CN-122028693-A - Method and device for correcting alignment deviation of wafer bonding pad and probe array

CN122028693ACN 122028693 ACN122028693 ACN 122028693ACN-122028693-A

Abstract

The invention discloses a method and a device for correcting alignment deviation of a wafer bonding pad and a probe array, and relates to the field of wafer testing and optical detection. The method is used for solving the problems of reduced testing accuracy, damage to the welding disc and subsequent packaging bonding failure caused by wafer rotation deviation in the wafer probe card test. The method comprises the steps of constructing a second reflectivity distribution function with rotation deviation based on Manhattan geometrical characteristics of a wafer, performing two-dimensional Fourier transform on the second reflectivity distribution function to obtain a mapping relation between airspace rotation deviation and frequency domain frequency spectrum characteristics, obtaining a frequency spectrum image according to imaging data of a region to be detected of the wafer to be detected, determining a frequency domain straight line angle based on Hough transform and the frequency spectrum image, obtaining the rotation deviation angle to be detected according to the mapping relation and the frequency domain straight line angle, and controlling a high-precision rotation displacement table to drive the wafer to be detected to reversely rotate if the rotation deviation angle to be detected is larger than an angle threshold value.

Inventors

FAN LIYI
LI MENGYAO
YIN SHANGJUN
XIE KAIXIANG
MENG JIAXIN

Assignees

广东省傲来科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260402

Claims (9)

1. A method for correcting misalignment of a wafer pad and a probe array, comprising: Constructing a wafer surface reflectivity distribution model based on Manhattan geometrical characteristics of a wafer, wherein the reflectivity distribution model comprises a first reflectivity distribution function without rotation deviation and a second reflectivity distribution function with rotation deviation, and the second reflectivity distribution function is determined based on the first reflectivity distribution function and the rotation deviation angle; Performing two-dimensional Fourier transform on the second reflectivity distribution function to obtain a mapping relation between the spatial domain rotation deviation and the frequency domain spectrum characteristic, wherein the mapping relation represents that the rotation deviation angle of the wafer is mapped into a frequency domain cross spectrum; Obtaining a preprocessed frequency spectrum image according to imaging data of a region to be detected of a wafer to be detected, and determining a frequency domain linear angle based on Hough transformation and the frequency spectrum image; And comparing the rotation deviation angle to be measured with a set angle threshold, and if the rotation deviation angle to be measured is larger than the angle threshold, controlling a high-precision rotation displacement table to drive the wafer to be measured to reversely rotate, wherein the reverse rotation angle is equal to the rotation deviation angle to be measured.
2. The method of claim 1, wherein the first reflectance distribution function is as follows: The second reflectance distribution function is as follows: Wherein, the A first reflectance distribution function of the wafer surface when no rotational deviation is indicated, Represents horizontal direction coordinates in the two-dimensional coordinates of the airspace, Representing the vertical direction coordinate in the airspace two-dimensional coordinate, Representing all horizontal trend fine structures on the wafer, and projecting and integrating in the vertical direction, and then performing one-dimensional intensity distribution functions in the horizontal direction; Representing all vertical trend fine structures on the wafer, projecting and integrating in the horizontal direction, and then carrying out one-dimensional intensity distribution function along the vertical direction, A second reflectance distribution function representing the wafer surface with a rotational bias, Indicating the rotational offset angle of the wafer relative to the optical inspection system or probe array, A cosine value representing the angle of rotation deviation, A sine value representing the rotation deviation angle, When the rotation deviation angle of the wafer is theta, the corresponding one-dimensional intensity distribution function is generated after the rotation transformation of the airspace two-dimensional coordinates of the horizontal trend fine structure, When the rotation deviation angle of the wafer is theta, the corresponding one-dimensional intensity distribution function is obtained after rotation transformation of the airspace two-dimensional coordinates of the vertical trend fine structure.
3. The method of claim 1, wherein the two-dimensional fourier transform is as follows: the frequency domain spectrum distribution formula is as follows: Wherein, the Representing the frequency domain spectrum characteristics corresponding to the wafer rotation deviation, A second reflectivity profile of the wafer surface with a rotational offset, Indicating the rotational offset angle of the wafer relative to the optical inspection system or probe array, A cosine value representing the angle of rotation deviation, A sine value representing the rotation deviation angle, When the rotation deviation angle of the wafer is theta, the corresponding one-dimensional intensity distribution function is generated after the rotation transformation of the airspace two-dimensional coordinates of the horizontal trend fine structure, When the rotation deviation angle of the wafer is theta, the corresponding one-dimensional intensity distribution function is generated after the rotation transformation of the airspace two-dimensional coordinates of the vertical trend fine structure, A kernel function representing a two-dimensional fourier transform, Representing the units of an imaginary number, The circumference ratio is indicated as such, Representing the spatial frequency in the horizontal direction, Representing the spatial frequency in the vertical direction; representing the intensity distribution function of a horizontal fine structure in a airspace The frequency domain corresponding function after one-dimensional Fourier transform, Representing vertical fine structure intensity distribution function in airspace The frequency domain corresponding function after one-dimensional Fourier transform, Representing dirac The function of the function is that, The frequency domain energy representing a defined horizontal structure is concentrated only in straight lines On the first spectrum arm corresponding to the cross spectrum, the frequency vector direction is that , The frequency domain energy representing a definite vertical structure is concentrated only in straight lines A second spectrum arm corresponding to the cross spectrum, the frequency vector direction of which is 。
4. The method of claim 1, wherein the frequency domain cross spectrum is composed of two mutually orthogonal spectrum arms, and the frequency vector directions corresponding to the two spectrum arms are respectively And The rotation angle of the frequency domain cross frequency spectrum is the same as the rotation deviation angle of the wafer.
5. The method of claim 1, wherein obtaining the preprocessed spectral image from imaging data of the region to be measured of the wafer to be measured, specifically comprises: acquiring an off-axis hologram of a region to be detected of a wafer to be detected by adopting a reflection type off-axis digital holographic optical system, performing two-dimensional Fourier transform on the off-axis hologram, and converting the off-axis hologram from a space domain to a frequency domain to obtain complete spectrum distribution containing an original image, a conjugate image and a zero-order item; The complete spectrum distribution is subjected to window filtering to obtain an original image spectrum, normalization processing and binarization processing are carried out on the original image spectrum to obtain a preprocessed spectrum image, and the spectrum image presents the distribution form of the cross spectrum to be detected and the rotation deviation angle to be detected.
6. The method according to claim 1, wherein the determining a frequency domain line angle based on the hough transform and the spectral image, in particular comprises: Mapping the spectrum image from an image space to a Hough straight line detection space, wherein the Hough straight line detection space represents each straight line by two parameters, namely a normal distance from the straight line to an original point and an included angle between the straight line normal line and the horizontal direction, and the two parameters are the normal distance from the straight line to the original point and the included angle between the straight line normal line and the horizontal direction; in a preset angle range, carrying out parameter space voting on non-zero frequency points included in the frequency spectrum image with a set step length to obtain a voting accumulation array; And determining the peak point with the highest vote number determined from the voting accumulation array as a global maximum peak point, wherein the global maximum peak point is used for representing the direction of a spectrum arm of the spectrum image, and obtaining the frequency domain straight line angle according to the included angle between the direction of the spectrum arm and the vertical direction.
7. An apparatus for correcting misalignment of a wafer pad with a probe array, comprising: a construction unit, configured to construct a wafer surface reflectivity distribution model based on manhattan geometrical characteristics of a wafer, where the reflectivity distribution model includes a first reflectivity distribution function without rotational bias and a second reflectivity distribution function with rotational bias, and the second reflectivity distribution function is determined based on the first reflectivity distribution function in combination with a rotational bias angle; The mapping unit is used for carrying out two-dimensional Fourier transform on the second reflectivity distribution function to obtain a mapping relation between the spatial domain rotation deviation and the frequency domain spectrum characteristic, wherein the mapping relation represents that the rotation deviation angle of the wafer is mapped into a frequency domain cross spectrum; The acquisition unit is used for acquiring a preprocessed frequency spectrum image according to imaging data of a region to be detected of the wafer to be detected, and determining a frequency domain linear angle based on Hough transformation and the frequency spectrum image; and the correction unit is used for comparing the rotation deviation angle to be detected with a set angle threshold value, and if the rotation deviation angle to be detected is larger than the angle threshold value, controlling the high-precision rotation displacement table to drive the wafer to be detected to reversely rotate, wherein the reverse rotation angle is equal to the rotation deviation angle to be detected.
8. A computer device comprising a memory and a processor, the memory storing a computer program which, when executed by the processor, causes the processor to perform a method of wafer pad and probe array misalignment correction as claimed in any one of claims 1 to 6.
9. A computer readable storage medium, storing a computer program which, when executed by a processor, causes the processor to perform a method of wafer pad and probe array alignment deviation correction as claimed in any of claims 1-6.

Description

Method and device for correcting alignment deviation of wafer bonding pad and probe array Technical Field The invention relates to the field of wafer testing and optical detection, in particular to a method and a device for correcting alignment deviation of a wafer bonding pad and a probe array. Background With the rapid development of the semiconductor industry towards high integration, high performance and miniaturization, the wafer manufacturing and advanced packaging have extremely high requirements on precision and quality control, the probe card electrical test is used as a wafer test core link, hundreds to thousands of micron-sized probes on the probe card are contacted with the wafer surface bonding pads, the full-function electrical screening of chips can be completed before the wafer is cut, bad chips are removed, the subsequent packaging cost is reduced, and the method is a key means for improving the overall yield. However, with the advance of the advanced process, the number of bonding pads on the wafer increases rapidly, the area continues to shrink, and the factors such as the variation of the superposition test conditions, etc., are prone to the problems such as stitch offset in the wafer test, and become the main bottleneck affecting the test stability and accuracy. The trace offset manifests itself as a probe actual contact point offset from the geometric center of the pad and even beyond the aluminum layer opening edge, which can cause damage to the passivation layer or exposure of the sidewalls of the pad window, and in severe cases, can cause subsequent bond failure or reliability hazards. The core reason for the stitch offset is that the wafer has rotation offset, so that alignment offset occurs between the probe and the wafer, the probe cannot accurately fall on the effective contact area of the bonding pad, and finally the stitch is led to deviate from the center of the bonding pad and even exceed the windowing range of the bonding pad. Therefore, the high-precision and rapid detection and correction of the rotational alignment deviation between the wafer bonding pad and the probe array are realized, the risk of needle mark deviation is eliminated from the source, and the method has key significance in improving the yield, stability and overall production efficiency of wafer testing. Disclosure of Invention The embodiment of the invention provides a method and a device for correcting alignment deviation of a wafer bonding pad and a probe array, which are used for solving the technical problems that the alignment deviation of a probe and a bonding pad, the deviation of a needle mark from the center of the bonding pad and even the deviation of the needle mark from the window opening range of the bonding pad occur due to the rotation deviation of a wafer in the test of a wafer probe card, so that the test accuracy is reduced, the bonding failure of the bonding pad and the subsequent packaging are caused, and the potential reliability hazard is caused. The embodiment of the invention provides a method for correcting alignment deviation of a wafer bonding pad and a probe array, which comprises the following steps: Constructing a wafer surface reflectivity distribution model based on Manhattan geometrical characteristics of a wafer, wherein the reflectivity distribution model comprises a first reflectivity distribution function without rotation deviation and a second reflectivity distribution function with rotation deviation, and the second reflectivity distribution function is determined based on the first reflectivity distribution function and the rotation deviation angle; Performing two-dimensional Fourier transform on the second reflectivity distribution function to obtain a mapping relation between the spatial domain rotation deviation and the frequency domain spectrum characteristic, wherein the mapping relation represents that the rotation deviation angle of the wafer is mapped into a frequency domain cross spectrum; Obtaining a preprocessed frequency spectrum image according to imaging data of a region to be detected of a wafer to be detected, and determining a frequency domain linear angle based on Hough transformation and the frequency spectrum image; And comparing the rotation deviation angle to be measured with a set angle threshold, and if the rotation deviation angle to be measured is larger than the angle threshold, controlling a high-precision rotation displacement table to drive the wafer to be measured to reversely rotate, wherein the reverse rotation angle is equal to the rotation deviation angle to be measured. The embodiment of the invention provides a device for correcting alignment deviation of a wafer bonding pad and a probe array, which comprises the following components: a construction unit, configured to construct a wafer surface reflectivity distribution model based on manhattan geometrical characteristics of a wafer, where the reflectivity distribution model in