CN-121985790-A - Wafer bonding strength evaluation method, system and medium

CN121985790ACN 121985790 ACN121985790 ACN 121985790ACN-121985790-A

Abstract

The invention relates to a wafer bonding strength evaluation method, a wafer bonding strength evaluation system and a wafer bonding strength evaluation medium, and relates to the technical field of semiconductor manufacturing quality monitoring and testing. The method comprises the steps of applying a preset number of chemical etching reagents to the edges of bonding wafer pairs under the condition of a preset ambient temperature, enabling the chemical etching reagents to be in contact with dielectric layers at the interface of the edges and starting timing, wherein the chemical etching reagents are only used for carrying out chemical etching on the dielectric layers, the dielectric layers are dielectric layers between the bonding wafer pairs, stopping etching reaction in response to the timing reaching the preset time, collecting etching morphology of the dielectric layers, and obtaining wafer bonding strength based on the mapping relation between the etching morphology and wafer bonding strength. Based on the scheme, the bonding strength can be quantitatively evaluated, and the nondestructive evaluation requirement is met, so that the wafer bonding strength evaluation cost is reduced.

Inventors

YE TONGDI
CHEN SHUBIN
WU XIAOHONG
ZHENG TAO
WANG YIHAO

Assignees

东莞触点智能装备有限公司

Dates

Publication Date: 20260505
Application Date: 20260206

Claims (13)

1. The wafer bonding strength evaluation method is used for evaluating the initial bonding strength after pre-bonding in the wafer bonding process and is characterized by comprising the following steps of: Under the condition of a preset ambient temperature, a preset number of chemical etching reagents are applied to the edges of the bonding wafer pairs, so that the chemical etching reagents are in contact with the dielectric layers at the interface of the edges and start timing; Terminating the etching reaction in response to the timing reaching the preset time; the method comprises the steps of preparing bonding wafer pairs under different process conditions, dividing the bonding wafer pairs into a plurality of areas for bonding wafer pairs under any process condition, evaluating at least one area in the plurality of areas by a preset wafer bonding strength evaluation method to obtain the wafer bonding strength, applying chemical etching reagents to dielectric layers of at least one area in other areas to perform chemical etching, and collecting etching morphology parameters to obtain the mapping relation between the wafer bonding strength and the etching morphology parameters, and obtaining the mapping relation between the different wafer bonding strengths and the etching morphology parameters obtained under different process conditions to obtain the mapping relation between the etching morphology and the wafer bonding strength.
2. The method of claim 1, wherein the predetermined ambient temperature condition is a room temperature condition.
3. The method of claim 1, wherein terminating the etching reaction comprises purging the etching interface with deionized water, a neutralizing solution, or an inert gas to terminate the etching reaction.
4. The wafer bond strength evaluation method according to claim 1, wherein the etched features comprise etched lengths and/or etched areas.
5. The wafer bond strength evaluation method of claim 1, wherein when the etch profile includes an etch length, the etch length is an etch length from a wafer edge.
6. The method of claim 1, wherein the predetermined wafer bonding strength evaluation method comprises any one of a blade method, a stretching method, and a shearing method, or both of the stretching method and the shearing method.
7. The method for evaluating the bonding strength of a wafer according to claim 1 or 6, wherein the evaluating the bonding strength of at least one region by a predetermined wafer bonding strength evaluating method includes evaluating a plurality of regions by a predetermined wafer bonding strength evaluating method to obtain a plurality of bonding strengths, comparing whether the values of the bonding strengths are within a predetermined error range, if so, taking an average value of the bonding strengths as the wafer bonding strength obtained by evaluating, and if not, interrupting the wafer bonding strength evaluating process of the corresponding bonding wafer pair.
8. The method for evaluating bonding strength of a wafer according to claim 1 or 6, wherein the step of chemically etching the dielectric layer of at least one of the other regions by applying a chemical etching agent thereto and collecting etching topography comprises chemically etching the dielectric layer of a plurality of regions by applying a chemical etching agent thereto and collecting etching topography parameters of each region, calculating an average value of all etching topography parameters, and taking the average value as the collected etching topography parameters.
9. The method of claim 7, wherein the wafer bonding strength is obtained first, and then the etching profile parameter is obtained, and the wafer bonding strength evaluation process for the corresponding bonded wafer pair is interrupted if the values of the plurality of wafer bonding strengths are not within a predetermined error range during the wafer bonding strength obtaining process.
10. The method of claim 8, wherein the etching profile parameters are obtained first, then the wafer bonding strength is obtained, and in the process of obtaining the etching profile parameters, whether a plurality of etching profile parameters are within a preset error range is compared, if not, the wafer bonding strength evaluation process corresponding to the bonding wafer pair is interrupted, and if so, an average value of all the etching profile parameters is calculated and is used as the collected etching profile parameters.
11. A wafer bonding strength evaluation system for evaluating an initial bonding strength after pre-bonding in a wafer bonding process, comprising: the bonding wafer pair fixing device is configured to fix the bonding wafer pair according to a preset pose; A chemical etching agent applying means configured to apply a predetermined amount of chemical etching agent to the edges of the bonded wafer pair such that the chemical etching agent is in contact with the dielectric layer at the edge interface; a timing module configured to begin timing for a preset time in response to application of the chemical etching reagent; An etching reaction termination device configured to terminate the etching reaction in response to the timing reaching a preset time; An etched feature acquisition module configured to acquire an etched feature of the dielectric layer, and The wafer bonding strength estimation module is configured to obtain the wafer bonding strength based on the obtained etching morphology and the mapping relation between the etching morphology and the wafer bonding strength.
12. The wafer bond strength evaluation system of claim 11, further comprising an ambient temperature control module configured to control an ambient temperature at which the chemical etching reagent is applied such that the ambient temperature is at a preset ambient temperature condition.
13. A computer-readable storage medium, wherein a program is stored in the medium, the program being capable of being loaded by a processor and executing the wafer bonding strength evaluation method according to any one of claims 1 to 10.

Description

Wafer bonding strength evaluation method, system and medium Technical Field The invention relates to the technical field of semiconductor manufacturing quality monitoring and testing, in particular to a wafer bonding strength evaluation method, a wafer bonding strength evaluation system and a wafer bonding strength evaluation medium. Background Wafer bonding technology is a critical process in the advanced packaging and semiconductor integration fields. The bonding process typically includes surface activation, pre-bonding, high temperature annealing, and the like. Before annealing, verification monitoring of the initial bonding strength is important, and the method can be used for judging whether the processes such as surface activation and cleaning are successful or not and ensuring that the bonded wafer can be safely transmitted to the annealing process. Currently, bond strength assessment prior to annealing is primarily dependent on destructive methods, such as blade, tensile or shear testing. The blade method is to insert a thin blade (similar to a chisel) at the edge of the wafer, pry the wafer along the interface using the lever principle, or measure the force required to pry the wafer apart. This is a fracture mechanics test. The stretching method is to fix the bonded wafer or chip on two test tables by glue or a special fixture, and apply a pulling force along the direction (Z axis) perpendicular to the interface until the wafer or chip breaks. The shearing method is to fix the sample, push the upper wafer parallel to the wafer surface with a push knife, and measure the maximum force required to slip or peel it. However, the above methods can directly damage the test wafer, which results in no access to the subsequent process and high cost. In the nondestructive detection, an ultrasonic scanning microscope (CSAM) can be adopted, and the quality (such as bubbles, defects and the like) of a bonding interface is indirectly reflected through attenuation and reflection intensity of an acoustic signal, but the quantitative intensity value cannot be provided, so that the application range is more limited. Disclosure of Invention The application aims to provide a wafer bonding strength evaluation method which has the characteristics of being capable of realizing nondestructive wafer bonding strength evaluation and providing quantitative strength values. In a first aspect, an embodiment provides a method for evaluating bonding strength of a wafer, where the method is used for evaluating initial bonding strength after pre-bonding in a wafer bonding process, and includes: Under the condition of a preset ambient temperature, a preset number of chemical etching reagents are applied to the edges of the bonding wafer pairs, so that the chemical etching reagents are in contact with the dielectric layers at the interface of the edges and start timing; Terminating the etching reaction in response to the timing reaching the preset time; the method comprises the steps of preparing bonding wafer pairs under different process conditions, dividing the bonding wafer pairs into a plurality of areas for bonding wafer pairs under any process condition, evaluating at least one area in the plurality of areas by a preset wafer bonding strength evaluation method to obtain the wafer bonding strength, applying chemical etching reagents to dielectric layers of at least one area in other areas to perform chemical etching, and collecting etching morphology parameters to obtain the mapping relation between the wafer bonding strength and the etching morphology parameters, and obtaining the mapping relation between the different wafer bonding strengths and the etching morphology parameters obtained under different process conditions to obtain the mapping relation between the etching morphology and the wafer bonding strength. In one embodiment, the predetermined ambient temperature condition is a room temperature condition. In one embodiment, the step of terminating the etching reaction comprises cleaning the etching interface by adopting deionized water, neutralizing liquid or inert gas to purge and terminate the etching reaction. In one embodiment, the etched features include etched length and/or etched area. In one embodiment, where the etch profile includes an etch length, the etch length is an etch length from the wafer edge. In one embodiment, the preset wafer bonding strength evaluation method includes any one of a blade method, a stretching method and a shearing method or two of the stretching method and the shearing method. In one embodiment, the at least one area is evaluated by a preset wafer bonding strength evaluation method to obtain wafer bonding strength, which includes that a plurality of areas are evaluated by a preset wafer bonding strength evaluation method to obtain a plurality of wafer bonding strengths, whether the values of the plurality of wafer bonding strengths are within a preset error range is compared, if ye