows from the top to the bottom of the baking cavity, and that a portion of the gas in the baking cavity is discharged through the exhaust port. The wafer oven of this invention, through downward-pressure air intake or downward-pressure air replenishment, forms a downward-pressure air duct and turbulence within the baking cavity, facilitating the deposition of solid particles. This facilitates the cleaning of solid particles and also gives the wafer oven a built-in cleaning function, greatly reducing the probability of solid particles adhering to the wafer surface.

Description

Technical Field

[0001] This invention relates to the field of wafer manufacturing technology, and in particular to a clean wafer oven. Background Technology

[0002] Wafer baking is one of the processes in semiconductor manufacturing. Currently, commonly used ovens are vacuum ovens and inert gas ovens. Inert gas ovens introduce inert gas, such as nitrogen, into the chamber. Nitrogen ovens have advantages such as faster heating and cooling speeds and higher upper temperature limits, making them an irreplaceable type of baking equipment in wafer baking processes. Inert gas ovens require the introduction of inert gas at the beginning of the baking process. Currently, inert gas ovens typically introduce inert gas from the bottom of the inner cavity. The introduced inert gas flows upward, creating turbulence inside the inner cavity. Excess gas is discharged through a gas exhaust valve located at the top of the oven, thereby achieving the purpose of removing oxygen and equalizing the temperature inside the cavity.

[0003] In this inert gas oven structure, during the process of introducing inert gas, solid particles remaining inside the oven will be carried up, such as metal particles and particulate impurities brought in from the outside air. These particles are likely to fall onto the wafers placed inside the inert gas oven. After being baked at high temperatures, these particles will adhere to the surface of the wafers, reducing the processing quality of the wafers and even causing wafer failure. Summary of the Invention

[0004] The purpose of this invention is to provide a clean wafer oven that improves the phenomenon of particulate matter being carried up inside the inert gas oven by changing the direction of the inert gas introduction, reduces the solid particulate matter adhering to the surface of the wafer, improves the wafer manufacturing quality, and also increases the wafer yield.

[0005] To solve the above-mentioned technical problems, the present invention provides a clean wafer oven, comprising: a cabinet and an air inlet;

[0006] The chamber has a baking cavity and a reflux channel. The chamber is provided with an exhaust port. The reflux channel is connected to the bottom of the baking cavity and the exhaust port.

[0007] The air intake is connected to the baking cavity and can be used to introduce inert gas into the interior of the baking cavity. The air intake is configured such that the inert gas introduced into the interior of the baking cavity flows from the top to the bottom of the baking cavity, and that a portion of the gas in the baking cavity is discharged from the exhaust port through the return channel.

[0008] Optionally, the clean wafer oven further includes at least two temperature sensors, each of which is arranged at intervals inside the baking cavity along a vertical setting direction, the vertical setting direction being the direction from the top to the bottom of the baking cavity. The temperature sensors are configured such that when the difference between the temperature value collected by the temperature sensor near the top of the baking cavity and the temperature value collected by the temperature sensor far from the top of the baking cavity along the vertical setting direction is greater than a temperature setting value, inert gas is introduced through the air inlet, and part of the gas in the baking cavity is discharged through the exhaust port.

[0009] Optionally, the clean wafer oven further includes at least two sets of heating units, one set of which is located near the top of the baking cavity and faces the top of the baking cavity in a vertical direction, the vertical direction being the direction from the top of the baking cavity to the bottom, and the other set of heating units is located on the side wall of the baking cavity.

[0010] Optionally, the clean wafer oven further includes a top grille, which is disposed inside the baking cavity and maintains a first predetermined distance from the top of the baking cavity. The top grille is provided with an array of first ventilation holes, wherein a group of heating units disposed near the top of the baking cavity are disposed on the top grille.

[0011] Optionally, the enclosure includes an inner enclosure and an outer enclosure, the inner enclosure being located inside the outer enclosure, and a sandwich layer being formed between the inner enclosure and the outer enclosure.

[0012] Optionally, the baking cavity and the reflux channel are located inside the inner box, the reflux channel is connected to the interlayer, and the exhaust port is located on the outer box and is connected to the interlayer.

[0013] Optionally, the reflux channel is located outside the baking cavity and is arranged circumferentially around the baking cavity, and the exhaust port communicates with the top of the baking cavity.

[0014] Optionally, the clean wafer oven further includes a flow guide located at the bottom of the baking cavity. The flow guide is used to change the flow direction of gas flowing from the top to the bottom of the baking cavity and to guide the gas flow into the return channel.

[0015] Optionally, the clean wafer oven further includes a bottom grille, which is disposed inside the baking cavity and maintains a second predetermined distance from the air guide, and the bottom grille is provided with an array of second ventilation holes.

[0016] Optionally, the flow guide includes a protrusion and a plurality of flow guides arranged around the protrusion. The flow guides have flow guide surfaces that extend into the return channel on the corresponding side to guide the gas flowing to the bottom of the baking cavity to flow evenly into the return channel.

[0017] Optionally, the clean wafer oven further includes an oxygen concentration detection unit, which is located at the exhaust port to detect the oxygen concentration of the discharged gas.

[0018] Optionally, the cleanable wafer oven further includes a filter disposed on the exhaust port.

[0019] Optionally, the clean wafer oven is configured to have three cooling modes: natural cooling mode, medium-speed cooling mode, and rapid cooling mode.

[0020] In the natural cooling mode: the heating unit is turned off, and the air intake and exhaust ports are closed;

[0021] In the medium-speed cooling mode: the heating unit is turned off, the air intake is turned off, and the exhaust port is opened to draw gas from the baking chamber.

[0022] In the rapid cooling mode: the heating unit is turned off, the air inlet is opened and gas is introduced into the baking cavity, and the exhaust port is opened to discharge the gas in the baking cavity.

[0023] In summary, the clean wafer oven provided by the present invention includes: a housing and an air inlet;

[0024] The chamber has a baking cavity and a reflux channel. The chamber is provided with an exhaust port. The reflux channel is connected to the bottom of the baking cavity and the exhaust port.

[0025] The air intake is connected to the baking cavity and can be used to introduce inert gas into the interior of the baking cavity. The air intake is configured such that the inert gas introduced into the interior of the baking cavity flows from the top to the bottom of the baking cavity, and that a portion of the gas in the baking cavity is discharged from the exhaust port through the return channel.

[0026] With this configuration, the wafer oven forms a downward airflow channel and turbulence within the baking cavity through downward air intake or downward air replenishment, facilitating the deposition of solid particles. This not only makes it easier to clean solid particles but also gives the wafer oven a built-in cleaning function. The deposited solid particles are then discharged through the exhaust port with the airflow, improving the cleanliness of the baking cavity and significantly reducing the probability of solid particles adhering to the wafer surface. This, in turn, improves the manufacturing quality and yield of the wafers. Furthermore, the built-in cleaning function effectively reduces the frequency of cleaning inside the wafer oven. During the operating cycle of the clean wafer oven, the total cleaning time is reduced, increasing the effective operating time of the equipment and thus improving equipment utilization. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of an existing baking oven;

[0028] Figure 2 This is a schematic diagram of the structure of a clean wafer oven according to an embodiment of the present invention;

[0029] Figure 3 for Figure 2 A top-view structural diagram;

[0030] Figure 4 This is a three-dimensional structural diagram of a clean wafer oven according to an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the airflow in a clean wafer oven according to an embodiment of the present invention.

[0032] The accompanying figure is labeled as follows:

[0033] 100-Nitrogen Oven;

[0034] 10-Box body; 11-Baking cavity; 12-Return channel; 13-Mezzanine; 101-Inner box body; 102-Outer box body; 103-Fan blade; 104-Motor; 105-Reducer; 106-Air chamber; 107-Exhaust port; 108-Upper chamber; 109-Lower chamber;

[0035] 20 - Intake section; 21 - Intake passage; 211 - Filler valve port;

[0036] 30 - Temperature sensor; 31 - First temperature sensor; 32 - Second temperature sensor;

[0037] 40 - Heating unit; 41 - First heating unit; 42 - Second heating unit;

[0038] 50 - Top grille;

[0039] 60 - Flow guide; 61 - Protrusion; 62 - Flow guide; 63 - Flow guide surface; 64 - Weight reduction hole;

[0040] 70-Oxygen analyzer;

[0041] 80-Filter;

[0042] 90- Bottom grille. Detailed Implementation

[0043] The clean wafer oven proposed in this invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The advantages and features of this invention will become clearer from the following description. It should be noted that the drawings are all in a very simplified form and use non-precise proportions, and are only used to facilitate and clarify the illustration of the embodiments of this invention.

[0044] In this invention, the definition of parallel and perpendicular should not be narrowly interpreted as an absolutely perpendicular or absolutely parallel relationship. Rather, it should be understood as allowing for a set angular error under the premise of corresponding perpendicularity or parallelism. This set angle is usually ±5°, and the specific value of the set angle is determined according to the required operating conditions.

[0045] In this invention, horizontal and vertical should not be narrowly interpreted as absolute horizontal and absolute vertical. Rather, they should be understood as allowing for a set angular error under the premise of the corresponding horizontal or vertical orientation. This set angular error is usually ±5°, and the specific value of the set angular error is determined according to the required operating conditions.

[0046] In this invention, "outer diameter" and "inner diameter" refer to the diameter of a circular structure, while for a non-circular structure, the inner diameter refers to the diameter of its inscribed circle and the outer diameter refers to the diameter of its circumscribed circle. "Axial direction" refers to the direction of the central axis of a cylindrical rod, while for a non-cylindrical rod, the axial direction refers to the length direction of the rod.

[0047] In this invention, "proximal end" and "far end" refer to the relative orientation, position, and direction of components or actions relative to each other from the perspective of the operator using the product. Although "proximal end" and "far end" are not restrictive, "proximal end" generally refers to the end of the product that is closer to the operator during normal operation, while "far end" generally refers to the end that is farther away from the operator.

[0048] As used in this invention, the singular forms “a,” “an,” and “the” include plural objects; the term “or” is generally used to mean “and / or”; the term “a number” is generally used to mean “at least one”; and the terms “at least two” or “more than” are generally used to mean “two or more”. 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. Additionally, as used in this invention, “installed,” “connected,” “linked,” and “set” on one element from another should be interpreted broadly, generally indicating only a connection, coupling, mating, or transmission relationship between the two elements, which can be direct or indirect through an intermediate element. This connection, coupling, mating, or transmission should not be construed as indicating or implying a spatial positional relationship between the two elements, i.e., one element can be located arbitrarily inside, outside, above, below, or to one side of another element, unless otherwise explicitly stated. For those skilled in the art, the specific meaning of the above terms in this invention can be understood according to the specific circumstances. Furthermore, directional terms such as above, below, up, down, upward, downward, left, right, etc., are used relative to exemplary embodiments as shown in the figures, with upward or up direction pointing towards the top of the corresponding figure, and downward or down direction pointing towards the bottom of the corresponding figure.

[0049] Please refer to Figure 1 As shown, taking a nitrogen oven as an example, existing nitrogen ovens 100 typically introduce inert gas from the bottom of the oven cavity. The introduced inert gas flows upwards along the arrow, creating turbulence inside the nitrogen oven cavity. Excess gas is discharged through a gas exhaust valve located at the top of the nitrogen oven 100, thereby achieving the functions of removing oxygen and equalizing the internal temperature. In this type of nitrogen oven, during the process of introducing nitrogen, a small amount of residual particulate matter inside the nitrogen oven 100 will be carried up, such as metal particles and particulate impurities brought in from the outside air. The carried-up particles are prone to falling onto the wafers placed inside the nitrogen oven 100. After high-temperature baking, these particles adhere to the surface of the wafers, reducing the processing quality of the wafers and even causing wafer failure.

[0050] The clean wafer oven in this embodiment includes: a housing 10 and an air inlet 20;

[0051] The box 10 has a baking cavity 11 inside, and the box 10 is provided with an exhaust port 107 communicating with the baking cavity 11;

[0052] The air intake 20 is connected to the baking cavity 11 and can be used to introduce inert gas into the interior of the baking cavity 11. The air intake 20 is configured such that the inert gas introduced into the interior of the baking cavity 11 flows from the top to the bottom of the baking cavity 11, and that a portion of the gas in the baking cavity 11 is discharged through the exhaust port 107.

[0053] The inert gas introduced into the air intake 20 can be nitrogen or other gases; the type of inert gas is not limited here.

[0054] The specific structure of the box 10 is not limited here. For example, the box can be cylindrical or rectangular, etc. Please refer to [reference needed]. Figure 1 As shown, in this embodiment, the box 10 has a cuboid structure.

[0055] The specific structure of the air intake 20 is not limited here. The air intake 20 can be a through hole opened on the housing 10, or the air intake 20 can be an air intake channel integrated inside the housing. The air intake port of the air intake 20 is connected to the air outlet end of the external air supply equipment, such as the air outlet of the air compressor.

[0056] The specific shape of the baking cavity 11 is not limited here. The baking cavity 11 can be adapted to the specific structure of the box 10. For example, when the box 10 is cylindrical, the baking cavity 11 is adapted to be cylindrical. When the box 10 is cuboid, the baking cavity 11 is adapted to be cuboid. Of course, the specific structure of the baking cavity 11 can also be adapted to the actual use requirements.

[0057] The specific shape and location of the exhaust port 107 are not limited here. For example, the exhaust port 107 can be a circular hole, a square hole or a hole of other shapes. The exhaust port 107 can be composed of multiple small holes arranged in an array. The location of the exhaust port should ensure that the gas injected through the air inlet 20 flows from the top to the bottom of the baking cavity 11 and is discharged through the exhaust port.

[0058] This wafer oven structure uses a downward-pressure air intake or downward-pressure air supply method to form a downward-pressure air duct and turbulence within the baking cavity 11, facilitating the deposition of solid particles. This not only makes it easier to clean solid particles but also gives the wafer oven a built-in cleaning function. The deposited solid particles are discharged through the exhaust port 107 with the airflow, improving the cleanliness of solid particles within the baking cavity 11. This significantly reduces the probability of solid particles adhering to the wafer surface, thereby improving wafer manufacturing quality and yield. Furthermore, the built-in cleaning function effectively reduces the frequency of cleaning inside the wafer oven. During the operating cycle of the clean wafer oven, the total cleaning time can be reduced, increasing the effective operating time of the equipment and thus improving equipment utilization.

[0059] Furthermore, the air outlet of the air inlet 20 is located at the top of the baking cavity 11. Specifically, the air inlet 20 includes an air inlet channel 21, and the air outlet of the air inlet channel 21 is located at the top of the baking cavity 11.

[0060] In this embodiment, the air intake 20 is set as a channel instead of just a through hole structure opened on the housing 10. This is mainly for the adaptability of other supporting equipment. Moreover, the air outlet of the air intake 20 is set at the top of the baking cavity 11, and its position is fixed. However, based on the setting of the air intake channel 21, the air intake end of the air intake channel 21 can be flexibly arranged, which is conducive to the adaptive and flexible layout of other supporting equipment based on the specific structure of the housing 10.

[0061] Please refer to Figure 2 As shown, Figure 2 To clearly show the specific internal structure of the enclosure 10, the front side wall of the enclosure 10 is hidden. In fact, the hidden side wall itself can be an openable door to open or close the enclosure. The door can be opened to place the wafer for baking or to remove the wafer after baking. Alternatively, a sealing window can be integrated on the hidden side wall, which can be opened or closed, thus serving the same function as the door.

[0062] Since the air intake channel can be flexibly arranged, the air intake end of the air intake channel 21 can extend to the top outside of the housing 10 or to the side or bottom of the housing.

[0063] Please continue to refer to this. Figure 2 As shown, in this embodiment, due to the specific structural design of the housing 10, there is sufficient installation space at the top position of the housing 10. Therefore, in this embodiment, the air intake end of the air intake channel 21 extends to the top of the housing 10. A fan blade 103 is installed inside the air intake channel 21, and a motor 104 is installed on the outer side of the top of the housing 10. The rotor of the motor 104 is driven to cooperate with the input end of the reducer 105, and the output end of the reducer 105 is driven to cooperate with the fan blade 103. The fan blade 103 is driven to rotate to pressurize the injected inert gas and to homogenize the inert gas. In addition, a water cooling unit is provided at the positions of the fan blade 103, the motor 104, and the reducer 105 to reduce the operating temperature of the bearings of the fan blade 103 and the gears or transmission belts in the reducer, thereby improving the service life of the components.

[0064] Furthermore, the clean wafer oven also includes at least two temperature sensors 30, each of which is arranged at intervals along a vertical setting direction inside the baking cavity 11. The temperature sensors 30 are configured such that when the difference between the temperature value collected by the temperature sensor 30 near the top of the baking cavity 11 and the temperature value collected by the temperature sensor 30 far from the top of the baking cavity 11 is greater than a set temperature value, inert gas is introduced through the air inlet 20, and part of the gas in the baking cavity 11 is discharged through the exhaust port 107.

[0065] In this embodiment, the vertical setting direction refers to the vertical direction corresponding to the position after the cleaning wafer oven is placed in place. The vertical setting direction is the same as... Figure 2 The vertical direction is consistent with the direction from the top to the bottom of the baking cavity 11.

[0066] In this embodiment, the number and location of the temperature sensors 30 are not limited. The number and location of the temperature sensors 30 can be adjusted according to the actual operating conditions. For example, in this embodiment, four temperature sensors 30 are provided, namely two first temperature sensors 31 and two second temperature sensors 32, which are arranged in pairs in two layers. The two first temperature sensors 31 in the upper layer are arranged horizontally near the top of the baking cavity 11, and the two second temperature sensors 32 in the lower layer are arranged horizontally near the bottom of the baking cavity 11. The temperature value collected by the two first temperature sensors 31 in the upper layer can be the average of the two values, or the maximum value can be selected as the collected temperature value. The temperature value collected by the two second temperature sensors 32 in the lower layer can be the average of the two values. The average value, or the minimum value, is taken as the collected temperature value. Generally, the temperature is higher closer to the top of the baking cavity 11. When the interpolation between the temperature value collected by the upper sensor and the temperature value collected by the lower sensor is greater than the temperature set value, it means that the temperature difference between the upper and lower parts is large. In this case, inert gas is introduced into the baking cavity 11 through the air inlet 20. Correspondingly, a part of the gas in the baking cavity 11 is discharged through the exhaust port 107. By introducing inert gas from top to bottom, the temperature near the top of the baking cavity 11 is reduced, and the temperature near the bottom of the baking cavity 11 is increased. When the temperature difference drops to within the temperature set value, the air inlet 20 is closed. In order to ensure that the temperature difference decreases slowly and reduce heat loss, the flow rate of the injected inert gas should be kept small. In addition, to ensure that excess gas is discharged through the exhaust port 107, an exhaust valve can be installed at the exhaust port 107. This exhaust valve can be an electric valve. Correspondingly, the clean-type wafer oven can be equipped with a control system. The control system receives the temperature information detected by the temperature sensor 30 and calculates the temperature difference. When the temperature difference is greater than the temperature set value, the control system controls the air intake 20 to open and inject inert gas. At the same time, the control system controls the exhaust valve at the exhaust port 107 to open and exhaust gas. When the detected temperature difference decreases to within the temperature set value, the air intake 20 and the exhaust port 107 are closed. Alternatively, the exhaust valve can be a one-way valve. When the gas pressure in the baking cavity 11 is greater than the exhaust valve... When the opening pressure is reached, the exhaust valve opens automatically; or the exhaust valve can be set as a manual valve. When the interpolated temperature value is greater than the set temperature value, the alarm is triggered to request manual intervention. After obtaining the alarm information, the manual operator controls the intake 20 to open and inject inert gas, and at the same time manually controls the exhaust valve at the exhaust port 107 to open and exhaust gas. At this time, an alarm can be set up to issue a warning, such as through audio tone, visual signal, tactile feedback and / or audible / visual alarm or other warning; for example, the alarm can be an alarm light, which flashes to alert, or the alarm can be a buzzer, which sounds to alert, or the alarm can be a warning sign integrated into the display interface.

[0067] The present invention adds multiple temperature sensors 30 to improve the accuracy of temperature control detection and facilitates precise control of the temperature inside the baking cavity 11, making the temperature inside the baking cavity 11 more uniform, thereby improving the baking quality of the wafer.

[0068] Furthermore, the clean wafer oven also includes at least two sets of heating units 40, each of which is disposed inside the baking cavity 11. One set of heating units 40 is disposed near the top of the baking cavity 11 and faces the top of the baking cavity 11 in a vertically set direction; the other set of heating units 40 is disposed on the side wall of the baking cavity 11.

[0069] There is no limit to the number of heating unit groups or the number of heating units in each group. The number of heating units in each group can be the same or different.

[0070] The structure of the heating unit is not limited here. The heating unit can be electrically heated, for example, the heating unit can be a straight rod, a coiled, a spiral wound or other shaped heating wire. The heating unit can also be gas heated, for example, an existing gas heating tube can be used.

[0071] The relative positional relationship of each heating unit is not limited here. Optimally, each heating unit is set along a vertical setting direction to uniformly heat the interior of the baking cavity 11.

[0072] Please refer to Figure 2 As shown, the heating unit 40 is a coiled heating wire. There are three heating units 40: one first heating unit 41 and two second heating units 42. The first heating unit 41 forms a group and is horizontally positioned facing the top of the baking cavity 11. The first heating unit 41 is also vertically positioned facing the air outlet of the air inlet 20. The two second heating units 42 form another group, vertically attached to the side wall of the baking cavity 11. The two second heating units 42 are horizontally positioned on two separate side walls of the baking cavity 11. Specifically, they are positioned along... Figure 2 The second heating units 42 are arranged on the left and right side walls of the baking cavity 11 in the left and right directions respectively. In another alternative embodiment, the number of the second heating units 42 can be adjusted adaptively. For example, three second heating units 42 can be provided and respectively provided on the left and right side walls and the rear side wall of the baking cavity 11. In addition, the number of the second heating units 42 can also be adjusted adaptively based on the structural form of the baking cavity 11. For example, when the baking cavity 11 is a cylindrical cavity, multiple second heating units 42 can be adaptively arranged along the circumference of the inner wall of the baking cavity 11.

[0073] The heating unit near the top of the baking cavity 11 heats the inert gas introduced at the source and radiates heat downwards. The heating unit set on the side wall of the baking cavity 11 radiates heat horizontally inwards. The multi-point heating method avoids the problem of poor heat uniformity emitted by a single heating wire and ensures the uniformity of the heating temperature inside the baking cavity 11.

[0074] Furthermore, the clean wafer oven also includes a top grille 50, which is disposed inside the baking cavity 11 and maintains a first set distance from the top of the baking cavity 11. The top grille 50 is provided with an array of first ventilation holes, and a layer of heating units 40 is disposed on the top grille 50 such that the layer of heating units 40 faces the top of the baking cavity 11 in a vertically set direction.

[0075] Please refer to Figure 2 and Figure 4 As shown, the top grille 50 has a cuboid structure and is set parallel to the top of the baking cavity 11. The first set distance between the top grille 50 and the top of the baking cavity 11 can be adjusted adaptively according to actual needs. The top grille 50 and the top of the baking cavity 11 actually form a buffer air cavity 106. The buffer air cavity 106 is used to buffer the inert gas entering through the air inlet 20, so that the inert gas is distributed more evenly in the air cavity 106. The top grille 50 further homogenizes the gas, so that the gas entering the baking cavity 11 is evenly distributed. In addition, the top grille 50 also provides an installation position for the first heating unit 41.

[0076] Furthermore, the housing 10 also has a return channel 12 that communicates with the exhaust port 107. The return channel 12 is connected to the bottom of the baking cavity 11 and the exhaust port 107 to guide the gas in the baking cavity 11 to be discharged to the outside through the exhaust port 107 via the return channel 12.

[0077] The specific flow path of the return channel 12 is not limited here. The return channel 12 is connected to the bottom of the baking cavity 11. The inert gas introduced through the air inlet 20 flows downward in the baking cavity 11 and discharges the gas located at the bottom of the baking cavity 11 into the return channel 12. In the initial stage of heating of the clean wafer oven, it is beneficial to quickly discharge the oxygen in the clean wafer oven. At the same time, the structure of the return channel 12 connected to the bottom of the baking cavity 11 can also guide the gas to be discharged along the bottom of the baking cavity 11, so that the solid particles in the baking cavity 11 are discharged along the gas flow direction, further improving its self-cleaning ability.

[0078] Furthermore, the reflux channel 12 is located outside the baking cavity 11 and is arranged circumferentially around the baking cavity.

[0079] The manner in which the reflux channel 12 surrounds the baking cavity 11 is not limited here. For example, the reflux channel 12 can be a complete channel that completely surrounds the baking cavity 11 in the circumferential direction, or the reflux channel 12 can be composed of several independent channels, each of which is arranged at intervals around the baking cavity 11 in the circumferential direction. The arrangement of the channels can be adjusted based on the structural adaptability of the baking cavity 11.

[0080] In this embodiment, two return channels 12 are provided and are respectively located on the horizontal sides of the baking cavity 11 along a horizontal setting direction, and the exhaust port 107 is connected to the top of the baking cavity 11.

[0081] The horizontal setting direction here refers to a specific horizontal direction after the cleaning wafer oven is placed in place. In this embodiment, the horizontal setting direction is the same as... Figure 2 The left and right directions are consistent;

[0082] Please refer to Figure 2 As shown, the two return channels 12 are located on the left and right sides of the baking cavity 11, respectively. When inert gas is added, the excess gas in the baking cavity 11 flows upward along the return channels 12 located on the left and right sides of the baking cavity 11. In fact, the return channels 12 can also act as a heat insulation layer, which is beneficial to the heat preservation of the baking cavity 11 and reduces heat loss. During the cooling process after baking, when the air inlet 20 introduces gas to make the internal and external gases circulate rapidly, the return channels 12 actually play an auxiliary heat dissipation role, which helps the baking cavity 11 to cool down quickly.

[0083] In other alternative embodiments, in Figure 2 Furthermore, a reflux channel 12 can be added to the rear side of the baking cavity 11. Alternatively, the structure of the opening and closing door located at the front side of the baking cavity 11 can be modified so that a reflux channel 12 is formed at the front side of the baking cavity 11 after the opening and closing door is closed, so that the reflux channel 12 can more tightly wrap the circumference of the baking cavity 11.

[0084] Furthermore, the clean wafer oven also includes a flow guide 60, which is disposed at the bottom of the baking cavity 11. The flow guide 60 is used to change the flow direction of the gas flowing from the top to the bottom of the baking cavity 11 and guide the gas to flow into the return channel 12.

[0085] A guide member 60 is added to adapt to the setting of the return channel 12 to guide the gas flow to the return channel 12. Furthermore, the guide member 60 includes a protrusion 61 and a plurality of guide portions 62 arranged around the protrusion. The guide portion 62 has a guide surface 63, which extends into the return channel 12 on the corresponding side to guide the gas flowing to the bottom of the baking cavity 11 to flow evenly in the circumferential direction into the return channel 12.

[0086] The number of guide sections 62 here is adapted to the specific structure of the return channel 12. For example, when the return channel 12 has multiple independent channels distributed circumferentially, the number of guide sections 62 is adapted to match the number of independent channels, and the position of each guide section 62 is matched with each independent channel in the radial direction. When the return channel 12 is a complete channel that completely wraps around the baking cavity 11 circumferentially, multiple guide sections 62 can be distributed circumferentially or each guide section 62 can be connected to form a smooth curved surface.

[0087] In this embodiment, the structure adapted to the return channel 12 includes a protrusion 61 and two guide sections 62. The two guide sections 62 are arranged on both sides of the protrusion 61 along a horizontal setting direction. Each guide section 62 has a guide surface 63, which extends into the return channel 12 on the corresponding side to guide the gas flowing to the bottom of the baking cavity 11 into the return channel 12 on the corresponding side.

[0088] Please refer to Figure 2 As shown, the protrusion 61 is an arc-shaped protrusion structure, and the guide surface 63 is an arc-shaped concave surface. The position of the protrusion 61 facilitates the adjustment of the gas ratio guided to the two return channels 12. In this embodiment, the protrusion 61 is located in the baking cavity 11 along a horizontally set direction. Figure 2 The center position in the left-right direction is designed so that the downward flowing gas in the baking cavity 11 is evenly guided into the two return channels 12, ensuring that the temperature in the two return channels 12 is approximately the same, thereby making the heat dissipation rate on the left and right sides of the baking cavity 11 roughly the same, and ultimately keeping the temperature in the baking cavity 11 uniform. In this embodiment, several weight reduction holes 64 are also provided on the guide 60 to reduce the amount of material used in the guide 60 and achieve a lightweight design.

[0089] Furthermore, the housing 10 includes an inner housing 101 and an outer housing 102, the inner housing 101 being located inside the outer housing 102, and a sandwich layer 13 being formed between the inner housing 101 and the outer housing 102.

[0090] Please refer to Figure 2 As shown, the inner box 101 is fixedly connected to the rear side wall of the outer box 102, forming a sandwich structure 13. This sandwich 13 serves as an insulation layer, which helps to reduce heat loss in the baking cavity 11. Moreover, the sandwich, in conjunction with the reflux channel 12, effectively makes the clean wafer oven have two insulation layers.

[0091] Furthermore, the baking cavity 11 and the reflux channel 12 are located inside the inner box 101, the reflux channel 12 is connected to the interlayer 13, and the exhaust port 107 is provided on the outer box 102 and is connected to the interlayer 13.

[0092] Please refer to Figure 5 As shown in the diagram, following the direction of gas flow indicated by the arrow, the inert gas introduced through the air inlet 20 flows downward in the baking cavity 11, causing some of the gas to flow through the guide 60 into the return channel 12 and then upward. The top of the inner box 101 has a through hole that connects the return channel 12 and the interlayer 13. The gas in the return channel 12 flows upward and then enters the interlayer 13. The gas in the interlayer is then discharged through the exhaust port 107. When inert gas is injected into the baking cavity 11 during baking, the above structure allows some of the hot air to flow into the return channel 12 and the interlayer 13, thus forming two layers of heat-insulating air, which helps to reduce the heat loss in the baking cavity 11.

[0093] Furthermore, the clean wafer oven also includes a bottom grille 90, which is disposed inside the baking cavity 11 and maintains a second predetermined distance from the guide member 60. The bottom grille 90 is provided with an array of second ventilation holes.

[0094] The second set distance between the bottom grille 90 and the guide 60 can be adjusted adaptively according to actual needs. The bottom grille 90 is located below the top grille 50, which provides a place for the wafer on the one hand and homogenizes the airflow on the other. The cooperation between the top grille 50 and the bottom grille 90 makes the gas flowing into and out of the baking cavity 11 more evenly distributed, which helps to improve the turbulence phenomenon in the baking cavity 11.

[0095] Furthermore, the clean wafer oven also includes an oxygen concentration detection unit, which is located at the exhaust port 107 to detect the oxygen concentration of the discharged gas.

[0096] Please refer to Figure 2As shown, the outer casing 102 has an upper chamber 108 and a lower chamber 109 that are distributed vertically and are independent. The inner casing 101 is located inside the upper chamber 108, and an oxygen analyzer 70 is installed in the lower chamber 109. The oxygen analyzer 70 has an oxygen concentration detection sensor. This oxygen concentration detection sensor is set at the exhaust port 107 as an oxygen concentration detection unit to detect the oxygen concentration at the exhaust port 107 in real time. The oxygen concentration detection unit is set at the exhaust port 107 to detect the oxygen concentration in the gas discharged from the exhaust port 107 during the initial introduction of inert gas. The oxygen concentration in the gas at the exhaust port 107 is generally the highest. When the oxygen concentration in the gas at this location is lower than the threshold, it means that the oxygen concentration in the gas in the baking chamber 11 must meet the standard, thus improving the accuracy of oxygen content detection.

[0097] Furthermore, the clean wafer oven also includes a filter 80, which is disposed on the exhaust port 107 for filtering at least a portion of the volatiles emitted from the wafer surface.

[0098] Depending on the size of the particles to be filtered, an appropriate filter can be selected, such as a HEPA filter or a ULPA filter. Please refer to [the relevant documentation / reference]. Figure 3 As shown, multiple exhaust ports 107 are provided on the top of the outer casing 102. Each exhaust port 107 is connected to the filter 80 through a pipe. In addition, an inert gas inlet valve port 211 is provided on the top of the outer casing 102. The inert gas inlet valve port 211 is connected to the air inlet channel 21. A valve is provided on the inert gas inlet valve port 211 to control the opening and closing of the inert gas inlet valve port 211.

[0099] Furthermore, the clean wafer oven is configured to have three cooling modes: natural cooling mode, medium-speed cooling mode, and rapid cooling mode.

[0100] In the natural cooling mode: the heating unit 40 is turned off, the air intake 20 and the exhaust port 107 are turned off;

[0101] In the medium-speed cooling mode: the heating unit 40 is turned off, the air intake 20 is turned off, and the exhaust port 107 is opened and the gas in the baking chamber 11 is drawn out through the exhaust port 107;

[0102] In the rapid cooling mode: the heating unit 40 is turned off, the air inlet 20 is turned on, the exhaust port 107 is turned on and the gas in the baking chamber 11 is drawn in through the exhaust port 107; or: the heating unit 40 is turned off, the air inlet 20 is turned on and gas is introduced into the baking chamber 11, and the exhaust port 107 is turned on to discharge the gas in the baking chamber 11.

[0103] Valves can be installed at the air inlet 20 and exhaust port 107 to control their opening and closing. Additionally, an external vacuum pump is connected to the exhaust port 107. The clean-type wafer oven is equipped with a control system. The control system adaptively sets three cooling modes. When the natural cooling mode is selected, the control system closes the air inlet 20 and exhaust port 107, and shuts down the heating unit 40 to achieve natural cooling. When the medium-speed cooling mode is selected, the control system closes the air inlet 20, opens the exhaust port 107, shuts down the heating unit 40, and starts the vacuum pump. Because the interior of the clean-type wafer oven is not in an ideal state... Strictly speaking, the chamber is sealed. As suction proceeds, outside gas enters the baking chamber 11 through certain gaps in the clean wafer oven. The entire suction process is relatively slow, achieving a slow airflow and thus medium-speed cooling. When the rapid cooling mode is selected, the control system opens the air inlet 20, opens the exhaust port 107, closes the heating unit 40, and starts the vacuum pump. As suction proceeds, outside gas is rapidly replenished into the baking chamber 11 through the air inlet 20. The entire suction process is relatively fast, achieving rapid airflow and thus rapid cooling. Alternatively, gas can be forcibly introduced through the air inlet 20, and the gas in the baking chamber 11 can be forcibly discharged through the exhaust port 107. In this case, the gas forcibly introduced through the air inlet 20 can be an inert gas or other gases, and the gas introduced can be selected according to the cooling requirements.

[0104] Alternatively, the cooling mode can be switched by manually controlling the opening and closing of each component.

[0105] The working principle of a clean-type wafer oven is as follows:

[0106] 1. Oxygen removal stage: The air intake 20 is opened to introduce inert gas, the exhaust port 107 is opened, and the motor 104 drives the fan blade 103 to rotate to pressurize the introduced inert gas, so that the inert gas is forced into the baking chamber 11.

[0107] 2. End of oxygen depletion stage: When the oxygen concentration detection unit detects that the oxygen content of the gas at the exhaust port 107 has decreased below the threshold, the intake 20 and the exhaust port 107 are closed, the motor 104 stops, the fan blades 103 stop working, the gas environment in the baking chamber 11 tends to stabilize, the heating unit 40 starts working, and the temperature inside the baking chamber 11 rises.

[0108] 3. Temperature Uniformity Control: During the baking process, the temperature inside the baking cavity 11 is collected by the temperature sensor 30. When the interpolation of the collected temperature value is greater than the temperature set value, the air intake 20 is slightly opened to allow inert gas to enter, the motor 104 operates at low load, and the exhaust valve at the exhaust port 107 is adaptively opened. The inert gas is forced to flow in one direction by the rotation of the fan blade 103, which lowers the temperature in the upper area inside the baking cavity 11 and raises the temperature in the lower area inside the baking cavity 11. When the temperature difference between the upper and lower parts drops to within the temperature set value, the air intake 20 and the exhaust port 107 are closed, and the motor 104 stops.

[0109] 4. Cooling stage control: After baking is completed, the baking chamber 11 and wafer are cooled using three cooling modes: natural cooling, medium-speed cooling, and rapid cooling to meet the needs of different products.

[0110] Natural cooling: The heating unit 40 is turned off, and the air intake 20 and the exhaust port 107 are turned off;

[0111] Medium-speed cooling: The heating unit 40 is turned off, the air inlet 20 is turned off, the exhaust port 107 is turned on, and the vacuum pump is turned on to draw gas from the baking chamber 11 through the exhaust port 107;

[0112] Rapid cooling: The heating unit 40 is turned off, the air inlet 20 is opened to introduce inert gas into the baking chamber 11, the motor 104 drives the fan blade 103 to rotate to force the inert gas to flow in one direction, the exhaust port 107 is opened and the vacuum pump is turned on to draw gas from the baking chamber 11, so as to achieve forced rapid flow of air inside and outside.

[0113] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0114] The above description is merely a description of preferred embodiments of the present invention and is not intended to limit the scope of the present invention in any way. Any changes or modifications made by those skilled in the art based on the above disclosure shall fall within the protection scope of the claims.

Claims

1. A clean type wafer oven characterized by, include: The housing and an air intake; The chamber has a baking cavity and a reflux channel. The chamber is provided with an exhaust port. The reflux channel is connected to the bottom of the baking cavity and the exhaust port. The air intake is connected to the baking cavity and can be used to introduce inert gas into the interior of the baking cavity. The air intake is configured such that the inert gas introduced into the interior of the baking cavity flows only from the top to the bottom of the baking cavity, and that a portion of the gas in the baking cavity is discharged from the exhaust port through the return channel. The clean wafer oven also includes a flow guide, which is disposed at the bottom of the baking cavity. The flow guide includes a flow guide portion and a curved flow guide surface. The flow guide surface extends into the reflux channel through the connection between the reflux channel and the baking cavity, so as to guide the gas flowing to the bottom of the baking cavity into the reflux channel.

2. The cleaning-type wafer oven according to claim 1, wherein The clean wafer oven further includes at least two temperature sensors, each of which is arranged at intervals inside the baking cavity along a vertical setting direction, the vertical setting direction being the direction from the top to the bottom of the baking cavity. The temperature sensors are configured such that when the difference between the temperature value collected by the temperature sensor near the top of the baking cavity and the temperature value collected by the temperature sensor far from the top of the baking cavity along the vertical setting direction is greater than a temperature setting value, inert gas is introduced through the air inlet, and part of the gas in the baking cavity is discharged through the exhaust port.

3. The cleaning-type wafer oven according to claim 1, wherein The clean wafer oven further includes at least two sets of heating units, one set of which is located near the top of the baking cavity and faces the top of the baking cavity in a vertical direction, the vertical direction being the direction from the top of the baking cavity to the bottom, and the other set of heating units is located on the side wall of the baking cavity.

4. The clean wafer oven as described in claim 3, characterized in that, The clean wafer oven further includes a top grille, which is disposed inside the baking cavity and maintains a first predetermined distance from the top of the baking cavity. The top grille is provided with an array of first ventilation holes, wherein a group of heating units disposed near the top of the baking cavity are disposed on the top grille.

5. The clean wafer oven as described in claim 1, characterized in that, The enclosure includes an inner enclosure and an outer enclosure, with the inner enclosure located inside the outer enclosure, and a sandwich layer formed between the inner enclosure and the outer enclosure.

6. The clean wafer oven as described in claim 5, characterized in that, The baking cavity and the reflux channel are located inside the inner box, the reflux channel is connected to the interlayer, and the exhaust port is located on the outer box and is connected to the interlayer.

7. The clean wafer oven as described in claim 1, characterized in that, The reflux channel is located outside the baking cavity and is arranged circumferentially around the baking cavity, and the exhaust port is connected to the top of the baking cavity.

8. The clean wafer oven as described in claim 7, characterized in that, The clean wafer oven also includes a bottom grille, which is disposed inside the baking cavity and maintains a second predetermined distance from the air guide. The bottom grille is provided with an array of second ventilation holes.

9. The clean wafer oven as described in claim 7, characterized in that, The flow guide includes a protrusion and a plurality of flow guides arranged around the protrusion. The flow guide surface extends into the return channel on the corresponding side to guide the gas flowing to the bottom of the baking cavity to flow evenly into the return channel.

10. The clean wafer oven as described in claim 1, characterized in that, The clean wafer oven also includes an oxygen concentration detection unit, which is located at the exhaust port to detect the oxygen concentration of the discharged gas.

11. The clean wafer oven as described in claim 1, characterized in that, The clean-type wafer oven also includes a filter, which is disposed on the exhaust port.

12. The clean wafer oven as described in claim 3, characterized in that, The clean wafer oven is configured with three cooling modes: natural cooling mode, medium-speed cooling mode, and rapid cooling mode. In the natural cooling mode: the heating unit is turned off, and the air intake and exhaust ports are closed; In the medium-speed cooling mode: the heating unit is turned off, the air intake is turned off, and the exhaust port is opened to draw gas from the baking chamber. In the rapid cooling mode: the heating unit is turned off, the air inlet is opened and gas is introduced into the baking cavity, and the exhaust port is opened to discharge the gas in the baking cavity.

Images