Self-aligned hybrid bonding structure and manufacturing method thereof

Abstract

The invention discloses a self-aligned hybrid bonding structure, comprising a self-aligned structure I with a trapezoidal metal structure and a self-aligned structure II with an inverted trapezoidal groove III; The self-aligned structure I comprises a metal interconnect structure I, a dielectric layer positioned above the metal interconnect structure I and a trapezoidal metal structure. The dielectric layer in the self-aligned structure I comprises a groove I positioned above the metal interconnect layer, and the trapezoidal metal structure is positioned above the groove. The self-aligned structure II comprises a metal interconnect structure II and a dielectric layer located on the metal interconnect structure II. The dielectric layer in the self-aligned structure II comprises an invertedtrapezoidal groove III located above the metal interconnect layer, the inverted trapezoidal groove III penetrates the dielectric layer, and a diffusion barrier layer and a metal layer are sequentiallydeposited on a side wall and a bottom. The invention provides a self-aligned hybrid bonding structure and a manufacturing method thereof, which can improve the alignment accuracy and the bonding quality when the hybrid bonding is performed.

Description

technical field [0001] The invention relates to a hybrid bonding technology, in particular to a self-aligned hybrid bonding structure and a manufacturing method thereof. Background technique [0002] With the development of semiconductor VLSI, the existing technology has approached the physical limit. Driven by the further miniaturization and multi-functionalization of electronic products, other new technologies, new materials, and new technologies have been explored. Three-dimensional stack packaging technology is one of them. The three-dimensional stacked packaging technology stacks silicon wafers through bonding technology to realize a three-dimensional metal interconnection structure, which can reduce the interconnection distance, increase the transmission speed, reduce the device volume, and provide the possibility of heterogeneous structure integration. [0003] Wafer bonding technology is one of the important means to realize three-dimensional stacking. Wafer bondi...

AI Technical Summary

Problems solved by technology

However, in this wafer bonding process with a smooth surface, high-precision metal-to-metal alignment is required during bonding. Since the current optical alignment technology for bonding alignment can only use infrared light sources, the alignment accuracy There is a theoretical limit, and there is usually a counter-rotation error. When the alignment error is large, the metal contact surface is too small, which will make the resistance too high

At the same time, the part where the metal-insulation layer contacts cannot obtain high-strength bonding force, which will reduce the reliability of the overall bonding

Therefore, the current optical alignment technology using infrared light sources can no longer meet the requirements of three-dimensional stacking technology. To further improve the bonding alignment accuracy, other process technologies are needed.

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