Thin film thickness adjustment for three-dimensional interferometry

Abstract

Interferometric quantitative phase imaging techniques are used to determine a 3D surface map of a workpiece. The workpiece comprises a transparent film or a stack of layers. The 3D surface map is corrected based on the thickness and refractive index of the transparent film or layer stack. This technique may be used in conjunction with an inspection system configured to perform interferometric quantitative phase imaging.

Description

Technical Field

[0001] This disclosure relates to measuring three-dimensional features on a workpiece. Background Technology

[0002] The evolution of the semiconductor or flat panel manufacturing industry places increasingly higher demands on yield management and, specifically, metrology and inspection systems. Critical dimensions continue to shrink, but the industry needs to reduce the time required to achieve high-yield, high-value production. Minimizing the total time from detecting a yield problem to resolving it maximizes the semiconductor manufacturer's return on investment.

[0003] Inspection processes are used at every step of the manufacturing process to detect defects, contributing to higher yields and therefore higher profits. Inspection has always been a crucial part of manufacturing integrated circuits (ICs). However, as device size decreases, inspection becomes even more critical for the successful manufacture of acceptable devices, because even small defects can cause device malfunctions. For example, as device size decreases, the detection of smaller defects has become necessary, because even relatively small defects can still cause unwanted aberrations in the device.

[0004] 2D imaging is a common inspection technique. The demand for 3D imaging is increasing. New designs require advanced inspection, such as accurately measuring the tilt of a device; accurately measuring the height of bumps, microbumps, or pillars; or other 3D measurements on densely packaged surfaces with both reflective and transmissive layers in a single field of view.

[0005] In relatively large structures provided as part of a semiconductor wafer, hemispherical bumps may have a diameter of approximately 100 μm, but other sizes are possible. Errors attributable to the presence of partially transparent passivation or resist layers surrounding and / or supporting the bump can make it difficult to measure the height of this bump from its substrate to its top. Conventionally, one or more measurements are taken of the planar position defining the substrate location of the hemispherical bump, and then the measurement of the top of the bump is captured and used to calculate the height of the bump. Errors caused by the variability of the optical quality of the integrated circuit device's structure must be identified and minimized.

[0006] In some semiconductor wafer manufacturing processes, bumps or pads are surrounded by layers or stacks of passivation or protective materials (e.g., dielectrics, polyimide (PI), polybenzoxazole (PBO), benzocyclobutene (BCB), etc.). Bumps can be electrically connected laterally via pathways from below or through traces. Bumps are used for electrical connections via mechanical contact (pressure) or solder joints. In both cases, bumps must meet certain physical criteria to be satisfactory. Bumps that are too high may cause difficulties when connecting to adjacent bumps. Bumps that are too low may not make sufficient contact. The ideal scenario is where all bumps are of the same height and have the same profile. Same height and profile allow for predictable connections.

[0007] Height can be measured relative to a substrate (e.g., the bottom surface surrounding the transparent layer stack) or relative to the top surface of the transparent layer stack. This height (coplanarity) measurement is required on small-sized dies or across the entire wafer.

[0008] Height measurement can also be used for positioning flat electronic devices on a planarization layer (e.g., directly or using electrical contacts within the layer). The tilt of each flat pad or device can be measured relative to a substrate (e.g., the bottom of a transparent layer stack) or the top transparent surface.

[0009] One method for measuring bump height and profile is laser triangulation. Laser triangulation involves directing a focused laser beam onto a surface and measuring the position of the reflected light (spot). Since the angle of incidence and the angle of reflection are defined identically, deviations in the reflected light are attributed to the height of the surface being measured. The height of the bump can be measured using sensors such as position sensing devices (PSDs) or charge-coupled device (CCD) / complementary metal-oxide-semiconductor (CMOS) cameras. Moving the device under test relative to the laser allows for the measurement of multiple positions of the device. The relative movement between the focused laser spot of the laser triangulation sensor and the device under test involves a combination of moving the device on a stage, grating scanning the focused laser spot, focusing the laser onto a line, and / or applying multiple laser spots simultaneously.

[0010] A reflectometer can be used to perform thin film thickness measurements and optical property characterization. The phase shift within each thin film layer is calculated based on the thickness and complex refractive index of each layer. This phase shift is then used to correct the phase map to a surface map conversion for each region within the field of view.

[0011] Bump height inspection can also be performed using laser or white light triangulation methods. These methods suffer from measurement errors due to the different types of materials within the field of view and, specifically, the presence of a single transparent layer or a stack of layers. Geometric corrections can be performed for height measurements caused by the presence of a single transparent layer. Triangulation methods may also have other drawbacks when measuring bump height, such as long scan times or bump shading due to the triangulation angle. Atomic force microscopy (AFM) is not an optical technique and is a slower method. However, its measurement accuracy is unaffected by the type of material being scanned, and this method can be used practically in research and development phases rather than on the production line.

[0012] Previously, optical triangulation was used for thin film correction. This prior technique for film thickness correction is unsuitable for quantitative phase imaging (QPI) because it involves geometric correction. Measurement inaccuracies of up to 20% can occur. Depending on the measurement wavelength, layer thickness, or the optical properties of the material, inaccuracies can even reach 100% if thickness adjustment is not performed for QPI. For example, the geometric correction of film thickness used in triangulation methods is not applicable to QPI. Therefore, improved systems and techniques are needed. Summary of the Invention

[0013] A system is provided in a first embodiment. The system includes: a stage configured to hold a workpiece; an inspection system configured to perform quantitative interferometric phase imaging; and a processor electronically communicating with the inspection system. The processor is configured to: determine a 3D surface map and correct the 3D surface map based on the thickness and complex refractive index of a transparent film or layer stack. The workpiece comprises a transparent film or layer stack near or on a feature portion.

[0014] The feature may be, for example, a bump, a micro-bump, a pillar, a metal nail, an electronic device, or a transparent feature.

[0015] The workpiece may be, for example, a semiconductor wafer, a flat panel, a printed circuit board, or a glass substrate.

[0016] The system may further include a reflectometer configured to measure the thickness and the refractive index.

[0017] The correction can be phase-shift correction. The transparent thin film or layer stacking technology can use single-wavelength, dual-wavelength, or multi-wavelength illumination.

[0018] The quantitative phase imaging of the interferometry can use coherent illumination, incoherent illumination, or partially coherent illumination.

[0019] A second embodiment provides a method. The method includes using quantitative interferometric phase imaging to determine a 3D surface map of a workpiece. The workpiece comprises a transparent film or layer stack near or on a feature. Using a processor, the determined 3D surface map is corrected based on the thickness and refractive index of the transparent film or layer stack.

[0020] The feature may be, for example, a bump, a micro-bump, a pillar, a metal nail, an electronic device, or a transparent feature.

[0021] The workpiece may be, for example, a semiconductor wafer, a flat panel, a printed circuit board, or a glass substrate.

[0022] The method may further include using a reflectometer to measure the thickness and the refractive index.

[0023] The correction can be phase-shift correction. The transparent thin film or layer stacking technology can use single-wavelength, dual-wavelength, or multi-wavelength illumination.

[0024] The quantitative phase imaging of the interferometry can use coherent illumination, incoherent illumination, or partially coherent illumination.

[0025] The thickness can be based on the measured phase difference between two points on the workpiece.

[0026] The refractive index may have a real part and an imaginary part.

[0027] A third embodiment provides a non-transitory computer-readable storage medium. The non-transitory computer-readable storage medium includes one or more programs for performing the following steps on one or more computing devices: Receiving a 3D surface map; Determining the 3D surface map using quantitative interferometric phase imaging technology; The workpiece comprising a transparent film or layer stack near or on a feature; Correcting the 3D surface map based on the thickness and refractive index of the transparent film or layer stack.

[0028] The feature may be, for example, a bump, a micro-bump, a pillar, a metal nail, an electronic device, or a transparent feature.

[0029] The workpiece may be, for example, a semiconductor wafer, a flat panel, a printed circuit board, or a glass substrate.

[0030] The correction can be phase-shift correction. The transparent thin film or layer stacking technology can use single-wavelength, dual-wavelength, or multi-wavelength illumination. Attached Figure Description

[0031] For a more complete understanding of the nature and purpose of this disclosure, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, wherein:

[0032] Figure 1A through 1F demonstrate thin-film calibration in quantitative phase measurements;

[0033] Figure 2 This is a flowchart of the method according to this disclosure;

[0034] Figure 3 This is another flowchart illustrating an embodiment of the present disclosure;

[0035] Figure 4 Demonstrates the principle of phase shift correction;

[0036] Figure 5 This is an example of layer effect correction based on reflectometer data using the embodiments disclosed herein; and

[0037] Figure 6 This is a diagram illustrating an example of interferometry with a transparent layer. Detailed Implementation

[0038] While the claimed subject matter will be described with reference to certain embodiments, other embodiments that include not all the benefits and features set forth herein are also within the scope of this disclosure. Various structural, logical, procedural, and electronic changes may be made without departing from the scope of this disclosure. Therefore, the scope of this disclosure is defined only by reference to the appended claims.

[0039] Various quantitative phase imaging techniques can be used to perform 3D measurements of features on a substrate. These techniques output phase maps, which are then converted into full-field surface maps. When different types of materials are present, including regions with thin / thick films or multilayer stacks, the output of the height surface map is often erroneous without correction.

[0040] The embodiments can be used in a variety of applications. In examples, the disclosed embodiments can be used with wafer-level packaging. This may include a substrate carrier, such as a wafer, panel, plate, or flexible carrier. Bumps with wafer-level packaging may have a pitch greater than, for example, 100 μm. Microbumps with wafer-level packaging may have a pitch of, for example, tens of micrometers. Pillars with wafer-level packaging may have a pitch of, for example, greater than a few micrometers. Metal studs with wafer-level packaging may have a pitch of, for example, less than a few micrometers and a height of a few nanometers above the transparent layer. In examples, the disclosed embodiments can be used with flat panel displays. This may include a substrate carrier, such as a wafer or glass. Transparent printed structures or electronic devices can be measured. In examples, the disclosed embodiments can be used with integrated circuits. This may include materials such as FR4, polyimide, thermosetting resins (e.g., BT), Ajinomoto laminate (ABF), or epoxy resin. In an example, millimeter-lateral-size devices can be measured. The feature shapes and / or sizes and manufacturing processes differ for these applications. Other applications are possible.

[0041] The disclosed thickness adjustment technique relates to height (e.g., 3D) measurement using one of the quantitative phase imaging methods. This can be divided into two subcategories: interferometric and non-interferometric methods for phase capture. Interferometric techniques can be classified as coaxial and off-axis interferometry. Off-axis interferometry (when the reference beam and sample beam are at an angle) can be used, for example, in digital holographic microscopy (DHM). The angle is realized by applying a fast Fourier transform (FFT) on a single interferogram and extracting the phase map of the surface. In coaxial interferometry, the angle between the reference and target beams is zero, and the phase map cannot be retrieved by FFT. Therefore, for coaxial interferometry, the method used for phase map extraction is phase-shifting interferometry. A typical example of phase-shifting interferometry is white light interferometry (WLI), in which the stage (or reference mirror or other component) is scanned and a set of phase-shifting interferograms is captured within seconds. As a final step, that set of images is used to generate the phase map of the surface. Another type of measurement is single-shot phase-shifting interferometry, in which the surface phase map is acquired without any moving components. The method can be based on any type of interferometer, any illumination source (coherent, incoherent, partially coherent), and any type of sensor. The output of the measurement is a phase map of the surface. The phase map is then converted into a 3D surface topography map. This 3D surface map can display the features and may include height information with a 2D arrangement.

[0042] Analyzing the phase map, a 3D surface map of the field of view is determined by using the relationship between phase and height for a given wavelength. A challenge with any quantitative phase imaging method is measuring surfaces where reflective features are surrounded by stacks of transparent layers.

[0043] The presence of a single transparent layer or a stack of transparent layers can cause erroneous height measurements. Additionally, different reflective materials can each cause slightly different phase shifts in the reflected beam. Hybrid material surfaces are typical, and it is rare for a single material to be imaged across the entire field of view. For high-precision tools, this can be compensated for when measuring height maps.

[0044] The embodiments disclosed herein include measurements of transparent film thickness or layer stacking, followed by calculations to correct for inaccurate height measurements of the 3D feature surrounded by the transparent layer or layer stack. This can provide... Figure 1 Any combination of reflective or transparent features shown in A through 1F. 3D measurement of surfaces containing 3D features and transparent layers or stacks is achieved using interferometric quantitative phase imaging. Each pixel in the surface map is corrected based on the thickness and optical properties (e.g., complex refractive index) of the transparent film or stack, as well as the optical properties of the different materials within the field of view.

[0045] Figure 2This is a flowchart of method 200. Interferometric quantitative phase imaging is used to measure the height 201 of a feature on a workpiece. The workpiece contains a mixed region of reflective and / or transparent features or layers. Using a processor, the measurement is corrected at 202 based on the thickness and complex refractive index of the transparent film and the optical properties of each layer or feature. For example, the measurement can be corrected based on the thickness and refractive index of the transparent film or layer stack. In this example, the feature is a bump. The workpiece can be a flat plate or another substrate.

[0046] In a specific example, quantitative interferometric phase imaging is used to determine a 3D surface map of the workpiece. Then, a processor is used to correct the 3D surface map based on the thickness and refractive index of the transparent film or layer stack. The 3D surface map correction is an example of a measurement correction at 202. The height of the feature can be measured to create the 3D surface map.

[0047] The workpiece may contain a membrane. The membrane may be or may contain a dielectric (e.g., SiO2 or SiN). x Polyimide (PI), polybenzoxazole (PBO), or benzocyclobutene (BCB) (e.g., in a redistribution layer (RDL) or planarization layer). Various passivation and / or protective layers may also be included. Features may include one or more bumps, microbumps, pillars, or metal studs (e.g., Cu) surrounded by a stack of passivated dielectric layers (which may be thin or thick stacks). Features may also include Cu metal interconnects within the polyimide layer of the RDL, electronic devices positioned on top of a polyimide stack with or without an additional dielectric layer, or other metal structures with or without a transparent layer but integrated on a special substrate or with a conductive transparent material. Other films, layers, or features are possible, and these are merely examples.

[0048] Figure 3 Show additional information about method 200. For example... Figure 3 As shown, thin-film measurements determine n,k,T (x,y), and interferometric phase imaging determines the phase map (x,y). Each pixel can be corrected to generate a height map (x,y). x and y can be the vertical dimension across the workpiece or other variables.

[0049] The refractive index has two parts: a real part and an imaginary part. The real part is denoted by n. The imaginary part is denoted by k and is sometimes referred to as the extinction ratio. Each material (transparent or reflective) has a specific set of n and k values ​​depending on the wavelength of illumination, where the wavelength refers to the optical properties of the material.

[0050] about Figure 3 Quantitative phase interferometry imaging can be used to form interferometric phase images. The phase can have a field of view that includes different types of materials. n,k,T (x,y) can be determined from reflectometer measurements.

[0051] Figure 1 A through 1F show the options for when calibration of quantitative phase measurements is required. The height h represents the height of a feature (e.g., a bump) on the workpiece. In the example, h is approximately 10 to 12 μm from the surface of the bare workpiece or the surface of the transparent film, but other dimensions are possible. Figure 1 A through 1F show simplified cross sections when measurements and corrections are applied across the entire field of view. Figure 1 A is an example that does not require significant adjustment because it is made of the same type of material. Figure 1 B demonstrates a device (directly or indirectly) positioned on a transparent (e.g., planarized) layer. The height is measured relative to the top or bottom of the transparent layer. Figure 1 C shows the adjustment of the field of view with an area of ​​first material type 101 and an area of ​​second material type 102. Each material type can be reflective or transparent, and can be a single layer or a stack of transparent layers. Figure 1 Other exemplary structures are displayed from D to 1F. Third material type 103 and fourth material type 104 are also shown. Figure 1 The embodiments from A to 1F can benefit from the embodiments disclosed herein. Other structures or designs can also benefit from the embodiments disclosed herein, and Figure 1 A through 1F are merely examples.

[0052] exist Figure 1 In A through 1F, substrate 100 may be thick and may be reflective or transparent. Examples of substrate 100 materials include Si, metal, PBC, or glass. A first material type 101 is reflective, such as semiconductor (SC) or metal. A second material type 102 is transparent (e.g., dielectric, polyimide, PBO) or transparently conductive. Layers of the second material type 102 may be a single layer or a stack of layers. A third material type 103 may be selected from the same group of materials as the first material type 101. A fourth material type 104 is a transparent material, such as a dielectric. Layers of the fourth material type 104 may be a single layer or a stack of layers.

[0053] The refractive index of the transparent film surrounding or lying beneath the bumps is rarely known in detail. During inspection, especially when processing equipment in multiple manufacturing facilities, the refractive index may be unknown. The complex refractive index of the material affects the phase of the reflected light. This additional phase shift, attributable to differences in the material, will translate into height measurement errors.

[0054] In triangulation methods, only the real part of the refractive index (along with the layer thickness) is considered. In the embodiments disclosed herein, the influence of both the real and imaginary parts, along with the thickness of each transparent layer, is attributed to a phase shift caused by reflections from the material or layer stack.

[0055] Figure 4This demonstrates phase shift correction. A reflectometer can be used to measure thickness and refractive index. Thickness and refractive index can be measured only for the transparent layer. In this example, the optical properties (n, k) are known prior to the measurement, and a reflectometer is used to measure only the thickness of the transparent layer. The optical properties or type of the material used for the reflective region are required as input.

[0056] The reflectometer measurements, along with the known optical properties of each element in the material, allow for the construction of models of the phase shift introduced in each region of the field of view (in...). Figure 4 (Middle mark). In some cases, a reflectometer is used to detect the presence of a thin, transparent layer. For example, a layer not previously reported by the manufacturer. This can be used for height correction.

[0057] The following equation can be used.

[0058]

[0059] like Figure 4 As shown, the central region 1 contains a first material type 101, such as a reflective material. The edge regions 2 use a different second material type 102, such as a substrate with a transparent layer or a stacked layer. Figure 4 In equations 1 and 2, T is the thickness of the transparent layer, and h is the height of the feature (which is the target of measurement). It is the measured phase of the reflected light in region 1. It is the measured phase of the reflected light in region 2. It is the measured phase map in each pixel (e.g., in region 1). ),and It is the measured phase difference between region 1 and region 2.

[0060] Generally speaking: The zero point of the phase diagram can be arbitrarily chosen. An arbitrary constant C can be added or subtracted. If region 1 and region 2 have different materials, then it is not possible to directly obtain the phase diagram from... Derivate h. If region 1 and region 2 are made of two different materials, then the correction should be applied. and Each of them.

[0061] The phase shift in region 1 is attributed to optical paths in the air (e.g., )and The phase shift in region 2 is attributed to optical paths in the air (e.g., In this example, k is the wavenumber k = 2π / wavelength, and the factor of 2 is attributed to the reflection mode. This is a calculated phase shift attributed to the first material type 101. This is a calculated phase shift attributed to the second material type 102. The correction for the phase shift in region 1 is... The correction for the phase shift in region 2 is... .

[0062] It is the phase difference after correction, from which h can be determined. It is linearly related to h.

[0063] The correction in step 202 of method 200 can use phase shift correction as disclosed herein. This can be used in conjunction with interferometric quantitative phase imaging techniques.

[0064] When a thin film layer is present on the workpiece, the embodiments disclosed herein can be applied to bump height inspection. Phase adjustment calculations can be performed as part of the inspection process.

[0065] The embodiments of height (3D) measurement disclosed herein can be considered a type of quantitative phase imaging. These methods include interferometric methods such as white light interferometry (WLI), phase shift measurement, single-shot phase shift measurement, holographic methods, and some non-interferometric phase capture methods. In all these methods, as a final step, a phase map of the surface is generated, which is then converted into a height map. The conversion to a height map is typically achieved through a linear relationship that depends on the wavelength. The embodiments disclosed herein may utilize a reflectometer that can be used to measure the properties of transparent materials.

[0066] In the absence of spatial locations containing different materials or transparent layers or stacks, the phase map of a surface can be linearly correlated with its height map. Reflections from different materials or transparent layers or stacks differ not only in intensity but also in phase. Therefore, the presence of different types of materials on the surface can be considered when converting the phase map to a height map. The embodiments disclosed herein create accurate height maps by considering the phase shift of light at each location. The phase shift can be calculated from the complex refractive index of the material, and in the case of transparent layers or stacks, also from the thickness of each of the transparent layers.

[0067] Given the known or measured optical properties of the material, and in the case of transparent layers, also given the measured thickness of each layer, the phase dependence on wavelength can be theoretically calculated. Then, additional phase shifts can be added to specific locations on the phase map and converted into a height map.

[0068] This method enables improved accuracy during bump inspection when a thin film layer is present on the workpiece. Figure 5This is an example of layer effect correction based on reflectometer data. One line shows the measured bump height along a particular sample using prior art (panoramic y-section). The other line shows the measured bump height along a particular sample using the embodiments of this disclosure (“after correction”). As shown, the embodiments of this disclosure are more accurate and avoid the inaccuracies shown in the prior art. Various drops in the measured bump height are avoided.

[0069] 3D measurement using single-shot methods such as digital holography or single-shot phase-shift interferometry is inherently fast and accurate. Furthermore, it achieves higher lateral resolution and is more accurate than conventional triangulation. Therefore, this technology is well-suited to market demands associated with dense and small features. These technologies can be used in wafer-level packaging, such as for bump heights of bumps surrounded by transparent layers or layer stacks. These technologies can also be used in conjunction with hybrid bonding, such as for copper pin heights or other metallic features surrounded by transparent layers or layer stacks.

[0070] These technologies can be further used in conjunction with solder resists in printed circuit board (IC substrate) applications (e.g., with near-infrared (NIR) illumination).

[0071] The embodiments disclosed herein may use additional modules to measure thin film thickness with improved accuracy. This module, which can run on a processor, is based on a reflectometer solution.

[0072] Figure 6 This diagram illustrates an example of interferometry with a transparent layer. The inspection system 200 includes a stage configured to hold a workpiece 201. The inspection system 200 is configured to perform quantitative interferometric phase imaging. This inspection system 200 may include an illumination source 202 (e.g., coherent, incoherent, or partially coherent) and sensors or multiple sensors 203. Both the reflective material (left) and the transparent film (right) can be measured within the same field of view. A reference beam (REF) is also included. Both the illumination source 202 and the reference beam are guided to optical components, such as beam splitters, mirrors, or other components.

[0073] Processor 204 can communicate electronically with inspection system 200. Processor 204 is configured to determine the height of a feature (e.g., copper or a transparent film) on workpiece 201. Workpiece 201 can be a flat plate, semiconductor wafer, glass, or another substrate. Workpiece 201 includes a transparent film near or on the feature. The processor is also configured to correct the measured height based on the thickness and refractive index of the transparent film. This can be achieved using phase-shift correction. Inspection system 200 may further include a reflectometer configured to measure the thickness and refractive index.

[0074] In some embodiments, the various steps, functions, and / or operations of the systems and subsystems and methods disclosed herein are implemented by one or more of the following: electronic circuits, logic gates, multiplexers, programmable logic devices, ASICs, analog or digital controllers / switches, microcontrollers, or computing systems. Program instructions for implementing methods such as those described herein may be transmitted via or stored on a carrier medium. The carrier medium may include storage media, such as read-only memory, random access memory, magnetic disks or optical disks, non-volatile memory, solid-state memory, magnetic tape, and the like. The carrier medium may include transmission media, such as wires, cables, or wireless transmission links. For example, the various steps described throughout this disclosure may be implemented by a single processor (or computer system) or alternatively by multiple processors (or multiple computer systems). Furthermore, different subsystems of the system may comprise one or more computing or logic systems. Therefore, the foregoing description should not be construed as limiting the scope of this disclosure but is merely illustrative.

[0075] In this example, the non-transitory computer-readable storage medium contains one or more programs for performing steps on one or more computing devices. The steps include receiving a 3D surface map. Interferometric quantitative phase imaging is used to determine the 3D surface map. The workpiece comprises a transparent film or layer stack near or on a feature. The 3D surface map can be corrected based on the thickness and refractive index of the transparent film or layer stack.

[0076] Although this disclosure has been described with respect to one or more specific embodiments, it will be understood that other embodiments of this disclosure may be made without departing from the scope of this disclosure. Therefore, this disclosure is to be considered limited only by the appended claims and their reasonable interpretation.

Claims

1. A system comprising: A stage configured to hold the workpiece; The inspection system is configured to perform interferometric quantitative phase imaging; and A processor that communicates electronically with the inspection system, wherein the processor is configured to: Determine a 3D surface map, wherein the workpiece comprises a stack of transparent films or layers near or on a feature; and The 3D surface map is corrected based on the thickness and complex refractive index of the transparent film or layer stack.

2. The system according to claim 1, wherein the feature is a bump, microbump, pillar, metal pin, electronic device, or transparent feature.

3. The system according to claim 1, wherein the workpiece is a semiconductor wafer, a flat panel, a printed circuit board, or a glass substrate.

4. The system of claim 1, further comprising a reflectometer configured to measure the thickness and the refractive index.

5. The system of claim 1, wherein the correction uses phase shift correction.

6. The system of claim 5, wherein the transparent film or layer stacking technology uses single-wavelength, dual-wavelength, or multi-wavelength illumination only.

7. The system of claim 1, wherein the interferometric quantitative phase imaging uses coherent illumination, incoherent illumination, or partially coherent illumination.

8. A method comprising: Interferometric quantitative phase imaging is used to determine a 3D surface map of a workpiece, wherein the workpiece contains a transparent film or layer stack near or on a feature; and The processor corrects the 3D surface map based on the thickness and refractive index of the transparent film or layer stack.

9. The method of claim 8, wherein the feature is a bump, microbump, pillar, metal pin, electronic device, or transparent feature.

10. The method of claim 8, wherein the workpiece is a semiconductor wafer, a flat panel, a printed circuit board, or a glass substrate.

11. The method of claim 8, further comprising using a reflectometer to measure the thickness and the refractive index.

12. The method of claim 8, wherein the correction uses phase shift correction.

13. The method of claim 12, wherein the transparent film or layer stacking technique uses only single-wavelength, dual-wavelength, or multi-wavelength illumination.

14. The method of claim 8, wherein the interferometric quantitative phase imaging uses coherent illumination, incoherent illumination, or partially coherent illumination.

15. The method of claim 8, wherein the thickness is based on a measured phase difference between two points on the workpiece.

16. The method of claim 8, wherein the refractive index has a real part and an imaginary part.

17. A non-transitory computer-readable storage medium comprising one or more programs for performing the following steps on one or more computing devices, the steps including: Receive a 3D surface map, wherein the 3D surface map is determined using interferometric quantitative phase imaging technology, and wherein the workpiece comprises a transparent film or layer stack near or on a feature; The 3D surface map is corrected based on the thickness and refractive index of the transparent film or layer stack.

18. The non-transitory computer-readable storage medium of claim 17, wherein the feature is a bump, microbump, pillar, metal pin, electronic device, or transparent feature.

19. The non-transitory computer-readable storage medium of claim 17, wherein the workpiece is a semiconductor wafer, a flat panel, a printed circuit board, or a glass substrate.

20. The non-transitory computer-readable storage medium of claim 17, wherein the correction uses phase-shift correction.

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