TW201809922A - Dense line extreme ultraviolet lithography system with distortion matching - Google Patents

Abstract

An extreme ultraviolet lithography system (10) that creates a new pattern (330) having a plurality of densely packed parallel lines (332) on a workpiece (22), the system (10) includes a patterning element (16); an EUV illumination system (12) that directs an extreme ultraviolet beam (13B) at the patterning element (16); a projection optical assembly (18) that directs the extreme ultraviolet beam diffracted off of the patterning element (16) at the workpiece (22) to create a first stripe (364) of generally parallel lines (332) during a first scan (365); and a control system (24). The workpiece (22) includes an existing pattern (233) that is distorted. The control system (24) selectively adjusts a control parameter during the first scan (365) so that the first stripe (364) is distorted to more accurately overlay the portion of existing pattern (233) positioned under the first stripe (364).

Description

Dense line extreme ultraviolet lithography system with distortion matching

This application claims the priority of each of the following U.S. Provisional Patent Applications: Dense Line Extreme Ultraviolet Lithography System, filed on June 20, 2016, entitled "Dense Line Extreme Ultraviolet Lithography System with Distortion Matching" U.S. Provisional Patent Application No. 62/352,545, filed on June 22, 2016, entitled "Extreme Ultraviolet Lithography System that Utilizes Pattern Stitching" US Provisional Patent Application No. 62/353,245; and an application filed on May 11, 2017, entitled "Illumination with a curved one-dimensional patterned mask for use in extreme ultraviolet exposure tools" System with Curved 1D-Patterned Mask for Use in EUV-Exposure Tool) US Provisional Patent Application No. 62/504,908. The respective contents of U.S. Provisional Patent Application Nos. 62/352,545, 62/353,245, and 62/504,908 are incorporated herein by reference for all purposes. This application also claims U.S. Patent Application Serial No. 15/599,148, filed on May 18, 2017, entitled "EUV Lithography System for Dense Line Patterning". The priority of the number. In addition, the present application also claims the application of the U.S. Patent Application No. 15 entitled "EUV Lithography System for Dense Line Patterning" on May 18, 2017, entitled "EUV Lithography System for Dense Line Patterning" Priority of /599,197. The contents of each of U.S. Patent Application Serial No. 15/599,148, and U.S. Patent Application Ser.

The following contents of the following US Provisional Patent Applications are hereby incorporated by reference in their entirety for all purposes: the application filed on May 19, 2016 and entitled "Ultraviolet lithography for dense line patterning" U.S. Provisional Patent Application No. 62/338,893 to the EUV Lithography System for Dense Line Patterning; an optical objective entitled "Dense Line Patterning in the Extreme Ultraviolet Spectral Region", filed on April 19, 2017 (Optical Objective for Dense Line Patterning in EUV Spectral Region), US Provisional Patent Application No. 62/487,245; and filed on April 26, 2017, entitled "Available in Extreme Ultraviolet Light Exposure Tools" U.S. Provisional Patent Application No. 62/490,313, the entire disclosure of which is incorporated herein by reference.

The present invention relates to an exposure tool for use in lithography processing of semiconductor workpieces, and more particularly to an exposure tool configured to form a pattern of parallel lines on a workpiece, the flat lines being separated from each other Ten nanometers or less.

A lithography system is typically used to transfer images from a patterned element to a workpiece during exposure. The next generation of lithography technology can use extreme ultraviolet (EUV) lithography to enable the fabrication of semiconductor workpieces with very small feature sizes.

One embodiment is directed to an EUV lithography system that forms a new pattern having a plurality of closely spaced parallel lines on a workpiece (eg, a semiconductor wafer) containing an existing pattern of distortion. The lithography system includes: a patterned element having a patterned element pattern; a workpiece stage mover assembly that holds and moves the workpiece relative to the patterned element; an extreme ultraviolet illumination system, Directing an extreme ultraviolet beam (eg, light having a wavelength of approximately 13.5 nanometers (nm)) onto the patterned element; projecting an optical assembly that directs the extreme ultraviolet beam diffracted from the patterned element to Forming, on the workpiece, a first stripe having densely arranged parallel lines on the workpiece, the densely arranged parallel lines extending substantially along a first axis; and a control system controlling the platform assembly in the The workpiece is moved relative to the exposure field along a first scan trajectory during a first scan, the first scan trajectory being substantially parallel to the first axis. As provided herein, the control system selectively adjusts control parameters during the first scan such that the first stripe having the parallel lines is more accurately relative to when the control parameters are not adjusted A portion of the existing pattern that is under the first stripe having the parallel lines is overlaid.

In one embodiment, the controlling parameter includes selectively adjusting the first scan trajectory to include movement along a second axis orthogonal to the first axis during the first scan and a movement centered about a third axis orthogonal to the first axis and the second axis such that the first stripe having the parallel lines more accurately overlaps the existing pattern with the parallel line The portion below the first stripe. The movement along the second axis and the movement centered on the third axis during the first scan is a function of the position of the workpiece along the first axis of the platform.

Additionally or alternatively, the controlling parameter can include selectively adjusting a magnification of the patterned element pattern image during the first scan such that the first stripe having the parallel lines overlaps more accurately The portion of the existing pattern is located below the first stripe having the parallel lines. Moreover, the control parameter can include selectively adjusting a magnification tilt of the patterned element pattern image during the first scan (ie, a linear magnification change across the exposure field) such that the parallel The first stripe of the line more appropriately overlaps the portion of the existing pattern that is below the first stripe having the parallel lines.

In one embodiment, the existing pattern includes a plurality of previously patterned dies (also referred to as exposure "shots" or "fields" because each shot can contain more In a pattern or semiconductor device, and the control system controls the extreme ultraviolet light illumination system such that every other die along the first scan track during the first scan is not exposed. Subsequently, the control system can control the extreme ultraviolet light illumination system to expose the unexposed die along the first scan trajectory during a second scan.

In another embodiment, the control system controls the extreme ultraviolet light illumination system to stop the first scan and reset the first scan trajectory at an interface of adjacent dies.

As provided herein, the control system can selectively adjust the first scan trajectory and the pitch of parallel lines transferred to the workpiece during the first scan such that the parallel line The first fringe distortion is described to more accurately overlap the portion of the existing pattern under the first stripe having the parallel lines.

Yet another embodiment is directed to a method of transferring a new pattern having a plurality of closely spaced lines to a workpiece containing a distorted existing pattern. The method can include: (i) providing a patterned element having a patterned element pattern; (ii) moving the workpiece using a workpiece platform mover assembly; directing an extreme ultraviolet beam to the using an extreme ultraviolet illumination system (iii) directing the EUV beam diffracted from the patterned element onto the workpiece using a projection optics assembly to move the workpiece relative to the exposure field during the first scan Forming the plurality of closely spaced parallel lines on the workpiece, the first stripe having the parallel lines extending generally along a first axis; and (iv) controlling using a control system during the first scan The platform assembly moves the workpiece relative to the exposure field along a first scan trajectory, the first scan trajectory being substantially parallel to the first axis; the control system including a processor; wherein the control system is Selectively adjusting control parameters during the first scan such that the first stripe having the parallel lines more accurately overlaps the existing pattern with the parallel lines A first portion below said stripe.

Embodiments are also directed to a device fabricated using the lithography system, and/or a workpiece (e.g., a semiconductor wafer) on which an image has been formed by the lithography system.

1A is a simplified, non-proprietary schematic diagram illustrating an extreme ultraviolet (EUV) lithography system 10 that includes an extreme ultraviolet illumination system 12 (irradiation device) that produces an initial extreme ultraviolet beam. 13A (illustrated using dashed lines); patterned component platform assembly 14, retaining patterned component 16 having patterned component pattern 16A; projection optics assembly 18; workpiece platform assembly 20, holding and positioning workpiece 22, workpiece 22 a semiconductor wafer; a control system 24 that controls the operation of the components of the system 10; and a shutter assembly 26 that defines the shape of the exposure field 28 on the workpiece 22, the exposure field 28 using shaped and diffracted poles The ultraviolet light beams 13D, 13E are formed. The design and location of such components may vary depending on the teachings provided herein.

Additionally, it should be noted that the extreme ultraviolet lithography system 10 will typically include more components than those illustrated in Figure 1A. For example, the extreme ultraviolet lithography system 10 can include a rigid device frame (not shown) to hold one or more of the components of the system. In addition, the extreme ultraviolet lithography system 10 can include one or more temperature control systems (not shown) to control the temperature of one or more of the components of the extreme ultraviolet lithography system 10. For example, the extreme ultraviolet illumination system 12, the patterning element 16, the projection optics assembly 18, and/or the workpiece platform assembly 20 may require a temperature control system for cooling.

Additionally, for example, the extreme ultraviolet light system 10 can include a closed chamber 29 to enable many of the components of the extreme ultraviolet lithography system 10 to operate in a controlled environment, such as a vacuum.

As an overview, the extreme ultraviolet lithography system 10 directs the exposure field 28 onto the workpiece 22, which moves along the scan trajectory to include a new pattern 330 comprising only a plurality of closely spaced substantially parallel lines 332 (described in Figure 3B). Transfer is made to the semiconductor workpiece 22 that already contains the existing pattern 233 (described in Figure 2A). In some embodiments, the extreme ultraviolet lithography system 10 adjusts one or more control parameters (eg, the scan trajectory of the workpiece 22, the magnification of the image of the patterned component pattern 16A, and the like) while scanning and exposing the workpiece 22. / The magnification of the image of the patterned element pattern 16A is tilted such that the new pattern 233 follows and more closely overlaps the existing pattern 233 than when one or more of the control parameters are not adjusted. Thus, in one embodiment, the present embodiment forms an incomplete new pattern 330 having closely spaced substantially parallel lines to better match the distorted existing pattern 233 and better overlap the distorted existing pattern 233. Moreover, in some embodiments, the extreme ultraviolet lithography system 10 can be controlled to form discontinuities between adjacent dies along the scan trajectory. More specifically, the extreme ultraviolet lithography system 10 can be controlled such that the stripe of each parallel line is scanned twice on the workpiece 22, thereby exposing every other grain in the first pass and in the second pass. The lieutenant alternately exposes the grains.

In summary, the extreme ultraviolet lithography system 10 is uniquely designed to adjust the scanning trajectory, magnification, and "magnification tilt" of the patterned element pattern 16A while scanning and exposing the workpiece 22. The new pattern 330 with lines is more accurately matched and overlaid with the existing pattern 233 that is distorted on the workpiece 22. The existing pattern is usually distorted due to the distortion of the workpiece and the characteristics of the formation of the layer of the existing pattern 233. For this embodiment, the new patterned element pattern 330 is printed to be distorted in a more closely matched manner.

Some of the figures provided herein include orientation systems that specify X, Y, and Z axes that are orthogonal to one another. In these figures, the Z axis is oriented in the vertical direction. It should be understood that the orientation system is for reference only and may vary. For example, the X axis can be swapped with the Y axis and/or the extreme ultraviolet lithography system 10 can be rotated. Moreover, as an alternative, the axes may be referred to as a first axis, a second axis, or a third axis. For example, the Y axis can be referred to as a first axis, the X axis can be referred to as a second axis, and the Z axis can be referred to as a third axis.

The extreme ultraviolet light illumination system 12 includes an extreme ultraviolet light illumination source 34 and an illumination optics assembly 36. The extreme ultraviolet light source 34 emits an initial extreme ultraviolet beam 13A, and the illumination optics assembly 36 directs and adjusts the extreme ultraviolet beam 13A from the illumination source 34 to provide a conditioned extreme ultraviolet beam 13C that is directed onto the patterned element 16. In FIG. 1A, the extreme ultraviolet illumination system 12 includes a single extreme ultraviolet illumination source 34 and a single illumination optics assembly 36. Alternatively, the extreme ultraviolet illumination system 12 can be designed to include a plurality of extreme ultraviolet illumination sources 34 and a plurality of illumination optics assemblies 36.

As provided herein, the extreme ultraviolet light source 34 emits an extreme ultraviolet light beam 13A in the extreme ultraviolet spectral range. As provided herein, "extreme ultraviolet spectral range" shall mean and include wavelengths in a narrow frequency band between about 5 nanometers and 15 nanometers, and preferably around 13.5 nanometers. As a non-proprietary example, the extreme ultraviolet light source 34 can be a plasma system, such as Laser Produced Plasma (LPP) or Discharge Produced Plasma (DPP).

Illumination optics assembly 36 is reflective and includes one or more optical components that can operate in the extreme ultraviolet spectral range. More specifically, each optical element includes a working surface that is coated to reflect light in the extreme ultraviolet spectral range. Furthermore, the optical elements are spaced apart from one another.

In FIG. 1A, the illumination optical assembly 36 includes a first illumination optical element 38, a second illumination optical element 40, and a third illumination optical element 42, a first illumination optical element 38, a second illumination optical element 40, and a third illumination optics. Element 42 cooperatively adjusts initial extreme ultraviolet beam 13A and directs regulated ultraviolet beam 13C onto patterned element 16. In one embodiment, the first illuminating optical element 38 is a fly's eye type reflector comprising a plurality of individual micro-mirrors (micro-mirrors or facets) arranged in a two-dimensional array (facet)), wherein each reflector comprises a working surface that is coated to reflect light in the extreme ultraviolet spectral range. Similarly, the second illuminating optical element 40 is a fly-eye type reflector comprising a plurality of individual micro-reflectors (micromirrors or facets) arranged in a two-dimensional array, wherein each reflector comprises a coating such that A working surface that reflects light in the extreme ultraviolet spectral range. Additionally, the third illumination optical element 42 is a reflector that includes a working surface that is coated to reflect light in the extreme ultraviolet spectral range. In some embodiments, the illumination optics 38, 40, 42 include a curved surface for focusing the extreme ultraviolet light.

In FIG. 1A, the extreme ultraviolet light source 34 emits the initial extreme ultraviolet beam 13A substantially downwardly onto the first illumination optics 38. A plurality of micro-reflectors of the first illuminating optical element 38 reflect the extreme ultraviolet beam and redirect it substantially upwardly onto the second illuminating optical element 40. Similarly, a plurality of micro-reflectors of the second illuminating optical element 40 reflect the extreme ultraviolet beam and redirect it substantially downwardly onto the third illuminating optical element 42. Next, the third illuminating optical element 42 acts as a repeater to collect the conditioned extreme ultraviolet beam 13C, reflect the conditioned extreme ultraviolet beam 13C, and focus substantially evenly upward onto the patterned element surface 16A of the patterned element 16. It should be noted that the facet mirror surface of the first illuminating optical element 38 forms an image of the extreme ultraviolet light source 34 on each of the facet mirror surfaces of the second illuminating optical element 40. In response, the facet mirror surface of the second illuminating optical element 40 reflects a uniform image of the first illuminating optical element 38 onto the patterned element 16 via the third illuminating optical element 42. In the illustrated embodiment, an intermediate image of the first illuminating optical element 38 is formed on the intermediate image plane 56 between the illuminating optical element 40 and the illuminating optical element 42. In other words, each facet of the second illuminating optical element 40 is optically conjugate with the extreme ultraviolet source 34 and the third illuminating element 42, and each facet and intermediate image plane of the first illuminating optical element 38 56 and patterned element 16 are optically conjugated. For such an arrangement, the image fields of each of the reflector surfaces of the first illuminating optical element 38 overlap at the patterned elements 16 to form a sufficiently uniform irradiance pattern on the patterned elements 16.

The patterned component platform assembly 14 holds the patterned component 16. In some embodiments, the patterned component platform assembly 14 can be designed to make slight adjustments to the position and/or shape of the patterned component 16 to improve the imaging performance of the extreme ultraviolet lithography system 10. For example, in some embodiments, the patterned component platform assembly 14 can shape, position, and/or move the patterned component 16 to make changes and adjustments to the magnification of the exposure field 28 and to expose the field The magnification of 28 is tilted to make a change. In one non-proprietary example, the patterned component platform assembly 14 can include a patterned component platform 14A and a patterned element stage mover 14B. In the non-proprietary embodiment illustrated in FIG. 1A, the patterned component platform 14A is unitary and includes a patterned component holder (not shown) that holds the patterned component 16. For example, the patterned component holder can be an electrostatic chuck or some other type of clamp.

The patterned component platform mover 14B controls and adjusts the position of the patterned component platform 14A and the patterned component 16. For example, the patterned element platform mover 14B can have six degrees of freedom (eg, along the X axis, along the Y axis and along the Z axis, and centered on the X axis, centered on the Y axis, and centered on the Z axis) To move the position of the patterned element 16. Alternatively, the patterned element platform mover 14B can be designed to move the patterned element 16 in less than six degrees of freedom (eg, in three degrees of freedom). Moreover, in some embodiments, control system 24 can control patterned component platform mover 14B and/or patterned component holder to cause patterning by stretching, bending, or compressing patterned element 16 as desired. The component 16 is distorted. As provided herein, the patterned component platform mover 14B can include one or more piezoelectric actuators, a planar motor, a linear motor, a voice coil motor, an attraction only actuator, and/or other types. Actuator. In some embodiments, the range of motion of the patterned element platform 14A is relatively small.

The patterned element 16 diffracts the conditioned extreme ultraviolet beam 13C to form an image that is projected onto the workpiece 22. For example, the patterned element 16 can be a diffraction grating. In one embodiment, the patterned element pattern 16A of the patterned element 16 includes reflecting and diffracting the conditioned extreme ultraviolet beam 13C in a plurality of directions (including a first diffracted pole extending in different directions away from the patterned element 16) The periodic structure of the ultraviolet beam 13D and the second diffracted extreme ultraviolet beam 13E). In one embodiment, the periodic structure of the patterned element 16 includes a pattern having parallel lines that are parallel to the Y axis. In an alternate embodiment, the patterned element 16 can be a periodic structure that changes the phase and/or intensity of the extreme ultraviolet beam 13C. For example, the periodic structure can be a pattern having reflective lines and non-reflective lines at appropriate pitches to form a desired diffracted beam. Alternatively, the periodic structure can be a pattern of lines having optical phase changes of extreme ultraviolet light to form a desired diffracted beam.

Projection optics assembly 18 directs the image of patterned element 16 through diffracted extreme ultraviolet beams 13D, 13E onto a photosensitive photoresist located on semiconductor workpiece 22 at the image plane of projection optics assembly 18. In one embodiment, projection optics assembly 18 is reflective and includes one or more optical components that can operate in the extreme ultraviolet spectral range. More specifically, each optical element includes a working surface that is coated to reflect light in the extreme ultraviolet spectral range. Furthermore, the optical elements are spaced apart from one another.

In FIG. 1A, projection optics assembly 18 directs extreme ultraviolet light (including first diffracted extreme ultraviolet beam 13D and second diffracted extreme ultraviolet beam 13E) reflected from patterned element 16 onto workpiece 22. In other words, for the present embodiment, light waves that are diffracted or scattered from the patterned element 16 are collected and recombined by the projection optics assembly 18 to produce an image of the patterned element 16 on the workpiece 22. Since the patterned element 16 that scatters/diffracts the extreme ultraviolet beam is imaged onto the workpiece 22, the edges appear as sharp boundaries in the photoresist of the workpiece 22. Thus, one of the significant advantages of projection optics 18 is that it achieves a well-defined edge for exposure field 28. In FIG. 1A, projection optics assembly 18 includes a first projection subassembly 44 and a second projection subassembly 46, the first projection subassembly 44 and the second projection subassembly 46 cooperating to form a pattern on the workpiece 22. An image of the component pattern. In contrast, if projection optics 18 directs only two diffracted extreme ultraviolet beams 13D, 13E to form an interference pattern on workpiece 22, the edges will appear defocused and blurred.

For example, (i) the first projection sub-assembly 44 can include a left first first projection optical element 44A and a right first projection optical element 44B that cooperatively guide the reflected extreme ultraviolet light; and (ii) a second projection subassembly 46 may include a left second projection optical element 46A and a right second projection optical element 46B that cooperatively direct the reflected extreme ultraviolet light. In one embodiment, each of the first projection optics 44A, 44B is a reflector that includes a working surface that is coated to reflect light in the extreme ultraviolet spectral range. Similarly, each of the second projection optics 46A, 46B is a reflector that includes a working surface that is coated to reflect light in the extreme ultraviolet spectral range. In some embodiments, the optical elements 44A, 44B are formed as part of a single extreme ultraviolet mirror. Similarly, optical elements 46A, 46B can be formed as part of a single extreme ultraviolet mirror. Depending on the particular application, optical elements 44A, 44B can be two parts of a single curved mirror, or they can be separate components. Similarly, optical elements 46A, 46B can be two portions of a single curved mirror, or they can be separate components.

The workpiece platform assembly 20 holds the workpiece 22, positions and moves the workpiece 22 relative to the exposure field 28 to form a pattern 330 of closely spaced parallel lines on the workpiece 22. As a non-proprietary example, the workpiece platform assembly 20 can include a workpiece platform 48 and a workpiece platform mover 50 (illustrated as a block).

In the non-proprietary embodiment illustrated in FIG. 1A, the workpiece platform 48 is unitary and includes a workpiece holder (not shown) that holds the workpiece 22. For example, the workpiece holder can be an electrostatic chuck or some other type of fixture.

The workpiece platform mover 50 controls and adjusts the position of the workpiece platform 48 and the workpiece 22 relative to the exposure field 28 and the remainder of the extreme ultraviolet lithography system 10. For example, the workpiece platform mover 50 can have six degrees of freedom (eg, along the X axis, along the Y axis and along the Z axis, and centered on the X axis, centered on the Y axis, and centered on the Z axis) The position of the workpiece 22 is moved. Alternatively, the workpiece platform mover 50 can be designed to move the workpiece 22 in less than six degrees of freedom (eg, in three degrees of freedom). As provided herein, the workpiece platform mover 50 can include one or more planar motors, linear motors, voice coil motors, suction only actuators, and/or other types of actuators.

In some embodiments, the scan speed may vary depending on the size of the exposure field 28. Moreover, in certain embodiments, the workpiece platform mover 50 moves the workpiece 22 at a substantially constant speed during each scanning process.

Control system 24: (i) electrically coupled to workpiece platform assembly 20 and directs and controls current to workpiece platform assembly 20 to control the position of workpiece 22; (ii) electrically coupled to patterned component platform assembly 14. and directs and controls the current to the patterned component platform assembly 14 to control the position and/or shape of the patterned component 16; (iii) is electrically coupled to the extreme ultraviolet illumination system 12, and directs and controls the extreme ultraviolet light. The illumination system 12 is operative to control the extreme ultraviolet beam 13; and (iv) is electrically coupled to the shutter assembly 26 and directs and controls the shutter assembly 26 to adjust the shape of the exposure field 28. Control system 24 can include one or more processors 54 and include an electronic data store.

The shutter assembly 26 shapes the extreme ultraviolet beam 13A and defines the shape of the exposure field 28 imaged on the workpiece 22. In one non-proprietary embodiment, the shutter assembly 26 forms an extreme ultraviolet beam such that the exposure field 28 has a generally rectangular shape.

FIG. 1B is a simplified side view of a non-proprietary example of a shutter assembly 26. In this embodiment, the shutter assembly 26 includes a rigid shutter housing 26A, a movable shutter 26C (illustrated using a block), and a shutter mover 26D (described using a block), a rigid shutter housing 26A defines a housing opening 26B (illustrated using dashed lines). In this embodiment, the housing opening 26B generally defines the shape and size of the exposure field 28 (described in FIG. 1A). However, in this embodiment, the shutter mover 26D can selectively move the movable shutter 26C relative to the housing opening 26B to selectively cover a portion of the housing opening 26B, covering all of the housing opening 26B. The housing opening 26B is not covered or adjusted to adjust the size of the exposure field 28 along the Y axis (described in FIG. 1A).

In FIG. 1B, the movable shutter 26C includes a shutter opening 26E. For this design, the movable shutter 26 can be moved back and forth to selectively and alternately adjust the size of the exposure field 28 from both directions along the Y axis (scanning direction).

Additionally, shutter mover 26D can be a motor controlled by control system 24 (described in FIG. 1A) to selectively and alternately adjust exposure field 28 from both directions along the Y axis during the scanning process in accordance with the scan direction. the size of. In an alternate embodiment, the shutter assembly 26 may include additional actuators or moving parts to enable modification of the shape of the exposure field 28, thereby correcting for non-uniformity of extreme ultraviolet light illumination or other effects.

Referring back to FIG. 1A, the shutter assembly 26 can be located in a number of different positions along the beam path 55 between the extreme ultraviolet illumination source 34 and the workpiece 22. For example, the shutter assembly 26 can be positioned along the beam path 55 to: (i) approach the patterned element 16, (ii) approach the workpiece 22, or (iii) be on or near the intermediate image plane. In the embodiment illustrated in FIG. 1A, the shutter assembly 26 is located along the beam path 55 on the intermediate image plane 56 between the second illumination optics 40 and the third illumination optics 42. Thus, the conditioned extreme ultraviolet beam 13C directed onto the patterned element 16 has been shaped. In an alternative embodiment having an intermediate image plane at another location (eg, between the patterned element 16 and the workpiece 22), the pattern shutter 26 can be located along the beam path 55 in the intermediate image plane (not shown) on.

It should be noted that any of the extreme ultraviolet beams 13A, 13C, 13D, 13E may be collectively referred to as an extreme ultraviolet beam. Moreover, the term "beam path 55" as used herein shall refer to the path of the extreme ultraviolet beam traveling from illumination source 34 to workpiece 22.

2A is a simplified top plan view of a workpiece 22 that has been processed to include an existing pattern 233 (only a portion of which is illustrated in a small circle) having a plurality of adjacent dies 260 on the workpiece 22 (also referred to as "exposure shots" Domain, "field" or "wafer"). The design of the existing pattern 233 and the number, size and shape of the dies 260 may vary. In the non-proprietary example illustrated in FIG. 2A, workpiece 22 has been processed to include ninety-six rectangular grains 260. Moreover, for a three hundred millimeter diameter workpiece 22, each of the dies 260 can be, for example, twenty-six millimeters (along the X axis) by thirty-three millimeters (along the Y axis). However, there may be other numbers and other sizes. The plus sign is used to identify the center of each die 260. Each die 260 can be formed on the workpiece 22 using a step and repeat lithography system or a step and scan lithography system (not shown), the step and repeat lithography system or step and scan micro The shadow system exposes an area on the workpiece 22 to form one of the dies 260 and then steps to another area to form another die 260. This process is repeated until the entire existing pattern 233 is completed.

Unfortunately, as provided herein, the existing pattern 233 on the workpiece 22 is often distorted. As a non-proprietary example, the distortion of the existing pattern 233 can be caused by: temperature change of the workpiece 22 during various processing steps, residual stress in the workpiece 22, clamping of the workpiece 22, etching of the workpiece 22, alignment Irregularities in the projection optics assembly of the reticle used in the repetitive lithography system and/or stepping and repeating lithography systems.

2B is a simplified diagram illustrating raw broad distortion data for workpiece 22 processed using a step and repeat lithography system. It should be noted that the original distortion data will be different for each workpiece 22. In FIG. 2B, distortion is represented by a plurality of tiny vectors (arrows) 262 at a plurality of alternately spaced apart locations on the workpiece 22. The vectors 262 illustrate how the existing pattern 233 (described in Figure 2A) is distorted at the particular location relative to the desired pattern (not shown). In general, the size of vector 262 represents the magnitude of the distortion, and the direction represents the direction of the distortion relative to its proper position.

In Fig. 2B, the X-axis dimension and the Y-axis dimension of the workpiece 22 are also illustrated for reference. In this example, the workpiece 22 has a diameter of three hundred millimeters. It should be noted that for the workpiece 22 illustrated in Figure 2B, the distortion is highest in the lower right quadrant and lowest in the upper left quadrant.

As a non-proprietary example, the distortion data can be generated by accurately measuring the existing pattern 233 and comparing the existing pattern 233 with the desired pattern.

It should be noted that the broad distortion data illustrated in Figure 2B contains two main effects, namely (i) how the workpiece 22 is stretched or distorted across the globe, and (ii) how each of the dies 260 is distorted. of.

2C is a simplified diagram illustrating only the global distortion data (using small arrows) of the workpiece 22. In other words, Figure 2C is a linear fit to the data illustrating how the entire workpiece 22 is distorted. This can also be referred to as inter-shot distortion data or workpiece distortion data.

It should be noted that for the workpiece 22 illustrated in Figure 2C, the global distortion of the workpiece 22 is highest in the lower right quadrant and lowest in the upper left quadrant.

For example, the global distortion data in FIG. 2C can be generated by fitting a linear equation of the X distortion component and the Y distortion component to the original data shown in FIG. 2B.

2D is a graph illustrating distortion data (using small arrows) for each die 260 of the workpiece 22. It should be noted that for the workpiece 22 illustrated in Figure 2D, the distortion of each die 260 is approximately the same (consistent and repeating). This is because the grain distortion during the step and repeat exposure process or the step and scan exposure is usually caused by the gravity droop of the reticle (not shown) used during the exposure, and the temperature of the reticle. Fluctuations, distortion of the reticle due to clamping, and distortion characteristics of the projection lens assembly of the lithography system. Grain distortion can also be referred to as intra-shot distortion data.

It should be noted that the grain distortion data can be calculated by subtracting the workpiece distortion data shown in Fig. 2C from the broad overall distortion data shown in Fig. 2B.

2E shows a graph generated by estimating the common distortion shape for each of the ninety-six dies 260 by using the grain distortion data shown in FIG. 2D. In Figure 2E, the graph illustrates the common distortion shape produced for each die using a linear polynomial equation (first order correction).

Figure 2F illustrates residual distortion data. More specifically, the residual distortion data illustrated in FIG. 2F is obtained by subtracting the graph shown in FIG. 2E from the grain distortion data shown in FIG. 2D.

FIG. 3A is a simplified flow diagram illustrating the steps taken to overlay the new pattern 330 produced by the extreme ultraviolet photolithography system 10 of FIG. 1A and to match the existing pattern 233. More specifically, at block 300, distortion data for an existing pattern on the workpiece is determined. Once the distortion data for the workpiece is determined, one or more control parameters needed to overlay the new pattern 302 with the new pattern are determined at block 302. In other words, using the distortion data of the existing pattern 233, the desired position and characteristics of the new pattern 330 can be determined, thereby causing the multiple lines of the new pattern 330 to match and overlay the distorted existing pattern 233. As provided herein, one or more control parameters for each scan that form a new pattern 330 may be determined such that the new pattern 330 overlaps the distorted existing pattern 233. Steps 300 and 302 can be performed offline and prior to beginning the exposure of the new pattern 330.

As a non-proprietary example, the control parameters of the extreme ultraviolet lithography system 10 during generation of the new pattern 330 may include adjustments to each scan trajectory (eg, X-axis offset of the workpiece, West Tower Z-axis of the workpiece (θz) Rotation), a change in magnification of the patterned element pattern during one or more scans and/or a tilt in the magnification of the patterned element pattern during one or more scans. Additionally, the control parameters may be determined based on the X-axis position and/or the Y-axis position of the workpiece. The desired new pattern can be determined by several potential methods and each of the control parameters can be found: (i) fitting a polynomial or other analytical formula to the measured data; (ii) in each quantity Interpolating between measurement points and smoothing any discontinuities; (iii) Solving optimization problems to minimize residual errors while maintaining trajectories that meet platform limits for speed, acceleration, and jerk And (iv) use a digital filter to smooth the trajectory.

Next, at block 304, the new pattern 330 is transferred to the workpiece 22 using control parameters. More specifically, the extreme ultraviolet lithography system 10 illustrated in FIG. 1A can be controlled to match and overlap the existing dense pattern 330 across the entire workpiece 22 by: overlying the workpiece 22 The scanning trajectory, the magnification of the patterned element pattern, and the magnification tilt are adjusted while scanning and exposing to compensate for distortion of the workpiece 22 during the previous processing. For such a design, the extreme ultraviolet lithography system 10 will create a new pattern 330 and distorte the new pattern 330 in a matching manner such that the new pattern 330 is more precisely aligned to the existing workpiece than when the control parameters are not adjusted. Existing pattern 233 on 22.

FIG. 3B is a simplified diagram of a workpiece 22 that includes a portion of a new pattern 330 of parallel lines 332 formed using the extreme ultraviolet photolithography system 10 of FIG. 1A. At this time, only the first stripe 364 having the closely arranged substantially parallel lines 332 is transferred to the workpiece 22. However, when completed, substantially the entire surface of the workpiece 22 will include closely spaced substantially parallel lines 232. It should be noted that in FIG. 3B, the X-axis pitch and shape of the line 332 are greatly enlarged for the sake of clarity. In this embodiment, each of the parallel lines 332 extends substantially parallel to the Y axis and orthogonal to the X axis across the entire workpiece 22. It should be noted that the parallel lines 332 shown in Figure 3B are merely illustrative. It should be understood that in one (ie, semiconductor wafer) non-proprietary embodiment, the spacing (pitch) between adjacent parallel lines 332 may range from ten (10) nanometers to forty (40) nanometers. Within the range of meters. However, it should be understood that this pitch range should not be construed as limiting. Parallel lines 332 having a pitch of less than ten (10) nanometers (for example) or greater than forty (40) nanometers (for example) may be patterned onto the workpiece 22 using the extreme ultraviolet light tool 10. In an alternative non-proprietary example, adjacent parallel lines 332 may have less than seventy nanometers, sixty nanometers, fifty nanometers, forty nanometers, thirty nanometers, twenty nanometers, ten nanometers. , or the pitch of five nanometers. Moreover, the phrase "densely packed" as used herein refers to a substantially continuous line pattern. Although in most cases, densely packed lines will cover substantially the entire surface of the workpiece, this is by no means a requirement. In an alternate embodiment, the parallel lines may have periodic gaps and/or pitch variations.

FIG. 3B also illustrates a rectangular exposure field 28 formed on workpiece 22 by the extreme ultraviolet photolithography system 10 of FIG. 1A. In this example, the first strip 364 of parallel lines 332 is transferred to the workpiece 22 during a first scan 365 of the workpiece 22 relative to the exposure field 28. During the first scan 365, the platform mover 50 (described in FIG. 1A) is controlled to move the workpiece 22 relative to the exposure field 28 along the first scan trajectory 366 (illustrated using thicker dashed lines) (in FIG. 3B) The page is downwards to form a first strip 364 of parallel lines 332. In FIG. 3B, the first scan trajectory 366 is jagged shaped and extends generally parallel to the Y axis. More specifically, in the first scan, the first scan trajectory 366 is generally along the Y axis, but includes movement along the X axis and movement centered on the Z axis such that the new pattern 330 matches the existing pattern 233. As provided herein, movement of the workpiece 22 along the X axis during the first scan and movement about the Z axis may be a function of the position of the workpiece 22 along the Y axis.

Additionally, as provided herein, the magnification of the patterned element pattern 16A (described in FIG. 1A) and the magnification of the patterned element tilt of the patterned element pattern 16A may vary during the first scan 365 such that the new pattern 330 The existing pattern 233 is closely overlapped. For example, in some embodiments, adjusting the focus position of patterning element 16 (described in FIG. 1A) or workpiece 22 will result in a change in magnification of parallel line 332. Using this effect, the patterning element 16 and/or the workpiece 22 can be moved slightly in the focus direction to make small changes to the pitch of the printed line 332. Furthermore, by slightly tilting the patterned element 16 and/or the workpiece 22 about the Y axis, a "magnification tilt" can be formed in which the printed pitch varies linearly across the exposure field 28 in the X direction.

Moreover, in FIG. 3B, the first stripe 364 includes eight spaced apart lines that represent only a significant number of prints onto the workpiece 22 during a single scan along the first scan trace 366 (eg, Millions of densely lined lines. In one embodiment, the first stripe 364 having line 332 (and the exposure field 328 on workpiece 22) may have a width of a few millimeters. For example, the exposure field 328 can have a width of approximately five millimeters. As an alternative non-proprietary example, the spacing (pitch) between adjacent parallel lines 232 can be less than about 5 nanometers, 10 nanometers, 20 nanometers, 30 nanometers, 40 nanometers, 50 nanometers, 60 nanometers. Meter or 70 nm. As provided herein, "densely aligned" means a substantially continuous line pattern without any gaps or without significant changes in spacing.

As illustrated in FIG. 3B, in some embodiments, during the printing of the first first strip 364 across the workpiece 22 using the extreme ultraviolet lithography system 10, adjacent dies 260 (described in FIG. 2A) are required. A relatively sudden change to the first scan trajectory 366 occurs at each boundary 367A (using a dashed oval to illustrate a boundary). In other words, during the first scan 365, the first scan trace 366 can extend generally along the Y axis with a sudden discontinuity point 367B at each boundary 367A of the adjacent die 260. The discontinuities 367B are needed to adjust the first scan trace 366 at the boundaries 367A such that the first strips 364 are overlaid on the die 260 using a step and repeat lithography system or a step and scan lithography system. Existing pattern 233 on. It should be noted that in FIG. 3B, the new pattern 330 is transferred across nine dies 260 aligned in a row. Thus, there are eight boundaries 367A and the first scan trajectory 366 includes eight discontinuous points 367B.

In some embodiments, to continuously transfer the first strip 364, the workpiece 22 may need to be moved slowly during the first scan 365 and/or the system needs to be designed such that the exposure field 28 has a relatively small Y-axis dimension 328. . For example, in an alternative non-proprietary example, the Y-axis dimension 328 can be less than about 0.2 millimeters, 1 millimeter, 2 millimeters, 3 millimeters, 5 millimeters, or 10 millimeters.

After forming the first strip 364, the workpiece 22 can be stepped along the X axis and then the workpiece 22 scanned in the opposite direction to form the next strip of parallel lines. The scanning process and the stepping process are alternately performed until the entire pattern 330 of the parallel lines 332 is formed on the workpiece 22.

More specifically, FIG. 3C is a simplified diagram of workpiece 22, except that first strip 364 formed using extreme ultraviolet lithography system 10 of FIG. 1A, workpiece 22 also includes second strips 368 of parallel lines 332 (short use) Dotted line to illustrate).

Figure 3C also illustrates a rectangular exposure field 28 formed on the workpiece 22 by the extreme ultraviolet photolithography system 10 of Figure 1A. In this example, the second strip 368 of parallel lines 332 is transferred to the workpiece 22 during a second scan 369 of the workpiece 22 with respect to the exposure field 28. In a second scan 369, the platform assembly 20 (described in FIG. 1A) is controlled to move relative to the exposure field 28 along a second scan trajectory 370 (illustrated using a thicker dashed line) (upward in the drawing) The workpiece 22 is formed to form a second strip 368 of parallel lines 332. In FIG. 3B, the second scan trace 370 has a sawtooth shape and extends generally parallel to the Y axis. More specifically, in the second scan 369, the second scan trajectory 370 is generally along the Y axis, but includes movement along the X axis and movement centered on the Z axis such that the new pattern 330 matches the existing pattern 233. As provided herein, movement along the X axis and movement about the Z axis can be a function of the position of the workpiece 22 along the Y axis. These adjustments will enable the printed new pattern 330 to be aligned with the average displacement of the existing pattern 233 in the X direction and to enable the patterned component line 332 to "steer" when the patterned component line 332 is printed across the diameter of the workpiece 22. )".

Additionally, as provided herein, the magnification of the patterned element pattern 16A (described in FIG. 1A) and the magnification tilt of the patterned element pattern 16A can be varied during the second scan 369 such that the adjustments are less In time, the new pattern 330 more closely overlaps the existing pattern 233.

It should be noted that the second scan trajectory 370 is slightly different from the first scan trajectory 366 because the distortion of the workpiece 22 is different in this region. Therefore, the second stripe 368 is slightly different from the first stripe 364.

Thus, as provided herein, the scan trajectory 366, 370 of the workpiece 22 relative to the exposure field 28 can be varied, tilted, and/or magnified for each scan 365, 369 and during each scan 365, 369. Variations are made to trim each stripe 364, 368 to more accurately overlap the existing pattern 233. In other words, based on the amount of distortion of the existing pattern 233, the scan trajectories 366, 370, the magnification and the magnification tilt will be different for different regions.

FIG. 3D is a simplified diagram of a portion of first strip 364 that is transferred to workpiece 22. In this figure, a portion of the first scan trajectory 366 is illustrated using a thicker dashed line, and the leftmost line 332L and the rightmost line 332R are illustrated. In this embodiment, the first scan trajectory 366 is generally along the Y axis, but includes movement along the X axis and movement about the Z axis such that the new pattern 330 matches the existing pattern 233.

It should be noted that the first strip 364 has a stripe width 372 measured between lines 332L, 332R along the X axis. As provided herein, the exposure apparatus 10 provided herein is controlled to selectively adjust the magnification of the patterned element pattern 16A directed onto the workpiece 22 during scanning to selectively adjust the first along the scan trajectory 366. The stripe width 372 of the stripe 364 causes the first stripe 364 to match the existing pattern 233. In Figure 3D, the stripe width 372 decreases from top to bottom. However, the stripe width 372 can be varied in any manner along the first scan trajectory 366 as desired, such that the first stripe 364 more accurately overlaps the existing pattern 233 as compared to when the magnification adjustment is not being made.

As a non-proprietary example, adjusting the focus position of the patterning element 16 (described in FIG. 1) or the workpiece 22 will produce a magnification change to change the stripe width 372 along the first scan trace 366. With this effect, the patterned element 16 and/or the workpiece 22 can be slightly moved in the focus direction (upward or downward along the Z axis) using the respective platform assembly to make the pitch of the printed lines 332L, 332R small. Change (selectively adjust the pitch). In another embodiment, the patterned element platform assembly 14 can selectively mechanically stretch or compress the patterned element pattern 16A (described in FIG. 1A) along the X axis to vary the magnification. Yet another option is that the temperature of the patterned element 16 can be adjusted to mechanically change the pitch of the patterned element pattern 16A.

FIG. 3E is a simplified diagram of another portion of the first strip 364 that is transferred to the workpiece 22. In this figure, a portion of the first scan trace 366 is illustrated using a thicker dashed line, and the leftmost line 332L and the rightmost line 332R are also illustrated. In this embodiment, the first scan trajectory 366 is also substantially along the Y axis, but includes movement along the X axis and movement about the Z axis such that the new pattern 330 and the existing pattern 233 are smaller than when the scan trajectory is not adjusted. Match more closely.

It should be noted that the first stripe 364 has: (i) a left intermediate width 374L measured substantially along the X axis between the leftmost line 332L and the scan trajectory 366, and (ii) substantially along the X axis at the most The right intermediate width 374R measured between the right line 332R and the scan track 366. As provided herein, the exposure apparatus 10 provided herein is controlled to selectively adjust the magnification tilt of the patterned element pattern 16A directed onto the workpiece 22 during scanning to selectively adjust the left intermediate width 374L and The right intermediate width 374R is such that the first strip 364 matches the existing pattern 233. In FIG. 3E, (i) the intermediate widths 374L, 374R are approximately equal at the top, and (ii) due to the adjustment of the tilt of the magnification, the left intermediate width 374L is greater than the right intermediate width 374R near the bottom. However, the intermediate widths 374L, 374R may optionally vary along the first scan trajectory 366 in such a manner that the first stripe 364 overlaps the existing pattern 233.

As a non-proprietary example, the patterned element pattern 16A can be rotated centered on the Y axis or the platform assembly 20 (described in FIG. 1A) can be used by using the patterned element platform mover 14B (described in FIG. 1A). The workpiece 22 is rotated around the Y axis to achieve an adjustment of the tilt of the magnification. By slightly tilting the patterning element 16 and/or the workpiece 22 about the Y axis, a "magnification tilt" can be formed in which the pitch of the printed lines 332L, 332R varies linearly across the exposure field in the X direction. For example, the patterning element 16 may be slightly rotated in the first direction about the Y axis to reduce the left intermediate width 374L, and the patterning element 16 may be slightly rotated in the opposite second direction centered on the Y axis, Increase the left middle width by 374L.

All of the adjustments provided herein will enable improved alignment of the printed new pattern 330 with the average displacement of the existing pattern 233 in the X direction, and will enable patterning of the component lines as the patterned component line 332 is printed across the workpiece 22. 332 "Steering".

3F is an enlarged, simplified view of a portion of a prior art pattern 233 (illustrated using a small circle representing points on an existing pattern) and a portion of a first strip 364 of a new pattern 330 that is transferred to the workpiece 22. FIG. 3F illustrates how the first stripe 364 is trimmed such that it closely overlaps the existing pattern 233. It should be noted that in the middle of each of the dies, the first stripe 364 closely overlaps the existing pattern 233. However, at the boundary 367A of the adjacent grains 260 (two lines are illustrated by dashed lines) (using a dotted ellipse to highlight a boundary), due to the rapid change at the boundary 367A of the adjacent grains 260, There may be some differences between a stripe 364 and an existing pattern 233.

Several alternative methods for controlling the extreme ultraviolet photolithography system 10 to enable the first fringes 364 to more closely follow the existing pattern 233 at the boundary 367A are provided herein.

By way of example, FIG. 4A is a simplified diagram of workpiece 22 illustrating yet another first scan 465 of workpiece 22 past exposure field 28 along first scan trajectory 466. In this embodiment, the extreme ultraviolet lithography system 10 (described in FIG. 1A) is controlled such that every other die 260 (illustrated as a dashed rectangle) in the die row 480 along the first scan track 466 is The first scan 465 is not exposed during the period. In this example, during the first scan 465, the workpiece 22 is moved such that nine of the dies 260 aligned in the die row 480 along the Y axis pass under the exposure field 28. It should be noted that the dies 260 are previously formed, and for clarity, only one of the dies rows 480 is illustrated in FIG. 4A. In addition, moving from the bottom to the top of the die row 480, the die 260 has been labeled 1 through 9 for ease of discussion.

In this example, the extreme ultraviolet lithography system 10 is controlled such that each odd-numbered die 260 (eg, die 1, 3, 5, 7, 9) is at the first along the first scan track 466 The first portion 464F is exposed during scanning 465 to form a first stripe, and such that each even-numbered die 260 (eg, die 2, 4, 6, 8) is in a first scan along the first scan track 466 Not exposed during the 465 period. For such a design, the platform assembly 20 can be controlled during the first scan 465 to better match the first portion 464F to the existing pattern 233 (described in Figure 2A) at the boundary 467A of the odd-numbered die 260. . Basically, during the first scan 465, the area of the evenly numbered dies 260 provides time for moving the workpiece 22 to a relative position suitable for accurately printing the next odd numbered dies 260. In summary, in the first scan 465, the light for exposure is turned off (and/or blocked by the shutter assembly 26 illustrated in FIG. 1A) when the "even numbered" die 260 is passed. In the case of a smooth trajectory, only the "odd numbered" dies 260 are exposed.

Subsequently, the extreme ultraviolet lithography system 10 is controlled to expose unexposed grains along the first scan trajectory 466 during the second scan 469. 4B is a simplified diagram of workpiece 22 illustrating a second scan 469 of workpiece 22 along exposure field 28 along second first scan trajectory 470. In this embodiment, the extreme ultraviolet lithography system 10 (described in FIG. 1A) is also controlled such that every other die 260 (described as a dashed rectangle) in the die row 480 along the second scan trace 470 Not exposed during the second scan 469.

In this example, the extreme ultraviolet lithography system 10 is controlled such that each of the evenly numbered dies 260 (eg, dies 2, 4, 6, 8) is in a second scan 469 along the second scan trajectory 470. The second portion 464S is exposed to form a first stripe, and such that each odd-numbered die 260 (eg, die 1, 3, 5, 7, 9) is not exposed during the second scan 469. For such a design, the platform assembly 20 can be controlled during the second scan 469 to better match the second portion 464S to the existing pattern 233 at the boundary 467A of the even numbered die 260. Basically, during the second scan 469, the area of the odd-numbered die 260 provides time for moving the workpiece 22 to a position suitable for printing the next even-numbered die 260. Therefore, when the second pass passes through the same region, the even crystal grains 260 are exposed by smooth interpolation using the odd-numbered crystal grains 260 that have been exposed.

It should be noted that the previously printed first portion 464F is not shown in FIG. 4B for clarity. However, referring to Figures 4A and 4B, the first portion 464F and the second portion 464S cooperate to form a complete first stripe having substantially parallel lines. It should also be noted that the scan tracks 466, 470 overlap partially, but are not identical. For this design, the workpiece 22 must be scanned twice by the exposure field 28 to completely form a new pattern.

In some embodiments, the shutter assembly 26 (described in FIG. 1A) can be used to accurately begin and stop exposure at the boundary 467A of the die 260. In this embodiment, shutter 26C is used to selectively define the Y-axis edge of exposure field 28. For this design, the shutter 26C can be used for opening and closing in conjunction with scanning. More specifically, shutter 26C can be controlled to gradually close as approaching boundary 467A and fully close at boundary 467A. Subsequently, the shutter 26C can be controlled to gradually open at the beginning of the next die 260. Alternatively, for example, the extreme ultraviolet light source 34 can be turned on and off as needed to initiate and stop exposure.

For this design, by scanning each stripe twice on the workpiece, exposing every other shot in the first pass and exposing the alternating shots in the second pass, Continuous scanning exposure has the problem of distortion matching with layers printed by conventional tools that create discontinuities between adjacent fields.

In yet another embodiment, referring to FIG. 4C, if the workpiece 22 is scanned at a relatively low scan speed relative to the exposure field 28 and the platform assembly 20 (described in FIG. 1A) has a high acceleration capability, then Exposure at the boundary 467A of a die 260 stops and the workpiece 22 can be stopped and retracted. Subsequently, exposure can begin at the next die 260. For this design, the extreme ultraviolet illumination system 10 illustrated in FIG. 1A is controlled to stop exposure and reset the scan trace 492 at the interface 467A of the adjacent die 260. In one embodiment, when the exposure field 28 reaches the interface 467A, the shutter 26 begins to close such that adjacent dies 260 are not exposed. Once the shutter is closed and the exposure has ceased, the platform is decelerated and accelerated in the reverse direction in the opposite Y direction. When the platform is sufficiently reversible of its position, it is decelerated again and accelerates in the scanning direction such that it is properly positioned when it reaches interface 467A again. As the exposure field 28 begins to pass through the interface 467A, the extreme ultraviolet illumination system 10 is controlled to resume illumination and the shutter 26 begins to open. Thus, during scan 490, scan trace 492 (illustrated using a thick solid line) includes a reverse movement along the Y-axis during exposure of first strip 494 (only the outer line is illustrated using dashed lines).

For such a design, by stopping and resetting at each die 260, it is resolved that the continuous scan exposure is performed with a layer printed by a conventional tool that forms discontinuities between adjacent die 260. Distortion matching problem. Thus, the first stripe 494 and subsequent strips will more preferably overlap the existing pattern 233 at the border 467A.

As described above, it can be constructed by assembling various subsystems (including each of the elements listed in the accompanying claims) so that the prescribed mechanical precision, electrical accuracy, and optical precision are maintained. The photolithography system of the above embodiment. To maintain various accuracies, each optical system is adjusted to achieve its optical accuracy before and after assembly. Similarly, each mechanical system and each electrical system are adjusted to achieve their respective mechanical and electrical accuracy. The process of assembling each subsystem into a photolithography system includes mechanical interfacing, circuit wiring connections, and air pressure pipe connections between each subsystem. Needless to say, there is also a process in which each subsystem is assembled before the various MEMS are assembled from the various subsystems. Once the various systems are assembled using the lithography system, overall adjustments are performed to ensure accuracy is maintained in the complete photolithography system. In addition, it is desirable to manufacture an exposure system in a clean room where temperature and cleanliness are controlled.

Further, the semiconductor device can be fabricated by the above-described system by the process generally shown in FIG. 5A. In step 501, the functionality and performance characteristics of the device are designed. Next, in step 502, a patterned mask (mask) is designed in accordance with the previous design step, and in a parallel step 503, the workpiece is made of tantalum material. In step 504, the mask pattern designed in step 502 is exposed to the workpiece from step 503 by the optical lithography system described above in accordance with an embodiment of the present invention. In step 505, the semiconductor device (including the dicing process, the bonding process, and the packaging process) is assembled, and finally, the device is subsequently verified in step 506.

FIG. 5B illustrates an example of a detailed flow chart of the above step 504 in the case of fabricating a semiconductor device. In Fig. 5B, in step 511 (oxidation step), the surface of the workpiece is oxidized. In step 512 (chemical vapor deposition (CVD) step), an insulating film is formed on the surface of the workpiece. In step 513 (electrode forming step), an electrode is formed on the workpiece by vapor deposition. In step 514 (ion implantation step), ions are implanted in the workpiece. The above steps 511 to 514 form a pre-processing step of the workpiece during the processing of the workpiece, and a selection is made at each step according to the processing requirements.

At each stage of the workpiece processing, the following post-processing steps are performed when the above pre-processing steps have been completed. During the post-processing, first, in step 515 (resistance forming step), a photoresist is applied to the workpiece. Next, in step 516 (exposure step), the circuit pattern of the mask (mask) is transferred to the workpiece using the above exposure apparatus. Next, in step 517 (developing step), the exposed workpiece is developed, and in step 518 (etching step), a portion other than the residual photoresist (the surface of the exposed material) is removed by etching. In step 519 (photoresist removal step), unnecessary photoresist remaining after etching is removed.

A plurality of circuit patterns are formed by repeating the pre-processing steps and post-processing steps.

Although the assemblies shown and disclosed herein are fully capable of achieving the objectives described above and providing the advantages described above, it should be understood that the assembly merely illustrates the presently preferred embodiments, and It is not intended to be limited to the details of construction or design shown herein, except as described in the appended claims.

1, 2, 3, 4, 5, 6, 7, 8, 9, 260‧‧ ‧ grains

10‧‧‧Extreme ultraviolet (EUV) lithography system / system / extreme ultraviolet light tool / exposure equipment

12‧‧‧ Extreme ultraviolet light irradiation system

13A, 13B, 13C, 13D, 13E‧‧‧ extreme ultraviolet light beam

14‧‧‧ patterned component platform assembly

14A‧‧‧patterned component platform

14B‧‧‧patterned component platform mover

16‧‧‧patterned components

16A‧‧‧patterned component pattern

18‧‧‧Projection Optical Assembly / Projection Optical System

20‧‧‧Workpiece platform assembly/platform assembly

22‧‧‧Workpiece/semiconductor workpiece

24‧‧‧Control system

26‧‧‧Shutter assembly

26A‧‧‧Rigid shutter housing

26B‧‧‧Shell opening

26C‧‧‧ movable shutter / shutter

26D‧‧‧Shutter mover

26E‧‧‧Shutter opening

28‧‧‧ Exposure field

29‧‧‧Closed room

34‧‧‧Extreme ultraviolet light source/irradiation source/extreme ultraviolet light source

36‧‧‧Optical optical assembly

38‧‧‧First illuminating optics/illuminating optics

40‧‧‧Second illumination optics/illumination optics

42‧‧‧3rd illuminating optics/illuminating optics

44‧‧‧First projection subassembly

44A‧‧‧First projection optics/optics

44B‧‧‧First projection optics/optics

46‧‧‧Second projection subassembly

46A‧‧‧Second projection optics/optics

46B‧‧‧Second projection optics/optics

48‧‧‧Workpiece platform

50‧‧‧Workpiece platform mover/platform mover

54‧‧‧ processor

55‧‧‧beam path

56‧‧‧Intermediate image plane

233, 330‧‧‧ patterns

262‧‧‧ Vector

300, 302, 304, 501, 502, 503, 504, 505, 506, 511, 512, 513, 514, 515, 516, 517, 518, 519 ‧ ‧ steps/blocks

328‧‧‧Y axis size

332‧‧‧Line/patterned component line

332L‧‧‧leftmost line/line

332R‧‧‧ far right line/line

364‧‧‧First Stripe/Stripes

365‧‧‧First scan/scan

366, 466‧‧‧First scan track/scan track

367A‧‧‧ border

367B‧‧‧ discontinuous point

368‧‧‧Second stripes/stripes

369‧‧‧Second scan/scan

370, 470‧‧‧Second scan track/scan track

372‧‧‧Strip width

374L‧‧‧left middle width / middle width

374R‧‧‧Right middle width/intermediate width

464F‧‧‧The first part of the first stripe

464S‧‧‧The second part of the first stripe

465‧‧‧First scan

467A‧‧‧Boundary/Interface

469‧‧‧Second scan

480‧‧‧ grain row

490‧‧‧ scan

492‧‧‧ scan track

X, Y, Z‧‧‧ axis

The novel features of the present invention, as well as the structure and operation of the present invention, will be better understood by reference to the accompanying drawings.

1A is a simplified schematic diagram illustrating an extreme ultraviolet photolithography system having features of an embodiment of the present invention.

1B is a simplified side view of a shutter assembly having features of an embodiment of the present invention.

2A is a simplified top view of a workpiece that has been processed to include an existing pattern.

2B is a simplified diagram illustrating raw broad distortion data for a workpiece processed using a step and repeat lithography system or a step and scan lithography system.

Figure 2C is a simplified diagram illustrating only the global distortion data for the workpiece.

Figure 2D is a simplified diagram illustrating distortion data for each die of the workpiece.

Figure 2E contains a graph illustrating the common distortion shape of each die.

Figure 2F contains a chart illustrating residual distortion data.

3A is a flow chart illustrating a procedure having features of an embodiment of the present invention.

Figure 3B is a simplified top plan view of a workpiece including a first strip of parallel lines.

3C is a simplified top plan view of a workpiece including a first strip of parallel lines and a second strip of parallel lines.

3D is a simplified top view of a portion of a patterned element pattern that is projected onto a workpiece.

Figure 3E is a simplified top plan view of another portion of the patterned element pattern projected onto the workpiece.

Figure 3F is a simplified top view of a portion of a workpiece in which a portion of the new pattern overlaps the existing pattern.

4A is a simplified top plan view of a workpiece having a first portion of a first stripe with parallel lines.

4B is a simplified top plan view of a workpiece having a second portion of a first stripe with parallel lines.

4C is a simplified top plan view of the workpiece, and yet another first strip of parallel lines.

Figure 5A is a flow chart summarizing the process of fabricating a device in accordance with an embodiment of the present invention.

Figure 5B is a flow chart outlining the device processing in more detail.

Claims (23)

An extreme ultraviolet lithography system for transferring a pattern of parallel lines to a workpiece comprising an existing pattern, the lithography system comprising: a workpiece platform assembly for holding and moving the workpiece; an extreme ultraviolet illumination system that will be extremely ultraviolet a beam of light directed to the patterning element, the patterning element defining the pattern of the parallel lines; a projection optics assembly, within the exposure field, as the workpiece moves relative to an exposure field during a first scan Projecting and transferring images of the plurality of parallel lines onto the workpiece, exposing to obtain a first stripe of the plurality of imaged lines extending substantially along the first axis; and controlling a system to control the total of the workpiece platform Moving the workpiece relative to the exposure field along a first scan trajectory during the first scan, the first scan trajectory substantially along the first axis; wherein the control system is in the substrate platform assembly Selectively adjusting control parameters during the first scan such that the first fringes of the parallel lines overlap the above more accurately with respect to the unadjusted control parameters The patterned portion located below said first stripes parallel lines. The extreme ultraviolet lithography system of claim 1, wherein the control parameter comprises selectively adjusting the first scan trajectory to include along the first axis during the first scan Movement of the orthogonal second axes such that the first stripe of the parallel lines more accurately overlaps the location of the existing pattern relative to when the movement along the second axis is not performed Said portion of said parallel line below said first stripe. The extreme ultraviolet lithography system of claim 2, wherein the control parameter comprises selectively adjusting the first scan trajectory to include the first axis during the first scan And a movement of the third axis orthogonal to the second axis, such that the first stripe of the parallel line more accurately overlaps the first stripe of the existing pattern on the parallel line The part below. The extreme ultraviolet lithography system of claim 3, wherein the movement along the second axis or the movement centered on the third axis during the first scan is A function of the position of the workpiece along the first axis relative to the movement of the second axis or the movement of the third axis. The extreme ultraviolet lithography system of claim 1, wherein the control parameter comprises selectively adjusting a magnification of the plurality of parallel lines during the first scanning so that relative to an unadjusted In the case of magnification, the first stripe of the parallel lines more accurately overlaps the portion of the existing pattern that is below the first strip of the parallel lines. The extreme ultraviolet photolithography system of claim 1, wherein the control parameter comprises selectively adjusting a magnification tilt of the plurality of parallel lines during the first scan, such that the parallel lines The first stripe more accurately overlaps the portion of the existing pattern that is below the first strip of the parallel lines. The extreme ultraviolet photolithography system of claim 1, wherein the control parameter comprises selectively adjusting one or more of: (i) the first during the first scan The scan trajectory is adjusted to include movement along a second axis orthogonal to the first axis and movement centered on a third axis orthogonal to the first axis and the second axis; (ii) at Adjusting a magnification of the patterned element pattern during a first scan; and (iii) adjusting a magnification tilt of the patterned element pattern during the first scan. The extreme ultraviolet photolithography system of claim 1, wherein the existing pattern comprises a plurality of crystal grains, and wherein the control system controls the extreme ultraviolet light illumination system such that the first scan Every other die along the first scan trajectory is not exposed. The extreme ultraviolet lithography system of claim 8, wherein the control system controls the crystal that the extreme ultraviolet light illumination system will not be exposed along the first scan trajectory during a second scan. Granular exposure. The extreme ultraviolet lithography system of claim 1, wherein the existing pattern comprises a plurality of dies, wherein the control system stops exposure at an interface of adjacent dies; and wherein the controlling The system controls the workpiece platform assembly to move the platform to reset the first scan trajectory such that the new pattern overlaps the existing pattern during exposure of the next die. The extreme ultraviolet lithography system of claim 10, wherein the extreme ultraviolet light illumination is stopped by a shutter assembly located on or near a plane optically conjugate with the workpiece. The extreme ultraviolet lithography system of claim 10, wherein the workpiece platform assembly resets the first scanning track by: decelerating the platform to stop scanning motion; The platform accelerates in the opposite direction; decelerating the platform to stop the reverse motion; accelerating the platform to resume scanning. The extreme ultraviolet lithography system of claim 1, wherein the control system selectively adjusts the first scan trajectory and the parallel transferred to the workpiece during the first scan The pitch of the lines is such that the first fringes of the parallel lines are distorted to overlap the portion of the existing pattern that is below the first strip of the parallel lines. A method of transferring a pattern onto a workpiece, the pattern having a plurality of parallel lines, the workpiece comprising a distorted existing pattern, the method comprising: providing a patterned element having a patterned element pattern; using a workpiece platform mover total Moving the workpiece; directing an extreme ultraviolet light beam onto the patterned element using an extreme ultraviolet illumination system; imaging the patterned element pattern onto the workpiece using a projection optical assembly, thereby Forming a plurality of the parallel lines on the workpiece when the workpiece is moved relative to the exposure field during a scan, the first stripe of the parallel lines extending substantially along a first axis; and Using a control system to control the workpiece platform assembly to move the workpiece relative to the exposure field along a first scan trajectory during a scan, the first scan trajectory substantially along the first axis; wherein the control system is at Selectively adjusting control parameters during the first scan such that the first fringes of the parallel lines are more accurate relative to when the control parameters are not adjusted The conventional pattern overlaps a portion under said first line of said parallel stripes. A method of transferring a pattern onto a workpiece as described in claim 14 wherein said controlling step comprises controlling said workpiece platform assembly during said first scanning such that said first scanning trajectory comprises Movement of a second axis orthogonal to the first axis such that the first stripe of the parallel lines more accurately overlaps the underlying strip of the existing pattern below the first strip of the parallel line section. A method of transferring a pattern onto a workpiece as described in claim 15 wherein said controlling step comprises controlling said workpiece platform assembly during said first scanning such that said first scanning trajectory comprises The movement of the first axis and the third axis orthogonal to the second axis is centered such that the first stripe of the parallel lines more accurately overlaps the aforementioned pattern of the existing pattern on the parallel line The portion below the first stripe. The method of transferring a pattern onto a workpiece as described in claim 16, wherein the controlling parameter comprises selectively adjusting a magnification of the patterned element pattern during the first scanning such that the parallel line The first stripe more accurately overlaps the portion of the existing pattern that is below the first strip of the parallel lines. The method of transferring a pattern onto a workpiece as described in claim 14, wherein the controlling parameter comprises selectively adjusting a magnification tilt of the patterned element pattern during the first scanning such that the parallel The first strip of the line more accurately overlaps the portion of the existing pattern that is below the first strip of the parallel line. The method of transferring a pattern onto a workpiece as described in claim 14, wherein the controlling comprises selectively adjusting at least one of: (i) the first scan during the first scan The trajectory is adjusted to include movement along a second axis orthogonal to the first axis and/or movement centered on a third axis orthogonal to the first axis and the second axis; (ii) at Adjusting a magnification of the patterned element pattern during the first scan; and (iii) adjusting a magnification tilt of the patterned element pattern during the first scan. The method of transferring a pattern onto a workpiece according to claim 14, wherein the existing pattern comprises a plurality of crystal grains, and wherein the controlling comprises controlling the extreme ultraviolet light illumination system such that the first Every other die along the first scan trajectory during the scan is not exposed. The method for transferring a pattern onto a workpiece as described in claim 20, further comprising controlling the extreme ultraviolet light illumination system to expose the unexposed film along the first scan track during a second scan . A method of transferring a pattern onto a workpiece as described in claim 14, wherein the existing pattern comprises a plurality of grains, and wherein the method comprises using the control system to control the extreme ultraviolet light illumination system The first scan trajectory is stopped and reset at the interface of adjacent dies. A method of transferring a pattern onto a workpiece as described in claim 14, comprising selectively adjusting the first scan trajectory and the workpiece transferred to the workpiece during the first scan using the control system The pitch of the parallel lines is such that the first fringes of the parallel lines are distorted to overlap the portion of the existing pattern that is below the first strip of the parallel lines.