A double-ring through-silicon via structure and its manufacturing method

Abstract

The invention relates to a double-ring silicon through silicon via structure and a manufacturing method thereof. The double-ring silicon through silicon via structure comprises a semiconductor substrate, a first dielectric layer, a first metal ring, a second dielectric layer, a second metal ring and a dielectric core layer sequentially from outside to inside. The manufacturing method of the double-ring silicon through silicon via structure includes: (1) forming a through via in the semiconductor substrate by etching; (2) preparing the first dielectric layer on the inner surface of the through via; (3) preparing the first metal ring on the surface of the first dielectric layer; (4) preparing the second dielectric layer on the surface of the first metal ring; (5) preparing the second metal ring on the surface of the second dielectric layer; (6) preparing the dielectric core layer on the surface of the second metal ring until fullness is achieved; (7) performing chemical mechanical polishing on the upper surfaces of the semiconductor substrate and the through silicon via. By adoption of the first metal ring which is arranged outside and grounded, a function of shielding noise signals is realized, and high integrity of high-frequency signals is achieved; by adoption of the second metal ring arranged inside, thermal stress is reduced, and thermo-mechanical property is improved.

Description

technical field [0001] The invention belongs to the field of three-dimensional integrated circuits for high-frequency applications, and relates to a through-silicon hole structure and a manufacturing method thereof, in particular to a double-ring through-silicon hole structure and a manufacturing method thereof. Background technique [0002] In the past few decades, the size of microelectronic devices has continued to decrease according to Moore's law, and the performance of electronic products has been improved unprecedentedly. However, after the size of the semiconductor manufacturing process was reduced to 16nm, the process technology gradually reached the physical limit, and small-scale effects such as quantum effects and short-channel effects became more and more prominent, which became the bottleneck for the continued development of Moore's Law. Three-dimensional integrated circuits no longer blindly pursue small size, but use three-dimensional stacking to improve syst...

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Problems solved by technology

[0003] However, in the process of making TSVs, TSVs and the entire semiconductor substrate need to undergo many thermal cycles, and the final annealing (275°C) and cooling to room temperature (25°C) process will bring huge damage to the entire structure. Temperature load (-250℃)

Due to the thermal expansion coefficient mismatch between the metal material (especially copper) and the semiconductor substrate, a large thermal stress will be introduced into the silicon substrate around the TSV, which will affect the carrier mobility and device performance and reliability.

On the other hand, with the continuous improvement of integration, the density of through-silicon holes has increased significantly, and the coupling and crosstalk between signal channels have also increased; with the increase of operating frequency of three-dimensional integrated circuits, especially those working in millimeter wave or In the submillimeter wave band, the influence of the parasitic parameters of the TSV itself is enough to submerge the entire signal transmission, seriously affecting the signal integrity of the signal channel

[0004] At present, the existing TSV structure can be divided into four types: cylindrical TSV, tapered TSV, ring TSV and coaxial TSV, among which cylindrical TSV and tapered TSV Due to structural limitations, TSVs and ring-type TSVs do not have the function of shielding signal noise, and are only suitable for low-frequency situations; while coaxial TSVs have superior high-frequency electrical resistance due to the existence of the outer grounding metal ring. Transmission characteristics, but because of the large proportion of metal, it introduces a large thermal stress in the surrounding semiconductor substrate

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