Extreme ultraviolet lithography system with exposure tool

Abstract

The embodiment of the utility model provides an extreme ultraviolet lithography system with an exposure tool. The extreme ultraviolet lithography system comprises a chip mounter used for automatically installing a film protecting frame on a mask in the exposure tool; a transparent film having an at least partially opaque pattern; a light source configured to irradiate the transparent film such that the pattern is projected onto a surface of the protective film to generate a reflective pattern; a digital image sensor configured to detect the reflection pattern; and a computer system configured to measure at least one of an angle and a line segment of the reflection pattern and generate an alarm to stop operation of the extreme ultraviolet (EUV) lithography system when the at least one of the angle and the line segment is distorted.

Description

Technical Field

[0001] An embodiment of the utility model relates to an extreme ultraviolet lithography system with an exposure tool. Background Art

[0002] In semiconductor device manufacturing, various types of plasma processes are used to deposit conductive and dielectric material layers on semiconductor substrates, and also for cover etching and selective etching of materials on substrates. One evolving technology for semiconductor manufacturing is extreme ultraviolet (EUV) lithography, which employs scanners that use light in the EUV spectrum of electromagnetic radiation, including wavelengths from about 1 nanometer (nm) to about 100 nm. In such a process, a substrate is secured to a substrate chuck in a processing chamber and a plasma is generated adjacent to the substrate surface. Various techniques have been developed to secure the substrate to the substrate chuck. For example, an electrostatic chuck (ESC) is used to clamp the substrate during a plasma process, which greatly reduces the likelihood of particle formation through abrasion and the like.

[0003] Repellents are used in such semiconductor manufacturing processes to reduce pattern defect rates. Repellents are placed on the reticle (or mask) inside EUV lithography equipment to capture tiny particles that would otherwise adhere to the reticle and inadvertently imprint on the wafer, causing defects in the device being manufactured. Defects in the reticle itself or in the way it is applied to the reticle can also cause similar manufacturing defects, adversely affecting manufacturing yields and costs. Utility Model Content

[0004] Some embodiments of the present invention provide an extreme ultraviolet lithography system with an exposure tool, comprising: a chip mounter for automatically mounting a pellicle frame on a mask within the exposure tool; a transparent film having a pattern that is at least partially opaque; a light source configured to illuminate the transparent film so that the pattern is projected onto the surface of the pellicle to produce a reflection pattern; a digital image sensor configured to detect the reflection pattern; and a computer system configured to measure at least one of an angle and a line segment of the reflection pattern, and to generate an alarm to stop the operation of the extreme ultraviolet (EUV) lithography system when at least one of the angle and the line segment is distorted. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] The present disclosure can be best understood through the following detailed description when read in conjunction with the accompanying drawings. It should be emphasized that, in accordance with industry standard practice, various features are not drawn to scale and are for illustration purposes only. In fact, the size of various features may be arbitrarily increased or reduced for clarity of discussion.

[0006] Figure 1A is a diagram of a lithographic apparatus according to some embodiments.

[0007] Figure 1B is a diagram of a source side and a scanner side according to some embodiments.

[0008] Figure 2A is a diagram of a wafer stage according to some embodiments.

[0009] Figure 2B is a diagram of a pellicle-mask structure according to some embodiments.

[0010] Figure 3A is a diagram of a pattern projection according to some embodiments.

[0011] Figure 3B is a second diagram of a pattern projection according to some embodiments.

[0012] Figure 3C is a third diagram of a pattern projection system according to some embodiments.

[0013] Figure 4A are exemplary patterns according to some embodiments.

[0014] Figure 4B is a second exemplary pattern according to some embodiments.

[0015] Figure 4C is a third exemplary pattern according to some embodiments.

[0016] Figure 4D is a fourth exemplary pattern according to some embodiments.

[0017] Figure 5A and Figure 5B is a diagram of a controller according to some embodiments.

[0018] Figure 6 is a flow chart of a process for inspecting a pellicle using pattern projection, according to some embodiments. DETAILED DESCRIPTION

[0019] The following disclosure provides many different embodiments or examples for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to simplify the present disclosure. Of course, these are merely examples and are not restrictive. For example, in the following description, forming a first feature on or above a second feature may include an embodiment in which the first and second features are formed in direct contact, and also includes an embodiment in which an additional feature is formed between the first and second features. The second feature, so that the first and second features are not in direct contact. In addition, the present disclosure may repeat reference numbers and / or letters in various examples. This repetition is for the purpose of simplicity and clarity, and does not itself dictate the relationship between the various embodiments and / or configurations discussed.

[0020] In addition, for ease of description, terms such as "beneath", "below", "lower", "above", and "upper" are used herein. Spatially relative terms are intended to encompass different orientations of the device or operation in use, in addition to the orientation depicted in the figures. The device / apparatus may be otherwise oriented (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein may likewise be interpreted accordingly. In addition, the term "made of" may mean "comprising" or "consisting of". In the present disclosure, the phrase "one of A, B, and C" means "A, B, and / or C" (A, B, C, A and B, A and C, B and C, or A, B and C), and does not mean one element in A, one element in B, and one element in C, unless otherwise specified.

[0021] As used herein, the term "optical" is intended to be broadly interpreted to include, but not necessarily limited to, one or more components that reflect and / or transmit and / or operate on incident light, and includes, but is not limited to, one or more lenses, windows, filters, wedges, prisms, grisms, gratings, transmission fibers, etalons, diffusers, homogenizers, detectors and other instrument components, apertures, axicons, and mirrors, including multilayer film mirrors, near normal incidence mirrors, grazing incidence mirrors, specular mirrors, diffuse mirrors, and combinations thereof. Furthermore, unless otherwise specified, the term "optical device" as used herein is not meant to be limited to components that operate only within one or more specific wavelength ranges, such as at EUV output light wavelengths, radiation laser wavelengths, wavelengths suitable for metrology, or any other specific wavelengths.

[0022] In this disclosure, the terms "mask", "photomask" and "reticle" are used interchangeably. In this embodiment, the mask is a reflective mask. One embodiment of the mask includes a substrate having a suitable material, such as a low thermal expansion material or fused silica. In various examples, the material includes TiO 2 Doped SiO 2Or other suitable materials with low thermal expansion. The mask includes multiple reflective layers deposited on the substrate. The multilayer film includes multiple film pairs, such as molybdenum-silicon (Mo / Si) film pairs (e.g., a molybdenum layer above or below the silicon layer in each film pair). Alternatively, the multilayer film may include a molybdenum-beryllium (Mo / Be) film pair, or other suitable materials that can be configured to highly reflect EUV light. The mask may also include a capping layer such as ruthenium (Ru) disposed on the ML for protection. The mask also includes an absorption layer deposited on the multilayer film, such as a tantalum boron nitride (TaBN) layer. The absorption layer is patterned to define an integrated circuit (IC) layer. Alternatively, another reflective layer can be deposited on the multilayer film and patterned to define an integrated circuit layer, thereby forming an EUV phase shift mask.

[0023] In various embodiments, the semiconductor substrate is a semiconductor wafer, such as a silicon wafer, or other types of wafers to be patterned. In this embodiment, the semiconductor substrate is coated with a photoresist layer that is sensitive to EUV light. Various components including those described above are integrated together and are operable to perform various lithography exposure processes. The lithography system also includes other modules or is configured to be integrated (or coupled) with other modules.

[0024] A photolithography system is essentially a light projection system. Light is projected through a "mask" or "reticle" that forms a blueprint of the pattern that will be printed on a workpiece, such as a silicon wafer. In various embodiments, the blueprint is four times larger than the intended pattern on the wafer or chip. With the pattern encoded in the light, the system's optics zoom out and focus the pattern onto a light-sensitive silicon wafer. Once the pattern is printed, the system moves the wafer slightly and makes another adjacent or adjacent copy. This process is repeated until the wafer is covered in the pattern, completing one layer of the final semiconductor device. To make a complete microchip, this process is repeated a hundred times or more, placing pattern on top of pattern until the entire device is complete. The size of the features to be printed varies from layer to layer, which means that different types of photolithography systems are sometimes used for different layers, from the latest generation EUV systems for the smallest features to older deep ultraviolet (DUV) systems for the largest features.

[0025] Figure 1A1 is a schematic diagram of an EUV lithography system 10. The EUV lithography system 10 includes an EUV radiation source device 100 for generating EUV light (sometimes referred to herein as the "source side" or one or more of its related parts), an exposure tool 300, such as a scanner, and an excitation laser source device 200. As shown in FIG. 1 , in some embodiments, the EUV radiation source device 100 and the exposure tool 300 are installed on the main floor (MF) of the clean room, while the excitation laser source device 200 is installed on the base floor (BF) below the main floor. Each of the EUV radiation source device 100 and the exposure tool 300 is placed on a pedestal plate PP1 and a pedestal plate PP2 via a damper DP1 and a damper DP2, respectively. The EUV radiation source device 100 and the exposure tool 300 are coupled to each other at a junction 330 by a coupling mechanism, and the coupling mechanism may include a focusing unit (not shown).

[0026] The EUV lithography system 10 is designed to expose a photoresist layer to EUV light (or EUV radiation). The photoresist layer is a material that is sensitive to EUV light. The EUV lithography system 10 uses an EUV radiation source device 100 to generate EUV light with a wavelength range between about 1 nanometer (nm) and about 100 nm. In one embodiment, the EUV radiation source device 100 generates EUV light with a wavelength centered at about 13.5 nm. In various embodiments, the EUV radiation source device 100 generates EUV radiation using a laser produced plasma (LPP).

[0027] like Figure 1A As shown, the EUV radiation source device 100 includes a target droplet generator 115 and an LPP collector 110, which are surrounded by a chamber 105. The target droplet generator 115 generates a plurality of target droplets 116. In some embodiments, the target droplets 116 are tin (Sn) droplets. In some embodiments, the target droplets 116 have a diameter of about 30 microns (μm). In some embodiments, the target droplets 116 are generated at a rate of about fifty droplets per second and are introduced into the excitation region 106 at a speed of about seventy meters per second (m / s or mps). Other materials can also be used for the target droplets 116, for example, a liquid material such as a eutectic alloy containing tin (Sn) and lithium (Li).

[0028] As the target droplets 116 move through the excitation region 106, a pre-pulse of the laser (not shown) first heats the target droplets 116 and converts them into a lower density target plume. Then, a main pulse 232 of laser light is directed through a window or lens (not shown) into the excitation region 106 to convert the target plume into an LPP. The window or lens is made of a suitable material that is substantially transparent to the pre-pulse and main pulse 232 of the laser. The generation of the pre-pulse and main pulse 232 is synchronized with the generation of the target droplets 116. In various embodiments, the pre-heating laser pulse has a spot size of about 100 μm or less, and the main laser pulse has a spot size of about 200-300 μm. The delay between the pre-pulse and the main pulse 232 is controlled to allow the target plume to form and expand to an optimal size and geometry. When the main pulse 232 heats the target plume, a high temperature LPP is generated. The LPP emits EUV radiation, which is collected by one or more mirrors of the LPP collector 110. More specifically, the LPP collector 110 has a reflective surface that reflects and focuses EUV radiation for a photolithography process. In some embodiments, a droplet catcher 120 is mounted opposite the target droplet generator 115. The droplet catcher 120 is used to capture excess target droplets 116, such as one or more target droplets 116 that are missed intentionally or otherwise by the pre-pulse or main pulse 232.

[0029] As shown in the figure, the target droplet generator 115 generates tin droplets along the vertical axis. Each droplet is CO 2 The droplet is hit by a laser pre-pulse (PP). The droplet changes its shape into a pancake accordingly during its axial movement. After a certain duration (PP to MP delay time), the pancake is hit by a CO laser near the primary focus (PF). 2 The laser main pulse (MP) strikes to generate EUV light pulses. The EUV light pulses are then collected by the LPP collector 100 and transmitted to the exposure tool 300 for wafer exposure.

[0030] The LPP collector 110 includes appropriate coating materials and shapes to act as a mirror for EUV collection, reflection, and focusing. In some embodiments, the LPP collector 110 is designed to have an elliptical geometry. In some embodiments, the coating material of the collector 100 is similar to the reflective multilayer film of the EUV mask. In some examples, the coating material of the LPP collector 110 includes a multilayer film, such as a plurality of molybdenum / silicon (Mo / Si) film pairs, and may further include a capping layer (e.g., ruthenium (Ru)) coated on the multilayer film to fully reflect EUV light.

[0031] The main pulse 232 is generated by the excitation laser source device 200. In some embodiments, the excitation laser source device 200 includes a preheating laser and a main laser. The preheating laser generates a pre-pulse for heating or preheating the target droplets 116 to produce a low-density target plume, which is then heated (or reheated) by the main pulse 232, thereby generating an increase in the emission of EUV light.

[0032] The excitation laser source device 200 may include a laser generator 210, a laser light guide optical device 220, and a focusing device 230. In some embodiments, the laser generator 210 includes a carbon dioxide (CO 2 ) laser source or a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser source. The laser light 231 generated by the laser generator 210 is guided by the laser light guide optical device 220, and is focused by the focusing device 230 into a main pulse 232 of the excitation laser, and then introduced into the EUV radiation source device 100 through one or more apertures, for example, the above-mentioned window or lens.

[0033] In such an EUV radiation source arrangement 100, the LPP generated by the main pulse 232 generates physical debris, such as ions, gases and atoms of the droplet 116, along with the desired EUV light. In operation of the lithography system 10, there is an accumulation of such debris on the LPP collector 110, and such physical debris leaves the chamber 105 and enters the exposure tool 300 (i.e., the "scanner side") and the excitation laser source arrangement 200.

[0034] In various embodiments, the buffer gas is supplied from the first buffer gas supply 130 through a hole in the LPP collector 110 through which the main pulse 232 of laser light is delivered to the tin droplets 116. In some embodiments, the buffer gas is hydrogen (H 2 ), helium (He), argon (Ar), nitrogen (N 2 ) or another inert gas. In certain embodiments, H 2 , because the H radicals generated by the ionization of the buffer gas can also be used for cleaning purposes. In addition, H 2 The least amount of EUV light generated by the source side is absorbed, and therefore the least amount of light used by semiconductor manufacturing operations performed on the scanner side of the lithographic apparatus 10 is absorbed. Buffer gas may also be provided toward the LPP collector 110 and / or around the edge of the LPP collector 110 by one or more second buffer gas supplies 135. In addition, and as described in more detail later below, the chamber 105 includes one or more gas outlets 140 so that the buffer gas is exhausted outside the chamber 105.

[0035] Hydrogen has a low absorption of extreme ultraviolet radiation. The hydrogen reaching the coating surface of the LPP collector 110 chemically reacts with the metal of the target droplet 116 to form a hydride, such as a metal hydride. When tin (Sn) is used as the target droplet 116, stannane (SnH) is formed as a gaseous byproduct of the EUV generation process. 4 ). Then, the gaseous SnH 4 However, it is difficult to exhaust all the gaseous SnH from the chamber. 4 And prevent Sn debris and SnH 4 Enter the exposure tool 300 and the excitation laser source device 200. In order to capture Sn, SnH 4 or other debris, one or more debris collectors 150 or debris collection devices 150 are used in the chamber 105. In various embodiments, the computer system 500 controls the EUV lithography system 10 and / or its components described above with respect to Figure 1A One or more components as shown and described.

[0036] like Figure 1B As shown, the exposure tool 300 (sometimes referred to herein as the "scanner side", referring to it or one or more of its related components) includes various reflective optical components, such as convex / concave / plane mirrors, a mask holding mechanism 310 including a mask stage (i.e., a reticle stage), and a wafer holding mechanism 320. The EUV radiation generated by the EUV radiation source device 100 and focused at the intermediate focus 160 is directed by the reflective optical component 305 to a mask (not shown) fixed on a mask plate platform 310 (also referred to as a "mask stage") in the processing chamber 306 (here). In various embodiments of the EUV lithography system 10, the pressure in the LPP source side is higher than the pressure in the scanner side. This is because the source side uses hydrogen gas to forcefully remove tin (Sn) debris in the air, while the scanner side is maintained near vacuum to avoid weakening the intensity of the EUV light (absorbed by air molecules) or otherwise interfering with the semiconductor manufacturing operations performed therein. In various embodiments, the intermediate focus 160 is set at the junction 330, i.e., the intersection of the source side and the scanner side.

[0037] In some embodiments, the distance between the intermediate focus 160 and the mask disposed on the scanner side is approximately 2 meters. In some embodiments, the mask size is approximately 152 mm by 152 mm. In some embodiments, the mask plate platform 310 includes an electrostatic chuck or "e-chuck" to secure the mask. EUV light patterned by the mask is used to process a wafer supported on a wafer stage 320. Because gas molecules absorb EUV light, the chambers and areas of the lithography system 10 used for EUV lithography patterning are maintained in a vacuum or low pressure environment to avoid EUV intensity loss. Nevertheless, a debris collector 370 similar in purpose and design to the debris collector 150 can be disposed on the scanner side to process and remove contaminants and residues that may accumulate in components on the scanner side. In various embodiments, the computer system 500 controls the following: Figure 1B Shown and about Figure 1B One or more components of EUV lithography system 10 are described.

[0038] Figure 2A 3 is a diagram of a wafer stage 320 placed within an exposure tool 300 of an EUV lithography system 10 according to some embodiments. The wafer stage 320 includes a wafer clamp 322, also referred to herein as a chuck. In various embodiments, the chuck 322 is an electrostatic chuck (ESC) disposed within the processing chamber 306, and the ESC is configured to receive a substrate 326. According to various embodiments, the substrate 326 includes a wafer, a silicon substrate, or any other useful wafer, workpiece, or substrate. In various embodiments, the chuck 322 also includes an internal chuck electrode (not shown) and a direct current (DC) power supply connected to the chuck electrode to provide power thereto.

[0039] In various embodiments, the substrate 326 is clamped by the chuck 322 by an electrostatic potential. In various embodiments, when a DC voltage from a DC power supply (not shown) is applied to the chuck electrode of the chuck 322 on which the substrate 326 is disposed, a Coulomb force is generated between the substrate 326 and the chuck electrode. The Coulomb force attracts and holds the substrate 326 on the chuck 322 until the application of the DC voltage from the DC power supply is stopped. In various embodiments, the DC voltage applied ranges from about 2000 volts to about 3200 volts. In some embodiments, the DC voltage applied is 3000 volts. In some cases, the DC power supply is configured to apply a DC voltage of about 10% to about 90% of the power applied during normal etching operations using direct current. In various embodiments, the DC power supply is configured to apply a DC voltage of about 20% to about 80%, about 30% to about 70%, or about 30% to about 50% of the power applied during normal photolithography operations using direct current. In some embodiments, the DC voltage is applied for a duration of about 10 seconds to about 60 seconds, about 10 seconds to about 50 seconds, about 20 seconds to about 40 seconds, or about 20 seconds to about 30 seconds.

[0040] In various embodiments, the surface of the electrostatic chuck 322 includes a plurality of burls 324 having a width in a range of about 100 μm to about 500 μm and a height in a range of about 1.0 μm to about 100 μm from the surface of the electrostatic chuck 322. In various cases, the burls 324 are spaced apart from each other in a range of about 1.0 μm to about 5.0 μm. In various embodiments, the electrostatic chuck 322 has more than two thousand such burls 324, comprising about 1.5% of the surface area of ​​the electrostatic chuck 322, so as to firmly support the substrate 326.

[0041] In various embodiments, the application of DC power causes particles or contaminants on the surface of substrate 326 to be positively charged. In various embodiments, the application of DC power causes particles or contaminants on the surface of wafer clamp 322 to be negatively charged, which particles or contaminants may be deposited on top of burl 324. In some embodiments, debris particles or contaminants are generated from substrate 326 during photolithography operations and / or due to electrostatic effects of wafer clamp 322. In one or more cases, the debris particles include, but are not limited to, the following elements: Cu, Al, Ni, Ti, O, F, Si, Cu, Al, Ge, Ni, Ti, W, Mo, Fe, Pb, Bi, and In, or alloys or compounds thereof. In some embodiments, the debris particles include, for example, Si x O y 、Al x O y and Ti x O yOver time, surface debris particles and / or contaminants must be removed from the electrostatic chuck 322 to prevent damage to components of the EUV lithography system 10. Various additional operations are performed here to prevent contaminants from migrating to the mask and other components.

[0042] A pellicle is a thin film or membrane that is mounted on a frame and placed over a wafer or mask during the photolithography process. The purpose of the pellicle is to protect such components from dust and other contaminants that could cause defects in the semiconductor device being manufactured. The pellicle is usually made of materials such as polyamide or silicon nitride and acts as a barrier to the photolithography process environment. It is placed on top of the substrate and the mask is placed on top of it. When the substrate is exposed, the mask pattern is transferred to the photoresist through the pellicle. In this way, it protects the photoresist from environmental factors such as dust, debris, and moisture while the pattern is transferred to the substrate.

[0043] Figure 2B is a diagram of a mask pellicle system 360 including a pellicle 301 and a mask 302 according to various embodiments. In some cases, the pellicle 301 includes a pellicle frame 304 and a film 307 (or pellicle) integrated together by an adhesive material layer 308. In various cases, the pellicle 301 and the mask 302 are integrated together by an adhesive material layer 310. In various cases, the mask 302 also includes a boundary area 312 for connecting the pellicle 301, and a circuit area 314 for defining a circuit pattern to be transferred to a semiconductor substrate 326 by a photolithography process. In some embodiments, the mask 302 is integrated into the mask pellicle system 360 and fixed together with the film 307 and the pellicle frame 304 of the pellicle 301 during the photolithography patterning process.

[0044] like Figure 2B As shown in , in various embodiments, the film 307 is configured to be close to the mask 302 and attached to the pellicle frame 304 to the first surface 304a of the adhesive material layer 308. In some cases, the film 307 is connected to the pellicle frame 304 by the adhesive material layer 308. In some embodiments, the mask 302 is further connected to the second surface 304b of the pellicle frame 304 by the adhesive material layer 310. In various cases, the pellicle 301 is attached to the boundary area 312. Therefore, in various examples, the mask 302, the pellicle frame 304 and the film 307 are configured and integrated to enclose the internal space. In various embodiments, the circuit area 314 of the mask 302 is enclosed in the internal space and is therefore protected from contamination during the photolithography patterning process and during mask handling and transportation.

[0045] In various embodiments, the film 307 is made of a thin film that is transparent to at least 13nm radiation and other wavelengths in the extreme ultraviolet band used in the EUV lithography patterning process, and reflects radiation in other bands, such as infrared, visible light, and ultraviolet wavelengths between about 200nm and about 1500nm. In some embodiments, the film 307 has a thermally conductive surface. In some cases, the film 307 is also configured to be close to the circuit area 314 on the mask 302. In various embodiments, the film 307 includes a transparent material layer having a thermally conductive film on one or both surfaces. In one or more embodiments, the film 307 is at least partially composed of silicon. In various cases, the length and width of the film are between 200 millimeters (mm) and 450 millimeters, and the thickness is in the range of 25 to 50 microns (μm).

[0046] In further embodiments, the mask pellicle system 360 includes a pellicle frame 304 configured so that a film 307 can be attached and secured to the pellicle frame 304. The pellicle frame 304 is designed with various sizes, shapes, and configurations. In alternative embodiments, the pellicle frame 304 has a single component or multiple components. In various embodiments, the pellicle frame 304 includes a material having sufficient mechanical strength and is designed with a size, shape, and configuration to properly secure the film 307 across the pellicle frame 304. In various embodiments, the pellicle frame 304 has a second surface 304b disposed on the adhesive material layer 310.

[0047] In various embodiments, the film frame 304 includes metal, metal alloy or ceramic material, including but not limited to: Ti, Ti 6 Al 4V, TiSi, Fe-Ni (INVAR), Fe-Ni-Co (Covar), or a combination thereof. In some embodiments, the metal or metal alloy material is doped with Cu, W, Mo, Cr, or a combination thereof. In one or more embodiments, the pellicle frame 304 is made of a material that provides selected properties, including: high mechanical strength, light weight, porosity, and / or thermal conductivity. In one or more embodiments, the pellicle frame 304 is formed by injection molding, compression molding, lathe, milling machine, laser cutting, sintering, or a combination thereof. In one or more embodiments, the pellicle frame 304 includes a low thermal expansion material (LTEM). In one or more embodiments, the pellicle frame 304 is made of a material having a thermal expansion coefficient similar to that of the substrate 302 and the film 307. Since the mask pellicle system 360 is used for lithography processes in a temperature range of about room temperature to about 150°C, providing a substrate 302, a pellicle frame 304, and a film 307 with similar thermal expansion coefficients helps alleviate the problem of differential expansion caused by material changes with temperature. In one or more embodiments, the coefficient of thermal expansion of the pellicle frame 304 is comparable to that of silicon.

[0048] In various embodiments, the adhesive material layer 310 includes an adhesive 310a (or glue), including but not limited to silicon, acrylic, epoxy, thermoplastic elastomer rubber, one or more acrylic polymers or copolymers, or a combination thereof. In some instances, the adhesive 310a includes methyl methacrylate. In various embodiments, the adhesive 310a includes a gel-like material. In various embodiments, the adhesive 310a is a crystalline and / or amorphous structure. In one or more embodiments, the maximum operating temperature of the adhesive 310a is the maximum temperature reached during the photolithography process. In some embodiments, the maximum operating temperature ranges from about room temperature to about 100°C. In one or more embodiments, the adhesive 310a may include a thermally conductive component to enhance thermal conduction within the adhesive material layer 310 and between the mask 302 and the pellicle frame 304. The enhanced heat conduction results in more uniform heating and smaller temperature gradients, thereby improving the transition of the adhesive 310a from a glassy state to a rubbery state. In various embodiments, the adhesive 310a exhibits other desirable properties, such as high mechanical strength, few defects, little outgassing, EUV compatibility (no significant degradation under EUV radiation), sustainability to high use temperatures, or combinations thereof.

[0049] In various embodiments, the second surface 304b undergoes a surface treatment of oxidation or nitridation. In some embodiments, the oxidation or nitridation is performed by a physical vapor deposition (PVD) process or a furnace process. In other embodiments, a surface coating (not shown) is applied to the second surface 304b. In some embodiments, the surface coating is applied by PVD or electroplating, which includes applying a metal or metal alloy, including W, Mo, Ni, Fe, Cr, Ti, Al or a combination thereof. In various cases, the surface treatment and / or surface coating enhances the bonding strength between the second surface 304b and the adhesive 310a. In various embodiments, the pattern 331 is formed using a photolithography patterning process applied to the second surface 304b.

[0050] Prior to being mounted on the mask 302, the pellicle 307 is visually inspected for uniformity and defect-free appearance. In some cases, after the pellicle 307 is mounted on the pellicle frame 304, the pellicle 307 is visually inspected again in the same manner. Uneven application of the pellicle 307 to the frame 304, or improper handling of the pellicle 301 after mounting, can cause the pellicle 307 to wrinkle or tear. If wrinkles, tears, contamination, or other defects are found on the pellicle 301 during any of the above inspections, the production process is stopped and the pellicle 301 is replaced to avoid such defects being optically transferred to the wafer during the lithography operation and exposing the mask 302 to contamination. In contrast, if the pellicle 307 appears to be defect-free, it is sent for air blade processing before being placed in the exposure tool 300 in preparation for the lithography operation. Direct visual inspection by a human inspector may inadvertently overlook small defects and in some cases fail to prevent lithography process errors. Therefore, automated inspection processes were introduced to avoid interruptions caused by various pellicle defects, including wrinkles, tears, contamination, and ruptures.

[0051] One property of various silicon (Si) films of EUV pellicles is that they reflect light of various wavelengths outside the EUV range like a mirror. To improve the accuracy of defect identification, it has been found that the reflective properties of film 307 in the wavelength range of 200nm to 1500nm are useful for enabling automated detailed inspection of EUV pellicle 30 itself. In particular, in various embodiments, a pattern is projected onto the surface of film 307 of pellicle 301 and the reflection of the pattern is analyzed to look for any distortion caused by defects in film 307.

[0052] Figure 3A3 is a first diagram of a pattern projection system according to various embodiments. In some embodiments, the pattern projection system is integrated with an automounter (not shown) that mounts the mask pellicle system to a mask stage above a wafer stage 320 within an exposure tool 300. In various cases, the automounter is programmed to initiate an inspection process once the mask pellicle system 360 is placed in the exposure tool 300 and is ready for operation, and to perform the inspection before starting a photolithography operation on a semiconductor wafer. In various cases, the pattern projection system includes a light source 365, a patterned film 366, and a light sensor 380. In one or more embodiments, the light source 365 generates light at one or more wavelengths between 200 nm and 1500 nm, and such light is directed through the patterned film 366 so that a shadow 367 of the pattern therein is projected on the film 307 of the pellicle 300. To maximize defect detection, in various cases, the shadow 367 extends along the entire length and width of the pellicle 301. In some cases, the shadow 367 extends just beyond the boundaries of the film 307 to ensure that the entire film is inspected. In other cases, the boundaries of shadow 367 extend just to the inner edge of the boundaries of film 307. In some embodiments, light sensor 380 detects the image of shadow 367 and automatically performs analysis to measure features of shadow 367 (e.g., lines or arc segments with a pattern and distances or angles between them) and compares such measurements with stored data values ​​of the pattern being used. Alternatively or in addition, in embodiments where the pattern includes regular shapes (e.g., regular polygons), the regularity of line or arc segments, distances, angles, etc. is measured and compared with other line or arc segments, distances, angles, and the like in shadow 367 for consistency, without reference to any stored values ​​of the original pattern. In some embodiments, a combination of these two methods is used. In various cases, the entire pattern formed by shadow 367 is examined. If any differences are found in the pattern based on this comparison, defects in pellicle 301 are identified at the corresponding locations, and the photolithography process is stopped when pellicle 301 is replaced in various embodiments.

[0053] In some embodiments, light source 365 is at least one of an infrared light source, a visible light source, a UV-A light source, a UV-B light source, and a UV-C light source. In various cases, light source 365 operates at one or more wavelengths between 200 nm and 1500 nm. In some cases, light source 365 is a unidirectional light source. In other embodiments, light source 365 is an omnidirectional light source. In some cases, light source 365 includes one or more bulbs and / or light emitting diodes (LEDs) to generate light.

[0054] In some embodiments, the patterned film 366 is a thin transparent film, such as mylar, etc., on which an at least partially opaque pattern is formed to be projected onto the protective film 301. In some embodiments, the pattern is applied to the patterned film 366 or formed together with the patterned film 366 by ink, metal or other opaque substances in a variety of ways, such as laser printing, inkjet printing, pattern transfer methods, metal deposition, etc. In various cases, the pattern includes a plurality of adjacent regular polygons or concentric circles to help check the shadow 367 generated by the pattern, as further described below. In some cases, the light source 365 includes one or more patterned lenses or similar optical components to directly generate the pattern without using an intermediate patterned film 366.

[0055] In various embodiments, light sensor 380 is a digital image sensor configured to detect light at one or more wavelengths between 200 nm and 1500 nm that match the wavelengths generated by light source 365. In some cases, light sensor 380 includes a charge coupled device (CCD). In some cases, light sensor 380 includes a processor and appropriate programming for analyzing shadow 367 to determine various length, distance, and angle measurements of the pattern therein. In other cases, data collected by light sensor 380 is transmitted to computer system 500 for such processing. In yet other embodiments, processing is performed in part by light sensor 380 and computer system 500 in cooperation.

[0056] Figure 3B 368 is a second diagram of a pattern projection system according to various embodiments. In some cases, inspection will reveal anomalies 368, such as deformations or differences in one or more lengths, distances, or angles of the pattern within shadow 367, which are damage or defects in the film 307 of the overcoat 301 of the projected pattern caused by underlying physical wrinkles, tears, contamination, etc. In some cases, anomalies 368 of appropriate size will be visible to the human eye. In other cases, anomalies 368 are small and can only be detected by machine inspection, such as optical sensor 380. In various cases, more than one anomaly 368 is present in various portions of the film 307 and is detected during inspection.

[0057] Figure 3C 3 is a third diagram of a pattern projection system according to various embodiments. In one or more cases, light passes from light source 365 through transparent film 366 at an angle less than 90 degrees from perpendicular (i.e., non-perpendicular) to allow separation between light source 365 and light sensor 380 to prevent any interference between them from stray light. In this case, the angle is between 5 degrees and 85 degrees. Thus, in those cases, the incident angle of shadow 367 from the pattern of patterned film 366 to the facing surface of film 307 (at Figure 3C 'a' in Fig. 3 is also between 5 and 85 degrees. As the angle of incidence increases from 5 degrees, the shadow 367 becomes less exaggerated. In one or more embodiments, the angle of incidence and the distance of the patterned film 366 from the film 307 are provided as inputs to the light sensor 380 and / or the computer system 500 to improve pattern recognition and measurement during the inspection process. In various embodiments, geometric corrections are made, if necessary, for such exaggerations in length or angle caused by the angle of incidence.

[0058] Light of the appropriate wavelength will then be reflected at an angle substantially equal to the angle of incidence ( Figure 3C The light sensor 380 is positioned and tilted (i.e., at the same angle as the reflection angle) to optimally receive the reflected light from the surface of the film 307 of the pellicle 301 for capture and subsequent analysis. In various cases, the distance of the light sensor 380 from the surface of the film 307 is determined and provided as an input to the light sensor 380 and / or the computer system 500 to further improve the accuracy of the pattern recognition and the measurements performed thereby during the inspection process.

[0059] Various types of patterns can be used for projection and measurement according to the methods described herein. In various embodiments, the pattern includes one or more individual and / or adjacent shapes, including but not limited to: triangles, squares, rectangles, circles (single or concentric), ellipses, ovals, pentagons, hexagons, heptagons, octagons, enneagons, decagons, other regular polygons, irregular polygons, honeycomb patterns, etc. When regular shapes are used, the ease of analysis is improved because simpler and more computationally efficient mathematics will be used for automatic pattern recognition and measurement calculations compared to irregular or complex shapes. Deformities or differences in patterns of regular shapes are generally easier to identify in manual inspections than complex patterns, especially when the size of such defects is reduced. However, the embodiments herein are not limited to this.

[0060] Figure 4AA first exemplary pattern 400 that can be used in a pattern projection system according to various embodiments is shown. In some embodiments, the pattern 400 includes a plurality of concentric circles having a maximum diameter 402 and radial spacing 404. In some embodiments, given that the film 307 used in photolithography is generally rectangular, the concentric circles extend beyond the maximum length and width of the film 307 when projected thereon so as to provide coverage across the entire film 307 without any portion being uncovered for inspection purposes. In some embodiments, the diameter of the smallest concentric circle is at or above the bottom end of the resolution range of the light sensor 380 used to measure it (e.g., in the range of 5-10 nm). Similarly, the radial spacing 404 of the concentric circles is greater than the minimum resolution range of the light sensor 380, i.e., at least 5-10 nm. In some embodiments, the maximum diameter 402 is between 205 mm and 500 mm to cover the entire film 307. In some embodiments, a spiral is used in a similar manner instead of concentric circles. In some embodiments, one or more nested ovals or ellipses are used in a similar manner instead of concentric circles.

[0061] During the inspection process, various circles in the pattern 400 are identified, such as by a pattern recognition algorithm in various embodiments. In various cases, any distortion in one or more circles, such as a missing portion of an arc or a change in radial spacing 404 from adjacent circles, is identified as a defect in the film 307. In various embodiments where the pattern 400 extends beyond the border of the film 307, the location of the endpoints of any overextended circles is recorded, and any defects extending beyond the border of the film 307 are programmatically ignored. For such purposes, the location of the border of the film 307 is provided as an input to the optical sensor 380 and / or computer system 500 or is programmatically identified by the optical sensor 380 and / or computer system 500 for use in improving the inspection process in various embodiments.

[0062] Figure 4B A second exemplary pattern 410 that can be used in a pattern projection system according to various embodiments is shown. In some embodiments, pattern 410 includes a plurality of triangles formed by line segments 414 and having three interior angles 412. In some cases, one or more triangles are separated from other triangles within the pattern. In some cases, one or more triangles are as shown. Figure 4B307. In some cases, adjacent triangles form a complete rectangle at the periphery of the membrane 307 boundary. In various cases, the triangle is an isosceles triangle. In some cases, the triangle is a right triangle. In some embodiments, each interior angle between any two sides of the triangle is between 5 and 170 degrees. In some embodiments, line segment 414 has a minimum length corresponding to the lowest resolution of light sensor 380 and a maximum length corresponding to the longest boundary length of membrane 307. In some cases, two interior angles 412 of the right triangle are both 45 degrees. In other cases, the two remaining interior angles 412 of the right triangle have different values ​​that add up to 90 degrees.

[0063] During the inspection process, various triangles in the pattern are identified, such as by a pattern recognition algorithm in various embodiments. In various cases, any distortion in one or more triangles, such as missing portions of its line segments 414 or changes in its internal angles 414, is identified as a defect in the film 307.

[0064] Figure 4C A third exemplary pattern 420 that can be used in a pattern projection system according to various embodiments is shown. In some embodiments, the pattern includes a plurality of rectangles formed by line segments 422 and having four equal 90 degree interior angles 424. In some cases, one or more rectangles are separated within the pattern. In some cases, one or more rectangles are as shown. Figure 4C In some cases, the adjacent rectangles form a complete rectangle at the periphery of the film 307 at the border. In various cases, the rectangle is a square. In some embodiments, line segment 414 has a minimum length corresponding to the minimum resolution of light sensor 380 and a maximum length corresponding to the longest border length of film 307.

[0065] During the inspection process, various rectangles in pattern 420 are identified, such as by a pattern recognition algorithm in various embodiments. In various cases, any deformation in one or more rectangles, such as missing portions of its line segments 422 or changes in its internal angles 424, is identified as a defect in film 307.

[0066] Figure 4D A fourth exemplary pattern 430 that can be used in a pattern projection system according to various embodiments is shown. In some embodiments, pattern 430 includes a plurality of polygons formed by more than four line segments 414 and having five or more interior angles 412. In some cases, one or more polygons are separated within the pattern. In some cases, one or more polygons are as shown. Figure 4B434. In some embodiments, the polygon is a regular polygon with an even number of connected line segments 432 and a constant internal angle 434. In some embodiments, the polygon is a pentagon (with a constant internal angle 434 of 108 degrees), a hexagon (such as Figure 4C 307 , and having a constant interior angle 434 of 120 degrees), a heptagon (having a constant interior angle 434 of 128.57 degrees), an octagon (having a constant interior angle 434 of 135 degrees), a nonagon (having a constant interior angle 434 of 140 degrees), and a decagon (having a constant interior angle of 144 degrees). Based on the resolution of light sensor 380 and the size of the polygons within the pattern, polygons larger than a decagon have increasing interior angles 434 that get closer and closer to 180 degrees, which are increasingly unable to be consistently distinguished and are therefore useless in various embodiments. In some embodiments, line segments 414 are all equal and have a minimum length corresponding to the minimum resolution of light sensor 380 and a maximum length corresponding to the longest border length of film 307. In other cases, the polygons are irregular polygons.

[0067] During the inspection process, various polygons in pattern 430 are identified, such as by a pattern recognition algorithm in various embodiments. In various cases, any deformation in one or more polygons, such as missing portions of its line segments 432 or changes in its internal angles 434, is identified as a defect in film 307.

[0068] Figure 5A and Figure 5B Illustrated is a computer system 500 for controlling the system 10 and its components according to various embodiments of the present disclosure. Figure 5A is a schematic diagram of an example of computer system 500. In some embodiments, computer system 500 is programmed to initiate a process for inspecting pellicle 301 of system 10 and provide an alarm when an error is detected on its surface. In some embodiments, the manufacture of semiconductor devices is stopped in response to such an alarm. Figure 5A As shown, computer system 500 is equipped with a computer 501, including a disc read-only memory (e.g., CD-ROM or DVD-ROM) drive 505 and a disk drive 506, a keyboard 502, a mouse 503 (or other similar input devices), and a monitor 504.

[0069] Figure 5B This is a diagram showing an example of the internal structure of the computer system 500. Figure 5BIn the embodiment, the computer 501 is provided with one or more processors 511, such as a micro-processor unit (MPU) or a central processing unit (CPU), in addition to an optical drive 505 and a magnetic disk drive 506; a read-only memory (ROM) 512, in which programs such as boot programs are stored; a random access memory (RAM) 513, connected to the processor 511, temporarily storing commands for application programs and providing a temporary electronic storage area; a hard disk 514 for storing application programs, operating system programs and data; and a data communication bus 515 connecting the processor 511, ROM 512, etc. Note that in some embodiments, the computer 501 includes a network card (not shown) for providing a connection to a computer network, such as a local area network (LAN), a wide area network (WAN), or any other useful computer network, for transmitting data used by the computer system 500 and the system 10. In various embodiments, the computer system 500 communicates with the system 10 and its components via a wireless or wired connection, as described herein.

[0070] In various cases, a program for causing the computer system 500 to perform processes for controlling the system 10 and its components and / or performing processes for manufacturing semiconductor devices according to the embodiments disclosed herein is stored in the optical disk 521 or the magnetic disk 522, inserted into the optical disk drive 505 or the magnetic disk drive 506, and transferred to the hard disk 514. In an alternative embodiment, the program is transmitted to the computer system 500 via a network (not shown) and stored in the hard disk 514. When executed, the program is loaded into the RAM 513. The program is loaded from the optical disk 521 or the magnetic disk 522, or directly from the network in various embodiments.

[0071] The stored program does not necessarily have to include, for example, an operating system (OS) or a third-party program to enable the computer 501 to perform the methods disclosed herein. In some embodiments, the program may only include a command portion to call the appropriate function (module) in a controlled mode and obtain the desired result. In various embodiments described herein, the computer system 500 communicates with the lithography system 10 to control its various functions.

[0072] In various embodiments, a computer system 500 is coupled to the system 10. The computer system 500 is configured to provide control data to those system components and to receive process and / or status data from those system components. For example, the computer system 500 includes a microprocessor, a memory (e.g., volatile or non-volatile memory), and a digital I / O terminal that is capable of generating control voltages sufficient to communicate and initiate processing system inputs, and monitor outputs from the lithographic apparatus 10. In addition, a program stored in the memory is used to control the above-mentioned components of the lithographic system 10 according to a process recipe. In addition, the computer system 500 is configured to analyze process and / or pattern data, compare the process and / or pattern data with target process and / or pattern data, and use the comparison to change process and / or control system components. In addition, the computer system 500 is configured to analyze process and / or pattern data, compare the process and / or pattern data with historical process and / or stored data, and use the comparison to predict, prevent, and / or declare a fault or alarm due to a film defect when an anomaly 368 is found.

[0073] Figure 6 6 is a flow chart of an inspection process 600 according to various embodiments. In some embodiments, the inspection process 600 is controlled by the computer system 500 and / or the optical sensor 380. In various embodiments, the inspection process 600 begins at operation 602 when the film 307 on the frame 304 of the pellicle 301 is visually inspected before being mounted on the mask 602. In some cases, the automated inspection operation described below is used in place of the manual visual inspection. If defects are found, the film 307 is replaced and the process 600 is restarted. When no obvious defects are found, the process 600 next involves providing an air knife or similar cleaning process to the film 307 (operation 604) in one or more embodiments.

[0074] Thereafter, in various embodiments, pellicle 301 is mounted to mask 302 in any of the ways described above (operation 606). After mounting, in some embodiments, pellicle 301 of film 307 is again inspected and replaced if defects or deformations are found (operation 608). In some cases, an automated inspection operation, described below, is used in place of manual visual inspection. When film 307 remains free of defects, in various embodiments, it is then loaded into exposure tool 300 over wafer 326 (operation 610) so that it and mask 302 are protected during photolithography operations. In some embodiments, an automated mounter is used to automatically load and unload mask pellicle structure 360 ​​from exposure tool 300. In some embodiments, the automated mounter includes a pattern projection system including light source 365, patterned film 366, and light sensor 380, as previously described.

[0075] With the mask pellicle system 360 in place, the pattern projection system projects a pattern onto the surface of the film 307 of the pellicle 301 at a known angle of incidence and distance from the surface (operation 612). In some cases, the projection of the pattern is arranged so that the pattern size is projected exactly at the same size onto the surface of the film 307. In alternative embodiments, the projected pattern is larger or smaller than the size of the actual pattern.

[0076] Next, the light sensor 380 receives the reflected pattern and is programmed to determine, alone and / or in conjunction with the computer system 500, whether there is a distortion in the reflected pattern (operation 614). In various embodiments, and as further described later, a distortion, anomaly 368, etc. is identified when one or more arcs, line segments, or internal angles measured from the reflected pattern do not match expected values. In some cases, the line segments, arc segments, radial distances, or internal angles measured at a given location in the reflected pattern are compared to stored or measured values ​​of the pattern on the patterned film, and any necessary geometric corrections are made based on the angles. The pattern is compared to the surface of the film 307 for consistency in occurrence and distance. In other cases, the measured values ​​are instead compared to other occurrences of such line segments, arc segments, or angles within the reflected pattern itself, particularly when the pattern includes regular shapes with repeating, uniform, line segments, arc segments, and internal angles. Such measurements and comparisons occur dozens, hundreds, or tens to thousands of times to cover every shape in the projected pattern during a single inspection process for a single wafer 326. Thus, the speed at which the inspection is performed will affect the overall manufacturing throughput. When any measured value is inconsistent with an expected stored value or measured value, in this case, an anomaly is identified 368 .

[0077] Next, at operation 616, when anomaly 368 is identified, an alarm is triggered by computer system 500 and the photolithography process is stopped while pellicle 301 is replaced and re-inspected as previously described. After replacement and successful inspection, the automounter and pattern projection system are removed from exposure tool 300 and the photolithography process is started (operation 618).

[0078] In various embodiments described above, reference has been made to the automatic measurement and analysis of one or more reflected patterns by the light sensor 380 and the computer system 500. In some cases, such analysis and measurement is performed by a suitable resident programmed artificial intelligence (AI) module that is programmed with expected values ​​for measured segments, arcs, other distances, and internal angles of the current shape in the reflected pattern. In other cases, a machine learning algorithm has been programmed with the results of previous detections of anomalies 368 in previous inspections to learn from them, as an alternative or additional use to the AI ​​module. In some cases, the comparison of the reflected pattern of the measured value with the original pattern is performed by examining the reflection of the pattern using an artificial intelligence module that measures multiple angles within the reflection of the pattern and identifies a distorted reflection of the pattern when at least one of the measured angles does not match a stored angle value. In some cases, the AI ​​module is used to examine the reflection of the pattern to measure multiple distances within the reflection of the pattern and identify distortion or difference when at least one of the measured distances in the reflection of the pattern does not match a stored expected distance value. In some cases, the AI ​​module measures at least one of the segment lengths, distances, and internal angles of the shape in the pattern and identifies distortion when at least one of them does not match a stored expected value. In various cases, the stored expected values ​​are based on the values ​​of line segments, distances, and internal angles present in the patterned film 366. In some cases, the AI ​​module measures at least one of the following: the lengths of a plurality of parallel line segments within the pattern and a plurality of angles between the parallel line segments within the pattern, and identifies the distorted parallel line segment when (i) at least one of the plurality of parallel line segments does not match the lengths of the remaining parallel line segments within the reflection, and (ii) at least one of the plurality of angles does not match another angle within the reflection. In some embodiments, the machine learning algorithm is programmed based on human recognition of shadows and blurs in a pattern without reference to a particular angle, distance, or length.

[0079] The present disclosure describes methods and apparatus for inspecting pellicles to prevent wrinkling, tearing, and cracking. Improving the accuracy and speed of such inspections using automated equipment increases the manufacturing throughput of the lithography system 10 due to fewer overlap errors, resulting in improved exposure quality on the scanner side. In various embodiments, EUV pellicle inspection by CCD module AI recognition reduces the use of cracked or damaged pellicles 301 in the tool 300 before and after processing. The disclosed inspection process avoids the risk of equipment and wafer damage and saves manpower, thereby reducing manufacturing process time.

[0080] According to various embodiments, a method for enhancing a semiconductor device manufacturing process includes placing a pellicle on a surface of a mask, projecting a pattern onto the surface of the pellicle, measuring a reflection of the pattern from the pellicle, and when the pattern includes a distortion, triggering an alarm to stop the semiconductor device manufacturing process. In some embodiments, placing the pellicle on the mask also includes adhering the pellicle to a frame and placing the frame on the surface of the mask. In some cases, projecting the pattern also includes activating a light source and directing light through a transparent film having a pattern. In some embodiments, directing the light also includes directing light through the surface of the transparent film at an incident angle between 5 degrees and 85 degrees. In some cases, the reflection angle of the pattern from the surface of the pellicle is between 5 degrees and 85 degrees. In some embodiments, the light has a wavelength between 200nm and 1500nm. In some cases, the pattern includes a plurality of concentric circles with a minimum spacing of 5nm between the circles. In some cases, the pattern includes a plurality of triangles, wherein each triangle has a leg with a minimum length of 5nm and an internal angle between the two legs is between 5 and 170 degrees. In some cases, the pattern includes a plurality of rectangles, wherein each rectangle has a leg with a minimum length of 5 nm and an internal angle between two legs is 90 degrees. In some cases, the pattern includes a plurality of regular polygons, wherein each regular polygon has a side with a minimum length of 5 nm and an internal angle between each side is between 108 degrees and 144 degrees. In some embodiments, the reflection of the pattern is examined with an artificial intelligence module, the module measures multiple angles within the reflection of the pattern, and identifies a distortion value when at least one measured angle in the reflection of the pattern does not match a stored angle. In some embodiments, the reflection of the pattern is examined with an artificial intelligence module, the module measures multiple distances within the reflection of the pattern, and identifies a distorted distance value when at least one measured distance in the reflection of the pattern does not match a stored distance.

[0081] According to various embodiments, a method for enhancing a semiconductor device manufacturing process includes: placing a pellicle on a surface of a mask; projecting a pattern onto the surface of the pellicle; measuring a reflection of the pattern from the pellicle; and when the reflection of the pattern includes distortion, triggering an alarm to stop the semiconductor device manufacturing process.

[0082] In an embodiment of the present invention, placing the protective film on the mask further comprises: adhering the protective film to a frame; and placing the frame on the surface of the mask.

[0083] In an embodiment of the present invention, projecting the pattern further comprises: activating a light source; and guiding the light to pass through a transparent film having the pattern.

[0084] In an embodiment of the present invention, guiding the light further comprises: guiding the light through the surface of the transparent film at an incident angle between 5 degrees and 85 degrees.

[0085] In an embodiment of the present invention, a reflection angle from the surface of the protective film to the pattern is between 5 degrees and 85 degrees.

[0086] In an embodiment of the present invention, the light has a wavelength between 200 nanometers (nm) and 1500 nm.

[0087] In an embodiment of the present invention, the pattern includes a plurality of concentric circles, and the minimum interval between the circles is 5 nm.

[0088] In an embodiment of the present invention, the pattern comprises a plurality of triangles, wherein each of the plurality of triangles has a side with a minimum length of 5 nanometers and an internal angle between two sides is between 5 and 170 degrees.

[0089] In an embodiment of the present invention, the pattern comprises a plurality of rectangles, wherein each of the plurality of rectangles has a side with a minimum length of 5 nanometers and an inner angle between two sides is 90 degrees.

[0090] In an embodiment of the present invention, the pattern comprises a plurality of regular polygons, wherein each of the plurality of regular polygons has a side with a minimum length of 5 nanometers and an internal angle between each side is between 108 degrees and 144 degrees.

[0091] In an embodiment of the present invention, the method further includes: using an artificial intelligence module to check the reflection of the pattern, the module measuring multiple angles within the reflection of the pattern, and identifying the distortion when at least one measured angle in the reflection of the pattern does not match a stored angle value.

[0092] In an embodiment of the utility model, the method further includes: inspecting the reflection of the pattern with an artificial intelligence module, the module measuring multiple distances within the reflection of the pattern, and identifying the distortion when at least one measured distance in the reflection of the pattern does not match a stored distance value. According to various embodiments, a method for inspecting a pellicle includes directing a light source through the pellicle, receiving a reflection of a pattern from a surface of the pellicle, and measuring (i) a length of a segment of the pattern and (ii) an angle between two segments of the pattern. In various embodiments, when at least one of the length and the angle matches a predetermined value of the length or the angle, a manufacturing process on an underlying semiconductor substrate is started. In various embodiments, when at least one of the length and the angle is distorted, an alarm is triggered, which stops the semiconductor device manufacturing process. In some embodiments, the pattern includes at least one of a circle, a triangle, a rectangle, and a regular polygon. In some embodiments, the reflection is measured with an artificial intelligence module, the module measuring at least one of the length and the angle and identifying the distortion when at least one of the length and the angle does not match a stored value of the pattern. In some embodiments, the reflection is measured with an artificial intelligence module, the module measuring at least one of the following: the length of multiple parallel line segments within the pattern and multiple angles between parallel line segments within the pattern. In such an embodiment, a distortion is identified when (i) at least one of the plurality of parallel line segments does not match the length of the remaining parallel line segments within the reflection and (ii) at least one of the plurality of angles does not match another angle within the reflection. In some cases, the reflection of the pattern reaches the surface of the pellicle at a reflection angle between 5 degrees and 85 degrees. In some cases, a CCD is used to receive the reflection.

[0093] According to various embodiments, a method for inspecting a pellicle includes: directing a light source through the pellicle; receiving a reflection of a pattern from a surface of the pellicle; measuring at least one of a length of a segment of the pattern and an angle between two segments of the pattern; starting a manufacturing process for an underlying semiconductor substrate when at least one of the length and the angle matches a stored value of the length or the angle; and triggering an alarm to stop the semiconductor device manufacturing process when at least one of the length and the angle is distorted.

[0094] In an embodiment of the present invention, the pattern includes at least one of a circle, a triangle, a rectangle and a regular polygon.

[0095] In an embodiment of the present invention, the measuring further comprises: measuring the reflection using an artificial intelligence module, the module measuring at least one of the length and the angle, and identifying distortion when at least one of the length and the angle does not match the stored value of the pattern.

[0096] In an embodiment of the present invention, the measurement also includes: measuring the reflection with an artificial intelligence module, the module measuring at least one of the following: the length of multiple parallel line segments in the pattern and multiple angles between the parallel line segments in the pattern; and identifying distortion when (i) at least one of the multiple parallel line segments does not match the length of the remaining parallel line segments in the reflection and (ii) at least one of the multiple angles does not match another angle in the reflection.

[0097] In an embodiment of the present invention, the reflection of the pattern is incident on the surface of the film and reflected at an angle, and the angle is between 5 degrees and 85 degrees.

[0098] In an embodiment of the present invention, a charge coupled device is used to receive the reflection.

[0099] According to various embodiments, an extreme ultraviolet (EUV) lithography system having an exposure tool includes a die mounter for automatically mounting a pellicle frame onto a mask within the exposure tool, a transparent film having a pattern that is at least partially opaque, a device configured to illuminate the transparent film so that the pattern is projected onto a surface of the pellicle to generate a reflection pattern, a digital image sensor configured to detect the reflection pattern, a computer system configured to measure at least one of an angle and a line segment of the reflection pattern, and to generate an alarm to stop operation of the EUV lithography system when at least one of the angle and the line segment is distorted. In some embodiments, the digital image sensor includes a CCD.

[0100] According to various embodiments, an extreme ultraviolet lithography system having an exposure tool includes: a die mounter for automatically mounting a pellicle frame on a mask within the exposure tool; a transparent film having a pattern that is at least partially opaque; a light source configured to illuminate the transparent film so that the pattern is projected onto a surface of the pellicle to produce a reflection pattern; a digital image sensor configured to detect the reflection pattern; and a computer system configured to measure at least one of an angle and a line segment of the reflection pattern, and to generate an alarm to stop operation of the extreme ultraviolet lithography system when at least one of the angle and the line segment is distorted.

[0101] In an embodiment of the present invention, the digital image sensor comprises a charge coupled device.

[0102] The features of several embodiments or examples are summarized above so that those skilled in the art can better understand aspects of the present disclosure. Those skilled in the art should understand that they can easily use the present disclosure as a basis for designing or modifying other processes and structures to achieve the same purpose and / or achieve the same advantages as the embodiments or examples introduced herein. Those skilled in the art should also recognize that such equivalent structures do not depart from the spirit and scope of the present disclosure, and they can make various changes, substitutions and modifications to them without departing from the spirit and scope of the present disclosure.

Claims

1. An extreme ultraviolet lithography system having an exposure tool, characterized in that: include: a die mounter for automatically mounting a pellicle frame on a mask in the exposure tool; a transparent film having an at least partially opaque pattern; a light source configured to illuminate the transparent film so that the pattern is projected onto a surface of the overcoat to produce a reflective pattern; a digital image sensor configured to detect the reflected pattern; and The computer system is configured to measure at least one of an angle and a line segment of the reflection pattern, and to generate an alarm to stop the operation of the EUV lithography system when at least one of the angle and the line segment is distorted.

2. The system according to claim 1, characterized in that The digital image sensor includes a charge coupled device.

3. The system according to claim 1, characterized in that The light source generates light, and the light illuminates the transparent film having the pattern.

4. The system according to claim 3, characterized in that The light passes through the surface of the transparent film at an incident angle between 5 degrees and 85 degrees.

5. The system according to claim 4, characterized in that A reflection angle from the surface of the overcoat to the pattern is between 5 degrees and 85 degrees.

6. The system according to claim 3, characterized in that The light has a wavelength between 200 nm and 1500 nm.

7. The system according to claim 1, characterized in that The pattern includes a plurality of concentric circles, and the minimum interval between the circles is 5 nm.

8. The system according to claim 1, characterized in that The pattern includes a plurality of triangles, wherein each of the plurality of triangles has a side having a minimum length of 5 nanometers and an internal angle between two sides is between 5 and 170 degrees.

9. The system according to claim 1, characterized in that The pattern includes a plurality of rectangles, wherein each of the plurality of rectangles has a side having a minimum length of 5 nanometers and an internal angle between two sides is 90 degrees.

10. The system according to claim 1, characterized in that The pattern includes a plurality of regular polygons, wherein each of the plurality of regular polygons has a side with a minimum length of 5 nanometers and an internal angle between each side is between 108 degrees and 144 degrees.

Images