CN220856496U

CN220856496U - Photoresist conveying system

Info

Publication number: CN220856496U
Application number: CN202322676490.4U
Authority: CN
Inventors: 李阳
Original assignee: SiEn Qingdao Integrated Circuits Co Ltd
Current assignee: SiEn Qingdao Integrated Circuits Co Ltd
Priority date: 2023-10-07
Filing date: 2023-10-07
Publication date: 2024-04-26
Anticipated expiration: 2033-10-07

Abstract

The utility model provides a photoresist conveying system, which comprises a photoresist conveying pipeline, a discharge pipeline, a return pipeline, and a photoresist bottle, a temporary storage device, a filter, a supply pump, a sensor and a suck-back valve which are sequentially arranged in the photoresist conveying pipeline; a first valve is arranged between the sensor and the back suction valve, and a second valve is arranged at the inlet end of the filter or the supply pump; when the sensor detects that bubbles exist in the photoresist, the controller is configured to open the first valve and the second valve, so that the photoresist flows back to the inlet end of the filter or the supply pump in the photoresist conveying pipeline through the return pipeline; the filter in the photoresistance conveying pipeline is used for filtering bubbles and particle impurities; the supply pump in the photoresist transporting pipeline is used for driving the photoresist to transport in the photoresist transporting pipeline and filtering bubbles and particle impurities again, and the bubbles and particle impurities filtered by the filter and the supply pump are discharged through the discharge pipeline. The system is used for accurately detecting the photoresist bubble and completing bubble removal at the same time, so that the yield of the wafer is improved.

Description

Photoresist conveying system

Technical Field

The utility model relates to the technical field of semiconductor manufacturing, in particular to a photoresistance transport system.

Background

In the field of semiconductors, a gluing link in a photoetching process is not bypassed, and the gluing condition directly influences the yield of products. In general, when a photoresist sprayed on the surface of a wafer has bubbles, the bubbles burst during the photoresist spin-off tiling and the subsequent baking process, which results in uneven film thickness, which affects the yield, and in severe cases, may cause wafer rejection. The structure of a conventional photoresist transporting system for semiconductor devices is shown in fig. 1, and includes a photoresist transporting pipe L1, a discharging pipe L2, and a photoresist bottle 1, a temporary storage 2, a filter 3, a supply pump 4 and a suck-back valve 5 which are sequentially disposed in the photoresist transporting pipe, wherein the photoresist in the photoresist bottle 1 is transported to a nozzle 6 above a wafer 7 through the photoresist transporting pipe L1. The working flow of the gas transportation system comprises the following steps: after 300cc of purification (Purge) is performed by the supply pump 4, the solenoid valve V1 is automatically opened to discharge the bubbles passing through the filter 3 and the supply pump 4 to the discharge pipeline L2, but whether the photoresist finally comes out of the supply pump 4 still has bubbles still cannot be completely confirmed, the spraying state of the pipeline or the nozzle can be confirmed only by naked eyes of a worker, and then the granularity in the photoresist conveying pipeline is re-detected until the detection result passes, so that the machine production can be restored. The regular NPW (non-product monitoring sheet) stops checking when the particle or film thickness in the monitored photoresistance exceeds the range value, then the bubble is discharged by manual operation, but the production can be recovered after the NPW monitoring result is reused after the manual bubble discharge is required to be done according to the requirements of the process and quality management departments. Therefore, the method relies on manual subjective judgment whether bubbles exist or not, reliability is insufficient, and production efficiency is affected due to shutdown inspection.

Disclosure of utility model

The utility model aims to provide a photoresist conveying system which is used for accurately detecting photoresist bubbles and completing bubble removal at the same time, so that the yield of wafers is improved.

The utility model provides a photoresist conveying system, which comprises a photoresist conveying pipeline, a discharge pipeline, a return pipeline, and a photoresist bottle, a temporary storage, a filter, a supply pump, a sensor and a suck-back valve which are sequentially arranged in the photoresist conveying pipeline; a first valve is arranged between the sensor and the back suction valve, and a second valve is arranged at the inlet end of the filter or the supply pump; when the sensor detects that bubbles exist in the photoresist conveying pipeline, the controller is configured to open the first valve and the second valve, so that the photoresist flows back to the inlet end of the filter or the supply pump in the photoresist conveying pipeline through the return pipeline;

The filter in the photoresistance conveying pipeline is used for filtering bubbles and particle impurities; the supply pump in the photoresist transporting pipeline is used for driving the photoresist to transport in the photoresist transporting pipeline and filtering bubbles and particle impurities again, and the bubbles and particle impurities filtered by the filter and the supply pump are discharged through the discharge pipeline.

In a possible embodiment, when the sensor detects that no air bubbles are present in the photoresist transport line, the controller is configured to maintain the first and second valves in a closed state such that photoresist in the photoresist bottle is transported through the photoresist transport line to a nozzle above the wafer.

In another possible embodiment, a check valve is disposed in the return line beside the second valve for preventing the photoresist in the photoresist transporting line from flowing through the return line to the first valve.

In other possible embodiments, the sensor is an optical sensor, an ultrasonic sensor, or a capacitive sensor.

In yet another embodiment, the optical sensor includes a light projecting portion and a light receiving portion; the light receiving part is connected with an optical fiber amplifier, and the optical signal received by the light receiving part is then converted into a digital signal and sent to the controller; the controller is configured to open the first valve and the second valve when the digital signal exceeds a set threshold.

In other possible embodiments, the controller is configured to respond to a detection result of the sensor when in the operation mode; the controller is not responsive to the detection result of the sensor when the controller is configured in the sleep mode.

In a possible embodiment, the temporary storage, the filter and the supply pump are all in communication with the discharge line via solenoid valves.

In other possible embodiments, the first valve and the second valve are three-way valves.

In yet another possible embodiment, the suck-back valve is used to turn the nozzle spray on and off, and to control the speed and height of the suck-back. The register is used for maintaining the photoresist to be always present in the photoresist conveying pipeline.

The photoresistance transport system provided by the utility model has the beneficial effects that: the sensor in this system can accurately detect whether bubble exists in the supply line, and the controller can be according to the photo resistance that testing result control return line backward flow has the bubble and carry out the filtration again and arrange the bubble action, compares the current scheme of directly arranging the photo resistance that has the bubble, can save the photo resistance to a certain extent, and on the other hand compares the outage and arranges the bubble, and this embodiment can reduce board downtime when improving the product yield, promotes production efficiency.

Drawings

FIG. 1 is a schematic diagram of a photoresist transportation system for a machine provided in the prior art;

FIG. 2 is a schematic diagram of an improved photoresist transportation system according to the present utility model;

FIG. 3 is a schematic diagram of another improved photoresist transportation system according to the present utility model;

FIG. 4 is a schematic diagram of an optical sensor according to the present utility model;

Fig. 5 is a schematic diagram of a detection principle corresponding to the optical sensor shown in fig. 4 according to the present utility model.

The icon illustrates:

A photoresist transportation pipeline L1; a discharge line L2; a return line L3; a photoresist bottle 1; a register 2; a filter 3; a supply pump 4; a suck-back valve 5; a nozzle 6; a wafer 7; a sensor 8; a one-way valve 9;

a first valve K1; a second valve K2; and a solenoid valve V1.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present utility model more apparent, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model. Unless otherwise defined, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this utility model belongs. As used herein, the word "comprising" and the like means that elements or items preceding the word are included in the element or item listed after the word and equivalents thereof without precluding other elements or items.

Fig. 2 shows a structural diagram of an improved photoresist transportation system provided by the present utility model, the photoresist transportation system comprising: the photoresist transporting pipeline L1, the discharging pipeline L2, the reflux pipeline L3, and the photoresist bottle 1, the temporary storage 2, the filter 3, the supply pump 4, the sensor 8 and the suck-back valve 5 are sequentially arranged in the photoresist transporting pipeline L1.

A first valve K1 is arranged between the sensor 8 and the back suction valve 5, and a second valve K2 is arranged at the inlet end of the filter 3; when the sensor 8 detects the presence of air bubbles in the photoresist transporting line L1, a controller (not shown) is configured to open the first valve K1 and the second valve K2 so that the photoresist is reflowed to the inlet end of the filter 3 in the photoresist transporting line L1 through the reflow line L3; when the sensor 8 detects that no bubble exists in the photoresist transporting line L1, the controller is configured to keep the first valve K1 and the second valve K2 in a closed state, so that the photoresist in the photoresist bottle 1 is transported to the nozzle 6 above the wafer 7 through the photoresist transporting line L1.

Wherein, pressurized nitrogen is input into the photoresist bottle 1, and the temporary storage 2 has the function of ensuring that the photoresist is always in the photoresist conveying pipeline, and the pressurized nitrogen cannot enter the inner wall of the pipeline because the photoresist bottle is empty; the filter 3 is used for filtering bubbles and particulate impurities; the supply pump 4 is used for driving the photoresist to be transported in the photoresist transportation pipeline and filtering bubbles and particle impurities again, and finally driving the photoresist to be transported from the temporary storage device 2 to the nozzle 6 above the wafer 7, and the suck-back valve 5 is used for opening and closing the nozzle spraying and controlling the speed and the height of suck-back. The temporary storage 2, the filter 3 and the supply pump 4 are all communicated with the discharge pipeline L2 through the electromagnetic valve V1. When the solenoid valve V1 is opened, the air bubbles and particulate impurities filtered by the filter 3 and the supply pump 4 can be discharged through the discharge line L2.

In a possible embodiment, a check valve 9 is provided beside the second valve K2, the check valve 9 being used to prevent photoresist in the photoresist line from flowing through the return line to the first valve K1.

In a possible embodiment, as shown in fig. 3, a second valve K2 may also be disposed at the inlet end of the supply pump 4, and when the sensor 8 detects the presence of air bubbles in the photoresist transporting line L1, a controller (not shown) is configured to open the first valve K1 and the second valve K2, so that the photoresist flows back to the inlet end of the supply pump 4 in the photoresist transporting line L1 through the return line L3; when the sensor 8 detects that no bubble exists in the photoresist transporting line L1, the controller is configured to keep the first valve K1 and the second valve K2 in a closed state, so that the photoresist in the photoresist bottle 1 is transported to the nozzle 6 above the wafer 7 through the photoresist transporting line L1. Therefore, the embodiments corresponding to fig. 2 and fig. 3 can reduce and eliminate bubbles in the photoresist pipeline as much as possible, and reduce the occurrence of wafer defects, thereby improving the product yield and reducing the downtime. It should be understood that the photoresist transportation system shown in fig. 2 can perform two times of filtering of bubbles through the filter 3 and the supply pump 4, respectively, and the filtering effect is relatively better.

In a possible embodiment, the sensor 8 may be an optical sensor, as shown in fig. 4, where the optical sensor includes a light projecting portion 41 and a light receiving portion 42, and a light resistance transport pipeline L1 passes between the light projecting portion 41 and the light receiving portion 42; the light receiving portion 42 is connected to an optical fiber amplifier 44, the optical fiber amplifier 44 is used for amplifying a signal, the light signal received by the light receiving portion 42 is then converted into a digital signal and sent to a controller, and the controller is configured to open the first valve K1 and the second valve K2 when the digital signal exceeds a set threshold. The first valve K1 and the second valve K2 may be three-way valves, for example.

Referring to fig. 5, the principle of the optical sensor is to detect the presence or absence of bubbles and the size of bubbles by using the difference in refractive index between liquid and air. In the first case, as shown in fig. 5 (a), generally, when there is a larger bubble in the photoresist transporting pipe, even when there is no photoresist liquid in the photoresist transporting pipe, the light emitted from the light projecting portion 41 will come out of the photoresist transporting pipe and enter the light receiving portion 42, the light receiving portion 42 is connected to the optical fiber amplifier 44, the optical fiber amplifier 44 amplifies the signal, and the light signal received by the light receiving portion 42 is then converted into a digital signal and sent to the controller. As shown in fig. 5 (b), when there is a slight fine bubble 45 in the resist transport line, a part of the light emitted from the light projecting section 41 is received by the light receiving section 42, and the other part is deviated from the light receiving section 42 due to the liquid refraction phenomenon, in which case the numerical value of the displayed digital signal is smaller than in the first case. As shown in (c) of fig. 5, when the photoresist in the photoresist transporting line is free of any bubble, all the light emitted from the light projecting section 41 is refracted and shifted, resulting in almost no light received by the light receiving section 42, in which case the numerical value of the digital signal displayed is lowest, close to zero. It can be seen that the larger the bubble in the photoresist transport line, the larger the digital signal value; the smaller the bubble in the photoresist transport line, or in the near absence of bubbles, the smaller the digital signal value. It should be understood that when the optical sensor is set, the threshold value for determining the logical "1" and "0" (light transmission/light shielding) sensitization number, i.e. the set threshold value, can be set according to the needs of the user. In the photoresist transportation system provided in the embodiment, the optical sensor is additionally arranged and is matched with the optical fiber amplifier for use, the optical signal received by the light receiving part is converted into a digital signal, and then a user sets the digital signal according to own detection requirements; in practical application, the triggered execution action is automatically realized by writing a PLC program or a singlechip 'IO logic', for example, after a digital signal exceeds a set value, the normal IO logic is changed from 0 to 1 abnormally, then the PLC program is automatically started, the first valve K1 and the second valve K2 are automatically controlled, the section of light resistance with bubbles is taken away from a bubble discharging route, and a user can set other functions such as product line pause or enhancement of a machine inspection link when the logic is changed to 1.

The workflow of the photoresist transportation system provided in this embodiment includes: firstly, a user sets a proper set threshold, namely proper detection sensitivity, when the sensor 8 detects that a large bubble exists, the logic of a PLC program or a singlechip is changed from 0 to 1, and a first valve K1 leading to a nozzle end is automatically closed, so that a photoresist is led into a return pipeline L3: after which the bubbles are re-passed through the filter 3 and/or the supply pump 4 and finally discharged through the solenoid valve to the discharge line end. In addition, the user can set how long the automatic bubble removal of the return line L3 is performed or how many times the supply pump is performed according to his own needs, and the sensor 8 detects that no bubble is in the photoresist transporting line L1, and the logic of the PLC program or the single chip microcomputer is automatically restored from "1" to "0", at this time, the first valve K1 and the second valve K2 controlled by the return line L3 are automatically closed, so that the photoresist is normally driven to be transported from the temporary storage 2 to the nozzle 6 above the wafer 7, thereby continuing the production.

In a possible embodiment, when the photoresist is installed or replaced by a new photoresist, the controller is configured to be in the sleep mode, and does not respond to the detection result of the sensor, that is, the return line and the first valve and the second valve are not operated, because the operations such as manually cleaning the line are required during actual production. Only when the controller is configured in the operating mode, it responds to the detection result of the sensor in the manner described above.

In summary, when the bubbles in the photoresist transporting pipeline are accurately detected, the program automatically executes the path changing to remove the bubbles, so that the photoresist with the bubbles can be effectively prevented from being sprayed on the surface of the wafer to cause the damage of the yield or the scrapping of the product.

It should be understood that the sensor may be an ultrasonic sensor or a capacitive sensor, or may be another type of sensor, which is not limited to this embodiment.

While embodiments of the present utility model have been described in detail hereinabove, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. It is to be understood that such modifications and variations are within the scope and spirit of the present utility model as set forth in the following claims. Moreover, the utility model described herein is capable of other embodiments and of being practiced or of being carried out in various ways.

Claims

1. The photoresist conveying system is characterized by comprising a photoresist conveying pipeline, a discharge pipeline, a return pipeline, and a photoresist bottle, a temporary storage, a filter, a supply pump, a sensor and a suck-back valve which are sequentially arranged in the photoresist conveying pipeline;

A first valve is arranged between the sensor and the back suction valve, and a second valve is arranged at the inlet end of the filter or the supply pump; when the sensor detects that bubbles exist in the photoresist conveying pipeline, the controller is configured to open the first valve and the second valve, so that the photoresist flows back to the inlet end of the filter or the supply pump in the photoresist conveying pipeline through the return pipeline;

2. The photoresist delivery system of claim 1, wherein when the sensor detects the absence of air bubbles in the photoresist delivery line, the controller is configured to maintain the first and second valves in a closed state such that photoresist in the photoresist bottle is delivered through the photoresist delivery line to a nozzle above a wafer.

3. The photoresist delivery system of claim 1, wherein a one-way valve is disposed in the return line beside the second valve for preventing photoresist in the photoresist delivery line from flowing through the return line to the first valve.

4. A light resistance transportation system according to any of claims 1 to 3, wherein the sensor is an optical sensor, an ultrasonic sensor or a capacitive sensor.

5. The light resistance transportation system of claim 4, wherein the optical sensor comprises a light projecting portion and a light receiving portion; the light receiving part is connected with an optical fiber amplifier; the optical signal received by the light receiving part is then converted into a digital signal and sent to the controller;

The controller is configured to open the first valve and the second valve when the digital signal exceeds a set threshold.

6. A light resistance transportation system according to any one of claims 1 to 3, wherein the controller is configured to respond to the detection result of the sensor when in an operational mode; the controller is not responsive to the detection result of the sensor when the controller is configured in the sleep mode.

7. A photoresist transportation system according to any one of claims 1 to 3, wherein the register, filter and supply pump are all in communication with the discharge line via solenoid valves.

8. A photoresist transportation system according to any one of claims 1 to 3, wherein said first valve and said second valve are each three-way valves.

9. A photoresist transportation system according to any one of claims 1 to 3, wherein the suck back valve is used to turn on and off nozzle spraying and to control the speed and height of suck back.

10. A photoresist transportation system according to any one of claims 1 to 3, wherein the register is adapted to maintain the photoresist transportation line always in the presence of photoresist.