Method for etching deep through silicon via (TSV)

Abstract

The invention provides a method for etching a deep through silicon via (TSV), belonging to the technical field of semiconductor manufacturing. The etching method comprises a reaction ion etching step and a polymer deposition step which are alternately carried out, wherein gases adopted in the etching step comprise a first gas for chemical reaction plasma etching of silicon and a second gas which reacts with the silicon to form a silicide protection film. When used for etching the TSV, the etching method has the characteristics of high etching efficiency and good smoothness of the side wall of the TSV.

Description

technical field [0001] The invention belongs to the technical field of semiconductor manufacturing, and in particular relates to a reactive ion etching (Reactive Icon Etching, RIE) technology, in particular to a deep through silicon via (Through-Silicon-Via, TSV) etching method. Background technique [0002] In the field of semiconductor manufacturing technology, in fields such as MEMS (Micro-Electro-Mechanical Systems, micro-electro-mechanical systems) and 3D packaging technology, it is usually necessary to etch deep via holes in materials such as silicon. For example, in bulk silicon etching technology, deep through-silicon-vias (Through-Silicon-Via, TSV) have a depth of hundreds of microns, and their aspect ratio is even much greater than 10. Reactive ion etching is usually used to etch the bulk silicon. silicon formed. [0003] figure 1 Shown is a schematic diagram of an etching method for deep TSVs in the prior art. In the prior art, the reactive ion etching of TSVs ...

AI Technical Summary

Problems solved by technology

More protection to the sidewall will significantly reduce the etching rate of silicon, while the sidewall protection gas such as C 4 f 8 It will accumulate on the sidewall, and the longer the etching time, the more it will accumulate, and a thick accumulation layer will be formed at the opening of the etched silicon hole, which will affect the entry of reactive gases and further reduce the etching rate.

The single-step etching method needs to realize the etching in one etching process and ensure the protection of the sidewall during a long etching time, but with the increase of the etching depth, the accumulation of polymer and the decrease of the etching speed The reduction will affect the final performance. It is difficult to achieve high-speed etching and adequate protection of the sidewall with a single-step etching method

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