Photoresist baking and curing tail gas emission device and photoresist baking and curing method

Abstract

The invention discloses a photoresist baking and curing tail gas emission device and a photoresist baking and curing method.The photoresist baking and curing tail gas emission device comprises a tail gas emission pipeline connected to a flange at the lower end of a reaction chamber, the tail gas emission pipeline is provided with a micro-oxygen content detector and a cold trap, and the micro-oxygen content detector is used for detecting the oxygen concentration in tail gas exhausted out of the reaction chamber; the cold trap is used for cooling tail gas and collecting by-products such as water vapor and organic solvent vapor generated in the reaction chamber; the outer surface of the tail gas exhaust pipeline is wrapped with a heat tracing piece so that tail gas can be prevented from being condensed and deposited in the tail gas exhaust pipeline. The device has the advantages of being compact in structure, convenient to operate, high in reliability and the like, particle pollution is effectively controlled, a factory end pipeline is prevented from being blocked, and imidization reaction can be promoted to be conducted in the positive direction.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wafer heat treatment processing, in particular to a photoresist baking and curing tail gas discharge device and a photoresist baking and curing method. BACKGROUND

[0002] In the storage chip, such as 3D NAND Flash and DRAM, etc. advanced semiconductor manufacturing, PIQ (Polyimide Curing) is a very key and advanced process. It is through high temperature, oxygen-free heat treatment, so that the polyimide precursor solution coated on the wafer surface imidization reaction, generating polyimide film, is one of the key technologies to ensure high yield, manufacturing complex 3D structure chip indispensable.

[0003] High temperature imidization is the core step of PIQ process, usually the furnace tube temperature rises to 300-450℃, polyamide acid molecule closed loop dehydration reaction, converted into polyimide. The technical difficulty of PIQ process lies in the accurate control of the heating / cooling rate, gas flow, oxygen concentration, tail gas treatment to ensure the imidization reaction completely, to ensure the process quality.

[0004] In the existing PIQ process implementation process, flammable toxic organic solvent steam and corrosive water vapor and other by-products will be released, this part of the tail gas needs to be collected and treated by the device, to control the particle pollution, reduce the factory end tail gas treatment pressure, keep the system running stable, so the tail gas discharge collection device is very important. SUMMARY The technical problem to be solved by the present application is to provide a photoresist baking and curing tail gas discharge device and a photoresist baking and curing method which are compact in structure, convenient to operate and stable and reliable.

[0005] In order to solve the above technical problems, the technical scheme adopted by the present application is: A photoresist baking and curing tail gas discharge device, comprising a tail gas discharge pipeline connected to the lower end flange of the reaction chamber, a micro-oxygen content detector and a cold trap are arranged on the tail gas discharge pipeline, the micro-oxygen content detector is used to detect the oxygen concentration in the tail gas discharged from the reaction chamber, and the cold trap is used to realize tail gas cooling and collect water vapor and organic solvent vapor generated by the reaction chamber; the outer surface of the tail gas discharge pipeline is wrapped with a heating element to prevent the tail gas from condensing and depositing in the tail gas discharge pipeline.

[0006] As a further improvement of the present application, a pressure controller is further arranged on the tail gas discharge pipeline to detect the tail gas pressure and control the tail gas flow rate.

[0007] As a further improvement of the present application, the tail gas discharge pipeline comprises a first discharge pipe, a second discharge pipe, a third discharge pipe, a fourth discharge pipe and a fifth discharge pipe arranged in sequence; the first discharge pipe is connected to the lower end flange of the reaction chamber, and the micro-oxygen content detector is arranged on the first discharge pipe; the cold trap is connected to the second discharge pipe and the third discharge pipe respectively, and the pressure controller is arranged between the fourth discharge pipe and the fifth discharge pipe.

[0008] As a further improvement of the present application, a control valve is arranged between the cold trap and the third discharge pipe for controlling the on-off connection between the cold trap and the third discharge pipe.

[0009] As a further improvement of the present application, the first discharge pipe, the second discharge pipe, the third discharge pipe, the fourth discharge pipe and the fifth discharge pipe are detachably connected to each other by a clamp.

[0010] As a further improvement of the present application, the heat tracing member is a flexible heating belt, and the heat tracing temperature is 100-300℃.

[0011] As a further improvement of the present application, the cold trap comprises an outer shell and an inner shell arranged in a nested manner, the gas inlet of the inner shell is connected to the second discharge pipe, the gas outlet of the inner shell is connected to the third discharge pipe, and the inner shell is uniformly provided with fins for cooling the tail gas and trapping particulate matters in the tail gas.

[0012] As a further improvement of the present application, the fins are in a semi-circular sheet structure, and large holes and small holes are alternately arranged on the fins, the fins are alternately and uniformly arranged in the inner shell in a vertical direction, and the large holes and the small holes of the fins are alternately arranged to form a turbulent flow of the tail gas in the cold trap.

[0013] As a general technical concept, the present application also provides a photoresist baking and curing method, wherein the photoresist baking and curing tail gas discharge device is connected to the lower end flange of the reaction chamber, and the method comprises the following steps: Step S1, the wafer boat is lifted to a preset process position in the reaction chamber; Step S2, the protective gas is introduced to purge the reaction chamber and the tail gas discharge device; Step S3, the oxygen concentration in the reaction chamber is detected by the micro-oxygen content detector; Step S4, if the oxygen concentration in the reaction chamber meets the standard, the process gas is introduced, the reaction chamber is heated to 150-300℃, and the imination reaction is carried out; if the oxygen concentration in the reaction chamber does not meet the standard, the purging is continued; Step S5, the oxygen concentration in the reaction chamber is detected again by the micro-oxygen content detector; Step S6, the process temperature in the reaction chamber is maintained at 150-300℃; Step S7, continue to heat the reaction chamber to 300-400℃, and the exhaust emission device continuously collects by-products in the reaction process; Step S8, reduce the temperature of the reaction chamber to 50-150℃; Step S9, the wafer boat is lowered to the preset wafer transfer position in the reaction chamber, and the process flow is completed.

[0014] As a further improvement of the application, in step S6, the process time is 40±5 min; in step S7, the process time is 60±5 min.

[0015] Compared with the prior art, the application has the following advantages: The photoresist baking and curing exhaust emission device and the photoresist baking and curing method of the application greatly improve the by-product collection rate, effectively control the particle pollution of the exhaust gas, ensure the stability of the gas flow rate, prevent the end pipe from being blocked, promote the reaction to proceed in the positive direction, improve the operation stability of the equipment, reduce the maintenance and use difficulty, and improve the effective output of the equipment. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 The figure is a structural principle diagram of the photoresist baking and curing exhaust emission device in the embodiment of the application; Figure 2 The figure is a structural principle diagram of the cold trap in the embodiment of the application; Figure 3 The figure is a structural principle diagram of the fin in the embodiment of the application.

[0017] Legend: 1, first exhaust pipe; 2, second exhaust pipe; 3, third exhaust pipe; 4, fourth exhaust pipe; 5, fifth exhaust pipe; 6, heat tracing element; 7, micro-oxygen content detector; 8, control valve; 9, cold trap; 91, outer shell; 92, inner shell; 93, fin; 931, large air hole; 932, small air hole; 10, clamp; 11, pressure controller; 100, reaction chamber. DETAILED DESCRIPTION

[0018] The application will be further described below in combination with the drawings and specific preferred embodiments, but the protection scope of the application is not limited by this.

[0019] In the description of the present application, it needs to be understood that the orientation or positional relationship indicated by the terms "side", "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like are based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the devices or elements indicated must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0020] In addition, the terms "first" and "second" are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated, so that the features with "first" and "second" can explicitly or implicitly include one or more of the features, and in the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly and specifically limited.

[0021] Embodiment As Figure 1 and Figure 2 shown, the photoresist baking and curing tail gas discharge device of the present application comprises a tail gas discharge pipeline connected to the lower end flange of the reaction chamber 100. Specifically, the tail gas discharge pipeline comprises a first discharge pipe 1, a second discharge pipe 2, a third discharge pipe 3, a fourth discharge pipe 4 and a fifth discharge pipe 5 arranged in sequence to form a tail gas discharge channel. The first discharge pipe 1 is connected to the lower end flange of the reaction chamber 100, a micro-oxygen content detector 7 is arranged on the first discharge pipe 1 and close to the gas outlet of the reaction chamber 100 to detect the oxygen concentration in the reaction chamber 100, and the process is allowed to proceed only when the oxygen concentration is lower than 10 ppm, ensuring stable and reliable operation of the process and improving the process effect. A cold trap 9 is connected to the second discharge pipe 2 and the third discharge pipe 3, respectively, and the cold trap 9 is used to realize tail gas cooling and collect by-products such as water vapor and organic solvent vapor generated by the reaction chamber 100. A pressure controller 11 is arranged between the fourth discharge pipe 4 and the fifth discharge pipe 5 to detect the tail gas pressure and control the tail gas flow rate, ensuring stable airflow field in the tail gas discharge pipeline and guaranteeing process quality. The tail gas discharge device of the present embodiment effectively collects process by-products under the premise of ensuring reliable sealing and operation, ensures complete imination reaction, thereby improving the stability of equipment operation, reducing particle pollution, reducing maintenance and use difficulty, and improving the effective output of equipment.

[0022] Further, a control valve 8 is provided between the cold trap 9 and the third discharge pipe 3 to control the on-off between the cold trap 9 and the third discharge pipe 3. In the present embodiment, the control valve 8 can adopt an angular valve, which is simple in structure and convenient to control.

[0023] As shown in Figure 1 The first exhaust pipe 1, the second exhaust pipe 2, the third exhaust pipe 3, the fourth exhaust pipe 4 and the fifth exhaust pipe 5 are detachably connected to each other through the clamp 10, which is convenient to disassemble and assemble and is convenient for daily maintenance.

[0024] As shown in Figure 1 The outer surfaces of the lower end flange of the reaction chamber 100, the first exhaust pipe 1, the second exhaust pipe 2, the third exhaust pipe 3, the fourth exhaust pipe 4 and the fifth exhaust pipe 5 are wrapped with the heat tracing element 6 to prevent the process by-products from condensing and depositing in the exhaust gas pipeline. The heat tracing element 6 is a flexible heating belt, and the heat tracing temperature is 100-300°C. The heat tracing element 6 can effectively reduce the condensation and deposition of the process by-products into solid substances in the exhaust gas system, facilitate the collection of the by-products in the cold trap, reduce the airflow fluctuation in the reaction chamber and improve the process gas flow stability.

[0025] As shown in Figure 2 The cold trap 9 includes the outer shell 91 and the inner shell 92 which are nested. The gas inlet at the bottom of the inner shell 92 is connected to the second exhaust pipe 2, and the gas outlet at the top of the inner shell 92 is connected to the third exhaust pipe 3. The inner shell 92 is uniformly provided with the fins 93 to cool the exhaust gas and trap the particulate matters in the exhaust gas.

[0026] As shown in Figure 3 The fin 93 is a semicircular sheet structure, and the fin 93 is alternately provided with the large air holes 931 and the small air holes 932. The fins 93 are alternately and uniformly arranged in the inner shell 92 in the vertical direction, and the large air holes 931 and the small air holes 932 between the fins 93 are staggered to increase the flow path of the exhaust gas in the cold trap 9 and form the turbulent flow of the exhaust gas in the cold trap 9, increase the contact area with the airflow and greatly enhance the condensation effect and improve the by-product collection rate. Specifically, the fin 93 can be made of stainless steel, which has a stable structure and high heat exchange efficiency.

[0027] In this embodiment, a photoresist baking and curing method is also provided. The photoresist baking and curing exhaust gas discharge device is connected to the lower end flange of the reaction chamber 100, and the method includes the following steps: Step S1, the wafer boat is raised to a preset process position in the reaction chamber 100.

[0028] Step S2, the inert protective gas is introduced to purge the reaction chamber 100 and the exhaust gas discharge device.

[0029] Step S3, the oxygen concentration in the reaction chamber 100 is detected by the micro-oxygen content detector 7.

[0030] Step S4, if the oxygen concentration in the reaction chamber 100 meets the standard, the process gas is introduced, the reaction chamber 100 is heated to 150-300°C, and the imination reaction is carried out; if the oxygen concentration in the reaction chamber 100 does not meet the standard, the purging is continued. It can be understood that the oxygen concentration standard and the type of process gas can be routinely selected according to the imination reaction, and need not be particularly limited.

[0031] Step S5, the oxygen concentration in the reaction chamber 100 is detected again by the micro-oxygen content detector 7.

[0032] Step S6, the process temperature in the reaction chamber 100 is maintained at 150-300°C, and the process time is 40 min.

[0033] Step S7, the reaction chamber 100 is continuously heated to 300-400°C, the process time is 60 min, and the exhaust gas collecting device continuously collects the by-products in the reaction process.

[0034] Step S8, the reaction chamber 100 is cooled to 50-150°C.

[0035] Step S9, the wafer boat is lowered to the preset wafer transfer position in the reaction chamber 100, and the process flow is completed.

[0036] The above only describes the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-described embodiments. Any technical solution falling within the concept of the present application belongs to the protection scope of the present application. It should be noted that, for ordinary skilled persons in the art, some improvements and refinements without departing from the principles of the present application are also considered to be within the protection scope of the present application.

Claims

1. A device for emitting exhaust gas from photoresist baking and curing, characterized in that, The system includes a tail gas discharge pipe connected to the lower flange of the reaction chamber (100). The tail gas discharge pipe is equipped with a micro-oxygen content detector (7) and a cold trap (9). The micro-oxygen content detector (7) is used to detect the oxygen concentration in the tail gas discharged from the reaction chamber (100). The cold trap (9) is used to cool the tail gas and collect the water vapor and organic solvent vapor generated in the reaction chamber (100). The outer surface of the tail gas discharge pipe is wrapped with a heat tracing element (6) to prevent the tail gas from condensing and depositing inside the tail gas discharge pipe.

2. The photoresist baking and curing exhaust gas emission device according to claim 1, characterized in that, The exhaust pipe is also equipped with a pressure controller (11) to detect the exhaust pressure and control the exhaust flow rate.

3. The photoresist baking and curing exhaust gas emission device according to claim 2, characterized in that, The exhaust gas emission pipeline includes a first emission pipe (1), a second emission pipe (2), a third emission pipe (3), a fourth emission pipe (4), and a fifth emission pipe (5) arranged in sequence; the first emission pipe (1) is connected to the lower flange of the reaction chamber (100), and the micro-oxygen content detector (7) is installed on the first emission pipe (1); the cold trap (9) is connected to the second emission pipe (2) and the third emission pipe (3) respectively, and the pressure controller (11) is installed between the fourth emission pipe (4) and the fifth emission pipe (5).

4. The photoresist baking and curing exhaust gas emission device according to claim 3, characterized in that, A control valve (8) is provided between the cold trap (9) and the third discharge pipe (3) to control the opening and closing of the connection between the cold trap (9) and the third discharge pipe (3).

5. The photoresist baking and curing exhaust gas emission device according to claim 3, characterized in that, The first discharge pipe (1), the second discharge pipe (2), the third discharge pipe (3), the fourth discharge pipe (4) and the fifth discharge pipe (5) are detachably connected to each other by clamps (10).

6. The photoresist baking and curing exhaust gas emission device according to any one of claims 1 to 5, characterized in that, The heat tracing element (6) is a flexible heating belt with a heat tracing temperature of 100℃~300℃.

7. The photoresist baking and curing exhaust gas emission device according to any one of claims 3 to 5, characterized in that, The cold trap (9) includes a nested outer shell (91) and an inner shell (92). The air inlet of the inner shell (92) is connected to the second exhaust pipe (2), and the air outlet of the inner shell (92) is connected to the third exhaust pipe (3). Heat sinks (93) are evenly distributed inside the inner shell (92) to cool the exhaust gas and trap particulate matter in the exhaust gas.

8. The photoresist baking and curing exhaust gas emission device according to claim 7, characterized in that, The heat sink (93) is a semi-circular thin sheet structure, and large air holes (931) and small air holes (932) are alternately provided on the heat sink (93). The heat sink (93) is alternately and evenly distributed in the inner shell (92) along the vertical direction, and the large air holes (931) and small air holes (932) between each heat sink (93) are staggered to achieve the formation of turbulence in the exhaust gas in the cold trap (9).

9. A method for baking and curing photoresist, characterized in that, Connecting the photoresist baking and curing exhaust gas emission device according to any one of claims 1 to 8 to the lower flange of the reaction chamber (100), the method includes the following steps: Step S1: The crystal boat is raised to the preset process position inside the reaction chamber (100); Step S2: Purge the reaction chamber (100) and exhaust gas device with protective gas; Step S3: Detect the oxygen concentration in the reaction chamber (100) using a micro-oxygen content detector (7); Step S4: If the oxygen concentration in the reaction chamber (100) meets the standard, process gas is introduced and the temperature of the reaction chamber (100) is raised to 150℃~300℃ to carry out the imidization reaction; if the oxygen concentration in the reaction chamber (100) does not meet the standard, purging continues. Step S5: Detect the oxygen concentration in the reaction chamber (100) again using the micro-oxygen content detector (7); Step S6: Maintain the process temperature in the reaction chamber (100) at 150℃~300℃; Step S7: Continue to heat the reaction chamber (100) to 300℃~400℃, and the exhaust gas emission device continuously collects the by-products in the reaction process; Step S8: Cool the reaction chamber (100) to 50℃~150℃; Step S9: The crystal boat descends to the preset wafer transfer position in the reaction chamber (100) to complete the process flow.

10. The photoresist baking and curing method according to claim 9, characterized in that, In step S6, the process time is 40±5 min; in step S7, the process time is 60±5 min.

Images