Photoresist self-circulation system and method

Abstract

The invention discloses a photoresist self-circulation system and method, and relates to the field of photoetching equipment, the system comprises a photoresist storage bottle, a liquid supplementing tank, a mini tank, a filter and a single-stage pump; a first valve is arranged on an outlet path of the liquid supplementing tank, a second valve is arranged at a photoresist spraying position, the first valve and the second valve are closed during self-circulation of photoresist, the photoresist circulates among the single-stage pump, the filter and the mini tank, and a plurality of valves are arranged on a circulation path. According to the photoresist self-circulation system, the photoresist is circulated in the system, so that the photoresist discharged every day is greatly reduced, the cost of one machine is reduced by about five millions every year, and the production cost is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the field of photolithography equipment, and more specifically, to a photoresist self-circulation system and method. Background Art

[0002] In the semiconductor photolithography process, the cleanliness of the photoresist affects the quality of the photolithography process. The coating equipment is a device that coats the photoresist on the wafer. The photoresist is stored inside the device. When the photoresist is not used for a long time, it will deteriorate and produce impurities. Therefore, in the prior art, the photoresist is often pre-sprayed before the formal coating process to discharge the deteriorated photoresist.

[0003] Take the glue quantity system of the single-pole pump commonly used in the current glue coating and developing equipment as an example. Even if the photoresist is not used normally, it must be sprayed at least once every hour. The purpose is to allow the photoresist that does not flow in the pipeline to be filtered out by the filter. Otherwise, the photoresist that does not flow will deteriorate over time. Spray the photoresist once every hour when the photoresist is idle. Spray 3ml each time, and spray 72ml a day. Figure 1 As shown, when the existing solution is used to remove the photoresist, the photoresist flows in one direction, which will lead to serious waste of photoresist. The price of photoresist is extremely high, resulting in high spraying costs. Summary of the invention

[0004] The purpose of the present invention is to provide a photoresist self-circulation system to solve the technical problems existing in the above-mentioned background technology.

[0005] The technical solution of the present invention provides a photoresist self-circulation system, including a photoresist storage bottle, a liquid replenishing tank, a mini tank, a filter and a single-stage pump; a valve one is arranged on the outlet of the liquid replenishing tank, and a valve two is arranged at the glue spraying place, and the valve one and the valve two are closed when the photoresist self-circulates, and the photoresist circulates between the single-stage pump, the filter and the mini tank, and a plurality of valves are arranged on the circulation path.

[0006] In a preferred embodiment, the filter is located upstream of the single-stage pump.

[0007] In a preferred embodiment, the liquid replenishing tank is divided into two routes downstream of the valve, the first pipeline is connected to the mini tank through a filter, and the second pipeline is directly connected to the mini tank; a branch is separated from the connecting pipeline between the mini tank and the liquid replenishing tank and connected to the upstream of the single-stage pump, and at the same time, a route is led out from the mini tank and connected to the downstream of the single-stage pump.

[0008] In a preferred embodiment, valve three is arranged in the first pipeline and upstream of the filter, and valve four is arranged in the second pipeline; valve five and valve six are arranged between the mini tank and the single-stage pump, and valve five is located upstream of the single-stage pump, and valve six is ​​located downstream of the single-stage pump.

[0009] In a preferred embodiment, the filter is located downstream of the single-stage pump.

[0010] In a preferred embodiment, the rehydration tank, mini tank, unipolar pump and filter are connected in sequence, and two routes are separated downstream of the filter, the first route is connected to the mini tank, and the second route flows into the nozzle through valve 2.

[0011] In a preferred embodiment, valve seven is provided in the first pipeline, and valve one is provided between the liquid infusion tank and the mini tank.

[0012] A photoresist self-circulation method, based on the above-mentioned photoresist self-circulation system, comprises the following steps:

[0013] S1: Determine whether the photoresist static time is greater than or equal to the set time T; if so, execute S2; if not, execute S1;

[0014] S2: Close valve 1, valve 2 and valve 5, and the single-stage pump squeezes the photoresist so that the photoresist enters the mini tank through valve 6;

[0015] S3: The photoresist enters the filter from the mini tank through valve 4 and valve 3 for filtration. After the filtration is completed, it enters the mini tank again;

[0016] S4: Determine whether the number of cycles n is greater than or equal to the set number of cycles N; if so, open valve two, and the single-stage pump discharges the photoresist, and then return to step S1; if not, close valve four and valve six, open valve five, and the photoresist enters the single-stage pump from the mini tank through valve five, and then return to step S1.

[0017] A photoresist self-circulation method, based on the above-mentioned photoresist self-circulation system, comprises the following steps:

[0018] S1: Determine whether the photoresist static time is greater than or equal to the set time T; if so, execute S2; if not, execute S1;

[0019] S2: Close valve 1 and valve 2, and the single-stage pump squeezes the photoresist, allowing the photoresist to enter the filter and then enter the mini tank through valve 7;

[0020] S3: Determine whether the number of cycles n is greater than or equal to the set number of cycles N; if so, open valve 2, the single-stage pump discharges the photoresist, and return to step S1; if not, the photoresist enters the single-stage pump from the mini tank, and return to step S1.

[0021] In a preferred embodiment, N=24 / T, rounded to the nearest integer.

[0022] The beneficial effects of the technical solution of the present invention are:

[0023] The photoresist self-circulation system of this solution circulates the photoresist in the system, which greatly reduces the amount of photoresist discharged every day. The cost of one machine is reduced by about five million per year, greatly reducing production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a flow chart of the prior art photoresist discharge solution.

[0025] Figure 2 This is a flow chart of the photoresist self-circulation scheme of Example 1 of the present invention,

[0026] Figure 3 This is a logic block diagram of the photoresist self-circulation scheme of embodiment 1 of the present invention.

[0027] Figure 4 This is a flow chart of the photoresist self-circulation scheme of Example 2 of the present invention,

[0028] Figure 5 This is a logic block diagram of the photoresist self-circulation scheme of embodiment 2 of the present invention.

[0029] Explanation of the reference numerals: 1 photoresist storage bottle, 2 liquid replenishing tank, 3 mini tank, 4 filter, 5 single-stage pump, 6 valve one, 7 valve two, 8 valve three, 9 valve four, 10 valve five, 11 valve six, 12 valve seven. DETAILED DESCRIPTION

[0030] The present invention is further described in detail below. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations will be apparent to those of ordinary skill in the art. The embodiments are selected and described to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and design various embodiments with various modifications suitable for specific uses.

[0031] like Figure 1 As shown, in the prior art, the photoresist flows out through the photoresist storage bottle, is temporarily stored in the refill tank, continues to flow into the mini tank, is sent to the filter for filtration by a single-stage pump, and is finally sent out. The photoresist flows in one direction. The unused photoresist is sprayed once an hour, 3 ml each time, and 72 ml is sprayed a day, resulting in a low utilization rate of the photoresist. The price of the photoresist is high, and the existing solution leads to a high spraying cost.

[0032] Example 1

[0033] like Figure 2-Figure 3As shown, the technical solution of the present invention provides a photoresist self-circulation system, including a photoresist storage bottle, a liquid replenishing tank, a mini tank, a filter and a single-stage pump. During self-circulation, valve 1 on the outlet of the liquid replenishing tank and valve 2 at the glue spraying place are closed, and the photoresist circulates between the single-stage pump, the filter and the mini tank, and a plurality of valves are arranged on the circulation path.

[0034] The photoresist passes through the filter to filter out impurities introduced by deterioration or other factors; the bubbles in the photoresist can be removed through the mini tank. Through the action of the filter and the mini tank, the photoresist is kept at the cleanliness required by the photolithography process.

[0035] In this example, the filter is located upstream of the single-stage pump. The replenishment tank is divided into two routes downstream of valve one. The first pipeline is connected to the mini tank through the filter, and the second pipeline is directly connected to the mini tank; a branch is separated from the connecting pipeline between the mini tank and the replenishment tank to connect to the upstream of the single-stage pump, and at the same time, a branch is led out of the mini tank to connect to the downstream of the single-stage pump. Valve three is set in the first pipeline and located upstream of the filter, and valve four is set in the second pipeline; valve five and valve six are set between the mini tank and the single-stage pump, and valve five is located upstream of the single-stage pump, and valve six is ​​located downstream of the single-stage pump.

[0036] In the above scheme, the photoresist is initially stored in the photoresist storage bottle, and the photoresist is replenished in the refill tank in time. When spraying, the single-stage pump works, and the photoresist flows out of the refill tank, passes through the filter, the mini tank and the single-stage pump in sequence, and then reaches the spraying place for spraying. When not spraying, the photoresist circulates between the filter, the mini tank and the single-stage pump to reduce the discharge volume of waste photoresist.

[0037] Based on the above-mentioned photoresist self-circulation system, the photoresist self-circulation method is as follows:

[0038] S1: Determine whether the photoresist static time is greater than or equal to the set time T; if so, execute S2; if not, execute S1;

[0039] S2: When the self-circulation is in progress, no glue spraying is performed at this time, so valve 2 is closed, and valves 1 and 5 also need to be closed at the same time, and then the single-stage pump is started, which squeezes the photoresist so that the photoresist enters the mini tank through valve 6 to eliminate bubbles in the photoresist;

[0040] S3: The photoresist then flows out of the mini tank and enters the filter through valve four and valve three in sequence for filtration to remove impurities introduced due to deterioration or other factors. After the filtration is completed, it enters the mini tank again;

[0041] S4: Determine whether the number of cycles n is greater than or equal to the set number of cycles N; if so, open valve 2, the single-stage pump discharges the photoresist, and then return to step S1; if not, close valve 4 and valve 6, open valve 5, the photoresist enters the single-stage pump from the mini tank through valve 5, and then return to step S1. Wherein, N = 24 / T, round up.

[0042] Example 2

[0043] like Figure 4-Figure 5 As shown, the circulation principle of this embodiment is the same as that of embodiment 1, except that in this embodiment, the filter is located downstream of the single-stage pump, and the positions of the corresponding components are adaptively adjusted, as follows:

[0044] The rehydration tank, mini tank, unipolar pump and filter are connected in sequence, and two routes are separated downstream of the filter, the first route is connected to the mini tank, and the second route flows into the nozzle through valve 2. Valve 7 is set on the first route, and valve 1 is set between the rehydration tank and the mini tank.

[0045] In the above scheme, the photoresist is initially stored in the photoresist storage bottle, and the photoresist is replenished in the refill tank in time. When spraying, the single-stage pump works, and the photoresist flows out of the refill tank, passes through the mini tank, the filter and the single-stage pump in sequence, and reaches the spraying place for spraying. When not spraying, the photoresist circulates between the filter, the mini tank and the single-stage pump to reduce the discharge of waste photoresist.

[0046] Based on the above-mentioned photoresist self-circulation system, the photoresist self-circulation method is as follows:

[0047] S1: Determine whether the photoresist static time is greater than or equal to the set time T; if so, execute S2; if not, execute S1;

[0048] S2: When the self-circulation is in progress, glue spraying is not performed at this time, so valve 2 is closed, valve 1 is closed at the same time, and then the single-stage pump is started, which squeezes the photoresist and allows the photoresist to enter the filter to remove impurities introduced due to deterioration or other factors. After the filtration is completed, the photoresist enters the mini tank through valve 7 to eliminate bubbles in the photoresist;

[0049] S3: Determine whether the number of cycles n is greater than or equal to the set number of cycles N; if so, open valve 2, the single-stage pump discharges the photoresist, and then return to step S1; if not, the photoresist enters the single-stage pump from the mini tank, and then return to step S1. Wherein, N = 24 / T, rounded.

[0050] Based on the above-mentioned Embodiment 1 and Embodiment 2, after 24 hours of self-circulation, a portion of the photoresist needs to be discharged to allow the photoresist in the refill tank to flow and eliminate the risk of the photoresist being left for a long time, causing more deterioration and thus contaminating the photoresist. The time T is set, and the photoresist just begins to deteriorate at this time, which will not cause the photoresist to produce more impurities and will not waste resources.

[0051] Taking the time T as 30 minutes as an example, the unused photoresist is set to cycle once every 30 minutes, and the glue is sprayed once 48 times a day, and 3 ml of glue is sprayed a day. ( The glue spraying volume can also be other volumes, which are determined based on the capacity of a single-stage pump discharged at a time). Compared with the existing solution, at least 69 ml of photoresist is saved per day. One photoresist line saves about 25 liters of photoresist per year (approximately equal to a 6.5-gallon bottle of photoresist). Based on the price of RMB 70,000 per bottle of glue for the hard mask of the SOC machine, one photoresist line saves about RMB 450,000 per year. A device has at least 20 glue circuit systems. If 10 glue circuit systems of a coating and developing device are idle, it can save about RMB 4.5 million per year.

[0052] Therefore, the photoresist self-circulation system of the present invention can significantly reduce the amount of photoresist discharged every day by allowing the photoresist to circulate within the system. The annual cost reduction for one machine is about five million, which greatly reduces the production cost.

[0053] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. The structures, devices and operating methods not specifically described and explained in the present invention are implemented according to the conventional means in the field unless otherwise specified and limited.

Claims

1. A photoresist self-circulation system, characterized in that: Includes photoresist storage bottle, refill tank, mini tank, filter and single-stage pump; A valve 1 is arranged on the outlet of the liquid replenishing tank, and a valve 2 is arranged at the glue spraying place. The valve 1 and the valve 2 are closed when the photoresist circulates by itself. The photoresist circulates between the single-stage pump, the filter and the mini tank, and several valves are arranged on the circulation path.

2. A photoresist self-circulation system according to claim 1, characterized in that: The filter is located upstream of the single-stage pump.

3. A photoresist self-circulation system according to claim 2, characterized in that: The replenishing tank is divided into two routes downstream of the valve, the first pipeline is connected to the mini tank through a filter, and the second pipeline is directly connected to the mini tank; a branch is separated from the connecting pipeline between the mini tank and the replenishing tank and connected to the upstream of the single-stage pump, and at the same time, a route is led out from the mini tank and connected to the downstream of the single-stage pump.

4. A photoresist self-circulation system according to claim 3, characterized in that: Valve three is arranged in the first pipeline and upstream of the filter, and valve four is arranged in the second pipeline; valve five and valve six are arranged between the mini tank and the single-stage pump, and valve five is located upstream of the single-stage pump, and valve six is ​​located downstream of the single-stage pump.

5. A photoresist self-circulation system according to claim 1, characterized in that: The filter is located downstream of the single-stage pump.

6. A photoresist self-circulation system according to claim 5, characterized in that: The rehydration tank, mini tank, unipolar pump and filter are connected in sequence, and two routes are separated downstream of the filter. The first route is connected to the mini tank, and the second route flows into the nozzle through valve 2.

7. A photoresist self-circulation system according to claim 6, characterized in that: A valve seven is arranged on the first pipeline, and a valve one is arranged between the liquid replenishing tank and the mini tank.

8. A photoresist self-circulation method, characterized in that: The photoresist self-circulation system according to any one of claims 1 to 4 comprises the following steps: S1: Determine whether the photoresist static time is greater than or equal to the set time T; if so, execute S2; if not, execute S1; S2: Close valve 1, valve 2 and valve 5, and the single-stage pump squeezes the photoresist so that the photoresist enters the mini tank through valve 6; S3: The photoresist enters the filter from the mini tank through valve 4 and valve 3 for filtration. After the filtration is completed, it enters the mini tank again; S4: Determine whether the number of cycles n is greater than or equal to the set number of cycles N; if so, open valve two, and the single-stage pump discharges the photoresist, and then return to step S1; if not, close valve four and valve six, open valve five, and the photoresist enters the single-stage pump from the mini tank through valve five, and then return to step S1.

9. A photoresist self-circulation method, characterized in that: The photoresist self-circulation system according to any one of claims 1, 5-7 comprises the following steps: S1: Determine whether the photoresist static time is greater than or equal to the set time T; if so, execute S2; if not, execute S1; S2: Close valve 1 and valve 2, and the single-stage pump squeezes the photoresist, allowing the photoresist to enter the filter and then enter the mini tank through valve 7; S3: Determine whether the number of cycles n is greater than or equal to the set number of cycles N; if so, open valve 2, the single-stage pump discharges the photoresist, and return to step S1; if not, the photoresist enters the single-stage pump from the mini tank, and return to step S1.

10. A photoresist self-circulation method according to claim 8, characterized in that: N=24 / T, round up.

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