Reactive ion etching method for etching silicon

Abstract

The invention provides a reactive ion etching method for etching silicon and belongs to the technical field of semiconductor manufacturing. In the reactive ion etching method, the adopted etching gas comprises a fluorine-containing gas and a gas which reacts with the silicon to form a passivation layer. When the etching process is finished, the fluorine-containing gas is stopped introducing first and then the gas which reacts with the silicon to form the passivation layer is stopped introducing. Holes formed by etching silicon in the method have smaller undercutting effect and bowl-shaped effect.

Description

technical field [0001] The invention belongs to semiconductor manufacturing technology, in particular to a reactive ion etching (Reactive Ion Etching, RIE) method, in particular to a reactive ion etching method for etching silicon. Background technique [0002] In the field of semiconductor manufacturing technology, it is often necessary to pattern and etch holes on silicon substrates or other silicon materials. In the prior art, dry RIE etching technology is usually used to generate F plasma ( Plasma) to etch silicon materials, for example, in the fields of MEMS ((Micro-Electro-Mechanical Systems, micro-electro-mechanical systems) and 3D packaging technology, it is usually necessary to perform bulk silicon etching to form deep through-silicon holes with a depth of several hundred microns (Through-Silicon-Via, TSV), the etching of deep silicon vias uses SF 6 and O 2 mixed gas for etching. [0003] In the process of reactive ion etching of silicon in the prior art, another...

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Problems solved by technology

However, the (1) method generally needs to close the reactive ion etching machine, and the plasma will be completely extinguished, and the etching of silicon holes usually requires multiple figure 1 The process shown is completed, so it is necessary to restart the machine and set parameters, which will greatly reduce the etching efficiency; in the second method, other gases are introduced, which is easy to cause fluctuations in the process, and a high vacuum pump is also required. The gas is pumped away, the etching efficiency is reduced, and it is difficult to maintain the stability of the radio frequency in the subsequent process

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