CN112987502A - Method for processing semiconductor wafer - Google Patents

Abstract

According to some embodiments, the present disclosure provides a method for processing a semiconductor wafer. The method comprises transporting a carrier together with a mask supported by the carrier in a lithographic exposure apparatus. The method further comprises modulating the particles in the carrier through a magnetic field. In addition, the method includes removing the mask from the carrier. The method also includes performing a lithography exposure process on the semiconductor wafer in the lithography exposure apparatus using the mask.

Description

Method for processing semiconductor wafer

Technical Field

The present disclosure relates to methods and apparatus for processing semiconductor wafers in lithographic exposure techniques.

Background

The semiconductor Integrated Circuit (IC) industry has experienced exponential growth. Technological advances in integrated circuits in materials and design have resulted in generations of integrated circuits, each of which has smaller, more complex circuits than the previous generation. In the course of the evolution of integrated circuits, the functional density (i.e., the number of interconnected devices per wafer area) has generally increased, while the geometry (i.e., the smallest component (or line width) that can be created using a manufacturing process) has decreased. Such a scaling down process can generally provide benefits by increasing production efficiency and reducing associated costs. This scaling down also increases the complexity of processing and manufacturing the integrated circuit.

The photolithography exposure process forms a patterned photoresist layer for various patterning processes, such as etching or ion implantation. In a lithographic exposure process, a photosensitive layer (photoresist) is applied to the surface of a semiconductor substrate and an image defining features of the semiconductor device elements is provided on the layer by exposing the layer to a pattern of high intensity light. As semiconductor processing advances to provide smaller critical dimensions and devices become smaller and more complex, including the number of layers, there is a need for a way to precisely pattern features to improve the quality, reliability, and yield of the devices.

Although many improvements to the methods of performing lithographic exposure processes have been developed, they are not entirely satisfactory in all respects. Accordingly, it is desirable to provide a solution to improve lithography systems to increase the production yield of semiconductor wafers.

Disclosure of Invention

According to some embodiments of the present disclosure, there is provided a method of processing a semiconductor wafer, comprising: transporting a carrier in a lithography exposure apparatus together with a mask supported by the carrier; modulating a plurality of microparticles in a carrier through a magnetic field; removing the mask from the carrier; and performing a photolithography exposure process on the semiconductor wafer in the photolithography exposure apparatus using the mask.

Drawings

Aspects of the present disclosure are best understood from the following detailed description when read with the accompanying drawing figures. It should be understood that the various features are not drawn to scale in accordance with standard practice in the industry. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

FIG. 1 is a schematic diagram of a lithographic exposure apparatus according to some embodiments;

FIG. 2A depicts an exploded view of a shipping box and carrier according to some embodiments;

FIG. 2B depicts an exploded view of the carrier according to some embodiments;

FIG. 3 depicts a schematic view of a carrier with a mask therein according to some embodiments;

FIG. 4 illustrates a top view of a substrate having a mask therein according to some embodiments;

FIG. 5A schematically illustrates the position of the poles of a magnetic element relative to a mask according to some embodiments;

FIG. 5B schematically illustrates the position of the poles of the magnetic element relative to the mask according to some embodiments;

FIG. 6 illustrates a top view of a substrate having a mask therein according to some embodiments;

FIG. 7 illustrates a top view of a substrate having a mask therein according to some embodiments;

FIG. 8 illustrates a top view of a substrate having a mask therein according to some embodiments;

FIG. 9 depicts a flow diagram depicting a method for transporting a mask for semiconductor fabrication, in accordance with some embodiments;

FIG. 10 is a schematic diagram depicting a stage in a method for transporting masks for semiconductor fabrication according to some embodiments in which a carrier is transported with the masks from a transport box to an interface module;

FIG. 11 is a schematic diagram depicting a stage in a method for transporting masks for semiconductor fabrication according to some embodiments, in which both the carrier and the masks are located in a load lock chamber;

FIG. 12 depicts a schematic view of a stage in a method for transporting masks for semiconductor fabrication according to some embodiments in which both the carrier and the masks are located in a mask library;

FIG. 13 depicts a schematic view of a stage in a method for transporting a mask for semiconductor fabrication according to some embodiments in which a carrier is opened in a lid processing chamber;

FIG. 14 depicts a schematic view of a stage in a method for transporting a mask for semiconductor fabrication according to some embodiments in which the mask is supported by a substrate and moved to a mask chuck;

FIG. 15 is a schematic illustration of a stage in a method for transporting a mask for semiconductor fabrication according to some embodiments in which particles are trapped on a magnetic element while a gas flow is generated;

FIG. 16 is a schematic diagram of a lithographic exposure apparatus according to some embodiments.

[ notation ] to show

10: lithographic exposure apparatus

11: load terminal

12: interface module

13: load lock chamber

14: vacuum container

15: shade library

16: upper cover processing chamber

17: shade exchange platform

18: conveying mechanism

19: mask suction cup

20: transport box

21: top cover

22: bottom door

23: gripping element

30: carrier

31: upper cover

32: substrate

33: the first part

34: the second part

35: the first part

36: the second part

40: shade cover

41: mask substrate

42: molybdenum layer

43: silicon layer

44: covering layer

45: absorbing layer

46: reflective multilayer structure

47: opaque region

48: reflective area

51: magnetic element

52: magnetic element

53: magnetic element

54: magnetic element

55: magnetic element

61: magnetic element

61 a: magnetic element

62: magnetic element

62 a: magnetic element

62 b: magnetic element

62c, the ratio of: magnetic element

63: groove

64: groove

65: magnetic field

66: groove

70: air flow

80: microparticles

81: light source

82: lighting device

83: projection optical box

84: substrate table

86: semiconductor wafer

121: shell body

122: mechanical arm

150: storage space

151: support frame

161: supporting element

310: groove

312: support piece

313: bolt

314: flange

315: air hole

316: mask suction cup

320: groove

323: short bar

324: inner surface

325: inner region

326: outer zone

327: boundary of

329: edge of a container

350: groove

400: center of a ship

401: edge of a container

402: bottom surface

403: anterior surface

410: pattern region

420: groove

430: boundary region

621: first magnetic element

622: second magnetic element

631: outer wall

632: inner wall

D: distance between two adjacent plates

W1: width of

W2: depth of field

S100: method of producing a composite material

S110: operation of

S120: operation of

S130: operation of

S140: operation of

S150: operation of

Detailed Description

The present disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and configurations are described below to simplify the present disclosure. Of course, these are merely examples and are not intended to be limiting. For example, in the description below, forming a first feature over or on a second feature may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact. Additionally, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

Furthermore, spatially relative terms (e.g., "below," "beneath," "above," "over," and the like) are used herein to describe one element or feature's relationship to another element or feature as illustrated. In use or operation, the spatially relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. Moreover, these devices may be rotated (90 degrees or at other angles) and the spatially relative descriptors used herein interpreted accordingly.

Particles falling on the reticle will damage the pattern on the semiconductor wafer, which results in increased rework costs and manufacturing time. To address this issue, embodiments of the present disclosure provide a method of trapping particles on a mask in a lithographic exposure apparatus by applying one or more magnetic fields. In some embodiments, the magnetic field is mounted in a carrier. The magnetic field may be bi-directional and may be induced by electromagnets or permanent magnets. The orientation of the magnetic field will be forward and the direction of the magnetic field will be vertical or horizontal. In some embodiments, one or more grooves are formed in the carrier and adjacent to the magnetic field to trap particles. By using the particle capturing mechanism, the particle dropping rate on the mask is reduced and the wafer yield is improved.

FIG. 1 depicts a schematic diagram of a lithographic exposure apparatus 10 according to some embodiments. The lithographic exposure apparatus 10, which may also be referred to generally as an exposure machine (scanner), may perform a lithographic exposure process using a mask 40 with a corresponding radiation source and exposure mode. In the present disclosure, the terms reticle and mask are used interchangeably.

The lithography exposure apparatus 10 is used to perform a lithography exposure process on a semiconductor wafer. The lithography exposure apparatus 10 may be any kind of lithography apparatus (e.g. immersion exposure machine, Extreme Ultraviolet (EUV) exposure machine, stepper (stepper), etc.). It should be understood that in other embodiments of the lithographic exposure apparatus 10, the features described below may be replaced or eliminated.

According to some embodiments, the lithography exposure apparatus 10 includes a load port 11, an interface module 12, a load lock chamber 13, a vacuum container 14, a mask library 15, a lid handling chamber 16, a mask exchange station 17, a transfer mechanism 18, and a mask chuck 19.

The loading end 11 is used to load a carrying case 20 (also referred to as an outer case) for storing one or more masks 40. As shown in fig. 2A, the transport box 20 includes a top cover 21 and a bottom door 22. The top cover 21 and the bottom door 22 collectively define a space that is free or substantially free of foreign particles. In some embodiments, the transport box 20 further includes a gripping element 23 secured to the top cover 21 to allow an Overhead Hoist Transport (OHT) assembly (not shown) to easily transport the transport box 20. In some embodiments, as shown in FIG. 1, the transport box 20 further includes two magnetic elements 51 for conditioning particles in the transport box 20. Two magnetic elements 51 are located on the top cover 21 and the bottom door 22, respectively. The two magnetic elements 51 may be permanent magnets or electromagnets electrically connected to a power control unit (not shown) of the transport box 20.

The carrier 30 is used so that the transport box 20 can be fitted around the carrier 30. In some embodiments, the carrier 30 has an upper lid 31 and a base plate 32. The upper cover 31 and the base plate 32 collectively define a space for accommodating the mask 40. When the mask 40 is transported to the load end 11, the carrier 30 is located in the transport box 20 and the mask 40 is located in the carrier 30. Thus, further protection may be provided for the mask 40. The structural features of the carrier 30 will be described in more detail later with reference to fig. 2B.

The interface module 12 is used to transport the carrier 30 from the transport box 20. In some embodiments, the interface module 12 includes a housing 121 and one or more transfer devices (e.g., robotic arms 122). In some embodiments, the interface module 12 includes an Equipment Front End Module (EFEM). The robot arm 122 is disposed within the housing 121. The robotic arm 122 is used to physically transport the carrier 30. For example, the robot arm 122 may retrieve the carrier 30 from the transport box 20 to the housing 121, or the robot arm 122 may transport the carrier 30 to the load lock chamber 13 or remove it from the load lock chamber 13. However, the position where the robot arm 122 can carry the carrier 30 is not limited by the present embodiment.

The load lock chamber 13 is located between the interface module 12 and the vacuum vessel 14. The load lock chamber 13 maintains the air pressure in the vacuum vessel 14 by separating the vacuum vessel 14 from the interface module 12. Depending on the intended next position of the loaded carrier 30, the load lock chamber 13 is capable of generating a gas pressure compatible with either the vacuum vessel 14 or the interface module 12. Varying the gas content of the load lock chamber 13 may be performed by methods such as adding gas or creating a vacuum, as well as other suitable methods for adjusting the gas pressure in the load lock chamber 13.

The vacuum vessel 14 maintains a vacuum environment at an ultra-high vacuum pressure. The mask stocker 15, the upper lid processing chamber 16, the mask exchanging station 17, and the mask suction cups 19 are located in the vacuum container 14. The mask library 15 is used to store one or more carriers 30 in the vacuum container 14. In some embodiments, the mask library 15 includes a plurality of storage spaces 150. The storage space 150 is partitioned by a plurality of holders 151 vertically arranged in the height direction of the mask library 15.

The lid processing chamber 16 is used to store one or more lids 31 removed from the carrier 30. In some embodiments, the lid processing chamber 16 includes a plurality of support elements 161 for supporting the lid 31 removed from the carrier 30. The mask chuck 19 is used to hold the mask 40 during the photolithography exposure process. In some embodiments, the shadow mask chuck 19 comprises an E-chuck (E-chuck) that generates a clamping force by generating an electrostatic field.

The mask exchanging station 17 serves to support the substrate 32 of the carrier 30 before fixing the mask 40 through the mask chuck 19 or after releasing the substrate 32 from the mask chuck 19. In some embodiments, the mask exchange station 17 is positioned relative to the mask chuck 19. In some other embodiments, the mask changing station 17 is movable by a drive element such as a linear motor (not shown). To place the mask 40 on the predetermined position of the mask chuck 19, an alignment tool (e.g., a camera, not shown) generates positional information about the mask exchange station 17 and/or the mask chuck 19, and the mask exchange station 17 is moved using the information from the alignment tool to perform an alignment process with respect to the mask chuck 19 with respect to the mask exchange station 17.

The transfer mechanism 18 is used to move the carrier 30 or the substrate 32 of the carrier 30 within the vacuum vessel 14. The transfer mechanism 18 can be raised, moved to the left and right, moved forward and backward, and rotated about a vertical axis to move the carrier 30 or the substrate 32 of the carrier 30 between the load lock chamber 13, the mask stocker 15, the upper lid processing chamber 16, and the mask exchanging station 17. The position where the transport mechanism 18 can move the carrier 30 or the substrate 32 of the carrier 30 is not limited by the embodiment.

In some embodiments, a plurality of magnetic elements (e.g., magnetic element 52, magnetic element 53, magnetic element 54, and magnetic element 55) are located at different positions in lithographic exposure apparatus 10. The magnetic element 52 is located in the housing 121 and is used to condition particles in the carrier 30 as the carrier 30 moves in the housing 121. The number of the magnetic elements 52 may be two (2), and are respectively arranged on the upper and lower sides of the moving path of the carrier 30 in the housing 121.

The magnetic element 53 is located in the load lock chamber 13 and is used to condition the particles in the carrier 30 when the carrier 30 is placed in the load lock chamber 13. The number of the magnetic elements 53 may be two (2) and are respectively disposed at upper and lower sides of a support (not shown) on which the carrier 30 is placed in the load lock chamber 13.

The magnetic elements 54 are located in the mask magazine 15 and are used to condition particles in the carrier 30 when the carrier 30 is placed in the mask magazine 15. Each holder 151 of the mask library 15 is provided with a magnetic element 54, and the top cover of the mask library 15 is also provided with a magnetic element 54. Thus, the two magnetic elements 54 are arranged on the upper and lower sides of the storage space 150, wherein the carrier 30 is placed in the mask magazine 15 in this storage space 150.

The magnetic element 55 is located in the upper lid processing chamber 16 and is used to condition particles in the carrier 30 when the carrier 30 is placed in the upper lid processing chamber 16. The number of the magnetic elements 55 may be two (2) and are respectively disposed at the upper and lower sides of the supporting element 161, wherein the supporting element 161 is for supporting the upper cover 31 of the carrier 30.

Fig. 2B shows an exploded view of carrier 30 according to some embodiments. Fig. 3 shows a schematic view of a carrier 30 having a mask 40 therein, according to some embodiments. The detailed features of the carrier 30 in fig. 3 are simplified to clearly show the relative relationship between the magnetic elements 61 and 62 and the mask 40. In some embodiments, the cover 31 includes a first portion 33 and a second portion 34. The first portion 33 is formed in a rectangular shape, and a plurality of air holes 315 penetrate the first portion 33. The second portion 34 surrounds the first portion 33. In one embodiment, the thickness of the second portion 34 is greater than the thickness of the first portion, and the first portion 33 and the second portion 34 define a recess 310 (shown in fig. 2B).

In some embodiments, the upper cover 31 further includes a plurality of supporting members 312 (e.g., four supporting members, however, only two supporting members are shown in fig. 2B and 3) and a plurality of latches 313 (e.g., four latches, but only two latches are shown in fig. 2B and 3). The supports 312 are located at the four corners of the first portion 33 and are located in the grooves 310. The pins 313 are respectively connected to the supports 312 and extend toward the substrate 32. The latch 313 is configured to abut against a bottom surface 402 (i.e., a surface without a pattern) of the shroud 40 to prevent the shroud 40 from moving in a vertical direction during transport. In some embodiments, the upper cover 31 further includes a plurality of flanges 314 protruding horizontally from the second portion 34 to facilitate movement of the upper cover 31 relative to the base plate 32.

In some embodiments, the upper lid 31 of the carrier 30 includes magnets for conditioning the particles in the carrier 30. In an exemplary embodiment, the first portion 33 of the upper cover 31 and the support 312 are permanent magnets or electromagnets, and in some embodiments of the present disclosure, the second portion 34 of the upper cover 31 is made of a nickel-plated non-magnetized aluminum alloy. In some embodiments of the present disclosure, the nickel coating is nickel-phosphorus (Ni-P) or nickel-chromium (Ni-Cr). The first portion 33 of the upper cover 31 and the support 312 may be made in one piece and connected to the second portion 34 of the upper cover 31 by means of a suitable technique, for example gluing. The latch 313 may be formed of a flexible material (e.g., rubber) to prevent scratching of the bottom surface 402 of the shade 40. The latch 313 may be connected to the support 312 via a suitable technique (e.g., threads). For illustrative purposes, in the following description, the first portion 33 of the upper cover 31 and the support 312 are collectively referred to as the magnetic element 61.

In some embodiments, as shown in FIG. 2B, the base plate 32 has an inner surface 324 facing the cover 31. The inner surface 324 of the substrate 32 has an inner region 325 and an outer region 326. The inner region 325 has a rectangular shape and is positioned relative to the center of the substrate 32. The outer region 326 surrounds the inner region 325 and connects the inner region 325 to an edge 329 of the substrate 32.

In some embodiments, a plurality of stubs 323 for positioning the mask 40 are formed on the inner surface 324. In some embodiments, as shown in FIG. 4, base 32 includes four (4) pairs of stubs 323 located adjacent four corners of base 32, respectively. Each pair of short rods 323 is configured such that when the mask 40 is supported by the base plate 32, a corner of the mask 40 is located between two short rods 323, and two intersecting edges 401 of the mask 40 respectively abut one of each pair of short rods 323. That is, each edge 401 of the mask 40 is adjoined by two stub bars 323 from two different pairs of stub bars 323.

In some embodiments, as shown in FIG. 2B, a stub 323 for abutting the edge 401 of the mask 40 is disposed along the boundary 327 of the inner region 325 and the outer region 326. Thus, as shown in FIG. 3, when the mask 40 is supported by the substrate 32, the boundaries 327 of the inner region 325 and the outer region 326 overlap the edges of the mask 40. In other words, the inner region 325 is defined by the vertical projection of the mask 40 when the mask 40 is supported by the substrate 32.

In some embodiments, as shown in FIG. 3, the substrate 32 includes a first portion 35 and a second portion 36. The first portion 35 defines a recess 350 disposed relative to the center of the substrate 32. The width of the groove 350 is greater than the width of the inner region 325 of the inner surface 324. The second portion 36 is located in the recess 350 of the first portion 35. The shape of the second portion 36 conforms to the shape of the recess 350, and thus the width of the second portion 36 is also greater than the width of the interior region 325 of the inner surface 324.

In some embodiments, the second portion 36 has another recess 320 disposed with respect to the center of the substrate 32. In addition, the second portion 36 has a groove 63 that completely surrounds the recess 320. As shown in fig. 3, the groove 63 has an inner wall 632 and an outer wall 631. The inner wall 632 is closer to the groove 320 than the outer wall 631. Both the inner wall 632 and the outer wall 631 are parallel to the edge 329 of the substrate 32. In some embodiments, the boundary 327 of the inner region 325 and the outer region 326 is located between the inner wall 632 and the outer wall 631. That is, when the mask 40 is placed on the substrate 32, the vertical projection of the edge 401 of the mask 40 is located within the trench 63. In some embodiments, the width W1 of the groove 63 is in the range of about 5mm to about 15mm, and the depth W2 is less than 5 mm. However, the size design of the trench 63 is not limited to this embodiment, but may be selected as long as particles can be trapped in the trench 63 and the patterned region of the mask is not contaminated.

In some embodiments, the substrate 32 of the carrier 30 includes magnets for conditioning the particles in the carrier 30. In an exemplary embodiment, the second portion 36 of the substrate 32 is a permanent magnet or an electromagnet, and in some embodiments of the present disclosure, the first portion 35 of the substrate 32 is made of a nickel-plated non-magnetized aluminum alloy. In some embodiments of the present disclosure, the nickel coating is nickel-phosphorus (Ni-P) or nickel-chromium (Ni-Cr).

The second portion 36 may be connected to the first portion 35 of the substrate 32 by a suitable technique, such as gluing. After assembly, the upper surface of the first portion 35 and the upper surface of the second portion 36 collectively comprise an inner surface 324 of the base plate 32. Thus, the entire interior region 325 of the inner surface 324 is magnetic. In addition, the region of the outer region 326 adjacent the inner region 325 is magnetic, and the remaining region of the outer region 326 adjacent the edge 329 of the substrate 32 is non-magnetic. For illustrative purposes, in the following description, the second portion 36 of the substrate 32 is referred to as the magnetic element 62.

It will be understood that although in the present embodiment at least a portion of the upper cover 31 of the carrier 30 or at least a portion of the base plate 32 of the carrier 30 is made of a magnetic element, many variations and modifications may be made to this embodiment. In some other embodiments, both the cover 31 and the substrate 32 are made of non-magnetic materials, and one or more layers of magnetic materials conformally cover the inner surfaces of the cover 31 and/or the substrate 32 opposite each other. In some embodiments, the magnetic elements may be positioned at any suitable location in carrier 30 and their perpendicular projections overlap the interior region 325 of substrate 32. In the embodiment shown in fig. 3, the projections of both magnetic elements 61 and 62 overlap a portion of the inner region 325 of the substrate 32 and the outer region 326 of the substrate 32.

In addition, although fig. 3 depicts two magnetic elements (e.g., magnetic element 61 and magnetic element 62) generating magnetic fields for conditioning particles, carrier 30 may include any number of magnetic elements to generate any number of magnetic fields. For example, the upper cover 31 is made of a non-magnetic material, and there is no magnetic element on the upper cover 31. The particles in the carrier 30 are conditioned by magnetic elements disposed on a substrate 32. When the magnetic member is mounted on the upper cover 31 and/or the base plate 32, the magnetic member may have a vortex shape in a plan view.

According to some embodiments, as shown in FIG. 3, the mask 40 includes a pattern area 410 and a border area 430. The pattern area 410 is located relative to the center 400 of the mask 40. The boundary region 430 may surround the pattern region 410 and may be separated from the pattern region 410 through the trench 420. The trench 420 may partially or completely surround the pattern area 410.

In some embodiments, the mask 40 is an Extreme Ultraviolet (EUV) mask. The EUV lithography exposure process uses a reflective mask rather than a transmissive mask. The euv lithography exposure process utilizes an euv exposure machine to emit light in the euv region, which is light having an euv wavelength (e.g., 10 nanometers (nm) to 15 nm). In some embodiments, the extreme ultraviolet source generates extreme ultraviolet light having a wavelength of about 13.6 nm. The partial euv exposure machine may use reflective optics (i.e., mirrors) and operate in a vacuum environment. The euv exposure machine may provide a desired pattern on an absorber layer (e.g., an "euv" mask absorber) formed on a reflective mask. All materials are highly absorbing in the extreme ultraviolet range. Therefore, reflective optical elements are used instead of refractive optical elements.

In some embodiments, the mask 40 includes a mask substrate 41, a reflective Multilayer (ML) structure 46, a cover layer 44, and an absorber layer 45. Further, according to some embodiments of the present disclosure, the mask substrate 41, the reflective multilayer structure 46, and the absorption layer 45 may be located in the pattern region 410 and the boundary region 430 of the mask 40.

The mask substrate 41 may be made of a suitable material (e.g., Low Thermal Expansion Material (LTEM) or fused silica). In some embodiments, the low coefficient of thermal expansion material comprises silicon dioxide (SiO2) doped with titanium dioxide (TiO2) or other suitable material having a low coefficient of thermal expansion. The reflective multilayer structure 46 may be located on the mask substrate 41. In some embodiments, the reflective multilayer structure 46 includes a plurality of film pairs (e.g., molybdenum silicon (Mo/Si) film pairs) (e.g., in each film pair, there is a molybdenum layer 42 above or below the silicon layer 43). In some other embodiments, the reflective multilayer structure 46 may include a molybdenum-beryllium (Mo/Be) film pair, or other suitable material that is highly reflective of extreme ultraviolet light.

The properties of the reflective multilayer structure 46 are selected to provide high reflectivity for a selected type/wavelength of electromagnetic radiation. For example, for euv lithography purposes, the reflective multilayer structure 46 may be designed to reflect light in the euv range. The thickness of each layer of the reflective multilayer structure 46 depends on the euv wavelength and the angle of incidence. In particular, the thickness of the reflective multilayer structure 46 (and the thickness of the film pairs) may be adjusted to achieve maximum constructive interference of the extreme ultraviolet light diffracted at each interface and minimum absorption of the extreme ultraviolet light. In some embodiments, the number of film pairs in the reflective multilayer structure 46 may be in the range of about 20 to about 80. However, any number of membrane pairs may be used. For example, the reflective multilayer structure 46 may include forty pairs of molybdenum silicon (Mo/Si) layers. For example, each molybdenum silicon (Mo/Si) film pair has a thickness of about 7nm, and the reflective multilayer structure 46 has a total thickness of 280 nm.

In some embodiments, the capping layer 44 is located over the reflective multilayer structure 46. The cover layer 44 is designed to be transparent to extreme ultraviolet light and to protect the reflective multilayer structure 46 from damage and/or oxidation. In addition, the capping layer 44 may serve as an etch stop layer during the patterning or repair/cleaning process of the absorber layer 45 over the capping layer 44. The cover layer 44 may have different etching characteristics than the absorber layer. In some embodiments, the capping layer 44 is formed of ruthenium (Ru), ruthenium (Ru) compounds (e.g., ruthenium boride (RuB) and ruthenium silicide (RuSi)), chromium (Cr) oxides, and chromium (Cr) nitrides. A low temperature deposition process is typically selected to form the capping layer 44 to prevent interdiffusion of the reflective multilayer structure 46. In particular embodiments, the thickness of the capping layer 44 may be in a range of about 2nm to about 7 nm.

An absorbent layer 45 may be positioned over the cover layer 44. The absorber layer 45 is used to form a desired exposure pattern (e.g., the absorber layer 45 in the pattern region 410) on the front side surface 403 of the mask 40. In some embodiments, the absorbing layer 45 is an absorbing material to absorb radiation in the extreme ultraviolet wavelength range that impinges on the pattern area 410 of the mask 40. In some examples, absorber layer 45 may include a plurality of film layers, each film comprising chromium, chromium oxide, chromium nitride, titanium oxide, titanium nitride, tantalum oxide, tantalum nitride, tantalum oxynitride, tantalum boron nitride, tantalum boron oxide, tantalum boron oxynitride, aluminum copper alloy, aluminum oxide, silver oxide, palladium, ruthenium, molybdenum, other suitable materials, and/or mixtures of some of the foregoing.

In some embodiments, the absorber layer 45 in the pattern region 410 may be patterned according to an integrated circuit layout pattern (or simply, an integrated circuit pattern). For example, absorber layer 45 may be patterned to form opaque region 47 and reflective region 48. In the opaque region 47, the absorbent layer 45 may remain. The incident light is almost completely absorbed by the absorber. In the reflective region 48, the absorbing layer 45 may be removed and the incident light is reflected by the underlying reflective multilayer structure 46.

In some embodiments, as shown in FIG. 3, the pattern area 410 faces the recess 320 when the mask 40 is positioned over the substrate 32. By virtue of the arrangement of the grooves 320, the absorption layer 45 is protected from being scratched by the substrate 32 during transportation of the mask 40. In some embodiments, mask 40 is supported by a short bar 323 (see FIG. 2B) so that front side surface 403 of mask 40 does not directly contact inner surface 324 of substrate 32 and a gap is formed between mask 40 and substrate 32. The distance D between the border region 430 and the substrate 32 may be in the range of about 200 microns to about 300 microns. The gap between the mask 40 and the substrate 32 may allow a flow of gas with contaminant particles to pass therethrough.

In some embodiments, the trenches 63 of the magnetic element 62 are located farther from the center 400 of the mask 40 in the horizontal direction than the trenches 420 separating the border region 430 and the pattern region 410. For example, as shown in fig. 3, the inner wall 632 of the trench 63 is located below the border area 430 and away from the trench 420. In some embodiments, at least a portion of the trench 63 is not covered by the mask 40 when the mask 40 is supported by the substrate 32. For example, as shown in FIG. 3, when mask 40 is positioned over substrate 32, outer wall 631 is spaced apart from edge 401 of mask 40, and mask 40 exposes a portion of recess 63 adjacent to outer wall 631.

In some embodiments, magnetic elements 61 and 62 are permanent magnets and the direction of the magnetic field is perpendicular. For example, as shown in fig. 5A, the magnetic elements 61 and 62 are positioned laterally on both sides of the mask 40. The magnetic element 61 is formed such that its magnetic north pole and magnetic south pole are arranged in a direction perpendicular to the mask 40, and the magnetic south pole faces the mask 40. The magnetic element 62 is formed such that its magnetic north pole and magnetic south pole are arranged in a direction perpendicular to the mask 40, and the magnetic north pole faces the mask 40. In such embodiments, the magnetic field 65 generated by the magnetic elements 61 and 62 is perpendicular to the mask 40.

In some embodiments, magnetic elements 61a and 62a are permanent magnets and the direction of the magnetic field is horizontal. For example, as shown in fig. 5B, the magnetic elements 61a and 62a are laterally positioned on both sides of the mask 40. The magnetic element 61a is formed such that its magnetic north pole and magnetic south pole are arranged in a direction parallel to the mask 40, with the magnetic south pole and magnetic north pole being located near the edge of the mask 40. The magnetic element 62a is formed such that its magnetic north pole and magnetic south pole are arranged in a direction parallel to the mask 40. The magnetic south pole of the magnetic element 62a faces the magnetic north pole of the magnetic element 61a, and the magnetic north pole of the magnetic element 62a faces the magnetic south pole of the magnetic element 61 a. In such an embodiment, the magnetic field 65 generated by the magnetic element 61a and the magnetic element 62a is parallel to the mask 40.

In some embodiments, magnetic elements 61 and 62 are electromagnets and may be magnetized to have a magnetic field perpendicular to mask 40 (as shown in FIG. 5A). Alternatively, the magnetic elements 61 and 62 may be magnetized to have a magnetic field parallel to the mask 40 (as shown in fig. 5B). The electromagnet may be electrically connected to a power control unit (not shown) mounted on the carrier 30.

It will be appreciated that the configuration of the magnetic elements is not limited to the above embodiments and may vary depending on the intended use or design parameters. Some exemplary embodiments will be provided below.

FIG. 6 shows a top view of the magnetic element 62a according to some embodiments. The difference between the magnetic element 62a and the magnetic element 62 includes that the magnetic element 62a further includes a groove 64. The groove 64 has a closed annular shape (or ring shape) and completely surrounds the groove 63. The groove 64 may extend parallel to the groove 63. In such an embodiment, the air flow 70 around the shroud 40 would pass through the grooves 64 and 63 in sequence before reaching the center 400 of the shroud 40.

FIG. 7 shows a top view of the magnetic element 62b according to some embodiments. The difference between the magnetic element 62b and the magnetic element 62 includes replacing the groove 63 with a groove 66. The groove 66 may have a spiral shape (or a swirl shape) in a plan view. In such embodiments, the airflow 70 around the shroud 40 will sequentially pass through at least two portions of the channel 66 before reaching the center 400 of the shroud 40.

FIG. 8 shows a top view of a magnetic element 62c according to some embodiments. The difference between the magnetic element 62c and the magnetic element 62 includes that the magnetic element 62c includes two or more magnetic elements having different magnetic fluxes. For example, the magnetic element 62c includes a first magnetic element 621 and a second magnetic element 622. The first magnetic element 621 has a ring shape on which the groove 63 is formed. The second magnetic element 622 has a rectangular shape and is surrounded by the first magnetic element 621. The second magnetic element 622 is smaller in area than the mask 40. When the mask 40 is supported by the substrate 32 (see fig. 3), the second magnetic element 622 is completely covered by the mask 40. The magnetic field strength of the first magnetic element 61 is greater than the magnetic field strength of the second magnetic element 62.

In this embodiment shown in fig. 8, the airflow 70 around the mask 40 will pass through the first magnetic element 621 and the second magnetic element 622 in sequence before reaching the center 400 of the mask 40. In some embodiments, the second magnetic element 622 is omitted, and the magnetic element 62c is formed by a ring-shaped magnetic element having a gap formed with respect to the center of the mask 40.

Fig. 9 depicts a flow diagram of a method S100 for transporting a mask (e.g., mask 40) for semiconductor fabrication according to some embodiments. For purposes of illustration, this flow chart will be described in conjunction with the drawings shown in fig. 1 and fig. 8-16. Other operations may be provided before, during, and after method S100, and portions of the operations described may be replaced or eliminated as other embodiments of this method.

The method S100 starts with operation S110, and in operation S110, the carrier 30 and the mask 40 supported by the carrier 30 are transferred. In some embodiments, the carrier 30 containing the mask 40 is moved from the transport box 20 to the mask exchange station 17 in the lithography exposure apparatus 10. In some embodiments, to perform a lithography exposure process using the mask 40, the transport box 20 containing the mask 40 in the carrier 30 is placed on the load end 11 of the lithography exposure apparatus 10 (as shown in FIG. 1). After the shipping box 20 is placed on the load end 11, the carrier 30 is removed from the shipping box 20 by the robotic arm 122 and moved toward the load lock chamber 13 in the direction indicated by the arrow in fig. 10.

As shown in fig. 11, when the carrier 30 is placed in the load lock chamber 13, the robot arm 122 returns to the housing 121. At this point, the load lock chamber 13 is sealed and a pressure compatible with the vacuum pressure in the vacuum vessel 14 is created by varying the gas content of the load lock chamber 13, such as by adding gas or creating a vacuum and other suitable methods for adjusting the pressure in the load lock chamber 13. When the correct pressure is reached, the transfer mechanism 18 will remove the carrier 30 from the load lock chamber 13. Therefore, the carrier 30 together with the mask 40 may move from the atmospheric environment (i.e., the space in the transport box 20 and the housing 121) to the vacuum environment (i.e., the space in the vacuum vessel 14).

In some embodiments, after moving the carrier 30 into the vacuum environment, the carrier 30 is transferred into the mask library 15 through the transport mechanism 18 (as shown in fig. 12). In some embodiments, the mask library 15 stores more than one carrier 30, and masks 40 having the same or different patterns are placed in the carrier 30. With the arrangement of the mask library 15, the time for exchanging the mask 40 in the lithography exposure apparatus 10 can be reduced.

In some embodiments, the carrier 30 is left in the mask library 15 until the mask 40 placed in the carrier 30 is to be used in the lithography exposure process. To mount the mask 40 to the mask chuck 19, the carrier 30 is pulled out of the mask magazine 15 by the transport mechanism 18 and brought to the upper lid processing chamber 16 (as shown in fig. 13). In the upper lid processing chamber 16, the flange 314 of the upper lid 31 is supported by the support member 161, and the upper lid 31 is left on the support member 161 by moving the substrate 32 downward. Thus, the upper cover 31 is removed from the substrate 32. At this point, the mask 40 is placed on the substrate 32 and the magnetic elements 62 on the substrate 32 are exposed to a vacuum environment.

In some embodiments, after removing the upper cover 31 from the substrate 32, the substrate 32 and the mask 40 are placed on the mask exchanging station 17 through the transfer mechanism 18 (as shown in fig. 14). Thereafter, the exchanging station 17 is raised to the loading position as shown by the dotted line in fig. 14 so that the bottom surface of the mask 40 and the mask chuck 19 are in direct contact. Thereby, operation S110 is completed.

The method S100 continues with operation S120, wherein the particles in the carrier 30 are modulated via the magnetic field. In some embodiments, particles in or around the carrier 30 are collected by magnetic elements 61 and 62 located in the carrier 30.

In some embodiments, operation S120 is performed whether the mask 40 is located in the carrier 30 or removed from the carrier 30. In the case where the mask 40 is supported by the carrier 30, particles accumulated on the mask 40 can be removed from the mask 40 to prevent a de-focus problem during the photolithography exposure. In the case where the mask 40 is not accommodated in the carrier 30, particles suspended around the carrier 30 may be attracted by the magnetic elements 61 and 62 to keep the surroundings of the carrier 30 clean. For example, the magnetic element 61 may be used to collect particles around the mask 40 when the lid 31 is left in the lid process chamber 16. In addition, the magnetic elements 62 may be used to collect particles around the mask exchange station 17 during movement of the substrate 32 over the mask exchange station 17.

In some embodiments, the magnetic elements 61 and 62 are designed to have sufficient strength so that particles around the carrier 30 can be attracted even when the carrier 30 is closed. For example, the magnetic elements 61 and 62 may be used to attract particles in the transport pod 20, the interface module 12, the load lock chamber 13, and/or the mask magazine 15 when the carrier 30 is located in or through the transport pod 20, the interface module 12, the load lock chamber 13, and/or the mask magazine 15.

In some embodiments, the magnetic elements 61 and 62 are electromagnets, and the magnetic elements 61 and 62 are magnetized at a specific point in time. In one exemplary embodiment, the magnetic elements 62 are magnetized when the mask 40 is returned from the mask chuck 19 to the substrate 32 after use in a lithography exposure process, and the magnetic elements 61 are magnetized when the substrate 32 with the used mask 40 is returned to the lid process chamber 16. The magnetic elements 61 and 62 may be used to remove particles from the mask 40 due to small particles or debris, such as tin (Sn) particles, that may collect on the mask 40 during a lithographic exposure process. Therefore, the life of the mask 40 can be extended.

In some embodiments, at least one of the magnetic elements 61 and 62 is periodically magnetized. For example, when the mask 40 is stored in the mask 40, the magnetic elements 61 and 62 may be magnetized according to a predetermined time frequency. In some embodiments, at least one of the magnetic elements 61 and 62 is magnetized a plurality of times according to a function (e.g., a sinusoidal function) to have different intensities, thereby creating different attractive forces on the particles. Thus, stubborn particles can be removed and collected by the magnetic elements 61 and 62.

In another exemplary embodiment, the magnetic elements 61 and 62 are magnetized during the execution of operation S130, as described below. In another alternative exemplary embodiment, in operation S140 described below, the magnetic elements 61 and 62 are magnetized for a predetermined period of time (e.g., 5 seconds, 10 seconds, or 15 seconds) before the mask 40 is removed from the carrier 30.

In some embodiments, particles in the carrier 30 or around the carrier 30 are conditioned by magnetic elements 51 to 55 located in the lithographic exposure apparatus 10. Specifically, when the carrier 30 is stored in the transport box 20, the particles in the carrier 30 or around the carrier 30 can be regulated by the magnetic element 51. As the carrier 30 moves within the interface module 12, particles in the carrier 30 or around the carrier 30 may be regulated by the magnetic elements 52. When the carrier 30 is resting in the load lock chamber 13, the particles in the carrier 30 or around the carrier 30 may be regulated by the magnetic element 53. When the carrier 30 is resting in the mask magazine 15, particles in the carrier 30 or around the carrier 30 may be regulated by the magnetic element 54. When the carrier 30 is placed in the upper lid process chamber 16, particles in the carrier 30 or around the carrier 30 may be regulated by the magnetic element 55.

In the case where the magnetic elements 51 to 55 are electromagnets, the magnetic elements 51 to 55 may be magnetized when the carrier 30 is located nearby. For example, the magnetic elements 52 may be magnetized as the carrier 30 moves through a passage between two magnetic elements 52. Therefore, a high magnetic flux is generated around the carrier 30 to adjust the fine particles in the carrier 30 or around the carrier 30. In another example, the magnetic element 53 may be magnetized when changing the pressure in the load lock chamber. In yet another example, the magnetic element 55 may be magnetized when the substrate 32 moves relative to the upper cover 31.

In some embodiments, at least one of the magnetic elements 51 to 55 is periodically magnetized. For example, when the carrier 30 is stored in the transport box 20 or the mask stocker 15, the magnetic elements 51 and 54 may be magnetized according to a predetermined time frequency. In some embodiments, at least one of the magnetic elements 51 to 55 is magnetized a plurality of times according to a function (e.g., a sinusoidal function) to have different intensities, thereby generating different attractive forces on the particles. Therefore, stubborn particles can be removed and collected by the magnetic elements 51 to 55.

In operation S130, an air flow is generated around the mask 40. In some embodiments, an air flow is generated around the mask 40 due to the movement of air relative to the carrier 30, and the air flow enters the carrier 30 through the air holes 315 formed in the upper cover 31. During movement of the carrier 30 in the ambient environment (e.g., in the interface module 12) (as shown in fig. 10), air currents may occur that result from movement of air relative to the carrier 30. During movement of the carrier 30 in a vacuum environment (e.g., in the vacuum vessel 14), an airflow may occur that results from movement of air relative to the carrier 30.

In some embodiments, the gas flow around the mask 40 is generated by actively generating a gas pressure difference in the lithographic exposure apparatus 10. For example, a gas flow 70 (shown in FIG. 11) may be generated when the load lock chamber 13 is activated to exhaust gas from the load lock chamber 13 or add gas to the load lock chamber 13. In another example, airflow may be generated when the interface module 12 is activated (e.g., via a fan) to generate a steady airflow from the top cover to the bottom substrate.

In some embodiments, the airflow around the mask 40 is generated by having relative motion between the cover 31 and the substrate 32. For example, the gas flow 70 (shown in FIG. 13) may be generated when the lid 31 is removed from the substrate 32 to open the carrier 30 in the lid processing chamber 16. Furthermore, gas flow is generated when the lid 31 is attached to the base plate 32 to close the carrier 30 in the lid chamber 16.

In some embodiments, as shown in FIG. 15, when the gas flow 70 is generated, a portion of the gas flow 70 may enter a gap formed between the mask 40 and the substrate 32 and contaminate the patterned region of the mask 40. However, due to the formation of the grooves 63 in the magnetic element 62, turbulence may be generated as the air flow 70 passes through the grooves 63, which will result in an increased path for the particles 80 entering the gap between the mask 40 and the substrate 32. Therefore, ferromagnetic particles can be more easily attracted to the magnetic element 62 by magnetic force, and non-magnetic particles can also be captured in the groove 63 by Van Der Waals force. In the case where the air flow 70 around the mask 40 sequentially passes through a plurality of grooves before reaching the center 400 of the mask 40 (as shown in fig. 6 to 8), turbulence may occur in each of the grooves in the flow path of the air flow 70, and the particles 80 may be captured by the grooves.

In operation S140, the mask 40 is removed from the carrier 30. In some embodiments, as shown in FIG. 14, the mask 40 is secured to the mask chuck 316 with a clamping force generated by the mask chuck 19 when the mask exchange station 17 is raised to the loading position as shown in phantom in FIG. 14. After the mask 40 is fixed by the mask chuck 19, the empty substrate 32 is lowered to its original position (shown by a solid line in fig. 14).

The method S100 continues with operation S150, in which a semiconductor process is performed using the mask 40. In some embodiments, the mask 40 is used in a lithographic exposure process (e.g., exposure to extreme ultraviolet light). The components of the lithographic exposure apparatus 10 for performing a lithographic exposure process will be described below.

FIG. 16 is a schematic diagram of a lithographic exposure apparatus 10 according to some embodiments. According to some embodiments, the lithographic exposure apparatus 10 further comprises a light source 81, an illuminator 82, a projection optics block (or POB) 83, and a substrate table 84. The light source 81 is used to generate radians having wavelengths in the range between about 1nm and about 100 nm. In a particular example, the light source 81 generates extreme ultraviolet light having a wavelength centered at about 13.5 nm. Therefore, the light source 81 is also referred to as an extreme ultraviolet light source. However, it should be understood that the light source 81 should not be limited to emitting ultraviolet light. The light source 81 may be used to perform any high intensity photon emission from the excited target material.

In various embodiments, the illuminator 82 comprises various refractive optical elements (e.g., a single lens or a lens system having a plurality of lenses (zone plates)), or alternatively reflective optical elements (for an euv lithographic exposure apparatus) (e.g., a single mirror or a mirror system having a plurality of mirrors, so as to direct light from the light source 81 onto the mask 40, particularly onto the mask 40 secured to the mask chuck 19). In the present embodiment, the light source 81 generates light in the extreme ultraviolet wavelength range, and therefore a reflective optical element is employed.

The projection optics module (or projection optics box) 83 is used to image the pattern of the mask 40 onto a semiconductor wafer 86 that is fixed on a substrate table 84 of the lithography exposure apparatus 10 for performing the lithography exposure process. In some embodiments, projection optics box 83 has refractive optics (e.g., for an ultraviolet lithography exposure apparatus) or, in various embodiments, optionally reflective optics (e.g., for an extreme ultraviolet lithography exposure apparatus). The projection optics box 83 collects light directed from a mask 40 (where this mask 40 carries an image of the pattern defined on the mask). The illuminator 82 and the projection optics box 83 are collectively referred to as the optics module of the lithographic exposure apparatus 10.

In this embodiment, the semiconductor wafer 86 may be made of silicon or other semiconductor material. Alternatively or additionally, the semiconductor wafer 86 may include other elemental semiconductor materials (e.g., germanium (Ge)). In some embodiments, the semiconductor wafer 86 is made of a compound semiconductor (e.g., silicon carbide (SiC), gallium arsenide (GaAs), indium arsenide (InAs), or indium phosphide (InP)). In some embodiments, the semiconductor wafer 86 is made of an alloy semiconductor (e.g., silicon germanium (SiGe), silicon germanium carbide (SiGeC), gallium arsenic phosphide (GaAsP), or indium gallium phosphide (GaInP)). In some other embodiments, semiconductor wafer 86 may be a silicon-on-insulator (SOI) or germanium-on-insulator (GOI) substrate.

In addition, the semiconductor wafer 86 may have various device elements. Examples of device elements formed in semiconductor wafer 86 include transistors (e.g., Metal Oxide Semiconductor Field Effect Transistors (MOSFETs), Complementary Metal Oxide Semiconductor (CMOS) transistors, Bipolar Junction Transistors (BJTs), high voltage transistors, high frequency transistors, P-channel and/or N-channel field effect transistors (PFETs/NFETs), etc.), diodes, and/or other suitable elements. Various processes (e.g., deposition, etching, implantation, lithography, annealing, and/or other suitable processes) are performed to form device elements. In this embodiment, the semiconductor wafer 86 is coated with a resist layer sensitive to extreme ultraviolet light. Various elements including those described above are integrated together and may be used to perform a lithographic exposure process.

In some embodiments, particles may accumulate on the bottom surface 402 or the front side surface 403 of the mask 40, which may result in a degraded quality of the projected pattern on the semiconductor wafer 86 during the photolithography exposure process. However, because the particles have been sufficiently removed from the mask 40 prior to loading the mask 40 onto the mask chuck 19, concerns over particle contamination (e.g., particles, powder, and organics) on the mask 40 can be eliminated or mitigated.

In some embodiments, after the lithographic exposure process is complete, the mask 40 is removed from the mask chuck 19 and returned to the substrate 32. Then, the substrate 32 is transferred to the upper lid processing chamber 16 to be engaged with the upper lid 31, and then the enclosed carrier 30 is conveyed to the mask stocker 15. Since the magnetic element 61 covers the entire area of the front side surface of the mask 40, particles accumulated on the mask 40 during a photolithography exposure process can be sufficiently removed when the mask 40 is placed on the substrate 32. In addition, after the upper cover 31 is attached to the substrate 32, since the magnetic element 62 covers the entire area of the bottom surface of the mask 40, particles accumulated on the mask 40 during the photolithography exposure process can be sufficiently removed when the carrier 30 is closed.

Embodiments of a method of transferring a mask in a lithography system use one or more magnetic elements to condition particles. The magnetic element prevents the mask from being contaminated. Therefore, the process quality and yield are improved. In addition, since the life span of the mask is extended, the manufacturing cost can be reduced since the mask does not need to be frequently maintained or repaired.

According to some embodiments, a method for processing a semiconductor wafer is provided. The method comprises transporting a carrier and a mask supported by the carrier together in a lithographic exposure apparatus. The method further includes conditioning the microparticles in the carrier through a magnetic field. In addition, the method includes removing the mask from the carrier. The method also includes performing a lithography exposure process on the semiconductor wafer in the lithography exposure apparatus using the mask.

According to some embodiments, the particles in the carrier are adjusted by the magnetic field, and the particles are attracted by a magnetic element located in the carrier and facing the mask.

According to some embodiments, conditioning the particles in the carrier through the magnetic field further comprises collecting the particles in a channel formed on the magnetic element and positioned relative to an edge of the mask.

According to some embodiments, modulating the particles in the carrier via a magnetic field includes attracting the particles via a first magnetic element disposed in the carrier and a second magnetic element surrounded by the first magnetic element, wherein a magnetic field strength of the first magnetic element is greater than a magnetic field strength of the second magnetic element.

According to some embodiments, the method further comprises generating a flow of gas around the mask.

According to some embodiments, modulating the particles in the carrier by a magnetic field comprises generating the magnetic field by at least one electromagnet positioned adjacent to the mask in a position in the lithographic exposure apparatus, wherein the magnetic field is generated during generation of the gas flow around the mask.

According to some embodiments, transporting a carrier in a lithography exposure apparatus together with a mask supported by the carrier comprises placing the mask in a load lock chamber of the lithography exposure apparatus and creating a gas pressure in the load lock chamber that is compatible with a predetermined next position of the carrier, wherein a gas flow is generated when the carrier is in the load lock chamber.

According to some embodiments, the gas flow is generated when a lid and a substrate of the carrier are separated.

According to some embodiments, a method for transporting a mask for semiconductor fabrication is provided. The method includes transporting a carrier and a mask supported by the carrier together. The method also includes generating an air flow around the mask. In addition, the method includes regulating the particles in the carrier through a magnetic field during the generation of the gas flow.

According to some embodiments, modulating the particles in the carrier by the magnetic field includes attracting the particles by a magnetic element located in the carrier and facing the mask.

According to some embodiments, modulating the particles in the carrier via the magnetic field further comprises collecting the particles in a channel, wherein the channel is formed on the magnetic element and is positioned relative to an edge of the mask.

According to some embodiments, modulating the particles in the carrier via a magnetic field includes attracting the particles via a first magnetic element disposed in the carrier and a second magnetic element surrounded by the first magnetic element, wherein a magnetic field strength of the first magnetic element is greater than a magnetic field strength of the second magnetic element.

According to some embodiments, the mask comprises a mask used in a lithographic exposure process.

According to some embodiments, modulating the particles in the carrier by a magnetic field comprises generating the magnetic field by at least one electromagnet adjacent to a position at which the mask is placed in the lithographic exposure apparatus, wherein the magnetic field is generated during generation of the gas flow around the mask.

According to some embodiments, transporting the carrier together with a mask supported by the carrier in the lithographic exposure apparatus comprises placing the mask in a load lock chamber of the lithographic exposure apparatus and creating a gas pressure in the load lock chamber that is compatible with the carrier in the predetermined next position, wherein a gas flow is generated when the carrier is in the load lock chamber.

According to some embodiments, the gas flow is generated when a lid and a substrate of the carrier are separated.

According to some embodiments, a carrier for storing shades is provided. The carrier includes a substrate having an inner region and an outer region surrounding the inner region, wherein the substrate includes a plurality of stubs disposed at a boundary of the inner region and the outer region. The carrier further includes an upper cover connected to the substrate to form a space for accommodating the mask. The carrier also includes a first magnetic element on one of the base plate and the cover, wherein a projection of the first magnetic element overlaps an interior region of the base plate.

According to some embodiments, the carrier further comprises a second magnetic element, wherein the first magnetic element and the second magnetic element are respectively located on the substrate and the cover.

According to some embodiments, the carrier further comprises a second magnetic element, wherein the first magnetic element and the second magnetic element are both located on one of the base plate and the lid, and the second magnetic element is surrounded by the first magnetic element, wherein a magnetic field strength of the first magnetic element is greater than a magnetic field strength of the second magnetic element.

According to some embodiments, the first magnetic element has a groove formed in an annular shape, and an outer wall of the groove is located in the outer region and an inner wall of the groove is located in the inner region.

The foregoing has outlined features of several embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may 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 benefits 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 may make various changes, substitutions and alterations herein without departing from the spirit and scope of the present disclosure.

Claims (1)

1. A method of processing a semiconductor wafer, comprising:

transporting a carrier in a lithography exposure apparatus together with a mask supported by the carrier;

adjusting a plurality of particles in the carrier through a magnetic field;

removing the mask from the carrier; and

a photolithography exposure process is performed on a semiconductor wafer in the photolithography exposure apparatus using the mask.

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