A detection structure and detection method for wafer bonding quality

Abstract

The invention relates to a detection structure and a detection method for detecting the quality of wafer bonding. According to the detection structure, a bottom metal layer, bottom pads, and bottom through holes between the bottom metal layer and the bottom pads of a bottom wafer form an interconnect structure which is used as a lower half part of the test structure; top pads, a top metal layer, and top through holes between the top pads and the top metal layer of a top wafer form an interconnect structure which is used as an upper half part of the test structure; and the top metal layer is used as a test pad, and the opening of the test pad is arranged in the top metal layer of the top wafer after the top wafer is thinned. The test structure is composed of three parts, wherein the left and right test structures are respectively a first test target and a second test target, and the middle structure mainly plays a lead role. The test structure is a symmetrical structure, which enables other additional resistors except the test targets in the circuit to be equal. By adopting the test structure of the invention, the problem that the Cu-Cu bonding resistance Rc in a 3D IC cannot be tested accurately is solved simply and effectively.

Description

technical field [0001] The invention relates to the field of semiconductors, in particular, the invention relates to a wafer bonding quality detection structure and detection method. Background technique [0002] In the field of electronic consumption, multi-function devices are more and more popular among consumers. Compared with devices with simple functions, the production process of multi-function devices will be more complicated, such as the need to integrate multiple chips with different functions on the circuit board, so 3D integrated circuit (integrated circuit, IC) technology, 3D integrated circuit (integrated circuit, IC) is defined as a system-level integrated structure, stacking multiple chips in the vertical plane direction, thereby saving space, the edge of each chip Multiple pins can be drawn out as needed, and these pins can be used to interconnect the chips that need to be connected to each other through metal wires, but the above method still has many short...

AI Technical Summary

Problems solved by technology

[0005] At present, the quality inspection of Cu-Cu bonding (wafer level Cu-Cu bonding) at the wafer level mainly uses the traditional resistance chain (Rc chain) method to test, such as figure 1 As shown, but the Rc in the traditional resistance chain (Rc chain) test includes the resistance of the joint (bonding), the metal layer metal, and the via (Via), Rc=R bonding +R Via +R metal , and the resistance value brought by normal bonding (bonding) accounts for a small proportion in Rc, only when the bonding quality (bonding quality) is poor, it can qualitatively reflect the quality of bonding (bonding), but it cannot be accurate The measurement of the contact resistance of the bonding itself cannot accurately reflect the quality of the bonding

[0006] Although there is a detection structure for the quality detection of Cu-Cu bonding at the wafer level (wafer level Cu-Cubonding) in the prior art, there are still various deficiencies. How to effectively detect the quality and yield of bonding (bonding) online , how to accurately measure the junction resistance R bonding become an urgent problem to be solved

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