CN-122029424-A - Ultrasonic inspection device and ultrasonic inspection method

CN122029424ACN 122029424 ACN122029424 ACN 122029424ACN-122029424-A

Abstract

The ultrasonic inspection device (11) is provided with a setting unit (17) which sets a first inspection region and a second inspection region as inspection target ranges of an object (15), a first inspection unit (19) which acquires a first inspection image in the first inspection region and acquires first defect candidate information based on the first inspection image, a second inspection unit (21) which acquires a second inspection image in the second inspection region and acquires second defect candidate information based on the second inspection image, and an output unit (29) which outputs an inspection result of the internal state of the object (15). An output unit (29) integrates the first defect candidate information acquired by the first inspection unit (19) and the second defect candidate information acquired by the second inspection unit (21) and outputs the result as an inspection result of the internal state of the subject (15).

Inventors

SAKAI TAKASHI
OHNO SHIGERU
Kobayashi Changxing
TAKANO YUSUKE
Kikukawa Kentaro

Assignees

株式会社日立电力解决方案

Dates

Publication Date: 20260512
Application Date: 20241004
Priority Date: 20231020

Claims (17)

1. An ultrasonic inspection apparatus for inspecting an internal state of a subject including a plurality of stacked semiconductor wafers using ultrasonic waves, The ultrasonic inspection device is provided with: a setting unit that sets a first examination region and a second examination region as examination target ranges for the subject, respectively; a first inspection unit that obtains a first inspection image using a first resolution in the first inspection region, and obtains first defect candidate information based on the first inspection image; A second inspection unit for acquiring a second inspection image using a second resolution in the second inspection region and acquiring second defect candidate information based on the second inspection image, and An output unit that outputs a result of an inspection of an internal state of the subject, The second inspection area is set to be within the first inspection area and narrower than the first inspection area, The second resolution is set to a higher value than the first resolution, The output unit integrates the first defect candidate information on the first inspection area acquired by the first inspection unit and the second defect candidate information acquired by the second inspection unit, and outputs the integrated first defect candidate information and the integrated second defect candidate information as an inspection result of the internal state of the subject.
2. The ultrasonic inspection apparatus according to claim 1, wherein, The setting unit sets the second inspection region based on the first defect candidate information on the first inspection region acquired by the first inspection unit.
3. The ultrasonic inspection apparatus according to claim 2, wherein, The first inspection unit acquires a first inspection image using a first resolution in the first inspection region, and acquires distribution information on a first defect candidate existing in the first inspection region based on the first inspection image.
4. An ultrasonic inspection apparatus according to claim 3, wherein, The ultrasonic inspection apparatus further includes a defect type database storing defect type information corresponding to each of a plurality of types of defect candidates, The first inspection unit obtains positional information about a first defect candidate based on the distribution information about the first defect candidate obtained by the first inspection unit, and obtains defect type information corresponding to the first defect candidate by referring to the defect type database, The second inspection unit obtains positional information on a second defect candidate obtained based on the second inspection image, and obtains corresponding defect type information by referring to the defect type database, The output unit outputs defect candidate information obtained by integrating the position information and defect type information on the first defect candidate and the position information and defect type information on the second defect candidate as an inspection result of the internal state of the subject.
5. The ultrasonic inspection apparatus according to claim 4, wherein, The first inspection unit adds first identification information on the first defect candidate to the position information and defect type information on the first defect candidate, The second inspection unit adds second identification information on the second defect candidate to the position information and defect type information on the second defect candidate, The output unit outputs the defect candidate information to which the first identification information and the second identification information are added, respectively, as an inspection result of the internal state of the subject.
6. The ultrasonic inspection apparatus according to claim 4, wherein, The ultrasonic inspection apparatus further includes: A defect generation factor database for storing information of defect generation factors in a manufacturing process related to the object in correspondence with a plurality of defect type information, respectively, and And an estimating unit for estimating a defect generation factor corresponding to the defect candidate information, with reference to the defect generation factor database.
7. The ultrasonic inspection apparatus according to any one of claims 1 to 6, wherein, The first inspection unit acquires the first inspection image using an array-type first ultrasonic probe, and the second inspection unit acquires the second inspection image using a single-type second ultrasonic probe.
8. The ultrasonic inspection apparatus according to claim 7, wherein, The setting unit extracts an irregularly offset region of a first defect candidate based on the distribution information on the first defect candidate acquired by the first inspection unit using the first ultrasonic probe, and sets the extracted region as the second inspection region.
9. The ultrasonic inspection apparatus according to claim 7, wherein, The setting unit extracts a normal region in which no defect candidate is extracted based on the distribution information on the first defect candidate acquired by the first inspection unit using the first ultrasonic probe, and sets the extracted normal region as a non-inspection region.
10. An ultrasonic inspection method for inspecting an internal state of a subject including a plurality of stacked semiconductor wafers using ultrasonic waves, characterized in that, The ultrasonic inspection method comprises the following steps: a setting step of setting a first examination region and a second examination region as examination object ranges for the subject, respectively; A first inspection step of acquiring a first inspection image at the first inspection region using a first resolution, and acquiring first defect candidate information based on the first inspection image; A second inspection step of acquiring a second inspection image using a second resolution in the second inspection region and acquiring second defect candidate information based on the second inspection image, and An output step of outputting a result of the inspection of the internal state of the subject, The second inspection area is set to be within the first inspection area and narrower than the first inspection area, The second resolution is set to a higher value than the first resolution, In the outputting step, the first defect candidate information acquired in the first inspecting step and the second defect candidate information acquired in the second inspecting step are integrated and outputted as an inspection result of the internal state of the subject.
11. The ultrasonic inspection method according to claim 10, wherein, In the setting step, the second inspection region is set based on the first defect candidate information acquired in the first inspection step.
12. The ultrasonic inspection method according to claim 11, wherein, In the first inspection step, a first inspection image is acquired using a first resolution in the first inspection region, and distribution information on a first defect candidate existing in the first inspection region is acquired based on the first inspection image.
13. The ultrasonic inspection method according to claim 12, wherein, In the first inspection step, positional information on the first defect candidate is acquired based on the distribution information on the first defect candidate acquired in the first inspection step, and defect type information corresponding to the first defect candidate is acquired by referring to a defect type database storing defect type information corresponding to each of a plurality of types of defect candidates, In the second inspection step, position information on a second defect candidate acquired based on the second inspection image is acquired, and corresponding defect type information is acquired with reference to the defect type database, In the outputting step, defect candidate information obtained by integrating the position information and defect type information on the first defect candidate and the position information and defect type information on the second defect candidate is outputted as a result of the inspection of the internal state of the subject.
14. The method of ultrasonography according to claim 13, In the first inspection step, first identification information on the first defect candidate is added to the position information on the first defect candidate and the defect type information, In the second inspection step, second identification information on the second defect candidate is added to the position information on the second defect candidate and the defect type information, In the outputting step, the defect candidate information to which the first identification information and the second identification information are added is outputted as a result of the inspection of the internal state of the subject.
15. The method of ultrasonography according to claim 14, The ultrasonic inspection method further includes an estimating step of estimating a defect generation factor corresponding to the defect candidate information with reference to a defect generation factor database storing information of the defect generation factor in a manufacturing process related to the subject in correspondence with each of a plurality of pieces of defect type information.
16. The method of ultrasonic inspection according to any one of claims 10 to 15, characterized in that, In the first inspection step, the first inspection image is acquired using an array-type first ultrasonic probe, and in the second inspection step, the second inspection image is acquired using a single-type second ultrasonic probe.
17. The method of ultrasonography according to claim 16, In the setting step, a region in which the first defect candidate is irregularly offset is extracted based on the distribution information on the first defect candidate acquired in the first inspection step using the first ultrasonic probe, and the extracted region is set as the second inspection region.

Description

Ultrasonic inspection device and ultrasonic inspection method Technical Field The present invention relates to an ultrasonic inspection apparatus and an ultrasonic inspection method for inspecting an internal state of a subject including a plurality of stacked semiconductor wafers using ultrasonic waves. Background In advanced processes for manufacturing semiconductor wafers, a new technology called "Hybrid Bonding" has been introduced in which silicon wafers or silicon wafers and silicon bare chips are bonded together by direct Bonding via copper (Cu) electrodes. Therefore, it is important to check the internal state of the wafer such as poor bonding, and to perform feedback related to improvement of the process conditions as early as possible. In order to examine the internal state of a multi-layered object in a nondestructive manner, ultrasonic examination is effective. In ultrasonic examination, an ultrasonic wave is irradiated from a probe to a subject, reflected waves from a joint interface are received, and an examination image is generated based on the intensity of the reflected waves. Appropriate image processing is performed on the generated inspection image to extract defects. In order to realize a high-sensitivity inspection using ultrasonic waves, the beam of ultrasonic waves irradiated while aiming at the inspection target site is reduced, and a single-scan type ultrasonic probe is used to generate a high-definition inspection image. However, in the single-scan type ultrasonic probe, a corresponding time is required for scanning the entire surface of the wafer. On the other hand, in order to realize high-speed inspection using ultrasonic waves, an array type ultrasonic probe of an electronic scanning system is effective. However, in the array type ultrasonic probe of the electronic scanning system, a reduction in resolution, that is, a reduction in image quality, of the generated inspection image is unavoidable as compared with the case of using the single type ultrasonic probe of the single scanning system. Non-patent document 1 discloses an ultrasonic inspection apparatus capable of simultaneously mounting both a single ultrasonic probe of a single scanning type capable of performing high-sensitivity inspection and an array ultrasonic probe of an electronic scanning type capable of performing high-speed inspection. Patent document 1 discloses an inspection technique for extracting defects from an inspection image by ultrasonic waves. In the inspection technique of patent document 1, an image of a reference die that is not affected by a defect is generated based on an inspection image of a bonding interface of a plurality of layered wafers obtained by ultrasonic waves, and the image of each die is compared with the reference image, and it is considered that a defect exists at a position where a difference in image attribute (brightness) is large, and the display is performed. Prior art literature Patent literature Patent document 1 Japanese patent application laid-open No. 2017-072501 Non-patent literature Non-patent document 1, ultrasonic inspection apparatus FineSAT Hybrid, [ online ], and 5, 22 days, internet ＜URL：https：/wwww.hitachi-power-solutions.com/product-site/finesat/products/finesat-hybrid/index.html＞ Disclosure of Invention Problems to be solved by the invention In the inspection technique of non-patent document 1, generally, the same image processing is performed on a pair of inspection images having different resolutions, which are obtained by an array type ultrasonic probe and a single type ultrasonic probe, respectively. Therefore, the kind of defects extracted from the respective inspection images depends on the resolution of the images. However, in the process using hybrid bonding, the types of defects generated are various. Therefore, in order to perform feedback on the process conditions, it is required to grasp all kinds of defects due to the process, which are related to the entire surface of the wafer, at high speed and with high sensitivity. In this regard, the inspection technique of non-patent document 1 cannot cope with the requirement. In the inspection technique of patent document 1, defect inspection is performed by utilizing a phenomenon that bare chips having a common circuit pattern are regularly formed at a bonding interface of a wafer. Specifically, first, an image of a bonding interface of a wafer is divided into a plurality of images in units of bare chips. Then, a statistical process is performed on the divided plurality of images in units of bare chips, and a dynamic threshold value for referencing the bare chip image and suppressing noise is generated based on the result of the statistical process. Then, they are used to extract minute bonding defects. However, in the inspection technique described above, since a plurality of images of the same pattern structure region are required for statistical processing, a corresponding time is required until the i