A wet treatment method for implementing a high-temperature chemical etching reaction

Abstract

The application provides a wet treatment method for realizing high-temperature chemical etching reaction, and specifically comprises the following steps: step S1, controlling a robot to place a wafer on a placing table, and controlling a ventilation device on the placing table to output a high-pressure airflow to make the wafer suspended on the placing table; step S2, spraying a first cleaning liquid to the surface of the wafer to perform high-temperature chemical etching, spraying a second cleaning liquid to the side of the wafer to perform wet treatment, and controlling the robot to take down the wafer. The beneficial effect is that the method makes the wafer in a suspended state through the ventilation device outputting the high-pressure airflow, and performs non-contact cleaning on the wafer; the first cleaning liquid is sprayed to the upper surface of the wafer to perform high-temperature chemical etching, the second cleaning liquid is sprayed to the side of the wafer to perform wet treatment, and the high-pressure airflow is sprayed to the lower surface of the wafer, so that the wafer is cleaned, etched and protected in all directions, and the stable high-temperature chemical etching reaction is realized through the first cleaning liquid with stable heating.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of wafer cleaning and etching technology, and particularly relates to a wet processing method for realizing high-temperature chemical etching reaction. BACKGROUND

[0002] With the rapid development of semiconductor technology, the requirements for wafers are getting higher and higher, so that a clean wafer surface is more and more important for the manufacturing of semiconductor devices. After each process in the wafer manufacturing process, cleaning is required.

[0003] At present, the cleaning and etching method for wafers often needs to set a large number of spray structures to spray different chemical solutions to the surface of the wafer for cleaning and etching, which results in low space utilization. In addition, due to the instability of the cleaning liquid temperature, it is not easy to produce a stable high-temperature chemical etching reaction on the surface of the wafer, which will greatly weaken the etching effect. SUMMARY

[0004] In view of the problems in the prior art, the present application provides a wet processing method for realizing high-temperature chemical etching reaction, which specifically comprises the following steps:

[0005] Step S1, a robot is controlled to place a wafer on a placement table, and a ventilation device on the placement table is controlled to output a high-pressure airflow to make the wafer float on the placement table;

[0006] Step S2, a first cleaning liquid is sprayed to the surface of the wafer for high-temperature chemical etching, and a second cleaning liquid is sprayed to the side of the wafer for wet processing, and the robot is controlled to take down the wafer.

[0007] Preferably, the step S1 comprises:

[0008] The ventilation device outputs the high-pressure airflow to the lower surface of the wafer according to a preset flow rate.

[0009] Preferably, the preset flow rate is in the range of 175L / min-225L / min.

[0010] Preferably, in the step S2, the wafer is cleaned by a cleaning device, and the cleaning device comprises:

[0011] a middle nozzle arranged above the wafer, for spraying a first cleaning liquid to the surface of the wafer to perform high-temperature chemical etching on the surface of the wafer;

[0012] a plurality of side nozzles symmetrically arranged on both sides of the placement table, for spraying a second cleaning liquid to the side of the wafer to perform wet processing on the side of the wafer;

[0013] a plurality of baffles respectively arranged at two ends of the surface of the placement table, for forming a receiving area with the surface of the placement table to receive the first cleaning solution and the second cleaning solution;

[0014] a plurality of drain grooves respectively arranged on the surface of the placement table, for conveying the first cleaning solution and the second cleaning solution received in the receiving area to an external recycling device for recycling.

[0015] Preferably, each of the drain grooves is connected to the recycling device through a first conveying pipe, and the step S1 comprises:

[0016] controlling the first conveying pipe to be conducted to convey the first cleaning solution and the second cleaning solution in the receiving area to the recycling device for recycling.

[0017] Preferably, each of the side nozzles is connected to the recycling device through a second conveying pipe, and the step S1 further comprises:

[0018] controlling the second conveying pipe to be conducted to convey the second cleaning solution remaining in the side nozzles to the recycling device for recycling.

[0019] Preferably, the step S2 comprises:

[0020] a step S21 of controlling the middle nozzle to spray the first cleaning solution to the surface of the wafer to perform high-temperature chemical etching on the surface of the wafer, and controlling each of the side nozzles to spray the second cleaning solution to the side surface of the wafer to perform wet processing on the side surface of the wafer;

[0021] a step S22 of controlling the robot to take the wafer off the placement table.

[0022] Preferably, the middle nozzle is internally provided with a plurality of spray pipes, each of which is filled with a chemical liquid, and in the step S21, one of the spray pipes is controlled to be conducted and the spray pipe is controlled to spray the corresponding chemical liquid as the first cleaning solution to perform high-temperature chemical etching on the surface of the wafer; or

[0023] a preset sequence is followed to control each of the spray pipes to be conducted in turn to spray the corresponding chemical liquid to perform high-temperature chemical etching on the surface of the wafer.

[0024] Preferably, each of the spray pipes is arranged in a heating device, and the step S21 further comprises:

[0025] controlling the heating device to be started to heat the chemical liquid in each of the spray pipes.

[0026] The above technical solution has the following advantages or beneficial effects:

[0027] (1) The method makes the wafer in a suspended state by the high-pressure airflow output by the ventilation device, and performs non-contact cleaning on the wafer, so that the wafer is not contaminated with new impurities when the cleaning is completed;

[0028] (2) The method sprays the first cleaning liquid on the upper surface of the wafer for high-temperature chemical etching, sprays the second cleaning liquid on the side surface of the wafer for wet processing, and sprays the high-pressure airflow on the lower surface of the wafer, so as to realize omnidirectional cleaning, etching and protection of the wafer;

[0029] (3) The method automatically picks up the wafer on the placement table by controlling a robot, reduces the participation of manual in the cleaning process, and reduces the impurity influence of manual factors on the wafer;

[0030] (4) The method controls the heating device in the middle nozzle to heat the chemical liquid in the spraying pipe, so that the chemical liquid can still meet the required temperature standard when sprayed out of the outlet of the middle nozzle, generates a stable high-temperature chemical etching reaction on the wafer surface through the stably heated first cleaning liquid, and reduces heat loss;

[0031] (5) The method sets multiple spraying pipes in the middle nozzle to reduce the number of spraying structures of external devices and increase the space utilization. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 For the preferred embodiment of the present application, the step flowchart of the method is shown in the figure;

[0033] Figure 2 For the preferred embodiment of the present application, the specific flowchart of step S2 is shown in the figure. DETAILED DESCRIPTION

[0034] The present application will be described in detail below with reference to the accompanying drawings and specific embodiments. The present application is not limited to this embodiment, and other embodiments can also belong to the scope of the present application as long as they meet the main idea of the present application.

[0035] In the preferred embodiment of the present application, based on the above-mentioned problems existing in the prior art, a wet processing method for realizing high-temperature chemical etching reaction is provided, as shown in the figure, which specifically includes the following steps: Figure 1

[0036] Step S1, a robot is controlled to place a wafer on a placement table, and a ventilation device on the placement table is controlled to output a high-pressure airflow to make the wafer suspended on the placement table;

[0037] ​Spraying a first cleaning liquid to the surface of the wafer for high-temperature chemical etching, and spraying a second cleaning liquid to the side of the wafer for wet processing, and controlling the robot to take out the wafer.

[0038] In the preferred embodiment of the present application, step S1 comprises:

[0039] According to a preset flow rate, the air supply device outputs a high-pressure airflow to the lower surface of the wafer.

[0040] In the preferred embodiment of the present application, the preset flow rate is in the range of 175 L / min-225 L / min.

[0041] Specifically, in the present embodiment, an airflow injection area can be provided on the lower surface of the wafer. Considering that when the airflow injection area is large, the preset flow rate of the high-pressure airflow output by the air supply device needs to be increased, and when the airflow injection area is small, the preset flow rate of the high-pressure airflow output by the air supply device is not enough to blow the wafer into a suspended state, therefore, the optimal range of the airflow injection area needs to be obtained.

[0042] Preferably, through testing, the optimal range of the airflow injection area is between 17% R-36% R, wherein R represents the radius of the wafer.

[0043] In the preferred embodiment of the present application, in step S2, the wafer is cleaned by a cleaning device, and the cleaning device comprises:

[0044] A middle nozzle is arranged above the wafer, for spraying a first cleaning liquid to the surface of the wafer for high-temperature chemical etching on the surface of the wafer;

[0045] A plurality of side nozzles are symmetrically arranged on both sides of the placement table, for spraying a second cleaning liquid to the side of the wafer for wet processing on the side of the wafer;

[0046] A plurality of baffles are respectively arranged at both ends of the surface of the placement table, for forming a storage area with the surface of the placement table to store the first cleaning liquid and the second cleaning liquid;

[0047] A plurality of leakage grooves are respectively arranged on the surface of the placement table, for conveying the first cleaning liquid and the second cleaning liquid stored in the storage area to an external recycling device for recycling.

[0048] Specifically, in the embodiment, the middle nozzle adopts a staggered up-and-down movable cavity with liquid flow guiding function. When the first cleaning liquid is subjected to high-temperature chemical etching, the first cleaning liquid is guided into the cavity, the staggered atmosphere is used for isolation, and the dispersion of exhaust is used for maintaining the separate flow guiding of the first cleaning liquid and the atmosphere, so that the high-risk acid liquid and the acid liquid prone to crystallization due to temperature difference and viscosity property can be effectively avoided, and the crystallization problem of chemical liquid such as nitric acid, sulfuric acid and phosphoric acid can be effectively improved.

[0049] Specifically, in the embodiment, the ventilation device is arranged at the center area of the surface of the placement table, and a non-contact bearing device with wafer rotation function is used. The high-pressure air flow is output to form an air flow field to generate air pressure at the upper and lower ends, so that the wafer can be carried in a suspended state, and the stable confluence is formed in the process of continuous air injection and pressure application of the air flow field, so that the particles and pollutants under the wafer cannot accumulate and rebound to the surface of the wafer due to the non-contact bearing mode in the rotation process.

[0050] Specifically, in the embodiment, there are corresponding pipelines in the clamping area on the outer side of the placement table. Nitrogen, gaseous or liquid isopropyl alcohol is sprayed through the pipelines to ensure the outward pushing of the air flow. In the rotation process of the wafer, the surface below the wafer is effectively sprayed with gas to perform preliminary drying and surface isopropyl alcohol covering.

[0051] Preferably, the temperature of the pure air in the air flow field is controlled to maintain the high-temperature air flow covering of the wafer in the overall range, maintain the stability of the wafer surface temperature, and reduce the heat loss.

[0052] Specifically, in the embodiment, the middle nozzle 4 can adopt a corresponding cleaning wet process required in the wafer rotation process. The first cleaning liquid generates centrifugal force, and the first cleaning liquid is rotated from the center to the outer end in the diffusion process on the wafer surface to perform the wet cleaning process.

[0053] Specifically, in the embodiment, the baffle is arranged at both ends of the placement table to prevent the first cleaning liquid or the second cleaning liquid from contacting the surface of the placement table and sputtering out of the storage area on the placement table in the downward flowing process.

[0054] In the preferred embodiment of the present application, each leakage groove is connected to an external recovery device through a first conveying pipe. Then, step S1 includes:

[0055] The first conveying pipe is controlled to be conducted to convey the first cleaning liquid and the second cleaning liquid in the storage area to the recovery device for recovery.

[0056] Specifically, in the embodiment, considering that the first cleaning liquid and the second cleaning liquid will continuously accumulate in the accommodation area, the first cleaning liquid and the second cleaning liquid accumulated need to be discharged in time, and therefore, the first conveying pipe and the leakage groove are arranged to convey the first cleaning liquid and the second cleaning liquid accumulated to the recycling device for recycling so as to be reused in the next cleaning.

[0057] In the preferred embodiment of the present application, each side nozzle is connected to the recycling device through a second conveying pipe, and therefore, step S1 further includes:

[0058] The second conveying pipe is controlled to be turned on to convey the second cleaning liquid remaining in the side nozzle to the recycling device for recycling.

[0059] Specifically, in the embodiment, considering that the second cleaning liquid remaining in the side nozzle needs to be discharged in time after the cleaning is completed, the second conveying pipe is arranged to convey the second cleaning liquid remaining to the recycling device for recycling and reuse.

[0060] In the preferred embodiment of the present application, as shown in Figure 2 step S2 includes:

[0061] Step S21, the middle nozzle is controlled to spray the first cleaning liquid to the surface of the wafer to perform high-temperature chemical etching on the surface of the wafer, and each side nozzle is controlled to spray the second cleaning liquid to the side surface of the wafer to perform wet processing on the side surface of the wafer.

[0062] Step S22, the robot is controlled to take the wafer off the placing table.

[0063] In the preferred embodiment of the present application, the middle nozzle is internally provided with a plurality of spraying pipes, each spraying pipe is internally provided with a chemical liquid, and therefore, in step S21, one of the spraying pipes is controlled to be turned on, and the spraying pipe is controlled to spray the corresponding chemical liquid as the first cleaning liquid to perform high-temperature chemical etching on the surface of the wafer; or

[0064] According to a preset sequence, each spraying pipe is controlled to be turned on in sequence to spray the corresponding chemical liquid to perform high-temperature chemical etching on the surface of the wafer.

[0065] Specifically, in the embodiment, the middle nozzle is provided with a plurality of spraying pipes to realize high-temperature chemical etching on the wafer by using a plurality of different chemical liquids, and the turning on of each spraying pipe can be controlled, thereby reducing the number of external spraying devices.

[0066] In the preferred embodiment of the present application, each spraying pipe is arranged in a heating device, and therefore, step S21 further includes:

[0067] The heating device is controlled to be started to heat the chemical liquid in each spraying pipe.

[0068] Specifically, in this embodiment, many cleaning devices do not have heating devices, but the spray pipe needs a stable, fast heating, and temperature regulating heating module. Therefore, an additional heating module is usually needed, which consumes the effective space of the device and reduces the maximum batch capacity of the cleaning device.

[0069] Preferably, taking the wafer cleaning device as an example, the cleaning device needs to heat according to different chemical solutions such as acid, alkali, organic solution, and pure water. The heating is performed through an external heating module, and the specific output heating gas or liquid is transmitted through a pipe. The heat loss is more obvious through the multi-pipe channel pipeline. Additional temperature control and continuous heat supply are needed to achieve the required temperature stability of the output liquid or gas, which affects the power consumption, material loss, and production capacity. Therefore, in this embodiment, the heating device is directly arranged in the middle nozzle, and the continuously injected chemical solution is directly heated at the outlet of the middle nozzle to reduce heat loss.

[0070] Specifically, in this embodiment, the chemical solution in each spray pipe is heated by the heating device to ensure that the chemical solution can maintain a stable and consistent temperature during output spraying, thereby reducing the phenomenon of inconsistent cleaning of wafers caused by unstable temperature of the chemical solution.

[0071] Specifically, in this embodiment, the middle nozzle adopts a composite nozzle structure, and a buffer confluence area is arranged in the middle nozzle. The chemical solution with bubbles is pushed to the upper end of the middle nozzle due to the inconsistent specific gravity under the confluence and gravity guiding effect of the continuously injected chemical solution. Under the interlocking hole structure of the inner and outer embedded pipes, a method for breaking bubbles is formed, and chemical solution without bubbles can be continuously drained and confluenced for output.

[0072] Specifically, in this embodiment, through special spray design, a unique sound wave control liquid drop output is constructed to maintain fine molecules, and nitrogen gas jet is overlapped in the output chemical solution spray area to make the nanometer chemical solution droplets have nanometer liquid drop retention ability under the action of nitrogen gas.

[0073] Specifically, in this embodiment, a monitoring device can be used to monitor the temperature and concentration of the first cleaning liquid sprayed by the middle nozzle in real time, and the heating power of the heating device can be adjusted in real time.

[0074] The above merely describes preferred embodiments of the present application, and is not intended to limit the implementation and protection scope of the present application. Those skilled in the art should be able to understand that any equivalent substitutions and obvious changes made according to the present application and drawings should be included in the protection scope of the present application.

Claims

1. A wet treatment method for implementing a high-temperature chemical etching reaction, characterized by, Specifically comprising the following steps: Step S1, controlling a robot to place a wafer on a placement table, and controlling a ventilation device on the placement table to output a high-pressure airflow to make the wafer float on the placement table; Step S2, spraying a first cleaning liquid to the surface of the wafer for high-temperature chemical etching, and spraying a second cleaning liquid to the side of the wafer for wet processing, and controlling the robot to take down the wafer; In the step S1, the airflow injection area of the high-pressure airflow ranges between 17% R-36% R, R representing the radius of the wafer; A pipeline is arranged on the outer clamping area of the annular placement table, and the nitrogen gas, gaseous or liquid isopropyl alcohol is sprayed through the pipeline; In the step S2, the wafer is cleaned by a cleaning device, and the cleaning device comprises: A middle nozzle is arranged above the wafer, and is used for spraying a first cleaning liquid to the surface of the wafer for high-temperature chemical etching; The middle nozzle adopts a staggered up-down movable cavity with liquid flow guiding function, and when the first cleaning liquid performs high-temperature chemical etching, the first cleaning liquid is guided into the cavity, and the first cleaning liquid and the atmosphere are separately guided by using staggered atmosphere isolation and exhaust dispersion.

2. The wet treatment method according to claim 1, characterized in that, The step S1 comprises: According to a preset flow rate, the ventilation device outputs the high-pressure airflow to the lower surface of the wafer.

3. The wet treatment method according to claim 2, characterized in that, The preset flow rate ranges from 175 L / min to 225 L / min.

4. The wet treatment method according to claim 1, characterized by, The cleaning device comprises: A plurality of side nozzles are symmetrically arranged on both sides of the placement table, and are used for spraying a second cleaning liquid to the side of the wafer for wet processing; A plurality of baffles are respectively arranged at both ends of the surface of the placement table, and are used for forming a storage area with the surface of the placement table to store the first cleaning liquid and the second cleaning liquid; A plurality of drain grooves are respectively arranged on the surface of the placement table, and are used for conveying the first cleaning liquid and the second cleaning liquid stored in the storage area to an external recycling equipment for recycling.

5. The wet treatment method according to claim 4, characterized in that, Each drain groove is connected to an external recycling equipment through a first conveying pipe, and the step S1 comprises: The first conveying pipe is controlled to be conducted to convey the first cleaning liquid and the second cleaning liquid in the storage area to the recycling equipment for recycling.

6. The wet treatment method according to claim 5, characterized in that, Each side nozzle is connected to the recycling equipment through a second conveying pipe, and the step S1 further comprises: The second conveying pipe is controlled to be conducted to convey the second cleaning liquid remaining in the side nozzle to the recycling equipment for recycling.

7. The wet treatment method according to claim 4, characterized by, The step S2 comprises: Step S21, controlling the middle nozzle to spray the first cleaning liquid to the surface of the wafer for high-temperature chemical etching, and controlling each side nozzle to spray the second cleaning liquid to the side of the wafer for wet processing; Step S22, controlling the robot to take down the wafer from the placement table.

8. The wet treatment method according to claim 7, characterized in that, The middle nozzle is internally provided with a plurality of spray pipes, each of which is respectively provided with a chemical liquid, and in the step S21, one of the spray pipes is controlled to be turned on and the corresponding chemical liquid is sprayed by the spray pipe as the first cleaning liquid to perform high-temperature chemical etching on the wafer surface. According to a preset sequence, each of the spray pipes is controlled to be turned on in sequence to spray the corresponding chemical liquid to perform high-temperature chemical etching on the wafer surface.

9. The wet treatment method according to claim 8, characterized in that, Each of the spray pipes is arranged in a heating device, and the step S21 further includes: controlling the heating device to be started to heat the chemical liquid in each of the spray pipes.

Images