Semiconductor device and manufacturing method thereof

Abstract

The invention provides a semiconductor device and a manufacturing method thereof. The semiconductor device comprises a first wafer which comprises a substrate and a device layer formed on the front surface of the substrate, a metal interconnection structure is formed in the device layer, a through hole is formed in the back surface of the substrate, the through hole penetrates through the substrate, and the back surface and the front surface of the substrate are opposite surfaces; a first oxide layer, a first nitride layer and a second oxide layer are sequentially formed on the inner surface of the through hole, an opening is formed in the bottom surface of the through hole, and the metal interconnection structure is exposed out of the opening; and a metal layer is filled in the through hole and the opening, and the metal layer is electrically connected with the metal interconnection structure. According to the technical scheme provided by the invention, the capabilities of preventing metal diffusion and resisting voltage breakdown are improved, so that the electrical stability is improved, and the production cost is reduced.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, in particular to a semiconductor device and a manufacturing method thereof. Background technique [0002] After fusion bonding the front side of the pixel wafer to the carrier wafer using BSI (Back-side Illumination, back-illuminated) technology, the TSV (Through Silicon Vias, through-silicon via) hole is made on the back side of the pixel wafer. The metal interconnection structure (including pads) located on the front side of the pixel wafer is led out. The specific steps include: first, etching the substrate on the back of the pixel wafer to form a through hole through the substrate; then, using ALD (Atomic Layer Deposition, atomic layer deposition) technology to form a silicon oxide layer on the side and bottom of the through hole ; Next, etch the silicon oxide layer on the bottom surface of the through hole and the dielectric layer below the silicon oxide layer t...

AI Technical Summary

Problems solved by technology

[0003] However, the use of ALD technology to form a silicon oxide layer is a process with high cost and low efficiency; and the ability of the silicon oxide layer to prevent metal diffusion in the metal layer and prevent voltage breakdown is limited, which can easily lead to electrical failure of the TSV structure

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