Bump measurement height measurement

Abstract

The present invention discloses a method for measuring the height difference between the top of a plurality of bumps and the upper surface of a layer. The method may include performing a first measurement on the height difference between the bumps and the corresponding regions by irradiating the bumps and corresponding regions with first radiation; wherein the first measurement is affected by a first measurement error; and determining the height difference between the bumps and the corresponding regions based on the first measurement and the first measurement error.

Description

[0001] Cross-referencing This application claims priority to U.S. Provisional Patent No. 62 / 705,731, filed June 13, 2020, and U.S. Provisional Patent No. 62 / 705,730, filed June 13, 2020. Both provisional patents are incorporated herein by reference. Background Technology

[0002] Bumps can be formed on the base layer or on intermediate elements on the base layer.

[0003] The top layer can be manufactured on the base layer. The upper part of the bump extends over the top layer. The lower part of the bump is surrounded by the top layer.

[0004] The top layer may be made of photo-definable polyimide (PI) and / or polybenzoxazole (PBO).

[0005] Top layers made of PI and / or PBO have been widely used as dielectrics for wafer-level redistribution layers.

[0006] The top layer made of PI and / or PBO is partially transparent to primary radiation such as visible light radiation.

[0007] Visible light-based triangulation can scan the bumps and the top layer to provide height measurements.

[0008] It may be necessary to measure the height difference between (a) the top of the bump and (b) the upper surface of the top layer.

[0009] Due to the partial transparency of the top layer—visible light-based triangulation does not measure the height of the top surface of the top layer—but rather the height of a virtual plane within the top layer. This virtual plane represents a virtual reflective plane within the top layer. Because of the difference between the refractive index of air and the refractive index of the top layer, light changes its propagation angle when entering the top layer. When light is reflected by the top surface of the base layer—the virtual plane represents the virtual reflective plane in the case where the propagation angle does not change within the top layer.

[0010] The distance between the upper surface of the top layer and the virtual plane is called the virtual penetration depth and is unknown—visible light-based triangulation does not provide a reliable measurement of the bump characteristics.

[0011] There is an increasing need to provide a reliable system and method for estimating the height difference between the top of the bump and the upper surface of the top layer. Summary of the Invention

[0012] The present invention can provide a system, non-transitory computer-readable medium, and method for estimating the height difference between the top of a bump and the upper surface of the top layer.

[0013] A method for measuring the height difference between the tops of a plurality of bumps and corresponding regions on the upper surface of a layer can be provided. The method may include: performing a first measurement on the height difference between the bumps and corresponding regions by irradiating the bumps and corresponding regions with a first radiation; wherein the first measurement may be affected by a first measurement error caused by the first radiation virtually penetrating into the layer; wherein each bump has a corresponding region adjacent to the bump; performing a second measurement on the height difference between a subgroup of the bumps and a subgroup of the corresponding regions by irradiating a subgroup of the bumps and a subgroup of the corresponding regions with a second radiation that does not penetrate the layer; wherein the duration of the second measurement exceeds the duration of the first measurement; determining a first measurement error based on the first and second measurements; and determining the height difference between the bumps and corresponding regions based on the first measurement and the first measurement error.

[0014] The bumps may be distributed along a circular semiconductor substrate, and the subgroups of the bumps may be located in spaced annular regions of the semiconductor substrate wafer.

[0015] The subgroup of the bumps may include less than 10 percent of the bumps.

[0016] The first radiation can be white light.

[0017] The layer may include at least one of photodefineable polyimide and polybenzoxazole.

[0018] Determining the height difference between the bump and the corresponding region may include estimating a first measurement error associated with (a) the bump that does not belong to the subgroup of the bump and (b) the corresponding region that does not belong to the subgroup of the corresponding region.

[0019] The estimation of the first measurement error may include extrapolation.

[0020] The estimation of the first measurement error may include performing a radial extrapolation method.

[0021] The execution of the first measurement may include performing a white light triangulation measurement.

[0022] The execution of the second measurement may include performing an interferometric measurement.

[0023] A measurement system for measuring the height difference between the tops of multiple bumps and corresponding regions on the upper surface of a layer can be provided. The system may include one or more measurement units and at least one processing unit configured to: perform a first measurement on the height difference between the bumps and corresponding regions by irradiating the bumps and corresponding regions with a first radiation; wherein the first measurement may be affected by a first measurement error caused by the first irradiation virtually penetrating into the layer; wherein each bump has a corresponding region adjacent to the bump; perform a second measurement on the height difference between a subgroup of the bumps and a subgroup of the corresponding regions by irradiating a subgroup of the bumps and a subgroup of the corresponding regions with a second radiation that does not penetrate the layer; wherein the duration of the second measurement exceeds the duration of the first measurement; determine a first measurement error based on the first measurement and the second measurement; and determine the height difference between the bumps and the corresponding regions based on the first measurement and the first measurement error.

[0024] The bumps may be distributed along a circular semiconductor substrate, and the subgroups of the bumps may be located in spaced annular regions of the semiconductor substrate wafer.

[0025] The subgroup of the bumps may include less than 10 percent of the bumps.

[0026] The first radiation can be white light.

[0027] The layer may include at least one of photodefineable polyimide and polybenzoxazole.

[0028] The measurement system can be configured to determine the height difference between the bump and the corresponding region by estimating a first measurement error related to (a) a bump that does not belong to the bump subgroup and (b) a corresponding region that does not belong to the corresponding region subgroup.

[0029] The estimation of the first measurement error may include extrapolation.

[0030] The measurement system can be configured to perform a radial extrapolation method.

[0031] In the measurement system, the first measurement unit may be a white light triangulation measurement unit.

[0032] The measurement system, wherein the second measurement unit may be an interferometer.

[0033] A non-transitory computer-readable medium may be provided for measuring the height difference between the tops of a plurality of bumps and corresponding regions on the upper surface of a layer. The non-transitory computer-readable storage instructions are configured to: perform a first measurement on the height difference between the bumps and corresponding regions by irradiating the bumps and corresponding regions with a first radiation; wherein the first measurement may be affected by a first measurement error caused by the first irradiation virtually penetrating into the layer; wherein each bump has a corresponding region adjacent to the bump; perform a second measurement on the height difference between a subgroup of the bumps and a subgroup of the corresponding regions by irradiating a subgroup of the bumps and a subgroup of the corresponding regions with a second radiation that does not penetrate the layer; wherein the duration of the second measurement exceeds the duration of the first measurement; determine a first measurement error based on the first measurement and the second measurement; and determine the height difference between the bumps and the corresponding regions based on the first measurement and the first measurement error.

[0034] The bumps may be distributed along a circular semiconductor substrate, and the subgroups of the bumps may be located in spaced annular regions of the semiconductor substrate wafer.

[0035] The subgroup of the bumps may include less than 10 percent of the bumps.

[0036] The first radiation can be white light.

[0037] The layer may include at least one of photodefineable polyimide and polybenzoxazole.

[0038] Determining the height difference between the bump and the corresponding region may include estimating a first measurement error related to (a) the bump that does not belong to the bump subgroup and (b) the corresponding region that does not belong to the corresponding region subgroup.

[0039] The estimation of the first measurement error may include extrapolation.

[0040] The estimation of the first measurement error may include performing a radial extrapolation method.

[0041] The execution of the first measurement may include performing a white light triangulation measurement.

[0042] The execution of the second measurement may include performing an interferometric measurement. Attached Figure Description

[0043] The invention will be more fully understood and appreciated from the following detailed description taken in conjunction with the accompanying drawings, in which: Figure 1 The diagram illustrates the first stage of the process; Figure 2 The diagram illustrates the second stage of the process; Figure 3The diagram illustrates the third stage of the process; and Figure 4 The illustration shows the first to fifth radial sets of the wafer and selected bumps; Figure 5 The diagram illustrates the wafer and the first through fifth estimation factors; Figure 6 The diagram illustrates the chip and bumps; Figure 7 An example of the system is illustrated; and Figure 8 An example of the method is illustrated. Detailed Implementation

[0044] Since the apparatus for implementing this invention is mostly composed of electronic components and circuits known to those skilled in the art, the circuit details will not be explained in any way beyond what the foregoing description deems necessary, in order to understand and comprehend the basic concepts of this invention, so as not to confuse or distract from the teachings of this invention.

[0045] Any references to the method in this specification, with necessary modifications, should be applicable to systems capable of executing the method, and with necessary modifications, should be applicable to non-transitory computer program products that store instructions that, once executed by a computer, result in the execution of the method. The non-transitory computer program product may be a chip, storage unit, disk, optical disk, non-volatile memory, volatile memory, magnetic memory, memristor, optical storage unit, etc.

[0046] Any references to the system in this specification, with necessary modifications, shall apply to methods that can be executed by said system, and with necessary modifications, shall apply to non-transitory computer program products that store instructions that, once executed by a computer, would result in the execution of said method.

[0047] Any references to non-transitory computer program products in the specification, after necessary modifications, shall apply to methods that can be executed when instructions stored in the non-transitory computer program product are applied, and after necessary modifications, shall apply to systems capable of executing instructions stored in the non-transitory computer program product.

[0048] The term “comprising” is synonymous with “including,” “containing,” or “having” (meaning the same) and is inclusive or open-ended and does not exclude additional, unlisted elements or methodological steps.

[0049] The term “composition” is closed (only including exactly what is stated) and excludes any additional, unlisted elements or methodological steps.

[0050] The term “mainly composed of” limits the scope to the specified materials or steps and those that do not materially affect the essential and novel properties.

[0051] In the claims and specification, any reference to the term "comprising" (or "including" or "containing") shall be applied to the term "composed of" with the necessary modifications, and the phrase "consistently composed of..." shall be applied with the necessary modifications.

[0052] In the claims and specification, any reference to the term "composes" shall be applied to the term "comprising" with necessary modifications, and the phrase "consistently made of" shall be applied with necessary modifications.

[0053] In the claims and the specification, any reference to the phrase “consistently of…” shall be applied to the term “comprising” with the necessary modifications, and the term “composes” shall be applied with the necessary modifications.

[0054] In the following description, the invention will be described with reference to specific examples of embodiments thereof. However, it will be apparent that various modifications and changes can be made without departing from the broader spirit and scope of the invention as set forth in the appended claims.

[0055] A system and method are provided for calculating the height difference between the top of a bump and the upper surface of a top layer, the top layer being at least partially transparent to radiation such as white light. The top layer may be made of PI and BPO.

[0056] Reference Figure 1 —It may be necessary to measure the height difference between (a) the top (11') of the bump 11 and (b) the upper surface 12' of the top layer 12. The height of the top of the bump is denoted as TopBumpHeight 21. The height of the upper surface of the top layer is denoted as UpperSurfaceHeight 22.

[0057] The irradiated visible light beam 71 propagates at a first angle 91 until it reaches the top layer, then changes its propagation angle to a second propagation angle 92 and advances within the top layer (see 72) until it strikes the top of the base layer 13 to provide a reflected light beam 73, which propagates within the top layer until it reaches the air, changes its propagation angle, and continues to propagate in the air to provide a detection light beam 74.

[0058] The virtual plane 18 is a virtual reflection plane that virtually continues the advance of the illumination beam 71 in the top layer, maintains a first angle 91 in the top layer (see virtual propagation line 81), and virtually (see arrow 82) coincides with the detection beam 74.

[0059] The height of the top of the bump is denoted as bump top height 21. The height of the upper surface of the top layer is denoted as upper surface height 22.

[0060] The position of the internal portion corresponds to the virtual penetration depth. The virtual penetration depth of visible light in the top layer is denoted as the penetration depth (PenetrateDepth) 24.

[0061] Therefore, the measured height can be equal to the height of the upper surface minus the penetration depth.

[0062] Therefore, the measured height difference by visible light-based triangulation is equal to: MeasuredHeightDifference = (bump top height + penetration depth) - upper surface height.

[0063] Figure 1 The illustration shows the first stage, during which visible light-based triangulation is applied to provide a measured height difference (measured height difference) 23, which is an example of the first measurement of the height difference.

[0064] The height of the upper surface is the height of the upper surface 12' of the top layer 12. The top layer 12 is located above the base layer 13. Figure 1 The diagram also shows an intermediate element 19 formed on the base layer 13. The protrusion 11 is formed on the intermediate element 19.

[0065] The bump top height 21 is the measured height of the top (11') of bump 11.

[0066] The penetration depth 24 is the virtual penetration depth of the first radiation within the top layer 12. This virtual penetration introduces a first measurement error—because the first measurement actually measures the height of the virtual penetration—which is equal to (upper surface height - penetration depth).

[0067] (Upper surface height - penetration depth) is measured near the bump - at a point that can be considered as the area corresponding to the bump.

[0068] The first measurement of the height difference (e.g., measuring height difference 23) is equal to the bump top height minus (upper surface height - penetration depth).

[0069] The measured height difference = (bump top height + penetration depth) - upper surface height.

[0070] The height difference is measured by measuring (top surface height - penetration depth) near each bump to be measured.

[0071] This phase applies to a set of bumps—for example, all the bumps on a wafer.

[0072] Figure 2 The illustration shows the second stage during precise height measurement—for example, CLIp interferometry using radiation that does not penetrate the top layer and provides a precise height difference 25.

[0073] The precise height difference of 25 is an example of a second measurement of the height difference.

[0074] The second stage applies only to subgroups of the bump group. The bump group may include all the bumps on the wafer or only some of the bumps on the wafer.

[0075] Therefore, for each bump in a bump subgroup, an imprecise measured height difference and a precise measured height difference are provided.

[0076] The second stage (see Figure 3 The third stage is to estimate one or more correction factors (which could be the estimated virtual penetration depth – estimated penetration depth 26).

[0077] The estimation may include, for example, subtracting the precise height difference from the measured height difference to provide an estimated penetration depth.

[0078] Subgroups of a convex block can be virtually divided into sets—for example... Figure 4 The first to fifth radial sets 31, 32, 33, 34 and 35 of the selected bumps are illustrated respectively.

[0079] Each set may include bumps located at the same distance from the center of the wafer.

[0080] Different sets are located at different distances from the center of the wafer.

[0081] The radial set described is merely one example of how the bumps of the wafer can be sampled. Any sampling scheme can be provided—for example, the sample bumps can be arranged as a rectangular grid, any ordered array (of any shape and size), a disordered array, etc.

[0082] The correction factor (first measurement error) for each set is processed (e.g., averaged) to provide a correction factor for each set.

[0083] For example, Figure 5 The first through fifth estimated correction factors (first measurement error) 41, 42, 43, 44, and 45 are shown. These correction factors are based on... Figure 4 The correction factors for the first to fifth radial sets 31, 32, 33, 34 and 35 of the selected bumps are calculated.

[0084] Phase 4 (see) Figure 6 This includes evaluating the correction factor for bumps (30') that do not belong to the subgroup. The evaluation of the correction factor for bumps that belong to the group but not to the subgroup is based on one or more calculated correction factors and the spatial relationship between the bump and a radial set of one or more selected bumps.

[0085] The evaluation may include interpolation or other methods to estimate the correction factor based on a previously calculated correction factor.

[0086] It should be noted that bump sets can be arranged in other ways—not just radially. The positions of bumps in a set can correspond to bumps with the same or similar correction factors.

[0087] The number of groups can be 2, 3, 4 or more.

[0088] The method offers an excellent trade-off between accuracy and inspection time. Only a portion of the bumps are measured using both the first and second stages—this saves time. The estimation of the correction factor is sufficiently accurate.

[0089] Figure 7 This is an example of measurement system 200.

[0090] The measurement system 200 is configured to measure the height difference between the top of a plurality of bumps and a corresponding area on the upper surface of the layer.

[0091] The measurement system 200 may include one or more measurement units and at least one processing unit, which is configured to: a. A first measurement is performed on the height difference between the bump and the corresponding region by irradiating the bump and the corresponding region with a first radiation; wherein the first measurement is affected by a first measurement error caused by the first irradiation virtually penetrating into the layer; wherein each bump has a corresponding region adjacent to the bump.

[0092] b. Perform a second measurement on the height difference between the subgroup of the bump and the subgroup of the corresponding region by irradiating the subgroup of the bump and the corresponding region with a second radiation that does not penetrate the layer; wherein the duration of the second measurement exceeds the duration of the first measurement.

[0093] c. Determine the first measurement error based on the first measurement and the second measurement.

[0094] d. Determine the height difference between the bump and the corresponding area based on the first measurement and the first measurement error.

[0095] The one or more measurement units may include a first measurement unit for performing a first measurement and a second measurement unit for performing a second measurement.

[0096] exist Figure 7 In this context, the first measurement unit is a triangulation unit 210, which can be a white light triangulation sensor. See, for example, US Patent 8363229.

[0097] exist Figure 7 In this context, the second measurement unit is the interferometer 220.

[0098] exist Figure 7 In the illustration, the chip 280 is supported by a chuck 290 and a processing unit 240 is also shown.

[0099] The determination of the first measurement error and / or the determination of the height difference can be performed by the at least one processing unit. The at least one processing unit may or may not belong to the one or more measurement units.

[0100] The processing unit can be a server, desktop computer, hardware accelerator, etc.

[0101] The measurement system may include other parts and / or components, such as a mechanical table.

[0102] Figure 8 An example of a method 100 for measuring the height difference between the top of multiple bumps and a corresponding area on the upper surface of a layer is illustrated.

[0103] Each bump has a corresponding region—this is the area closest to the bump. Proximity can be within millimeters (e.g., less than one centimeter or a fraction of a centimeter). The corresponding region can be closer to the bump relative to another bump. The corresponding region can contact and / or surround the bump. The corresponding region can be of any shape or size—e.g., it can be on the order of millimeters. The size of the corresponding region can be equal to (or slightly larger than) the size of the radiating point (the first radiating point and / or the second radiating point). Optionally, the corresponding region may be much larger than the size of the radiating point.

[0104] Method 100 may include steps 110 and 120.

[0105] Step 110 may include performing a first measurement of the height difference between the bump and the corresponding region by irradiating the bump and the corresponding region with a first radiation. The first measurement is affected by a first measurement error caused by the first radiation virtually penetrating into the layer.

[0106] Step 120 may include irradiating the subgroup of the bump and the subgroup of the corresponding region with a second radiation that does not penetrate the layer, and performing a second measurement of the height difference between the subgroup of the bump and the subgroup of the corresponding region.

[0107] The subgroup of the bump (related to step 120) can be a portion of the bump (related to step 110). This portion can be up to (1 / Q) of the bump, where Q can be 2, 3, 4, 5, 6, 7, 8 and more.

[0108] The choice of the value of this portion can provide a trade-off between throughput and accuracy. A smaller portion will speed up the execution of method 100, but may provide less accurate measurements.

[0109] The duration of the second measurement (different measurements at a single altitude) can exceed the duration of the first measurement (different measurements at a single altitude).

[0110] The duration of the second measurement can exceed the duration of the first measurement, and can be a factor of at least 2, 4, 5, 10, 15, 20 or even more.

[0111] The first and / or second measurement of the height difference may include measuring or receiving the height of the top of the bump, and measuring the height of the corresponding area.

[0112] Step 110 can be performed before step 120. Step 110 can be performed after step 120.

[0113] Step 110 can be executed in parallel with step 120.

[0114] At least some of the first measurements can be performed in parallel with at least some of the second measurements. Such time overlap can be achieved when one measurement does not interfere with the other.

[0115] The first radiation can be white light.

[0116] The layer may include at least one of photodefined polyimide and polybenzoxazole.

[0117] Step 110 may include performing white light triangulation. See, for example, U.S. Patent 8363229.

[0118] Step 120 may include performing an interferometric measurement.

[0119] Steps 110 and 120 may be followed by step 130, which determines the first measurement error based on the first measurement and the second measurement.

[0120] Step 130 may include steps 132 and 134.

[0121] Step 132 may include comparing (a) a second measurement of the height difference between a subgroup of the bump and a subgroup of the corresponding region, and (b) a first measurement of the height difference between a subgroup of the bump and a subgroup of the corresponding region.

[0122] The difference between (a) and (b) reflects a first measurement error related to the subgroup of the bump and the corresponding subgroup of the region.

[0123] Step 134 may include estimating a first measurement error associated with the bumps other than the subgroup of the bumps and the corresponding regions other than the subgroup of the corresponding regions. Step 134 is based in part on the results of step 132.

[0124] The bumps can be distributed along a circular semiconductor substrate, and the subgroups of the bumps are located in spaced annular regions of the semiconductor substrate wafer.

[0125] Step 134 may include extrapolation.

[0126] Step 134 may include performing a radial extrapolation method. The radial extrapolation method may include estimating a first measurement error associated with the bump based on the distance of the bump from the center of the bump.

[0127] Step 130 can be followed by step 140, which involves determining the height difference between the bump and the corresponding region—at least for bumps not included in the subgroup.

[0128] For the bumps of the subgroup, the precise height difference was measured in step 120.

[0129] For bumps that do not belong to the subgroup, step 140 may include subtracting the first measurement error from the first measurement.

[0130] For example, subtract the estimated penetration depth from the measured height difference.

[0131] The invention has been described in the foregoing specification with reference to specific examples of embodiments thereof. However, it will be apparent that various modifications and changes can be made thereto without departing from the broader spirit and scope of the invention as set forth in the appended claims.

[0132] Those skilled in the art will recognize that the boundaries between the functions of the above operations are merely illustrative. The functions of multiple operations can be combined into a single operation, and / or the functions of a single operation can be distributed across additional operations. Furthermore, alternative embodiments may include multiple instances of a particular operation, and the order of operations may be varied in various other embodiments.

[0133] Therefore, it should be understood that the architecture described herein is merely exemplary, and many other architectures can actually be implemented to achieve the same functionality. In an abstract but still explicit sense, any arrangement of components that achieve the same functionality is effectively “associated” to achieve the desired function. Thus, any two components combined here to achieve a particular function can be considered “associated” with each other to achieve the desired function, regardless of the architecture or intermediate components. Similarly, any two components so associated can also be considered “operably connected” or “operably coupled” with each other to achieve the desired function.

[0134] However, other modifications, changes, and substitutions are also possible. Therefore, the specification and drawings are considered illustrative rather than restrictive.

[0135] The word "comprising" does not exclude the presence of other elements or steps besides those listed in the claims. It should be understood that the terms used so far are interchangeable where appropriate, such that embodiments of the invention described herein can be operated, for example, in directions other than those illustrated herein or otherwise described.

[0136] Furthermore, the terms “a” or “an” as used herein are defined as one or more. Additionally, the use of introductory phrases such as “at least one” and “one or more” in the claims should not be construed as implying that the introduction of another claim element by the indefinite article “a” or “an” limits any particular invention containing such an introductory claim element to an invention containing only one such element, even if the same claim includes the introductory phrases “one or more” or “at least one” and indefinite articles such as “a” or “an”. The same applies to the use of definite articles. Unless otherwise stated, terms such as “first” and “second” are used to arbitrarily distinguish the elements described by these terms.

[0137] Therefore, these terms are not necessarily intended to indicate the timing or other priority of these elements. The fact that certain measures are listed only in mutually different claims does not suggest that a combination of these measures cannot be advantageous.

Claims

1. A method for measuring the height difference between the tops of a plurality of bumps and corresponding regions on the upper surface of a layer, wherein the bumps are distributed along a semiconductor substrate wafer, the method comprising: A first measurement is performed on the height difference between the bump and the corresponding region by irradiating the bump and the corresponding region with a first radiation; wherein the first measurement is affected by a first measurement error caused by the first radiation virtually penetrating into the layer; wherein each bump has a corresponding region adjacent to the bump; A second measurement is performed on the height difference between the subgroup of the bumps and the subgroup of the corresponding region by irradiating the subgroup of the bumps and the subgroup of the corresponding region with a second radiation that does not penetrate the layer; wherein the duration of the second measurement exceeds the duration of the first measurement; wherein the subgroup of the bumps includes at least a first bump and a second bump, the first bump having a first distance from the center of the semiconductor substrate wafer, and wherein the second bump having a second distance from the center of the semiconductor substrate wafer, the first distance being different from the second distance; The first measurement error is determined based on the first measurement and the second measurement, wherein the first measurement error includes at least a first correction factor for the first bump and a second correction factor for the second bump; and The height difference between the bump and the corresponding region is determined based on the first measurement and the first measurement error, wherein determining the height difference includes extrapolating the height difference between the third bump and the corresponding region, wherein the third bump is not included in the subgroup.

2. The method according to claim 1, wherein, The bumps are distributed along the circular semiconductor substrate wafer, and the subgroups of the bumps are located in spaced annular regions of the circular semiconductor substrate wafer.

3. The method according to claim 1, wherein, The bumps belong to multiple radial sets, each radial set having a corresponding distance from the center of the semiconductor substrate wafer, wherein each radial set includes bumps located at the same distance from the center of the semiconductor substrate wafer, wherein subgroups of the bumps are divided into the multiple radial sets, and the first bump and the second bump belong to the first radial set and the second radial set, respectively.

4. The method according to claim 3, wherein, The first measurement error for each radial set is processed to provide a correction factor for each radial set.

5. The method according to claim 1, wherein, The layer comprises at least one of a photodefined polyimide and a polybenzoxazole.

6. The method according to claim 1, wherein, Determining the height difference between the bump and the corresponding region includes estimating a first measurement error for bumps that do not belong to the subgroup of the bump and corresponding regions that do not belong to the subgroup of the corresponding region.

7. The method according to claim 6, wherein, The estimation of the first measurement error includes extrapolation.

8. The method according to claim 6, wherein, The estimation of the first measurement error includes performing a radial extrapolation method.

9. The method according to claim 1, wherein, The execution of the first measurement includes performing a white light triangulation measurement.

10. The method according to claim 1, wherein, The execution of the second measurement includes performing an interferometric measurement.

11. A measurement system for measuring the height difference between the tops of a plurality of bumps and corresponding regions on the upper surface of a layer, wherein the bumps are distributed along a semiconductor substrate wafer, the system comprising: One or more measurement units and at least one processing unit, configured as follows: A first measurement is performed on the height difference between the bump and the corresponding region by irradiating the bump and the corresponding region with a first radiation; wherein the first measurement is affected by a first measurement error caused by the first radiation virtually penetrating into the layer; wherein each bump has a corresponding region adjacent to the bump; A second measurement is performed on the height difference between the subgroup of the bumps and the subgroup of the corresponding region by irradiating the subgroup of the bumps and the subgroup of the corresponding region with a second radiation that does not penetrate the layer; wherein the duration of the second measurement exceeds the duration of the first measurement; wherein the subgroup of the bumps includes at least a first bump and a second bump, the first bump having a first distance from the center of the semiconductor substrate wafer, wherein the second bump has a second distance from the center of the semiconductor substrate wafer, and the first distance is different from the second distance; The first measurement error is determined based on the first measurement and the second measurement, wherein the first measurement error includes at least a first correction factor for the first bump and a second correction factor for the second bump; and The height difference between the bump and the corresponding region is determined based on the first measurement and the first measurement error, wherein determining the height difference includes extrapolating the height difference between the third bump and the corresponding region, wherein the third bump is not included in the subgroup.

12. The measurement system according to claim 11, wherein, The bumps are distributed along a circular semiconductor substrate wafer, and the subgroups of the bumps are located at spaced annular regions of the circular semiconductor substrate wafer, wherein the spaced annular regions correspond to a plurality of radial sets, each radial set having a corresponding distance from the center of the circular semiconductor substrate wafer, wherein each radial set includes a bump located at the same distance from the center of the circular semiconductor substrate wafer, wherein the subgroups of the bumps are divided into the plurality of radial sets, and the first bump and the second bump belong to a first radial set and a second radial set, respectively.

13. The measurement system according to claim 11, wherein, The subgroup of the bumps comprises less than 10 percent of the bumps.

14. The measurement system according to claim 12, wherein, The first measurement error for each radial set is processed to provide a correction factor for each radial set.

15. The measurement system according to claim 11, wherein, The layer comprises at least one of a photodefined polyimide and a polybenzoxazole.

16. The measurement system according to claim 11, wherein, The measurement system is configured to determine the height difference between the bump and the corresponding region by estimating a first measurement error between the bump that does not belong to the subgroup of the bump and the corresponding region that does not belong to the subgroup of the corresponding region.

17. The measurement system according to claim 16, wherein, The estimation of the first measurement error includes extrapolation.

18. The measurement system according to claim 16, wherein, The measurement system is configured to perform a radial extrapolation method.

19. The measurement system according to claim 11, wherein, The first measurement unit is the white light triangulation measurement unit.

20. The measurement system according to claim 11, wherein, The second measurement unit is the interferometer.

21. A non-transitory computer-readable medium for measuring the height difference between the tops of a plurality of bumps and corresponding regions on the upper surface of a layer, wherein the bumps are distributed along a semiconductor substrate wafer, the non-transitory computer-readable medium storing instructions for: A first measurement is performed on the height difference between the bump and the corresponding region by irradiating the bump and the corresponding region with a first radiation; wherein... The first measurement is affected by a first measurement error caused by the first radiation virtually penetrating into the layer; wherein each bump has a corresponding region adjacent to the bump; A second measurement is performed on the height difference between the subgroup of the bumps and the subgroup of the corresponding region by irradiating the subgroup of the bumps and the subgroup of the corresponding region with a second radiation that does not penetrate the layer; wherein the duration of the second measurement exceeds the duration of the first measurement; wherein the subgroup of the bumps includes at least a first bump and a second bump, the first bump having a first distance from the center of the semiconductor substrate wafer, wherein the second bump has a second distance from the center of the semiconductor substrate wafer, and the first distance is different from the second distance; The first measurement error is determined based on the first measurement and the second measurement, wherein the first measurement error includes at least a first correction factor for the first bump and a correction factor for the second bump; and The height difference between the bump and the corresponding region is determined based on the first measurement and the first measurement error, wherein determining the height difference includes extrapolating the height difference between the third bump and the corresponding region, wherein the third bump is not included in the subgroup.

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