Developing method

Abstract

The invention discloses a developing method which comprises the following steps: providing a substrate, coating a photoresist on the substrate, and exposing a target area in the photoresist; spraying an auxiliary developing solution to the photoresist under the first flow, and forming an aqueous solution buffer area on the surface of the photoresist; spraying deionized water to the photoresist at a second flow to remove particles on the surface of the photoresist, wherein the first flow is smaller than the second flow; spraying an auxiliary developing solution to the photoresist at a third flow; and spraying the main developing solution to the photoresist at the fourth flow to remove the exposed photoresist. In the process of developing the exposed photoresist, the auxiliary developing solution is sprayed at a small flow rate to form the aqueous solution buffer region, then the deionized water is sprayed at a large flow rate to remove particles on the surface of the photoresist, and then the auxiliary developing solution and the main developing solution are sprayed in sequence to remove the exposed photoresist. Therefore, the annular defect caused by spraying of the photoresist by the deionized water with relatively large flow can be avoided.

Description

Technical Field

[0001] The present application relates to the technical field of semiconductor devices and integrated circuits, and particularly to a developing method. Background Art

[0002] In the semiconductor integrated circuit manufacturing industry, the lithography process usually includes processes such as photoresist coating, baking, exposure, development, etching, and measurement. The purpose is to transfer the pattern on the mask to the wafer or the thin film layer on the wafer to form an effective pattern window or functional pattern. As an important part of pattern transfer, the defects generated in the lithography process will affect the subsequent processes.

[0003] In the lithography process, defects are usually generated in the developing process, which affects the after develop inspection (ADI). In view of this, in the related art, in the developing process, high-flow deionized water, low-flow sub-developer and main-developer, and cleaning solution are usually used in sequence to perform the developing process and remove defects at the same time. However, when a photoresist with low hardness is used on some levels of the wafer, the photoresist on the wafer surface is easily subjected to stress impact of high-flow deionized water in the first step of the developing process, which is likely to form ring coin defects, thereby affecting the reliability and yield of the product. Summary of the Invention

[0004] The present application provides a developing method, which can solve the problem that the ring coin defects are easily formed on the photoresist due to the spraying of deionized water with a large flow rate in the developing method provided in the related art. The method includes:

[0005] Providing a substrate, on which a photoresist is coated, and a target area in the photoresist is exposed;

[0006] Spraying a sub-developer on the photoresist at a first flow rate to form an aqueous solution buffer zone on the surface of the photoresist;

[0007] Spraying deionized water on the photoresist at a second flow rate to remove the particles on the surface of the photoresist, where the first flow rate is less than the second flow rate;

[0008] Spraying a sub-developer on the photoresist at a third flow rate;

[0009] Spraying a main-developer on the photoresist at a fourth flow rate to remove the exposed photoresist.

[0010] In some embodiments, the third flow rate is less than the second flow rate.

[0011] In some embodiments, the fourth flow rate is less than the second flow rate.

[0012] In some embodiments, the value range of the first flow rate is from 100 ml / min to 300 ml / min.

[0013] In some embodiments, the value range of the second flow rate is from 300 ml / min to 500 ml / min.

[0014] In some embodiments, the value range of the third flow rate is from 100 ml / min to 300 ml / min.

[0015] In some embodiments, the value range of the fourth flow rate is from 200 ml / min to 400 ml / min.

[0016] The technical solution of the present application has at least the following advantages:

[0017] During the development of the exposed photoresist, the auxiliary developer is first sprayed at a relatively small flow rate, and then deionized water is sprayed at a relatively large flow rate to remove the particles on the surface of the photoresist. Then, the auxiliary developer and the main developer are sprayed in sequence to remove the exposed photoresist. Since an aqueous solution buffer zone is formed on the surface of the photoresist by spraying the auxiliary developer at a relatively small flow rate before spraying the deionized water, it is possible to avoid the formation of annular defects caused by the spraying of deionized water with a relatively large flow rate, thereby improving the product reliability and yield to a certain extent. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 It is a flowchart of a development method provided by an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0020] The following will clearly and completely describe the technical solutions in the present application with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0021] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation to the present application. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0022] In the description of the present application, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", "coupled" shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and can also be the communication inside two elements. It can be a wireless connection or a wired connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0023] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0024] Referring to Figure 1 , which shows a flowchart of a developing method provided by an exemplary embodiment of the present application. As Figure 1 shown, the method includes:

[0025] Step S1: Provide a substrate coated with photoresist, and the target area in the photoresist is exposed.

[0026] Exemplarily, before step S1, the wafer can be placed on a spin coater, and photoresist is coated on the wafer by spin coating. Then the wafer is placed on an exposure machine, and exposure is performed through a mask plate so that the target area in the photoresist is exposed.

[0027] Step S2: Spray an auxiliary developer solution on the photoresist at a first flow rate to form an aqueous solution buffer zone on the surface of the photoresist.

[0028] Exemplarily, the wafer can be fixed on the wafer stage of the developing machine. While the wafer stage drives the wafer to rotate, an auxiliary developing solution is sprayed on the photoresist at a first flow rate, thereby forming an aqueous solution buffer zone on the surface of the photoresist. Among them, the value range of the first flow rate is from 100 milliliters per minute (mL / min) to 300 milliliters per minute (for example, it can be 250 milliliters per minute). The spraying of the auxiliary developing solution in this step is used to wet the wafer. It is necessary to ensure that the surface of the wafer can be cleaned and has a cleaning effect, and at the same time, it cannot damage the topography of the photoresist. Therefore, a relatively small flow rate (the first flow rate) is required.

[0029] Step S3, deionized water is sprayed on the photoresist at a second flow rate to remove particles on the surface of the photoresist, and the first flow rate is less than the second flow rate.

[0030] Exemplarily, after spraying the auxiliary developing solution, deionized water is sprayed on the photoresist at a relatively large flow rate (the second flow rate, which is greater than the first flow rate) to remove particles on the surface of the photoresist. Among them, the value range of the second flow rate is from 350 milliliters per minute to 450 milliliters per minute (for example, it can be 400 milliliters per minute).

[0031] Step S4, an auxiliary developing solution is sprayed on the photoresist at a third flow rate.

[0032] Exemplarily, after spraying deionized water, an auxiliary developing solution is sprayed on the photoresist at a third flow rate. Among them, the third flow rate can be less than the second flow rate, and the value range of the third flow rate is from 100 milliliters per minute to 300 milliliters per minute (for example, it can be 250 milliliters per minute). It should be noted that the purpose of spraying the auxiliary developing solution in Step S2 and Step S4 is to enable better reaction with the photoresist after spraying the main developing solution in subsequent Step S5.

[0033] Step S5, a main developing solution is sprayed on the photoresist at a fourth flow rate to remove the exposed photoresist.

[0034] Among them, the chemicals used in the main developing solution and the auxiliary developing solution are the same. The duration of Step S5 is greater than the durations of Step S2 and Step S4.

[0035] Exemplarily, after spraying the auxiliary developing solution, a main developing solution is sprayed on the photoresist at a fourth flow rate. The main developing solution can dissolve the exposed photoresist, thereby removing the exposed photoresist. Among them, the fourth flow rate is less than the second flow rate, and the value range of the fourth flow rate is from 200 milliliters per minute to 400 milliliters per minute (for example, it can be 300 milliliters per minute).

[0036] In summary, in the embodiment of the present application, during the development of the photoresist after exposure, the auxiliary developer is first sprayed at a relatively small flow rate, and then deionized water is sprayed at a relatively large flow rate to remove the particles on the surface of the photoresist. Then, the auxiliary developer and the main developer are sequentially sprayed to remove the exposed photoresist. Since the auxiliary developer is sprayed at a relatively small flow rate before spraying deionized water to form an aqueous solution buffer zone on the surface of the photoresist, it is possible to avoid the annular defects formed by the spraying of deionized water with a relatively large flow rate on the photoresist, thereby improving the product reliability and yield to a certain extent.

[0037] Obviously, the above embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom are still within the protection scope of the present application.

Claims

1. A developing method, characterized in that: include: Providing a substrate, on which a photoresist is coated, and a target area in the photoresist is exposed; spraying an auxiliary developer on the photoresist at a first flow rate to form an aqueous solution buffer zone on the photoresist surface; Spraying deionized water on the photoresist at a second flow rate to remove particles on the surface of the photoresist, wherein the first flow rate is less than the second flow rate; spraying an auxiliary developer on the photoresist at a third flow rate; The main developer is sprayed on the photoresist at a fourth flow rate to remove the exposed photoresist.

2. The method according to claim 1, characterized in that The third flow rate is smaller than the second flow rate.

3. The method according to claim 2, characterized in that The fourth flow rate is smaller than the second flow rate.

4. The method according to any one of claims 1 to 3, characterized in that: The first flow rate has a value range of 100 ml / min to 300 ml / min.

5. The method according to claim 4, characterized in that The second flow rate has a value range of 300 ml / min to 500 ml / min.

6. The method according to claim 5, characterized in that The third flow rate ranges from 100 ml / min to 300 ml / min.

7. The method according to claim 6, characterized in that The fourth flow rate has a value range of 200 ml / min to 400 ml / min.

Images