Method for improving static electricity on photomask surface

Abstract

The present application provides a method for improving static electricity on the surface of a photomask, which relates to the field of photomasks, and the steps are as follows: subjecting the photomask to high-temperature baking and / or plasma surface treatment; wherein the temperature of the high-temperature baking is 80-200°C, and the plasma surface treatment uses a fluorine-containing gas. By removing static electricity from the surface of the photomask by high-temperature baking, plasma surface treatment, or high-temperature baking plus plasma surface treatment, the static electricity on the surface of the photomask can be effectively removed, so that after the photoresist removal step is completed, the photomask can be measured by CD-SEM without waiting for a long time.

Description

Technical Field

[0001] The present application relates to the field of photomasks, and in particular to a method for improving static electricity on the surface of a photomask. Background Art

[0002] After the photoresist is removed from the photomask, static electricity will exist on the surface, which will cause the CD-SEM measurement to not be carried out immediately and accurately. It is necessary to wait for the static electricity to dissipate naturally before accurate measurement can be carried out. The time for the static electricity on the photomask surface to dissipate is about one week, so the waiting time is relatively long.

[0003] Therefore, a method for treating static electricity on the surface of a photomask is needed, which can quickly eliminate static electricity on the surface of the photomask, so that the photomask can be measured by CD-SEM without waiting for a long time after the photoresist removal step is completed. Summary of the invention

[0004] In view of this, the embodiments of this specification provide a method for improving static electricity on the surface of a photomask, which can quickly eliminate static electricity on the surface of the photomask, so that the photomask can be measured by CD-SEM without waiting for a long time after completing the photoresist removal step.

[0005] The embodiments of this specification provide the following technical solutions:

[0006] The embodiment of this specification provides a method for improving static electricity on the surface of a photomask, and the steps are as follows:

[0007] subjecting the photomask to high temperature baking and / or plasma surface treatment;

[0008] The high temperature baking temperature is 80-200°C, and the plasma surface treatment uses fluorine-containing gas.

[0009] Through the above technical solution, the static electricity on the surface of the photomask is removed by high temperature baking, plasma surface treatment or high temperature baking plus plasma surface treatment, which can effectively remove the static electricity on the surface of the photomask, so that the photomask can be measured by CD-SEM without waiting for a long time after completing the photoresist removal step.

[0010] Preferably, the method specifically comprises the following steps:

[0011] S1, placing the photomask in a dust-free environment;

[0012] S2, high temperature baking of the photomask;

[0013] S3, subjecting the photomask that has been baked at high temperature to ultraviolet irradiation;

[0014] The high-temperature baking time is 6-15 minutes, the ultraviolet irradiation time is 6-15 minutes, and the wavelength range of the ultraviolet irradiation is 160-180nm.

[0015] Through the above technical solution, a combined method is used to remove static electricity, which is more effective than a single method, and the time required for a single step is also effectively shortened.

[0016] Preferably, step S3 further includes step S4:

[0017] The photomask that has been irradiated with ultraviolet rays is subjected to plasma surface treatment, wherein the plasma surface treatment time is 10-20 minutes.

[0018] Preferably, the high temperature baking temperature is 100-200°C.

[0019] Preferably, the high temperature baking temperature is 140-160°C.

[0020] Preferably, the high temperature baking time is 8-12 minutes.

[0021] Preferably, the wavelength of the ultraviolet radiation is in the range of 170-175 nm.

[0022] Preferably, the ultraviolet irradiation time is 8-12 minutes.

[0023] Preferably, high temperature baking is used to eliminate static electricity from the photomask, wherein the temperature of the high temperature baking is 140-160° C. and the time of the high temperature baking is 8-12 minutes.

[0024] Preferably, the static electricity of the photomask is eliminated by plasma surface treatment, wherein the plasma surface treatment time is 25-35 minutes.

[0025] Compared with the prior art, the beneficial effects that can be achieved by at least one of the above technical solutions adopted in the embodiments of this specification include at least:

[0026] By removing static electricity from the photomask surface by high temperature baking, plasma surface treatment or high temperature baking plus plasma surface treatment, the static electricity on the photomask surface can be effectively removed, so that the photomask can be measured by CD-SEM without waiting for a long time after completing the photoresist removal step. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0028] Figure 1 It is a flow chart of a photomask surface electrostatic treatment method in the present application;

[0029] Figure 2 It is a flow chart of a method for electrostatic treatment of a photomask surface in Embodiment 1 of the present application;

[0030] Figure 3 It is a flow chart of a photomask surface electrostatic treatment method in Embodiment 2 of the present application;

[0031] Figure 4 This is a flow chart of a method for electrostatic treatment of the surface of a photomask in Example 3 of the present application. DETAILED DESCRIPTION

[0032] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0033] The following describes the implementation methods of the present application through specific examples, and those skilled in the art can easily understand other advantages and effects of the present application from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The present application can also be implemented or applied through other different specific implementation methods, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present application. It should be noted that, in the absence of conflict, the following embodiments and the features in the embodiments can be combined with each other. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0034] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on the present application, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number and aspect described herein can be used to implement the device and / or practice the method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this device and / or practice this method.

[0035] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present application. The drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0036] Additionally, in the following description, specific details are provided to facilitate a thorough understanding of the examples. However, it will be understood by those skilled in the art that the examples can be practiced without these specific details.

[0037] After the photoresist is removed from the photomask, static electricity will exist on the surface, which will cause the CD-SEM measurement to not be carried out immediately and accurately. It is necessary to wait for the static electricity to dissipate naturally before accurate measurement can be carried out. The time for the static electricity on the photomask surface to dissipate is about one week, so the waiting time is relatively long.

[0038] In view of this, the inventors have proposed a method for electrostatic treatment of the photomask surface through in-depth research and exploration of electrostatic removal methods and analysis of the characteristics of photomasks. The method can quickly eliminate the static electricity phenomenon on the surface of the photomask, so that the photomask can be measured by CD-SEM after completing the photoresist removal step without waiting for a long time.

[0039] The technical solutions provided by various embodiments of the present application are described below in conjunction with the accompanying drawings.

[0040] like Figure 1 As shown, the embodiment of this specification provides a method for improving static electricity on the surface of a photomask, and the steps are as follows:

[0041] The photomask is subjected to high temperature baking and / or plasma surface treatment.

[0042] The high temperature baking temperature is 80-200°C, and the plasma surface treatment uses fluorine-containing gas.

[0043] By removing static electricity from the photomask surface by high temperature baking, plasma surface treatment or high temperature baking plus plasma surface treatment, the static electricity on the photomask surface can be effectively removed, so that the photomask can be measured by CD-SEM without waiting for a long time after completing the photoresist removal step.

[0044] Embodiment 1

[0045] like Figure 2 As shown, the first embodiment of this specification provides a method for improving static electricity on the surface of a photomask, and the steps are as follows:

[0046] Step S100, high temperature baking is used to eliminate static electricity from the photomask.

[0047] The high temperature baking temperature is 80-200°C, and the high temperature baking time is 8-12 minutes.

[0048] Preferably, the high temperature baking temperature is 140-160° C., and the high temperature baking time is 10 minutes.

[0049] By high-temperature baking under the above conditions, more than 80% of the static electricity on the surface of the photomask can be removed. Therefore, on the premise of eliminating more than 80% of the static electricity phenomenon, the photomask can be directly put into the CD-SEM measurement step, reducing additional waiting time and improving production efficiency.

[0050] Embodiment 2

[0051] like Figure 3 As shown, the second embodiment of this specification provides a method for improving static electricity on the surface of a photomask, and the steps are as follows:

[0052] Step S101, using plasma surface treatment to eliminate static electricity on the photomask.

[0053] Among them, the plasma surface treatment time is 25-35 minutes.

[0054] Preferably, the plasma surface treatment time is 30 minutes.

[0055] Among them, in the active atmosphere, the free radicals in the plasma will fully react with the ionic components that cause static electricity on the surface of the photomask. By reducing or removing the ionic components that cause static electricity, the purpose of reducing static electricity on the surface of the photomask is achieved. As a result, after the photoresist is removed, the photomask can be directly put into the CD-SEM measurement step, reducing additional waiting time and improving production efficiency.

[0056] Embodiment 3

[0057] like Figure 4 As shown, the third embodiment of this specification provides a method for improving static electricity on the surface of a photomask, and the steps are as follows:

[0058] S1, place the photomask in a dust-free environment.

[0059] S2, baking the photomask at high temperature.

[0060] S3, irradiating the photomask after high temperature baking with ultraviolet rays.

[0061] The high temperature baking temperature is 80-200° C., the high temperature baking time is 6-15 minutes, the ultraviolet irradiation time is 6-15 minutes, and the wavelength range of the ultraviolet irradiation is 160-180 nm.

[0062] Preferably, the high temperature baking temperature is 100-200°C.

[0063] Furthermore, the temperature of high temperature baking is 140-160°C.

[0064] Preferably, the wavelength of the ultraviolet radiation is in the range of 170-175 nm.

[0065] Furthermore, the ultraviolet irradiation time is 8-12 minutes.

[0066] The method further comprises step S4, which is arranged after step S3:

[0067] S4, performing plasma surface treatment on the photomask after ultraviolet irradiation.

[0068] The plasma surface treatment time is 10-20 minutes.

[0069] By combining high temperature baking, ultraviolet irradiation, and plasma surface treatment processes, on the one hand, the time required for a single step can be effectively reduced. On the other hand, the static reduction ratio on the photomask surface can be effectively reduced by combining the static reduction methods, which is 10%-20% better than the static reduction effect of high temperature baking or plasma surface treatment alone.

[0070] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0071] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A method for improving static electricity on the surface of a photomask, characterized in that: Here are the steps: After the photomask has completed the photoresist removal step, the photomask is subjected to high temperature baking and / or plasma surface treatment to reduce the waiting time for CD-SEM measurement; The high temperature baking temperature is 80-200°C, and the plasma surface treatment uses fluorine-containing gas.

2. The method for improving static electricity on the surface of a photomask according to claim 1, characterized in that: The specific steps include: S1, placing the photomask in a dust-free environment; S2, high temperature baking of the photomask; S3, subjecting the photomask that has been baked at high temperature to ultraviolet irradiation; The high-temperature baking time is 6-15 minutes, the ultraviolet irradiation time is 6-15 minutes, and the wavelength range of the ultraviolet irradiation is 160-180nm.

3. The method for improving static electricity on the surface of a photomask according to claim 2, characterized in that: Step S3 further includes step S4: The photomask that has been irradiated with ultraviolet rays is subjected to plasma surface treatment, wherein the plasma surface treatment time is 10-20 minutes.

4. The method for improving static electricity on the surface of a photomask according to claim 2, characterized in that: The high temperature baking temperature is 100-200°C.

5. The method for improving static electricity on the surface of a photomask according to claim 4, characterized in that: The high temperature baking temperature is 140-160°C.

6. The method for improving static electricity on the surface of a photomask according to claim 2, characterized in that: The high temperature baking time is 8-12 minutes.

7. The method for improving static electricity on the surface of a photomask according to claim 2, characterized in that: The wavelength of the ultraviolet radiation is in the range of 170-175 nm.

8. The method for improving static electricity on the surface of a photomask according to claim 2, characterized in that: The ultraviolet irradiation time is 8-12 minutes.

9. The method for improving static electricity on the surface of a photomask according to claim 1, characterized in that: The photomask is subjected to static elimination by high temperature baking, wherein the temperature of the high temperature baking is 140-160° C. and the time of the high temperature baking is 8-12 minutes.

10. The method for improving static electricity on the surface of a photomask according to claim 1, characterized in that: Plasma surface treatment is used to eliminate static electricity from the photomask, wherein the plasma surface treatment time is 25-35 minutes.

Images