Method and apparatus for etching silicon
AssigneesNisso Engineering Co., Ltd., Disco Corporation
InventorsAkira Yoneya, Noriyuki Kobayashi, Nobuhiko Izuta
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Abstract
An etching method and an etching apparatus for applying an etchant containing nitric acid and hydrofluoric acid to silicon to etch the silicon. The etchant used in etching is recovered, and brought into contact with a gas inert to the etchant, whereby the etchant is regenerated. At least a part of the regenerated etchant is reused in etching.
Claims13
An etching method comprising an etching step of applying an etchant containing nitric acid and hydrofluoric acid to silicon to etch the silicon, including:
- a recovery/regeneration step of recovering the etchant used in the etching step, and bringing a gas inert to the etchant into contact with the recovered etchant to regenerate the etchant,
- at least a part of the regenerated etchant after recovery and regeneration in the recovery/regeneration step being reused in the etching step.
An etching apparatus for applying an etchant containing nitric acid and hydrofluoric acid to silicon to etch the silicon, comprising:
- support means for supporting the silicon to be etched;
- transport means for carrying the silicon to be etched onto the support means, and carrying the etched silicon out of the support means;
- a circulation tank accommodating the etchant containing nitric acid and hydrofluoric acid;
- etchant applicator means for applying the etchant accommodated in the circulation tank to the silicon supported by the support means;
- recovery means for recovering the etchant applied to the silicon supported by the support means;
- regeneration means for bringing a gas inert to the etchant into contact with the etchant recovered by the recovery means to regenerate the etchant;
- and
- circulation means for returning at least a part of the etchant regenerated by the regeneration means to the circulation tank.
Dependencies are inferred from the claim text.