Lithographic exposure system and method for the same

Abstract

A lithography exposure system and a method for the same. The method for the lithography exposure system includes forming a photocatalyst material on an inner wall of an exposure chamber of an exposure apparatus. An integrated circuit wafer is transported into the exposure chamber. A photoresist liquid is applied on the integrated circuit wafer. An exposure process is performed on the photoresist liquid. A reaction of a vapor of the photoresist liquid is catalyzed by the photocatalyst material.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a lithography exposure system and a method for the same. BACKGROUND

[0002] The semiconductor integrated circuit (IC) industry has experienced rapid growth. ICs have evolved from a technology that provided a limited number of logic gates and flip-flops to a highly sophisticated state-of-the-art technology that provides millions of transistors with sub micron feature size. In general, the IC industry has experienced a trend of increasing functionality and speed while decreasing cost and power consumption. This evolution would not have been possible without the development of semiconductor processing technology, including the development of lithography technology. SUMMARY

[0003] According to some embodiments of the present disclosure, a method for a lithography exposure system includes transferring an IC wafer into an exposure chamber. A photoresist liquid is coated on the IC wafer, wherein a portion of the photoresist liquid is evaporated to generate a vapor. An exposure process is performed on the photoresist liquid, and the vapor is catalyzed to react by a photocatalyst material.

[0004] According to some embodiments of the present disclosure, a method for a lithography exposure system includes forming a photocatalyst material on an inner wall of an exposure chamber of an exposure system. An IC wafer is transferred into the exposure chamber. A photoresist liquid is coated on the IC wafer. After the photocatalyst material is formed, an exposure process is performed on the photoresist liquid.

[0005] According to some embodiments of the present disclosure, a lithography exposure system includes an exposure chamber, a wafer stage, a photocatalyst material layer, an optical system, and a vacuum device. The exposure chamber has an inner wall. The photocatalyst material layer is formed on the inner wall. The optical system is connected to the exposure chamber to perform an exposure process. The vacuum device is connected to the exposure chamber. BRIEF DESCRIPTION OF DRAWINGS

[0006] The aspects of the disclosure will best be understood from the following detailed description when read in conjunction with the accompanying drawings. It is noted that, according to common practice, the various features are not necessarily drawn to scale. Indeed, the dimensions of the various features can be arbitrarily increased or decreased for clarity. Further, it should be understood that the drawings are not intended to limit the disclosure in any way.

[0007] Figure 1 A schematic diagram of a lithography exposure system according to some embodiments of the present disclosure;

[0008] Figure 2 A schematic diagram of a lithography exposure system according to some embodiments of the present disclosure;

[0009] Figure 3Schematic diagram of a lithography exposure system according to some embodiments of the present disclosure;

[0010] Figure 4 Schematic diagram of a lithography exposure system according to some embodiments of the present disclosure;

[0011] Figure 5 Schematic diagram of a lithography exposure system according to some embodiments of the present disclosure;

[0012] Figure 6 Schematic diagram of a lithography exposure system according to some embodiments of the present disclosure;

[0013] Figure 7 Schematic diagram of a lithography exposure system according to some embodiments of the present disclosure;

[0014] Figure 8 Schematic diagram of a lithography exposure system according to some embodiments of the present disclosure;

[0015] Figure 9 Schematic diagram of a lithography exposure system according to some embodiments of the present disclosure;

[0016] Figure 10 Schematic diagram of a lithography exposure system according to some embodiments of the present disclosure;

[0017] Figure 11 Schematic diagram of a lithography exposure system according to some embodiments of the present disclosure;

[0018] Figure 12 Planar schematic diagram of a photocatalytic material within a lithography exposure system according to some embodiments of the present disclosure;

[0019] Figure 13 Schematic diagram of a lithography exposure system according to some embodiments of the present disclosure;

[0020] Figure 14 Method flowchart for a lithography exposure system according to some embodiments of the present disclosure;

[0021] Figure 15 Method flowchart for a lithography exposure system according to some embodiments of the present disclosure.

[0022]

Symbol explanation

[0023] 100a: lithography exposure system

[0024] 100b: lithography exposure system

[0025] 100c: lithography exposure system

[0026] 100d: lithography exposure system

[0027] 100e: lithography exposure system

[0028] 100f: lithography exposure system

[0029] 100g: lithography exposure system

[0030] 100h: lithography exposure system

[0031] 100i: lithography exposure system

[0032] 100j: lithography exposure system

[0033] 100k: lithography exposure system

[0034] 100m: lithography exposure system

[0035] 102: exposure chamber

[0036] 102a: opening

[0037] 102b: opening

[0038] 102d: opening

[0039] 104: wafer stage

[0040] 106: evacuation device

[0041] 108: optical system

[0042] 109: light source

[0043] 110: integrated circuit wafer

[0044] 112: photocatalytic material

[0045] 112a: pores

[0046] 113: vapor

[0047] 115: particulates

[0048] 300: method

[0049] 302: operation

[0050] 304: operation

[0051] 306: operation

[0052] 308: operation

[0053] 310: operation

[0054] 400: method

[0055] 402: operation

[0056] 404: OPERATION

[0057] 406: OPERATION

[0058] 408: OPERATION

[0059] 410: OPERATION

[0060] 412: OPERATION DETAILED DESCRIPTION

[0061] The following disclosure provides many different embodiments, or examples, for implementing different characteristics of the provided subject matter. Specific examples of elements and arrangements are described below to simplify the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the making of a first feature on top of or over a second feature in the following description can include embodiments in which the first feature is formed directly in contact with the second feature, and can also include embodiments in which one or more additional features can be formed between the first and second features such that the first and second features can not be directly in contact. Additionally, the present disclosure can repeat use of certain elements or names thereof in the various examples. This repetition is for the sake of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and / or configurations discussed.

[0062] In addition, spatially relative terms, such as "beneath", "below", "lower", "above", "upper" and the like, can be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. The devices can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

[0063] The advanced lithography processes, methods, and materials described in the present disclosure can be used in many applications, including fin-type field effect transistors (FinFETs). For example, fins can be patterned to produce relatively close spacing between features suitable for use in the following disclosure. In addition, spacers used to form FinFET fins can be processed according to the following disclosure.

[0064] Figure 1FIG. 1 is a schematic diagram of a lithography exposure system 100a according to some embodiments of the present disclosure. In some embodiments, the lithography exposure system 100a includes an exposure chamber 102 of an exposure apparatus, a wafer stage 104, a pumping apparatus 106, and an optical system 108. A photocatalytic material 112 is formed on the inner walls of the exposure chamber 102. Before an exposure process is performed, an integrated circuit wafer 110 is gripped by a robot (not shown in the figure) and is transferred through an opening 102a of the exposure chamber 102 to the wafer stage 104. Then, a photoresist liquid is coated on the integrated circuit wafer 110 to cover the area to be patterned. In cooperation with a photomask, the optical system 108 performs an exposure process on the photoresist liquid / layer on the integrated circuit wafer 110, so as to copy the pattern on the photomask to the photoresist liquid / layer. After the exposure process, the integrated circuit wafer 110 is then gripped by the robot and is transferred through the opening 102a of the exposure chamber 102 to a subsequent development process step.

[0065] The lithography exposure system can also be referred to as a scanner, which is operable to perform a lithography exposure process with different radiation sources and exposure modes. In some embodiments, the lithography exposure system is an extreme ultraviolet (EUV) lithography system designed to expose a resist layer to EUV light. The resist layer is a material sensitive to EUV light. The EUV lithography system uses a semiconductor device to generate EUV light, such as EUV light having a wavelength ranging between about 1 nm and about 100 nm.

[0066] In some embodiments, the optical system 108 is connected to an opening 102d of the exposure chamber 102 and performs an exposure process through the opening 102d. When performing the exposure process, the wafer stage 104 continuously moves the integrated circuit wafer 110 so that each area on the wafer that needs to be exposed can be performed.

[0067] In some embodiments, the material of the inner walls of the exposure chamber 102 is stainless steel or other suitable metal. In some embodiments, when the coated photoresist liquid contains benzene ring (e.g., toluene, xylene, or the like) solvents, the benzene ring solvents with conjugated double bonds are prone to be adsorbed on the inner walls of the stainless steel in the form of carbon-containing deposits after volatilizing into vapor. When the carbon deposits fall off, they become particle or dust contaminants of the lithography exposure process. When too many carbon-containing deposits fall off, they become one of the reasons affecting the yield and output of the integrated circuit wafer 110.

[0068] In some embodiments, the photoresist liquid is coated on the wafer using a photoresist coater. The main mechanism of the photoresist coater is a rotating main system that uses a vacuum chuck to hold the wafer and spin the wafer to drop the photoresist liquid on the wafer. The rotating system provides a proper vacuum level to hold the wafer placed on it. After the wafer is spun by the rotating system, the photoresist liquid on the wafer surface moves to the periphery of the wafer due to the centrifugal force, and finally forms a photoresist layer with a very uniform thickness. During the coating process, the excess photoresist liquid will be collected in the drip funnel, which can be easily cleaned. The main components of the photoresist liquid include resin, photosensitizer, and solvent. The main function of the resin is to enable the photoresist to form a protective film sufficient for etching or ion implantation. The photosensitizer is originally an insoluble substance, but after light irradiation, its solubility increases. The solvent functions to make the photoresist liquid, facilitating subsequent photoresist coating processes. The aforementioned carbon-containing deposits mainly come from the benzene ring-containing solvents in the photoresist liquid. After the photoresist coating process, the soft baking process follows. The main purpose of soft baking is to remove the residual solvent inside the photoresist after coating. When the benzene ring-containing solvent is baked, it volatilizes into the exposure chamber.

[0069] In some embodiments, the photocatalytic material 112 in the exposure chamber 102 can be used to catalyze the photoresist liquid vapor to generate a redox reaction at a suitable temperature, such as catalyzing the photoresist liquid vapor containing benzene ring solvents to generate a redox to produce carbon dioxide (CO2) and water vapor (H2O), rather than being adsorbed on the inner wall of the stainless steel to generate carbon-containing deposits. The pumping device 106, such as a vacuum pump, is connected to the opening 102b of the exposure chamber 102, thereby removing the process gas (such as carbon dioxide (CO2), water vapor (H2O), or photoresist liquid vapor) in the exposure chamber 102. Therefore, the carbon-containing deposits on the inner wall of the exposure chamber 102 are reduced, which reduces the source of particulate or dust pollutants, thereby improving the yield and output of the integrated circuit wafer 110. Other non-carbon-containing organic particulate or dust pollutants (Particulate Matter) also have a self-decomposition mechanism with the photocatalytic material 112 and suitable heating.

[0070] In some embodiments, the photocatalyst can be a semiconductor crystalline material. After being irradiated by light, the electrons in the material jump out and leave a positively charged hole with strong oxidizing ability. These electrons and holes are chemically referred to as "electron-hole pairs". When the electrons meet the oxygen molecules in the air, super oxygen molecules with strong reactivity are generated. When the holes meet the water vapor in the air, the electrons of the hydroxyl radical are lost, and at this time, the hydroxyl radical becomes unstable. Once the unstable hydroxyl radical encounters an external organic matter, it tends to be stable by stealing the electrons of the other party. In this way, the organic matter is oxidized into water and carbon dioxide.

[0071] In some embodiments, the photocatalyst material 112 comprises titanium dioxide (TiO2), gallium phosphide (GaP), gallium arsenide (GaAs), zinc oxide (ZnO), tin dioxide (SnO2), cadmium sulfide (CdS), any combination thereof, or the like. A plurality of holes 112a can also be formed on the photocatalyst material 112 to increase the surface area for catalysis. In some embodiments, a plurality of nano-sized particles can also be formed on the photocatalyst material 112 to increase the surface area for catalysis. Photocatalyst refers to a catalyst that is capable of accelerating photochemical reactions, a phenomenon known as photocatalysis. Photons have energy, and when they strike certain materials (such as semiconductors), the energy is absorbed by an electron, which jumps from a valence band to a conduction band, leaving a positively charged hole in its place, i.e., a photo-generated electron and a photo-generated hole. Because the electron and hole have strong reducing and oxidizing properties, respectively, they can cause redox reactions on the surface of the semiconductor, thereby converting light energy into chemical energy. These materials are known as photocatalysts or photo-catalysts. On the surface of the photocatalyst particles, oxygen combines with the electrons to form oxygen ions, and water molecules are oxidized by the holes to form hydroxyl radicals, both of which are extremely unstable and can combine with organic matter to degrade it back into carbon dioxide and water.

[0072] In some embodiments, the initiation energy for the photocatalyst material to initiate the photochemical reaction can come from the light entering the exposure chamber 102 when the optical system 108 performs the exposure step.

[0073] Reference is made to Figure 2 which is a schematic diagram of a lithography exposure system 100b according to some embodiments of the present disclosure. Figure 2 The illustrated embodiments are similar to Figure 1 The difference between the illustrated embodiments is that in some embodiments, because of the shape of the exposure chamber 102 and the influence of the process conditions, benzene ring solvents are more likely to reach the inner wall of the upper half of the exposure chamber 102. In this case, the photocatalyst material 112 can be selected to be formed only on the inner wall of the upper half of the exposure chamber 102, rather than on all the inner walls of the exposure chamber. As for other related structural and process details, they are the same as Figure 1 the illustrated embodiments, and thus are not repeated here.

[0074] Reference is made to Figure 3 which is a schematic diagram of a lithography exposure system 100c according to some embodiments of the present disclosure. Figure 3 The illustrated embodiments are similar to Figure 1The illustrated embodiments differ in that, in some embodiments, due to the shape of the exposure chamber 102 and the effects of process conditions, benzene ring solvents are more easily accessible to the lower inner wall of the exposure chamber 102. In this case, the photocatalytic material 112 can be selectively formed only on the lower inner wall of the exposure chamber 102, rather than on all of the inner walls of the exposure chamber. As for other related structural and process details, they are the same as those of the lithography exposure system 100a according to some embodiments of the present disclosure. Figure 1 The illustrated embodiments are the same, and thus are not repeated here.

[0075] Please refer to Figure 4 which is a schematic diagram of a lithography exposure system 100d according to some embodiments of the present disclosure. Figure 4 The illustrated embodiments are the same as those of the lithography exposure system 100a according to some embodiments of the present disclosure, and thus are not repeated here. Figure 1 The illustrated embodiments differ in that, in some embodiments, due to the shape of the exposure chamber 102 and the effects of process conditions, benzene ring solvents are more easily accessible to the upper and lower inner walls of the exposure chamber 102. In this case, the photocatalytic material 112 can be selectively formed only on the upper and lower inner walls of the exposure chamber 102, rather than on all of the inner walls of the exposure chamber. As for other related structural and process details, they are the same as those of the lithography exposure system 100a according to some embodiments of the present disclosure. Figure 1 The illustrated embodiments are the same, and thus are not repeated here.

[0076] Please refer to Figure 5 which is a schematic diagram of a lithography exposure system 100e according to some embodiments of the present disclosure. Figure 5 The illustrated embodiments are the same as those of the lithography exposure system 100a according to some embodiments of the present disclosure, and thus are not repeated here. Figure 1 The illustrated embodiments differ in that, in some embodiments, due to the shape of the exposure chamber 102 and the effects of process conditions, benzene ring solvents are more easily accessible to the upper inner wall of the exposure chamber 102. In this case, the photocatalytic material 112 can be selectively formed only on the upper inner wall of the exposure chamber 102, rather than on all of the inner walls of the exposure chamber. As for other related structural and process details, they are the same as those of the lithography exposure system 100a according to some embodiments of the present disclosure. Figure 1 The illustrated embodiments are the same, and thus are not repeated here.

[0077] Please refer to Figure 6 which is a schematic diagram of a lithography exposure system 100f according to some embodiments of the present disclosure. Figure 6 The illustrated embodiments are the same as those of the lithography exposure system 100a according to some embodiments of the present disclosure, and thus are not repeated here. Figure 1 The illustrated embodiments differ in that, in some embodiments, due to the shape of the exposure chamber 102 and the effects of process conditions, benzene ring solvents are more easily accessible to the lower inner wall of the exposure chamber 102. In this case, the photocatalytic material 112 can be selectively formed only on the lower inner wall of the exposure chamber 102, rather than on all of the inner walls of the exposure chamber. As for other related structural and process details, they are the same as those of the lithography exposure system 100a according to some embodiments of the present disclosure. Figure 1 The illustrated embodiments are the same, and thus are not repeated here.

[0078] Please refer toFigure 7 which is a schematic view of a lithography exposure system 100g according to some embodiments of the present disclosure. Figure 7 The illustrated embodiment is similar to Figure 1 The difference between the illustrated embodiment and the illustrated embodiment is that in some embodiments, due to the shape of the exposure chamber 102 and the effect of process conditions, the benzene ring type solvent is more likely to reach the left side inner wall of the exposure chamber 102. In this case, the photocatalytic material 112 can be selectively formed only on the left side inner wall of the exposure chamber 102. As for other related structural and process details, they are the same as those of Figure 1 The illustrated embodiment is similar to

[0079] Please refer to Figure 8 which is a schematic view of a lithography exposure system 100h according to some embodiments of the present disclosure. Figure 8 The illustrated embodiment is similar to Figure 1 The difference between the illustrated embodiment and the illustrated embodiment is that in some embodiments, due to the shape of the exposure chamber 102 and the effect of process conditions, the benzene ring type solvent is more likely to reach the left side inner wall of the exposure chamber 102. In this case, the photocatalytic material 112 can be selectively formed only on the left side inner wall of the exposure chamber 102. As for other related structural and process details, they are the same as those of Figure 1 The illustrated embodiment is similar to

[0080] Please refer to Figure 9 which is a schematic view of a lithography exposure system 100i according to some embodiments of the present disclosure. Figure 9 The illustrated embodiment is similar to Figure 1 The difference between the illustrated embodiment and the illustrated embodiment is that in some embodiments, due to the shape of the exposure chamber 102 and the effect of process conditions, the benzene ring type solvent is more likely to reach the right side inner wall of the exposure chamber 102. In this case, the photocatalytic material 112 can be selectively formed only on the right side inner wall of the exposure chamber 102. As for other related structural and process details, they are the same as those of Figure 1 The illustrated embodiment is similar to

[0081] Please refer to Figure 10 which is a schematic view of a lithography exposure system 100j according to some embodiments of the present disclosure. Figure 10 The illustrated embodiment is similar to Figure 1 The difference between the illustrated embodiment and the illustrated embodiment is that in some embodiments, due to the shape of the exposure chamber 102 and the effect of process conditions, the benzene ring type solvent is more likely to reach the left half inner wall of the exposure chamber 102. The photocatalytic material 112 can be selectively formed only on the left half inner wall of the exposure chamber 102, rather than all the inner walls of the exposure chamber. As for other related structural and process details, they are the same as those ofFigure 1 The illustrated embodiments are the same, and thus repeated description is omitted.

[0082] Reference is made to Figure 11 which is a schematic view of a lithography exposure system 100k according to some embodiments of the present disclosure. Figure 11 The illustrated embodiments are the same, and thus repeated description is omitted. Figure 1 The illustrated embodiments differ in that, in some embodiments, because of the shape of the exposure chamber 102 and the effect of the process conditions, benzene ring solvents are more likely to reach the inner wall of the right half of the exposure chamber 102. The photocatalytic material 112 can be selected to be formed only on the inner wall of the right half of the exposure chamber 102. As for other related structural and process details, they are the same as those of Figure 1 The illustrated embodiments are the same, and thus repeated description is omitted.

[0083] Reference is made to Figure 12 which is a plan view of a photocatalytic material in a lithography exposure system according to some embodiments of the present disclosure. In some embodiments, the aperture of the plurality of holes 112a included in the photocatalytic material 112 can be within a predetermined range to facilitate the generation of redox reactions by the vapor of the catalytic photoresist liquid.

[0084] Reference is made to Figure 13 which is a schematic view of a lithography exposure system 100m according to some embodiments of the present disclosure. Figure 13 The illustrated embodiments are the same, and thus repeated description is omitted. Figure 1 The illustrated embodiments differ in that, in some embodiments, a light source 109 can be provided in the exposure chamber 102, so as to irradiate the photocatalytic material of the entire inner wall or part of the inner wall of the exposure chamber to initiate photochemical reactions during non-exposure steps. The light source 109 is a light source independent of the optical system 108. As for other related structural and process details, they are the same as those of Figure 1 The illustrated embodiments are the same, and thus repeated description is omitted.

[0085] Reference is made to Figure 14FIG. 3 is a flowchart illustrating a method 300 for a lithography exposure system, according to some embodiments of the present disclosure. In operation 302, a photocatalyst material (e.g., the photocatalyst material 112 described above) is formed on the inner walls of an exposure chamber (e.g., the exposure chamber 102 described above) of an exposure apparatus. In some embodiments, the photocatalyst material can be formed on the inner walls of the exposure chamber during the manufacture of the exposure apparatus. In some embodiments, the photocatalyst material can be formed on the inner walls of the exposure chamber after the exposure apparatus is manufactured, using a suitable method (e.g., sputtering or evaporation). In some embodiments, the photocatalyst material includes nano-sized powder particles. In some embodiments, the photocatalyst material can be formed on all or part of the inner walls of the exposure chamber. In some embodiments, the photocatalyst material includes titanium dioxide (Ti02), gallium phosphide (GaP), gallium arsenide (GaAs), zinc oxide (ZnO), tin dioxide (Sn02), cadmium sulfide (CdS), any combination thereof, or the like. In operation 304, an integrated circuit wafer (e.g., the integrated circuit wafer 110 described above) is transferred into a wafer carrier (e.g., the wafer carrier 104 described above) inside the exposure chamber. In operation 306, a photoresist liquid is coated on the integrated circuit wafer, for example, using a spin coating method to uniformly coat the photoresist liquid on the integrated circuit wafer, i.e., after the photoresist liquid is applied, the carrier that supports the integrated circuit wafer is accelerated to a desired spin speed and photoresist thickness. In operation 308, an exposure process is performed on the photoresist liquid / layer using an optical system (e.g., the optical system 108 described above). The integrated circuit wafer can then be removed from the exposure chamber for subsequent processes such as development, hard baking, and etching of the photoresist layer. In operation 310, the photocatalyst material on the inner walls of the exposure chamber catalyzes the production of oxidizing and reducing self-decomposition reactions of the photoresist liquid vapor by absorbing light energy during the exposure process, thereby reducing the generation of carbon-containing deposits and thus reducing the source of particulate or dust contaminants, which can improve the yield and output of the integrated circuit wafer. In some embodiments, operation 308 and operation 310 can be performed at least partially simultaneously. In some embodiments, the optical system 108 can be an EUV optical system. After the exposure process, the integrated circuit wafer can then be removed from the exposure chamber for subsequent processes such as development, hard baking, and etching of the photoresist layer.

[0086] Please refer to Figure 15FIG. 4 illustrates a flowchart of a method 400 for a lithography exposure system, according to some embodiments of the present disclosure. In operation 402, a photocatalyst material (e.g., the photocatalyst material 112 described above) is coated on the stainless steel inner walls of an exposure chamber (e.g., the exposure chamber 102 described above) of an exposure apparatus. In some embodiments, the photocatalyst material can be coated on the stainless steel inner walls of the exposure chamber when the exposure apparatus is manufactured. In other embodiments, the photocatalyst material can be coated on the stainless steel inner walls of the exposure chamber after the exposure apparatus is manufactured using a suitable method (e.g., sputtering or evaporation), without limitation. In other embodiments, the photocatalyst material can be coated on all or a portion of the inner walls of the exposure chamber, without limitation. In operation 404, an integrated circuit wafer (e.g., the integrated circuit wafer 110 described above) is transferred into a wafer stage (e.g., the wafer stage 104 described above) in the exposure chamber using a robot. In operation 406, a photoresist liquid containing a benzene ring solvent is coated on the integrated circuit wafer, for example, by using a spin coating method to uniformly coat the photoresist liquid on the areas of the integrated circuit wafer to be patterned. When the coated photoresist liquid contains a benzene ring solvent, such as toluene, xylene, etc., the benzene ring solvent with conjugated double bonds is easily adsorbed on the inner walls of the stainless steel in the form of carbon-containing deposits after the benzene ring solvent volatilizes into vapor. When the carbon-containing deposits are peeled off, they become particulate or dust contaminants of the lithography exposure process. In operation 408, an optical system (e.g., the optical system 108 described above) is used to perform an exposure process on the photoresist liquid. In operation 410, after the exposure process is performed, a light source (e.g., the light source 109 described above) is used to irradiate the photocatalyst material, causing the photocatalyst material to catalyze the photoresist vapor to generate a redox self-decomposition reaction, thereby reducing the generation of carbon-containing deposits and the source of particulate or dust contaminants, improving the yield and throughput of the integrated circuit wafer. In some embodiments, the light source used in operation 410 can be a light source independent of the optical system 108, so as to be used to irradiate the photocatalyst material coated on all or a portion of the inner walls of the exposure chamber to initiate a photochemical reaction during a non-exposure step. In operation 412, after the exposure process, an exhaust apparatus (e.g., the exhaust apparatus 106 described above) is used to remove process gases, such as carbon dioxide, water vapor, or photoresist vapor, from the exposure chamber. After the exposure process, the integrated circuit wafer can then be removed from the exposure chamber for subsequent processes such as development, hard baking, and etching of the photoresist layer.

[0087] Without intending to be limiting, some embodiments of the present disclosure provide many benefits to a lithography exposure system for integrated circuits and related processes. For example, some embodiments of the present disclosure form a photocatalyst material on the inner walls of an exposure chamber of a lithography exposure system, thereby providing a mechanism for self-decomposition of organic contaminants, effectively reducing the source of carbon-containing deposits or other organic particulate, dust contaminants, and thereby improving the yield and throughput of integrated circuit wafers.

[0088] According to some embodiments of the disclosure, a method for a lithography exposure system includes transferring an integrated circuit wafer into an exposure chamber. A photoresist liquid is applied to the integrated circuit wafer, wherein a portion of the photoresist liquid volatilizes to produce a vapor. An exposure process is performed on the photoresist liquid, and the vapor is catalyzed to react by a photocatalyst material. Catalyzing the vapor to react by the photocatalyst material causes the vapor to be converted to carbon dioxide and water. The exposure process is performed on the photoresist liquid at least partially simultaneously with catalyzing the vapor to react by the photocatalyst material. The photocatalyst material includes titanium dioxide, gallium phosphide, gallium arsenide, zinc oxide, tin dioxide, cadmium sulfide, or any combination thereof. The method further includes forming a plurality of pores in the photocatalyst material.

[0089] According to some embodiments of the disclosure, a method for a lithography exposure system includes forming a photocatalyst material on an inner wall of an exposure chamber of an exposure system. An integrated circuit wafer is transferred into the exposure chamber. A photoresist liquid is applied to the integrated circuit wafer. After forming the photocatalyst material, an exposure process is performed on the photoresist liquid. After performing the exposure process, the photocatalyst material is irradiated with a light source to cause the photocatalyst material to catalyze a vapor produced by the photoresist liquid to react. The exposure process causes the photocatalyst material to catalyze a vapor produced by the photoresist liquid to react.

[0090] According to some embodiments of the disclosure, a lithography exposure system includes an exposure chamber, a wafer stage, a photocatalyst material layer, an optical system, and a vacuuming device. The exposure chamber has an inner wall. The photocatalyst material layer is formed on the inner wall. The optical system is connected to the exposure chamber to perform an exposure process. The vacuuming device is connected to the exposure chamber. The photocatalyst material has a plurality of pores therein.

[0091] The foregoing outlines features of several embodiments so that a thorough comprehension of the present disclosure can be attained. Those skilled in the art should appreciate that they can readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and / or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they can make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.

Claims

1. A method for a lithography exposure system, characterized by, Comprising: transporting an integrated circuit wafer into an exposure chamber; applying a photoresist liquid on the integrated circuit wafer, wherein a portion of the photoresist liquid will evaporate to generate a vapor; performing an exposure process on the photoresist liquid, and catalyzing the vapor to react through a photocatalyst material; and forming a plurality of pores on the photocatalyst material.

2. The method of claim 1, wherein, Catalyzing the vapor to react through the photocatalyst material will cause the vapor to be converted into carbon dioxide and water.

3. The method of claim 1, wherein, Performing the exposure process on the photoresist liquid is at least partially simultaneous with catalyzing the vapor to react through the photocatalyst material.

4. The method of claim 1, wherein, The photocatalyst material comprises titanium dioxide, gallium phosphide, gallium arsenide, zinc oxide, tin dioxide, cadmium sulfide, or any combination thereof.

5. The method of claim 1, wherein, Irradiating the photocatalyst material with a light to perform the exposure process on the photoresist liquid catalyzes the vapor to decompose.

6. A method for a lithography exposure system, characterized by, Comprising: forming a photocatalyst material on an inner wall of an exposure chamber of an exposure apparatus; transporting an integrated circuit wafer into the exposure chamber; applying a photoresist liquid on the integrated circuit wafer; and performing an exposure process on the photoresist liquid after forming the photocatalyst material. Further comprising:

7. The method of claim 6, wherein, irradiating the photocatalyst material with a light source after performing the exposure process to cause the photocatalyst material to catalyze a vapor generated by the photoresist liquid to react. The exposure process causes the photocatalyst material to catalyze a vapor generated by the photoresist liquid to react.

8. The method of claim 6, wherein, Comprising:

9. A lithography exposure system, characterized by, an exposure chamber having an inner wall; a wafer stage located in the exposure chamber; a photocatalyst material formed on the inner wall of the exposure chamber; an optical system connected to the exposure chamber to perform an exposure process; and a vacuuming apparatus connected to the exposure chamber. The photocatalyst material has a plurality of pores therein.

10. The lithography exposure system of claim 9, wherein, ​

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