Wafer baking device

Abstract

The utility model relates to the technical field of semiconductor equipment, in particular to a wafer baking device. According to the wafer baking device provided by the utility model, the baking tray assembly, the ventilation hood assembly, the hot air assembly, the air supply assembly and the air draft assembly are arranged on the base, so that 1, the hot air assembly heats solvent steam extracted by the air draft assembly, and the possibility that the solvent steam is condensed and attached to the ventilation hood assembly due to temperature reduction is reduced; the service life and the use efficiency of the equipment are improved; and 2, the wafer is mainly heated and baked by the baking tray assembly, and in addition, the hot air assembly heats the gas blown to the upper surface of the wafer by the air supply assembly, so that the gas on the upper surface of the wafer is subjected to auxiliary hot air blowing, the baking temperature difference between the upper surface and the lower surface of the wafer is reduced, the baking efficiency of the wafer is improved, and the solvent on the surface of the wafer is more uniformly volatilized.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of semiconductor equipment especially relates to a wafer baking device. BACKGROUND

[0002] In the semiconductor manufacturing process, wafer baking mainly occurs in several key steps of the photolithography process, such as pre-treatment baking, soft baking, hard baking, and possibly other processes such as etching and ion implantation before and after baking. The existing wafer baking device has four general structures: heating, bearing, airflow, and control. Soft baking enhances the exhaust system, micro-negative pressure sealed cavity, and solvent evaporation control components on this basis. This is because the main purpose of soft baking is to evaporate the organic solvents (such as PGMEA, propylene glycol methyl ether, etc.) in the photoresist. These solvents will form a large amount of steam when heated (90-120°C). The solvents will turn into steam when heated, and the organic solvent additives and other volatile substances at high temperatures need to be removed by the exhaust system. The "sealing" of the micro-negative pressure sealed cavity is not absolute sealing, but a controllable environment formed by the dynamic balance of air intake and exhaust. This is the key to ensuring efficient solvent discharge and avoiding pollution and temperature fluctuations. Then, the solvent vapor is prone to condense in the exhaust pipeline when it is discharged, forming liquid or solid residues such as resin or additives in the photoresist. Long-term accumulation can block the pipeline and affect the baking efficiency.

[0003] For example, the Chinese utility model patent with patent announcement number CN220738326U and announcement date April 9, 2024 discloses a device for wafer baking, which includes a heating system and an exhaust system. The heating system includes a frame, a hot plate, a support structure, and a heat preservation structure. The support structure includes a motor, a connection block A, a connection block B, a connection block C, a fixed block, a top pin, and a needle cap.

[0004] The device for wafer baking in the utility model patent has the following general structure and principle: place the wafer on the support structure, heat it with the hot plate inside the heating system, and heat the wafer's position. Apply glue to the wafer, support it with multiple top pins to avoid contact with the support structure, move the needle cap with the top pins to adjust the wafer's position, control the heating effect, save the temperature with the heat preservation structure, avoid high energy consumption, cool down with the exhaust system, lower the wafer's temperature, and remove it for further processing without affecting the subsequent process.

[0005] However, the device for wafer baking has at least the following disadvantages in actual use, in other words, the technical problems to be solved by the utility model: 1. The solvent vapor is easy to condense and adhere to the inner wall of the exhaust system when being discharged, causing blockage, affecting the exhaust effect and baking efficiency; 2. The wafer is heated and baked only by the heat plate at the bottom, the baking efficiency is low, and the temperature difference between the upper and lower surfaces of the wafer is large, causing uneven solvent evaporation, resulting in film cracking or uneven thickness.

[0006] Therefore, as described above, there is an urgent need for a new wafer baking device which is not easy to block and is more uniform in baking. Utility model content

[0007] The utility model provides a kind of wafer baking device, it can be by the way of setting baking tray assembly, ventilating hood assembly, hot air component, air supply component and exhaust component on base, so that: 1, hot air component is heated to solvent vapor extracted by exhaust component, reduce the possibility that solvent vapor condenses and adheres to ventilating hood assembly due to temperature reduction, to improve the service life and use efficiency of equipment;2, wafer mainly relies on baking tray assembly to heat and bake, in addition, hot air component is heated to the gas swept to the upper surface of wafer by air supply component, to assist hot air to sweep the gas on the upper surface of wafer, reduce the baking temperature difference between the upper and lower surfaces of wafer, improve the baking efficiency of wafer, so that wafer surface solvent evaporation is more uniform.

[0008] The utility model solves the technical scheme that the above problem adopts: a wafer baking device, including base, setting in the base, and being used for heating wafer baking tray assembly, setting ventilating hood assembly above the baking tray assembly, hot air component is set on the ventilating hood assembly, setting air supply fan on the ventilating hood assembly, and being located above the hot air component, and being used for extracting solvent vapor on the wafer outwardly exhaust fan.

[0009] Further preferred technical scheme is in that: the ventilating hood assembly includes the cover body being set above the wafer, and the lower end opening, two ventilating pipes being set respectively on both sides of the cover body, and being used for connecting the exhaust fan and the air supply fan, air port valve being set on the ventilating pipe, and uniform air plate being set on the cover body, and being close to the position of wafer.

[0010] Further preferred technical scheme is in that: the uniform air plate includes wind-shedding plate, and several guide holes are set on the wind-shedding plate.

[0011] Further preferably, the uniform air plate further comprises a plurality of flow converging channels arranged on the air diffusing plate and avoiding the air flow holes, and used for avoiding impurities from falling onto the wafer surface from the air flow holes.

[0012] Further preferably, the cover body comprises an upper cover body and a lower cover body, the uniform air plate is arranged on the upper cover body, and a lower end of the upper cover body is provided with an L-shaped connecting leg used for clamping an upper end of the lower cover body.

[0013] Further preferably, the upper cover body comprises an upper cover body body, a connecting cover body arranged at a lower end of the upper cover body body and used for mounting the L-shaped connecting leg at a bottom end, and an extension plate arranged at the lower end of the upper cover body body and the upper end of the connecting cover body respectively, and bolts arranged on the two extension plates.

[0014] Further preferably, a diameter of the air flow hole decreases from a side close to the wafer to a side away from the wafer.

[0015] Further preferably, the flow converging vertical plate is an inclined plate.

[0016] Further preferably, the baking tray assembly comprises a heating tray arranged on the base, and a plurality of supporting columns arranged on the heating tray and used for supporting the wafer.

[0017] Further preferably, the hot air assembly is a heating pipe.

[0018] The beneficial effects of the present application are as follows: 1. The hot air assembly heats the solvent vapor extracted by the air extraction assembly, reduces the possibility of the solvent vapor adhering to the ventilation cover assembly due to temperature reduction, and avoids the condensate from blocking the pipeline and affecting the air extraction effect; 2. The baking tray assembly plays a main baking function, the air supply assembly and the hot air assembly assist in blowing hot air on the upper surface of the wafer, so that the temperature difference between the upper and lower surfaces of the wafer is reduced, and the external blowing of the hot air assembly makes the baking of the upper surface of the wafer more uniform and the baking efficiency higher; 3. The hot air assembly simultaneously heats the extracted and blown gas, and has strong structural linkage. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical scheme of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 The exploded view is for the utility model.

[0021] Figure 2 The position section view is for the ventilation cover assembly and the baking tray assembly in the utility model.

[0022] Figure 3 The perspective view is for the utility model.

[0023] Figure 4 The perspective view is for the utility model.

[0024] Figure 5 The perspective view is for the utility model.

[0025] Figure 6 The section view schematic diagram is for the air supply fan start in the utility model.

[0026] Figure 7 The section view schematic diagram is for the air exhaust fan start in the utility model.

[0027] Figure 8 The perspective view is for Figure 6 The local enlarged view of A in the utility model.

[0028] Figure 6 , Figure 7 The broken line shown in the figure is the pipeline connecting line.

[0029] Wafer a;

[0030] Base 1, baking tray assembly 2, ventilation cover assembly 3, hot air assembly 4, air supply fan 5, air exhaust fan 6;

[0031] Heating disc 21, support column 22, support table 23, cover body 31, ventilation pipe 32, air inlet valve 33, air distribution plate 34;

[0032] Upper cover body 311, lower cover body 312, L-shaped connecting leg 313, air distribution plate 341, air guide hole 342, air flow channel 343;

[0033] Upper cover body 311a, connecting cover body 311b, extension plate 311c, bolt 311d, air flow vertical plate 343a, air flow bottom plate 343b. DETAILED DESCRIPTION

[0034] The utility model embodiments are described in detail below in conjunction with the drawings, and the following description is only the preferred embodiment of the utility model, and does not limit the scope of the utility model.

[0035] The directional terms such as up, down, left, right, front, back, front, back, top, bottom, etc., mentioned or possibly mentioned in this specification are defined relative to the structure shown in the accompanying drawings. The terms "inner" and "outer" refer to the direction toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive terms.

[0036] As attached Figures 1-8 As shown, a wafer baking apparatus includes a base 1, a baking tray assembly 2 disposed on the base 1 for heating a wafer a, a ventilation hood assembly 3 disposed above the baking tray assembly 2, a hot air assembly 4 disposed on the ventilation hood assembly 3, a blower 5 disposed on the ventilation hood assembly 3 and above the hot air assembly 4 for blowing onto the wafer a, and an exhaust fan 6 disposed on the ventilation hood assembly 3 and above the hot air assembly 4 for drawing solvent vapor from the wafer a outward.

[0037] In this embodiment, the base 1 serves as the bottom support structure of the wafer baking apparatus, used to mount the baking tray assembly 2. The ventilation hood assembly 3 directly covers the baking tray assembly 2 and is in contact with the upper surface of the base 1. The baking tray assembly 2 uses a conventional heating system, with core components including a heating plate, a temperature control system, and a heat source. These components are common knowledge and will not be described in detail in this embodiment. The base 1 is a hollow box-shaped structure, and the baking tray assembly 2 can be embedded within it. The heating plate of the baking tray assembly 2 is positioned close to the wafer placement area. The baking tray assembly 2 is placed in the middle of the base 1, directly below the ventilation hood assembly 3, and covered by it, so that the wafer a is baked in a relatively enclosed space.

[0038] Further, the ventilation cover assembly 3 can be shaped as required, such as a cube or a cylinder, and the lower end of the ventilation cover assembly 3 is provided with an opening for covering the baking tray assembly 2 and the wafer a on the baking tray assembly 2. The upper end of the ventilation cover assembly 3 is connected to the air supply fan 5 and the air exhaust fan 6, and the hot air assembly 4 is located on the ventilation cover assembly 3 and below the air supply fan 5 and the air exhaust fan 6, so as to heat the gas blown by the air supply fan 5 and the solvent vapor extracted by the air exhaust fan 6. The air supply fan 5 supplies external gas into the ventilation cover assembly 3, and the external gas can be nitrogen or dry air, which can be filtered before being blown in. The air exhaust fan 6 is used to exhaust the volatile solvent vapor on the surface of the wafer a, and to exhaust impurities, propylene glycol methyl ether or PGMEA, etc., so as to improve the baking effect of soft baking. In addition, if the wafer a needs to be cooled, the baking tray assembly 2 and the hot air assembly 4 can be turned off, and the air supply fan 5 or the air exhaust fan 6 can be turned on to quickly cool the wafer a, and the structure has strong flexibility.

[0039] Further, the hot air assembly 4 mainly uses heat radiation to heat the gas and vapor, and can use resistance heating or infrared heating, etc. When the hot air assembly 4 is an electric heater, it mainly includes heating wires or hollow heating coils, a temperature control system and a power supply. The above-mentioned heating coils, temperature control systems and power supplies are well known, and therefore will not be described in detail. In order to avoid direct contact between the heating wires and the internal gas, the heating wires can be coated on the outside.

[0040] Finally, the ventilation cover assembly 3 is provided with an air inlet and an air outlet for maintaining a micro-negative pressure state. When the wafer baking device is performing soft baking, it is not completely sealed, but needs to maintain a dynamically balanced sealed environment. A micro-negative pressure (10-50 Pa) is formed by the difference between the air inlet amount (50-100 L / min) and the air extraction amount (80-150 L / min), to ensure that no external particles enter after the solvent vapor is discharged. The ventilation cover assembly 3 is opened, the wafer a is placed on the baking tray assembly 2, the ventilation cover assembly 3 is closed, so that the wafer baking device is in a relatively sealed state, the baking tray assembly 2 is turned on to bake the wafer a, at this time the hot air assembly 4 is turned on for preheating, at this time the air supply fan 5 and the air extraction fan 6 are in a closed state. The air supply fan 5 is turned on, so that external gas enters the ventilation cover assembly 3, and the gas is heated by the hot air assembly 4 and then blown downward to the wafer a, thereby assisting in blowing the wafer a with hot air from the upper surface of the wafer a. The air speed of the air supply fan 5 should not be too large to avoid causing the wafer a to wrinkle. By assisting in heating the upper surface of the wafer a, the temperature difference between the upper and lower surfaces of the wafer a is reduced, the baking efficiency is improved, and the baking time is reduced. When the baking progress reaches about 60%-80%, the air supply fan 5 is turned off, at this time the baking tray assembly 2 continues to bake the wafer a, the organic solvent on the surface of the wafer a volatilizes into vapor and suspends above the wafer a, after baking is completed, the air extraction fan 6 is turned on to extract the solvent vapor above the wafer a. The air inlet and outlet amounts of the air supply fan 5, the air extraction fan 6, and the air inlet and outlet of the ventilation cover assembly 3 need to be adjusted accordingly to ensure that the environment in the wafer baking device is relatively stable. The effect can also be achieved by simultaneously turning on the air supply fan 5 and the air extraction fan 6, as long as the air supply efficiency and the gas amount of the air supply fan 5 are greater than the air supply efficiency and the gas amount of the air extraction fan 6.

[0041] The ventilation cover assembly 3 includes a cover body 31 arranged above the wafer a and having an open lower end, two ventilation pipes 32 arranged at both ends of the cover body 31 and used for connecting the air extraction fan 6 and the air supply fan 5, air port valves 33 arranged on the ventilation pipes 32, and an air uniformizing plate 34 arranged on the cover body 31 and close to the wafer a.

[0042] In the embodiment, the cover 31 is open at the lower end for covering the wafer a, the ventilation pipes 32 are arranged on the two sides of the cover 31 for connecting the air supply fan 5 and the air exhaust fan 6, the air outlet valves 33 are arranged on the ventilation pipes 32 for selectively opening or closing the ventilation pipes 32. The air outlet valves 33 mainly include a valve body, a valve flap, a valve rod, a sealing element, a bearing, a position indicator, a limiting device, a connecting component and a sensor, which are all existing ventilation valve devices, and thus the embodiment will not be described in detail. The air uniformizing plate 34 is arranged below the hot air assembly 4 and close to the upper position of the wafer a for combing the gas flow direction blown to the surface of the wafer a, so that the flow rate is more gentle and the flow is more uniform, and a relatively stable baking space is formed between the air uniformizing plate 34 and the base 1.

[0043] The air uniformizing plate 34 includes the air diffusing plate 341 and a plurality of flow guide holes 342 arranged on the air diffusing plate 341.

[0044] In the embodiment, the air uniformizing plate 34 includes the air diffusing plate 341 and a plurality of flow guide holes 342 arranged on the air diffusing plate 341, and the gas above and below the air diffusing plate 341 flows through the flow guide holes 342.

[0045] The air uniformizing plate 34 further includes a plurality of converging channels 343 arranged on the air diffusing plate 341 and avoiding the flow guide holes 342 for avoiding impurities from falling back to the surface of the wafer a from the flow guide holes 342; the converging channels 343 include two converging vertical plates 343a and a converging bottom plate 343b connecting the bottoms of the two converging vertical plates 343a.

[0046] In the embodiment, the converging channels 343 are used for accumulating impurities, and the upper surface of the converging channels 343 is lower than the upper cross section of the flow guide holes 342. After the air exhaust fan 6 exhausts the solvent vapor and impurities above the wafer a, a small amount of impurities will remain in the cover 31 and fall back and accumulate on the upper surface of the air diffusing plate 341 or the wafer a. The converging channels 343 make the impurities or condensate accumulate in the channels, reducing the possibility of falling back to the wafer a through the flow guide holes 342. Preferably, the converging channels 343 are grooves arranged on the air diffusing plate 341. The converging channels 343 include two converging vertical plates 343a and the converging bottom plate 343b connecting the two converging vertical plates 343a. The converging channels 343 are arranged between two adjacent rows or columns of the flow guide holes 342, and the upper surface of the converging bottom plate 343b is lower than the upper surface of the flow guide holes 342.

[0047] The cover 31 comprises an upper cover 311 and a lower cover 312, the uniform air plate 34 is arranged on the upper cover 311, and the lower end of the upper cover 311 is provided with an L-shaped connecting leg 313 for clamping the upper end of the lower cover 312.

[0048] In the embodiment, the cover 31 is divided into the upper cover 311 and the lower cover 312, the lower cover 312 encloses and keeps warm the space around the periphery of the wafer a, and the upper cover 311 is used for mounting the hot air assembly 4 and the uniform air plate 34 and connecting the air supply fan 5 and the air exhaust fan 6. The wafer a can be put in or taken out by only removing the upper cover 311. The upper cover 311 and the lower cover 312 are clamped through the L-shaped connecting leg 313, the L-shaped connecting leg 313 is protrudingly arranged at the lower end of the upper cover 311 and clamped with the upper end of the lower cover 312.

[0049] The upper cover 311 comprises an upper cover body 311a, a connecting cover 311b arranged at the lower end of the upper cover body 311a and used for mounting the L-shaped connecting leg 313 and fixedly connected with the side end of the uniform air plate 34, extension plates 311c arranged at the lower end of the upper cover body 311a and the upper end of the connecting cover 311b respectively, and bolts 311d arranged on the two extension plates.

[0050] In the embodiment, the upper cover body 311a is used for mounting the hot air assembly 4 and connecting the air supply fan 5 and the air exhaust fan 6, the connecting cover 311b is integrally formed with the uniform air plate 34, and the L-shaped connecting leg 313 is located at the lower end of the connecting cover 311b so as to be clamped with the lower cover 312. The extension plates 311c and the bolts 311d are used for detachably connecting the upper cover body 311a and the connecting cover 311b. When the uniform air plate 34 needs to be cleaned or replaced, the connecting cover 311b can be only detached, so that the cleaning is convenient and flexible.

[0051] The diameter of the flow guide hole 342 is reduced from the side close to the wafer a to the side far from the wafer a.

[0052] In the embodiment, as shown in FIG. 4, the uniform air plate 34 is provided with a plurality of flow guide holes 342. Figure 7As shown, the flow guide hole 342 includes an upper flow guide hole and a lower flow guide hole, the upper flow guide hole and the lower flow guide hole are located at the same axis, the upper flow guide hole has a smaller diameter than the lower flow guide hole, and an inclined surface is formed between the upper flow guide hole and the lower flow guide hole, which narrows from the lower flow guide hole to the upper flow guide hole. When the air flow is blown by the air blower 5 to the surface of the wafer a, the air flow enters a larger space from a narrow space when passing through the flow guide hole 342, and the air flow is more uniform. At the same time, due to the different diameters of the upper and lower surfaces of the flow guide hole 342, the impurities or condensate above the flow guide hole 342 are reduced.

[0053] The converging vertical plate 343a is an inclined plate.

[0054] In this embodiment, the converging vertical plate 343a is an inclined plate, and preferably, the distance between the upper ends of the two converging vertical plates 343a is greater than the distance between the lower ends, so as to converge and guide the impurities and condensate.

[0055] The baking tray assembly 2 includes a heating tray 21 arranged on the base 1, and a plurality of support columns 22 arranged on the heating tray 21 and used for supporting the wafer a.

[0056] In this embodiment, when the wafer a is baked, there are cases that only one side has a film or both sides have a film. The heating tray 21 is arranged at the upper end of the base 1 and used for heating and baking the wafer a, wherein a plurality of support columns 22 are arranged on the heating tray 21, which can support the bottom of the wafer a and have certain heat conduction performance, thereby reducing the problem that the wafer a is overheated and damaged or the bottom film is unevenly baked due to the direct contact between the wafer a and the heating tray 21. Preferably, the support columns 22 support the outer side periphery of the wafer a. Preferably, the support platform 23 is arranged at the upper end of the support column 22 and in contact with the lower surface of the wafer a, which is used for enlarging the contact surface with the wafer a, improving the support stability, and avoiding the wafer a from being inclined.

[0057] The hot air assembly 4 is a heating pipe.

[0058] In this embodiment, the hot air assembly 4 is a heating pipe, which adopts an electric heating form, and the outer surface of the heating pipe is provided with a protective coating. The heating pipe can be sprayed with Teflon, so that there is no metal ion in the cavity.

[0059] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical solutions of the present application, and they should be covered in the scope of the present application.

Claims

1. A wafer baking apparatus characterized by comprising: The base (1), the baking tray assembly (2) arranged on the base (1) and used for heating the wafer (a), the ventilation cover assembly (3) arranged above the baking tray assembly (2), the hot air assembly (4) arranged on the ventilation cover assembly (3) and above the hot air assembly (4), the air supply fan (5) arranged on the ventilation cover assembly (3) and above the hot air assembly (4) and used for blowing the wafer (a), and the air exhaust fan (6) arranged on the ventilation cover assembly (3) and above the hot air assembly (4) and used for extracting the solvent vapor on the wafer (a).

2. The wafer baking apparatus according to claim 1, wherein The ventilation cover assembly (3) comprises a cover body (31) arranged above the wafer (a) and having an open lower end, two ventilation pipes (32) arranged at both ends of the cover body (31) and used for connecting the air exhaust fan (6) and the air supply fan (5), air port valves (33) arranged on the ventilation pipes (32), and an air uniformizing plate (34) arranged on the cover body (31) and close to the wafer (a).

3. The wafer baking apparatus of claim 2, wherein The air uniformizing plate (34) comprises a wind-shielding plate (341) and a plurality of guide holes (342) arranged on the wind-shielding plate (341).

4. The wafer baking apparatus according to claim 3, wherein The air uniformizing plate (34) further comprises a plurality of flow converging channels (343) arranged on the wind-shielding plate (341) and avoiding the guide holes (342) and used for avoiding impurities from falling back to the surface of the wafer (a) through the guide holes (342); the flow converging channel (343) comprises two flow converging vertical plates (343a) and a flow converging bottom plate (343b) connecting the bottoms of the two flow converging vertical plates (343a).

5. The wafer baking apparatus of claim 2, wherein The cover body (31) comprises an upper cover body (311) and a lower cover body (312), the air uniformizing plate (34) is arranged on the upper cover body (311), and the lower end of the upper cover body (311) is provided with an L-shaped connecting leg (313) used for clamping the upper end of the lower cover body (312).

6. The wafer baking apparatus according to claim 5, wherein The upper cover body (311) comprises an upper cover body body (311a), a connecting cover body (311b) arranged at the lower end of the upper cover body body (311a) and used for mounting the L-shaped connecting leg (313) at the bottom end and fixedly connected with the side end of the air uniformizing plate (34), an extension plate (311c) arranged at the lower end of the upper cover body body (311a) and the upper end of the connecting cover body (311b) respectively, and a bolt (311d) arranged on the two extension plates.

7. The wafer baking apparatus of claim 3, wherein The diameter of the guide hole (342) decreases from the side close to the wafer (a) to the side away from the wafer (a).

8. The wafer baking apparatus of claim 4, wherein The flow converging vertical plate (343a) is an inclined plate.

9. The wafer baking apparatus of claim 1, wherein The baking tray assembly (2) comprises a heating tray (21) arranged on the base (1) and a plurality of support columns (22) arranged on the heating tray (21) and used for supporting the wafer (a).

10. The wafer baking apparatus of claim 1, wherein The hot air assembly (4) is a heating pipe.

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