System and method for measuring substrate and film thickness distribution

Abstract

The present invention relates to systems and methods for measuring substrate and film thickness distribution. The system includes a dual interferometer subsystem configured to measure flatness across a substrate. The system includes a mass sensor configured to measure the quality of the substrate. The system includes a controller communicatively coupled to the dual interferometer subsystem and the mass sensor. The controller includes one or more processors. The one or more processors are configured to execute a set of program instructions stored in a memory, the set of program instructions being configured to cause the one or more processors to determine a thickness distribution of at least one of the substrate or a film deposited on the substrate as a function of position across the substrate based on one or more flatness measurements from the dual interferometer subsystem and one or more quality measurements from the mass sensor.

Description

[0001] This application is a divisional application of the invention patent application with the invention name “System and method for measuring substrate and film thickness distribution”, application number 201880009926.3, and application date February 7, 2018.

[0002] CROSS REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 62 / 456,651, filed on February 8, 2017, entitled “METHOD TO USE MASS GAUGE IN WSPWG FORWAFER AND FILM THICKNESS DISTRIBUTION MEASUREMENT,” naming Dengpeng Chen and Andrew Zeng as inventors, the entirety of which is incorporated herein by reference. Technical Field

[0004] The present invention relates to measuring substrate and film thickness, and in particular to utilizing a mass meter and measurements from a dual interferometer to determine substrate or film thickness distribution. Background Art

[0005] Interferometry is a useful technique for measuring one or more spatial characteristics of a sample based on information associated with illumination reflected from a test surface of the sample (e.g., a semiconductor wafer or any other semiconductor or non-semiconductor substrate). As semiconductor manufacturing continues to require higher levels of accuracy and precision, improved interferometry techniques are needed to meet the needs of modern manufacturing technology. It is generally desired to measure the absolute thickness distribution t(x, y) of a wafer or film. Currently, the measurement of the absolute thickness distribution t(x, y) of a bare wafer is achieved by a combination of dual interferometry measurements performed across the wafer and capacitance meter (CG) or optical thickness meter (OTG) measurements. CG measurements involve the use of capacitive displacement sensors that can only be used to measure substrates that can be virtually grounded. OTG measurements involve the use of laser displacement sensors and can sense the surface of a material only when the material surface reflects an incident laser beam. Both approaches are subject to significant limitations. Therefore, it is desirable to provide a system and method that overcomes the deficiencies of the previous approaches discussed above. Summary of the invention

[0006] According to one or more embodiments of the present invention, a system for measuring substrate and / or film thickness is disclosed. In one embodiment, the system includes a dual interferometer subsystem configured to measure flatness across a substrate. In another embodiment, the system includes a mass sensor configured to measure the quality of the substrate. In another embodiment, the system includes a controller communicatively coupled to the dual interferometer subsystem and the mass sensor. In another embodiment, the controller includes one or more processors, wherein the one or more processors are configured to execute a set of program instructions stored in a memory. In another embodiment, the set of program instructions is configured to cause the one or more processors to determine a thickness distribution of at least one of the substrate or a film deposited on the substrate as a function of position across the substrate based on one or more flatness measurements from the dual interferometer subsystem and one or more quality measurements from the mass sensor.

[0007] According to one or more embodiments of the present invention, a method for measuring the thickness of a substrate is disclosed. In one embodiment, the method obtains one or more flatness measurements of the substrate as a function of position across the substrate. In another embodiment, the method obtains one or more quality measurements of the substrate. In another embodiment, the method determines an average thickness of the substrate based on the one or more quality measurements. In another embodiment, the method determines one or more thickness distributions of the substrate as a function of position across the substrate based on the one or more flatness measurements of the substrate and the average thickness. In another embodiment, the method adjusts one or more process tools based on the one or more determined thickness distributions of the substrate.

[0008] According to one or more embodiments of the present invention, a method for measuring film thickness is disclosed. In one embodiment, the method obtains a first flatness measurement and a first quality measurement of the substrate before the film is deposited on the substrate. In another embodiment, the method determines an average thickness of the substrate based on the first quality measurement before the film is deposited on the substrate. In another embodiment, the method obtains a second flatness measurement and a second quality measurement of the substrate after the film is deposited on the substrate. In another embodiment, the method determines an average thickness of the substrate based on the second quality measurement after the film is deposited on the substrate. In another embodiment, the method determines a thickness distribution of the film as a function of position across the substrate based on the first flatness measurement and the first average thickness before the film is deposited on the substrate and the second flatness measurement and the second average thickness of the substrate after the film is deposited on the substrate. In another embodiment, the method adjusts one or more process tools based on the determined thickness distribution of the film.

[0009] According to one or more embodiments of the present invention, a method for measuring film thickness of a film disposed on one or more pre-layers is disclosed. In one embodiment, the method receives a first flatness measurement and a first quality measurement of a substrate before depositing the film on the substrate and after depositing one or more pre-layers on the substrate. In another embodiment, the method receives a second flatness measurement and a second quality measurement of the substrate after depositing the film on the pre-layers of the substrate. In another embodiment, the method determines the thickness of the film as a function of position across the substrate based on the density of the film, the first flatness measurement, the first quality of the substrate, the second flatness measurement, and the second quality of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] With reference to the accompanying drawings, those skilled in the art may better understand the numerous advantages of the present invention, wherein:

[0011] Figure 1 is a block diagram of a system for measuring thickness distribution of a substrate or film according to one or more embodiments of the present invention;

[0012] Figure 2A is a simplified schematic view of a dual interferometer subsystem according to one or more embodiments of the present invention;

[0013] Figure 2B is a simplified schematic view of a cavity of a dual interferometer subsystem according to one or more embodiments of the present invention;

[0014] Figure 3A is a conceptual view of a film / coating deposition process on a substrate according to one or more embodiments of the present invention;

[0015] Figure 3B is a conceptual diagram of a film deposition process on a substrate having one or more pre-layers according to one or more embodiments of the present invention;

[0016] Figure 4 A process flow chart depicting a method for measuring thickness distribution of a substrate according to one or more embodiments of the present invention is shown;

[0017] Figure 5 A process flow chart depicting a method for measuring a thickness profile of a film deposited on a substrate according to one or more embodiments of the present invention is shown;

[0018] Figure 6 A process flow diagram depicting a method for measuring a thickness profile of a film deposited on a substrate having one or more pre-layers in accordance with one or more embodiments of the present invention is shown. DETAILED DESCRIPTION

[0019] Reference will now be made in detail to the disclosed subject matter which is illustrated in the accompanying drawings.

[0020] Figures 1 to 6 Systems and methods for measuring the thickness distribution of a substrate or film according to one or more embodiments of the present invention are depicted. Embodiments of the present invention relate to determining a thickness distribution associated with a substrate using one or more quality measurements of a substrate. Embodiments of the present invention also relate to determining a thickness distribution associated with a film (e.g., a metal film or a dielectric film) deposited on a substrate using one or more quality measurements of a substrate. Films suitable for this measurement process include, but are not limited to, silicon films (e.g., epitaxially grown silicon films), carbon films (e.g., carbon hardmasks), tungsten films, photoresists, oxide films, nitride films, and polymeric layers (e.g., polysilicon layers). Embodiments of the present invention also relate to determining a thickness distribution associated with a film deposited on a substrate using one or more quality measurements of a substrate formed with one or more pre-layers (e.g., metal or dielectric pre-layers).

[0021] One or more embodiments of the present invention are particularly advantageous because they do not require knowledge of certain material properties of the film and substrate, such as, but not limited to, film transparency, conductivity, etc. In addition, one or more embodiments of the present invention are suitable for application to both metal and dielectric films (e.g., transparent or opaque films).

[0022] Figure 1 A conceptual diagram of a system 100 for measuring thickness distribution of a substrate or a film across a substrate is shown in accordance with one or more embodiments of the present invention.

[0023] In one embodiment, system 100 includes a dual interferometer subsystem 102 (or dual interferometer tool), a quality sensor 104, and a controller 106. In one embodiment, dual interferometer subsystem 102 is configured to measure flatness across substrate 101. In another embodiment, quality sensor 104 is configured to measure the quality of substrate 101. Substrate 101 may include any substrate known in the art, including but not limited to semiconductor wafers such as silicon wafers. The substrate may be coated with one or more films and may include one or more pre-layers, as discussed in further detail herein.

[0024] In another embodiment, the controller 106 includes one or more processors 108 and a memory 110. For example, the memory 110 may maintain program instructions configured to cause the one or more processors 108 to perform any of the one or more process steps described throughout the present invention.

[0025] In one embodiment, the one or more processors 108 of the controller 106 are communicatively coupled to the dual interferometer subsystem 102 and the quality sensor 104. In this regard, the one or more processors 108 are configured to receive measurements from the dual interferometer subsystem 102 and the quality sensor 104. In one embodiment, the one or more processors are configured to determine a thickness profile of the substrate 101 as a function of position across the substrate 101 based on the one or more flatness measurements received from the dual interferometer subsystem and the one or more quality measurements received from the quality sensor 104. It should be noted that the system 100 can be used to measure the thickness profile of a substrate and / or the thickness profile of a thin film deposited on a substrate with or without a pre-layer, which will be described in additional detail further herein.

[0026] The mass sensor 104 may include any mass / weight sensor known in the art capable of measuring the mass of a substrate, such as but not limited to a semiconductor wafer. For example, the mass sensor 104 may include but not limited to a high precision load cell with an accuracy between 0.1 mg and 0.3 mg.

[0027] The dual interferometer subsystem 102 may include any dual interferometer tool known in the art that is capable of measuring flatness across the substrate 101. For example, the dual interferometer subsystem 102 may include, but is not limited to, a dual wavelength dual Fizeau interferometer (DWDFI). The dual interferometer subsystem 102 may be configured to measure any number of spatial characteristics of the substrate 101, such as, but not limited to, shape variation, thickness variation, and / or other spatial parameter variation of the sample. In another embodiment, the dual interferometer subsystem 102 may be adapted to perform patterned wafer geometry (PWG) measurements on the sample, whereby the dynamic range of the sample slope (e.g., wafer slope) measured by the dual interferometer subsystem 102 is extended by stitching together different regions of sample (e.g., wafer) measurements.

[0028] A product description of a dual wavelength dual interferometer is described in U.S. Patent No. 6,847,458, issued on January 25, 2005, which is incorporated herein by reference in its entirety. A product description of a dual wavelength dual interferometer is described in U.S. Patent No. 8,068,234, issued on November 29, 2011, which is incorporated herein by reference in its entirety. A product description of a dual wavelength dual interferometer is described in U.S. Patent Publication No. 2014 / 0293291, issued on October 2, 2014, which is incorporated herein by reference in its entirety. A product description of a dual wavelength dual interferometer for measuring the shape and thickness of high slope samples is described in U.S. Patent No. 7,847,954, issued on December 7, 2010, which is incorporated herein by reference in its entirety. It should be recognized herein that the present invention can be extended to any phase shifting interferometry system configured to utilize a wavelength tunable illumination source for phase shifting. Therefore, the following description of dual interferometer subsystem 102 is in no way intended to limit the present invention.

[0029] Figure 2A A simplified schematic diagram of a dual interferometer subsystem 102 is shown in accordance with one or more embodiments of the present invention.

[0030] In one embodiment, subsystem 102 of system 100 includes two interferometers 250 and 251. In one embodiment, subsystem 102 includes an illumination source or illuminator 201 configured to provide light to interferometers 250 and 251 along channel 1 and channel 2.

[0031] In another embodiment, optical channels 1 and 2 of subsystem 102 include optical fibers 228 and 229 configured to transmit light from illumination source 101 to interferometer inputs 252 and 253. In one embodiment, interferometer inputs 252 and 253 include one or more optical elements connected in series with one or more optical fibers 228 and 229. In another embodiment, interferometer inputs 252 and 253 may include optical fibers 228 and 229. Interferometer inputs 252 and 253 may direct at least a portion of the light from illuminator 201 to phase-shifting interferometers 250 and 251.

[0032] In one embodiment, the interferometers 250 and 251 each include one or more polarization beam splitters 212, 213 configured to receive light from the interferometer inputs 222, 223. In another embodiment, the beam splitters 212, 213 direct a portion of the light to quarter wave plates 254, 255. The light that passes through the polarization beam splitters 212, 213 and through the quarter wave plates 254 and 255 may be circularly polarized. The circularly polarized light may then be received by lenses 214, 215, which are configured to collimate the light into a beam having a diameter greater than the diameter of the substrate 101. The one or more lenses 214, 215 may also direct the collimated beam to a reference plane 216, 217 (e.g., parallel to the reference plane). The substrate 101 may be located at the center of a cavity 219 defined by the reference planes 216, 217. In another embodiment, the collimated beam may be transmitted through the reference planes 216, 217 to the substrate 101.

[0033] In another embodiment, a first portion of each of the transmitted light beams is directed to one or more surfaces 220, 221 of the substrate 101. Furthermore, a second portion of each of the transmitted light beams is directed to a reference surface of reference planes 216, 217 that is located opposite to the one or more transmission reference planes 216, 217.

[0034] In another embodiment, the subsystem 102 includes detectors 222, 223. The detectors 222, 223 may include, but are not limited to, one or more CCD detectors, one or more TDI-CCD detectors, one or more CMOS detectors, or any other light detectors known in the art. In one embodiment, the detectors 222, 223 may be configured to detect a portion of the illumination reflected from one or more surfaces 220, 221 of the substrate 101. In another embodiment, the detectors 222, 223 are configured to detect a portion of the light reflected from the corresponding reference surfaces of the reference planes 216, 217. In another embodiment, the system 100 includes one or more controllers 226 communicatively coupled to the detectors 222, 223. In another embodiment, the one or more controllers 226 obtain information associated with the light detected from the detectors 222, 223. In another embodiment, the controller 126 may execute a measurement algorithm from program instructions stored on a memory to determine one or more spatial characteristics of the substrate 101 based on measurements from the substrate 101. Measurement algorithms for determining spatial characteristics of a sample using a phase-shift interferometry system are known in the art. It should be noted that any measurement process known in the art can be implemented using the system 100 and one or more controllers 226. In addition, Figure 2A The one or more controllers 226 depicted in FIG. 1 may be embodied in Figure 1 and vice versa.

[0035] Figure 2B A conceptual diagram of a double Fizeau cavity 219 according to one or more embodiments of the present invention is shown. Figure 2B , the double Fizeau cavity 219 may be configured to hold the substrate 101 in a substantially vertical position. For example, the double Fizeau cavity 219 may include a set of point contact devices (not shown) configured to receive a wafer in a substantially free state and hold the wafer in a substantially upright position. With two reference planes 216 and 217 acting as reference surfaces for the interferometer, the double Fizeau interferometer can analyze various parameters associated with the substrate and its spatial relationship with the reference planes 216 and 217.

[0036] The dual interferometer subsystem 102 can simultaneously measure the thickness variation of both the front side surface 220 and the back side surface 221 of the substrate 101. The height variation measured at the measurement points of the front side and / or back side surface can then be used to calculate the shape value at each of those points. The wafer shape s(x,y) as a function of the XY position on the wafer surface can be expressed as a function of the cavity distance between the surface of the substrate 101 and the corresponding reference planes 216, 217.

[0037] In this case, d A (x, y) represents the cavity distance between the first reference plane 217 of the cavity 219 and the first side 221 (eg, the front side) of the substrate, d B (x, y) represents the cavity distance between the second reference plane 216 and the second side 220 (eg, back side) of the wafer. In this regard, the cavity distance d A (x,y) varies with the thickness t of the first side of the substrate A (x,y) variation with reference plane r A Similarly, the cavity distance d B (x,y) varies with the thickness t of the second side of the substrate B (x,y) variation with reference plane r B The difference between the changes in the surface of (x,y) is related.

[0038] Using these relationships, a two-dimensional XY shape map can be constructed by calculating the shapes at multiple locations on the substrate. Double Fizeau interferometry, which is suitable for measuring the front and back side topography of a substrate (e.g., a semiconductor wafer), is described in detail in Klaus Freischlad et al., "Interferometry for Wafer Dimensional Metrology," Proc. SPIE 6672, 1 (2007), the entire text of which is incorporated herein by reference. In addition, double-sided interferometry is generally described in U.S. Pat. No. 6,847,458, issued on January 25, 2005, and U.S. Pat. No. 8,068,234, issued on November 29, 2011, the entire text of which is incorporated herein by reference.

[0039] In one embodiment, one or more processors 108 of the controller 106 of the system 100 may determine a thickness distribution of the substrate 101 as a function of position across the substrate 101 based on one or more flatness measurements from the dual interferometer subsystem 102 and one or more quality measurements from the quality sensor 104. In one embodiment, the one or more processors 108 receive one or more flatness measurements f(x,y) of the substrate 101 as a function of XY position across the substrate 101 from the dual interferometer subsystem 102. In another embodiment, the one or more processors 108 receive one or more quality measurements of the substrate from the quality sensor 104. In another embodiment, the one or more processors 108 determine an average thickness of the substrate 101 based on the one or more quality measurements. In another embodiment, the one or more processors 108 determine a thickness distribution t(x,y) of the substrate 101 as a function of position across the substrate 101 based on the one or more flatness measurements and the average thickness of the substrate 101.

[0040] It should be noted that in order to obtain a thickness that varies as a function of the XY position across the substrate 101, a thickness reference constant may be implemented. Due to the nλ phase ambiguity, the interferometer subsystem 102 cannot provide this reference. The thickness across the substrate 101 can be expressed in terms of the flatness of the substrate 101 as follows:

[0041] t(x,y)=f(x,y)+K Equation 1

[0042] Where t(x,y) represents the thickness distribution across the substrate as a function of X,Y position, f(x,y) represents the flatness of the substrate as a function of XY position, and K represents a reference constant.

[0043] It should be noted that the mass sensor 104 may provide average thickness information, where the average thickness t ave Given by the following equation:

[0044]

[0045] Where w is the weight (or mass) of the wafer measured using mass sensor 104, p is the material density of substrate 101, and A is the area of ​​substrate 101. The average thickness is expressed in terms of flatness and constant K as follows:

[0046]

[0047] If the average thickness t ave Knowing that, then Equation 3 can be rearranged to provide a solution for K as follows:

[0048]

[0049] Next, based on Equation 1 and Equation 4, the one or more processors 108 may determine a thickness distribution t(x,y) of the substrate 101 as a function of the XY position.

[0050] In another embodiment, one or more processors 108 of the controller 106 of the system 100 may determine the thickness of the film as a function of position across the substrate 101 based on two or more flatness measurements of the substrate 101 and two or more quality measurements of the substrate 101. For example, Figure 3A As shown in FIG. 1 , a first flatness measurement of the substrate 101 may be performed before depositing the film 301. pre (x,y) and the first mass measurement m pre Next, after the film 301 is deposited, a second flatness measurement may be performed on the substrate 101. post (x,y) and the second mass measurement m post Based on a set of flatness measurements f pre (x,y) and f post (x,y) and a set of mass measurements m pre 、m post , the one or more processors 108 may determine the thickness distribution of the deposited film 301. In one embodiment, the one or more processors 108 receive a first flatness measurement f of the substrate 101 before depositing the film 301 on the substrate 101. pre (x,y) and the first mass measurement m pre In another embodiment, the one or more processors 108 determine the film 301 based on a first quality measurement m before depositing the film 301 on the substrate 101. pre The average thickness of the substrate 101 is determined. In another embodiment, after the film 301 is deposited on the substrate 101, the one or more processors 108 receive a second flatness measurement f of the substrate 101 (ie, the substrate and the film). post (x,y) and the second mass measurement m postIn another embodiment, the one or more processors 108 measure the film quality m based on the second quality measurement m after the film is deposited on the substrate 101. post Determine a second average thickness of substrate 101. In another embodiment, one or more processors 108 measure the flatness of substrate 101 before depositing film 301 onto the substrate based on a first flatness measurement f pre (x, y) and the first average thickness and the second flatness measurement f of the substrate 101 after depositing the film 301 on the substrate post (x, y) and the second average thickness determine the film thickness t as a function of position across the substrate 101 film (x,y).

[0051] The thickness distribution of the film as a function of the XY position can be expressed as follows:

[0052] t film (x,y)=t post (x,y)-t pre (x,y)=f post (x,y)-f pre (x,y)+K post -K pre Equation 5

[0053] The constant K post and K pre Given by the following equation:

[0054]

[0055]

[0056] Next, based on Equation 5, Equation 6, and Equation 7, the one or more processors 108 may determine the film thickness distribution t of the film 301 as a function of the XY position across the substrate 101. film (x,y).

[0057] In another embodiment, where one or more pre-layers are deposited on substrate 101 prior to depositing film 301, one or more processors 108 of controller 106 of system 100 may determine the thickness of the film as a function of location across substrate 101. It should be noted that in many semiconductor manufacturing environments, one or more pre-layers are deposited on a substrate prior to depositing a thin film / coating of interest. In one embodiment, system 100 may utilize the density of film 301 to determine the thickness of deposited film 301. In this regard, the thickness of film 301 may be determined without knowing the material or density of the one or more pre-layers deposited prior to film 301.

[0058] It should be noted that the average thickness of the film 301 before and after deposition can be expressed as:

[0059]

[0060] Where m pre and m post is the mass of the substrate 101 before and after the deposition of the film 301, ρ film is the density of the film of interest 301, and A is the area of ​​the substrate 101. Equation 8 can be rewritten in terms of flatness to provide:

[0061]

[0062] like Figure 3B As shown in FIG. 1 , one or more pre-layers 303 may be deposited onto the surface of substrate 101 prior to depositing film of interest 301. In one embodiment, a first flatness measurement of substrate 101 may be performed prior to depositing film 301. pre (x,y) and the first mass measurement m pre Next, after depositing the film 301 onto the one or more pre-layers 303, a second flatness measurement may be performed on the substrate 101. post (x,y) and the second mass measurement m post Based on the density of the membrane of interest, ρ film , a set of flatness measurements f pre (x,y) and f post (x,y) and a set of mass measurements m pre 、m post , one or more processors 108 may determine a thickness profile of the deposited film 301 .

[0063] In one embodiment, before depositing film 301 on substrate 101 and after depositing one or more pre-layers 303 on substrate 101, one or more processors 108 receive a first flatness measurement f of substrate 101. pre (x,y) and the first mass measurement m pre In another embodiment, after depositing film 301 onto pre-layer 303 of substrate 101, one or more processors 108 receive a second flatness measurement f of substrate 101. post (x,y) and the second mass measurement m post In another embodiment, one or more processors 108 determine the density of the film 301 based on the density of the film 301. film , the first flatness measurement f pre (x, y), the first mass m of the substrate 101 pre , the second flatness measurement f post (x, y) and the second mass m of the substrate 101 post (See, eg, Equation 9) to determine the thickness of the film 301 as a function of position across the substrate 101.

[0064] It should be noted herein that in the context of a multilayer coating that has been applied to a substrate, the thickness of the entire substrate is approximate because a common material density (e.g., the density of Si) is assumed. In contrast, thickness measurements of the film of interest will provide better results because, as observed in Equation 9, the film thickness does not require knowledge of the density of the pre-layer material.

[0065] In another embodiment, the system 100 includes a user interface device 112 communicatively coupled to the one or more processors 108 of the controller 106. The controller 106 may utilize the user interface device 112 to accept information, selections, and / or instructions from a user. For example, a display may be used to display data or prompts to a user (not shown). In turn, the user may input information, selections, and / or instructions into the memory 110 of the controller 106 via the user interface device 112.

[0066] Although the foregoing description focuses on the quality sensor 104 in communication with one or more processors 108, such a configuration does not limit the scope of embodiments of the present invention. In alternative embodiments, the quality information discussed above may be input into the memory 110 of the controller 106 by a user via the user interface 112. In this regard, the quality information input into the memory 110 via the user interface 112 may be utilized to perform the various thickness distribution calculations described above.

[0067] In one embodiment, upon determining the thickness distribution of the substrate 101 and / or film 301, the one or more processors 108 may transmit one or more control / adjustment instructions to one or more process tools. For example, in response to determining the thickness distribution of the substrate 101 and / or film 301 that deviates from the preferred thickness distribution, the one or more processors 108 may adjust one or more parameters of process tools along the semiconductor manufacturing facility in order to mitigate observed defects associated with the substrate, film, and / or final semiconductor device. In this regard, the one or more processors 108 may provide feedback information to an upstream process tool to adjust process conditions for a subsequent substrate that follows an initial substrate along the semiconductor manufacturing line. In addition, the one or more processors 108 may provide feed-forward information to a downstream process tool to adjust process conditions for the substrate in question as the substrate in question progresses along the semiconductor manufacturing line.

[0068] The one or more processors 108 of the controller 106 may include any one or more processing elements known in the art. In this sense, the one or more processors 108 may include any microprocessor-type device configured to execute software algorithms and / or instructions. In one embodiment, the one or more processors 108 may be composed of a desktop computer, a large computer system, a workstation, an image computer, a parallel processor, or other computer systems (e.g., networked computers) configured to execute a program configured to operate the system 100, as described throughout the present invention. It should be recognized that the steps described throughout the present invention may be implemented by a single computer system, or alternatively by multiple computer systems. In general, the term "processor" may be broadly defined to encompass any device having one or more processing elements that execute program instructions from a non-transitory memory medium 110. In addition, different subsystems of the system 100 (e.g., the dual interferometer subsystem / tool ​​102, the quality sensor 104, or the user interface 112) may include processors or logic elements suitable for implementing at least a portion of the steps described throughout the present invention.

[0069] The storage medium 110 may include any storage medium known in the art suitable for storing program instructions that are executable by one or more associated processors 108. For example, the storage medium 110 may include, but is not limited to, read-only memory, random access memory, magnetic or optical storage devices (e.g., disks), tapes, solid-state drives, etc. In another embodiment, the storage medium 110 is configured to store one or more results from the dual interferometer subsystem 102 and / or the quality sensor 104, and / or outputs of the various data process steps described herein. It should be further noted that the storage medium 110 may be housed in a common controller housing with the one or more processors 108. In alternative embodiments, the storage medium 110 may be remotely located relative to the physical location of the processors and controller 106. For example, the one or more processors 108 of the controller 106 may access a remote storage (e.g., a server) that is accessible via a network (e.g., the Internet, an intranet, etc.).

[0070] It should be further noted that although Figure 1 Controller 106 is depicted as embodied separately from dual interferometer subsystem 102 and mass sensor 104, but such configuration of system 100 does not limit the scope of the present invention and is provided for illustrative purposes only. For example, controller 106 may be embodied in a controller of dual interferometer subsystem 102 and / or mass sensor 104.

[0071] The user interface device 112 may include any user interface known in the art. For example, the user interface 112 may include, but is not limited to, a keyboard, a keypad, a touch screen, a joystick, a knob, a scroll wheel, a trackball, a switch, a dial, a slide bar, a scroll bar, a slider, a handle, a touch pad, a manual joystick, a steering wheel, a joystick, a bezel input device, etc.

[0072] Figure 4 A process flow diagram is shown depicting a method 400 for measuring a thickness distribution of a substrate according to one or more embodiments of the present invention. In step 402, one or more flatness measurements of the substrate are obtained as a function of a location across the substrate 101. In step 404, one or more quality measurements of the substrate 101 are obtained. In step 406, an average thickness of the substrate 101 is determined based on the one or more quality measurements. In step 408, one or more thickness distributions of the substrate as a function of a location across the substrate are determined based on the one or more flatness measurements and the average thickness of the substrate 101. In step 410, one or more process tools are adjusted based on the one or more determined thickness distributions of the substrate 101.

[0073] Figure 5 A process flow diagram is shown depicting a method 500 for measuring a thickness distribution of a film deposited on a substrate according to one or more embodiments of the present invention. In a first step 502, a first flatness measurement and a first quality measurement of the substrate are obtained before the film is deposited on the substrate 101. In a second step 504, an average thickness of the substrate is determined based on the first quality measurement before the film is deposited on the substrate. In step 506, a second flatness measurement and a second quality measurement of the substrate are obtained after the film is deposited on the substrate 101. In step 508, an average thickness of the substrate is determined based on the second quality measurement after the film is deposited on the substrate. In step 510, a thickness distribution of the film as a function of position across the substrate is determined based on the first flatness measurement and the first average thickness after the film is deposited on the substrate and the second flatness measurement and the second average thickness of the substrate after the film 301 is deposited on the substrate. In step 512, one or more process tools are adjusted based on the determined thickness distribution of the film 301.

[0074] Figure 6A process flow diagram is depicted depicting a method 600 for measuring a thickness distribution of a film deposited on a substrate having one or more preformed pre-layers according to one or more embodiments of the present invention. In step 602, a first flatness measurement and a first quality measurement of the substrate are obtained before depositing the film on the substrate and after depositing the one or more pre-layers on the substrate. In step 604, a second flatness measurement and a second quality measurement of the substrate are obtained after depositing the film on the pre-layers of the substrate. In step 606, a thickness of the film as a function of position across the substrate is determined based on the density of the film, the first flatness measurement, the first quality of the substrate, the second flatness measurement, and the second quality of the substrate. In step 608, one or more process tools are adjusted based on the determined thickness distribution of the film 303.

[0075] Although embodiments of methods 400, 500, and 600 are discussed herein, it is further contemplated that the various steps of methods 400, 500, and 600 may be included, eliminated, rearranged, and / or implemented in many ways without departing from the essence of the present invention. Accordingly, the foregoing embodiments and implementations of methods 400, 500, and 600 are included merely as examples and are in no way intended to limit the present invention.

[0076] All methods described herein may include storing the results of one or more steps of a method embodiment in a storage medium. The result may include any result described herein and may be stored in any manner known in the art. The storage medium may include any storage medium described herein or any other suitable storage medium known in the art. After the result has been stored, the result may be accessed in the storage medium and used by any method or system embodiment described herein, formatted to be displayed to a user, used by another software module, method or system, etc. In addition, the result may be stored "permanently", "semi-permanently", "temporarily" or over a period of time. For example, the storage medium may be a random access memory (RAM), and the result may not necessarily remain in the storage medium indefinitely.

[0077] It should be further contemplated that each of the above method embodiments may include any other steps of any other method(s) described herein. In addition, each of the above method embodiments may be performed by any system described herein.

[0078] Those skilled in the art will recognize that it is common in the art to describe devices and / or processes in the manner described herein, and thereafter use engineering practices to integrate such described devices and / or processes into a data processing system. That is, at least a portion of the devices and / or processes described herein can be integrated into a data processing system through a reasonable amount of experimentation. Those skilled in the art will recognize that a typical data processing system typically includes one or more of the following: a system unit housing; a video display device; memory, such as volatile and non-volatile memory; a processor, such as a microprocessor and a digital signal processor; a computing entity, such as an operating system, a driver, a graphical user interface, and an application; one or more interactive devices, such as a touch pad or touch screen; and / or a control system, which includes feedback loops and control motors (e.g., feedback for sensing position and / or velocity; control motors for moving and / or adjusting components and / or quantities). A typical data processing system can be implemented using any suitable commercially available components, such as those typically found in data computing / communication and / or network computing / communication systems.

[0079] The subject matter described herein sometimes illustrates different components contained in different other components or connected with different other components.It should be understood that such depicted architecture is only exemplary, and many other architectures that realize the same function can actually be implemented.In a conceptual sense, any component arrangement that realizes the same function is effectively "associated" so that the desired function is realized.Therefore, any two components combined to realize a specific function herein can be regarded as "associated" with each other so that the desired function is realized, regardless of the architecture or intermediate components.Similarly, any two components so associated can also be regarded as "operably connected" or "operably coupled" to realize the desired function, and any two components that can be so associated can also be regarded as "operably coupled" to realize the desired function.The specific examples of operably coupling include but are not limited to physically pairable and / or physically interactive components, and / or wirelessly interactive and / or wirelessly interactive components, and / or logically interactive and / or logically interactive components.

[0080] Those skilled in the art will understand that, in general, the terms used herein, and especially in the appended claims (e.g., the body of the appended claims), are generally intended to be "open" terms (e.g., the term "including" should be interpreted as "including but not limited to," the term "having" should be interpreted as "having at least," the term "includes" should be interpreted as "including but not limited to," etc.). Those skilled in the art will further understand that if a specific number of introduced claim recitations is intended, such intent will be explicitly recited in the claims, and in the absence of such recitation, no such intent is present. For example, to aid understanding, the appended claims may contain the use of the introductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed as implying that the introduction of a claim recitation by the indefinite article "a" or "an" limits any particular claim containing such introduced claim recitation to an invention containing only one such recitation, even if the same claim contains the introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should generally be construed as "at least one" or "one or more"); the same applies to the definite article introducing the claim recitation. In addition, even if a specific number of introduced claim recitations is explicitly recited, those skilled in the art will recognize that such recitation should generally be construed to mean at least the recited number (e.g., a brief recitation of "two recitations" without other modifiers generally means at least two recitations, or two or more recitations). Furthermore, in those cases where a convention similar to “at least one of A, B, and C, etc.” is used, generally, such constructions are intended to have the meaning that one skilled in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include, but not be limited to, systems having only A, only B, only C, A and B in common, A and C in common, B and C in common, and / or A, B, and C in common, etc.). In those cases where a convention similar to “at least one of A, B, or C, etc.” is used, generally, such constructions are intended to have the meaning that one skilled in the art would understand the convention (e.g., “a system having at least one of A, B, and C” would include, but not be limited to, systems having only A, only B, only C, A and B in common, A and C in common, B and C in common, and / or A, B, and C in common, etc.). Those skilled in the art will further understand that virtually any antonymous conjunction and / or phrase presenting two or more alternative terms (whether in the detailed description, claims, or figure description) should be understood to encompass the possibility of including one of the terms, either of the terms, or both of the terms. For example, the phrase "A or B" will be understood to include the possibility of "A" or "B" or "A and B".

[0081] Although particular aspects of the subject matter described herein have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the subject matter described herein and its broader aspects based on the teachings herein, and therefore, the appended claims are intended to cover within their scope all such changes and modifications that come within the true spirit and scope of the subject matter described herein. Furthermore, it should be understood that the invention is defined by the appended claims.

Claims

1. A method for measuring the thickness of a substrate and a film deposited on the substrate, comprising: determining a thickness profile of at least one of the substrate or the film deposited on the substrate as a function of position across the substrate based on one or more flatness measurements and one or more quality measurements from a dual interferometer subsystem; Wherein determining a thickness distribution of the substrate as a function of position across the substrate based on one or more flatness measurements and one or more quality measurements from the dual interferometer subsystem comprises: receiving from the dual interferometer subsystem one or more flatness measurements of the substrate as a function of position across the substrate; receiving one or more quality measurements of the substrate; determining an average thickness of the substrate based on the one or more mass measurements, a material density of the substrate, and an area of ​​the substrate; determining the thickness distribution of the substrate as a function of position across the substrate based on the one or more flatness measurements and the average thickness of the substrate; and Wherein determining a thickness distribution of the film deposited on the substrate as a function of position across the substrate based on one or more flatness measurements and one or more quality measurements from a dual interferometer subsystem comprises: determining a thickness distribution of the film as a function of position across the substrate based on the two or more flatness measurements of the substrate and the two or more quality measurements of the substrate, comprising: receiving a first flatness measurement and a first quality measurement of a substrate before depositing a film on the substrate and after depositing one or more pre-layers on the substrate; receiving a second flatness measurement and a second quality measurement of the substrate after depositing the film onto the pre-layer of the substrate; and The thickness distribution of the film as a function of position across the substrate is determined based on a density of the film, the first flatness measurement of the substrate, the first quality measurement of the substrate, the second flatness measurement of the substrate, and the second quality measurement.

2. The method of claim 1 , wherein receiving the one or more quality measurements comprises: receiving the one or more quality measurements of the substrate from: Users through the user interface; or Memory.

3. The method according to claim 1, further comprising: One or more process tools are adjusted based on the determined thickness distribution of at least one of the substrate or the film as a function of position across the substrate.

4. The method of claim 1, wherein the dual interferometer subsystem comprises: Dual-wavelength dual-Fizeau interferometer DWDFI subsystem; or The substrate comprises: Semiconductor wafer.

5. The method according to claim 1, further comprising: A mass sensor is configured to measure the mass of the substrate.

6. The method according to claim 5, further comprising: One or more process tools are adjusted based on the determined thickness distribution of at least one of the substrate or the film as a function of position across the substrate.

7. The method of claim 5, wherein the dual interferometer subsystem comprises: Dual-wavelength dual-Fizeau interferometer DWDFI subsystem; or The quality sensor comprises: High-precision load cell; or The substrate comprises: Semiconductor wafer.

8. A system for measuring the thickness of a substrate and a film deposited on the substrate, the system comprising: a dual interferometer subsystem configured to measure flatness across the substrate; a mass sensor configured to measure the mass of the substrate; and a controller communicatively coupled to the dual interferometer subsystem and the mass sensor, the controller comprising one or more processors, wherein the one or more processors are configured to execute a set of program instructions stored in a memory, the set of program instructions configured to cause the one or more processors to: determining a thickness profile of at least one of the substrate or the film deposited on the substrate as a function of position across the substrate based on one or more flatness measurements from a dual interferometer subsystem and one or more quality measurements from the quality sensor; Wherein determining a thickness distribution of the substrate as a function of position across the substrate based on one or more flatness measurements from the dual interferometer subsystem and one or more quality measurements from the quality sensor comprises: receiving from the dual interferometer subsystem one or more flatness measurements of the substrate as a function of position across the substrate; receiving one or more quality measurements of the substrate from the quality sensor; determining an average thickness of the substrate based on the one or more quality measurements; and determining the thickness distribution of the substrate as a function of position across the substrate based on the one or more flatness measurements and the average thickness of the substrate; and wherein determining a thickness distribution of the film deposited on the substrate as a function of position across the substrate based on one or more flatness measurements from the dual interferometer subsystem and one or more quality measurements from the quality sensor comprises: receiving a first flatness measurement and a first quality measurement of a substrate before depositing a film on the substrate and after depositing one or more pre-layers on the substrate; receiving a second flatness measurement and a second quality measurement of the substrate after depositing the film onto the pre-layer of the substrate; and The thickness distribution of the film as a function of position across the substrate is determined based on a density of the film, the first flatness measurement of the substrate, the first quality measurement of the substrate, the second flatness measurement of the substrate, and the second quality measurement.

9. The system of claim 8, wherein the one or more processors are further configured to: One or more process tools are adjusted based on the determined thickness distribution of at least one of the substrate or the film as a function of position across the substrate.

10. The system of claim 8, wherein the dual interferometer subsystem comprises: Dual-wavelength dual-Fizeau interferometer DWDFI subsystem.

11. The system of claim 8, wherein the mass sensor comprises: High precision load cell.

12. The system of claim 8, wherein the substrate comprises: Semiconductor wafer.

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