US 11,901,185 B2Granted

Etching method

AssigneeKabushiki Kaisha Toshiba

InventorsMitsuo Sano, Susumu Obata, Kazuhito Higuchi, Takayuki Tajima

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Abstract

According to an embodiment, an etching method includes forming a first layer on a substrate having a main surface including first and second regions adjacent to each other, the first layer including a portion covering the first region and having a plurality of openings or one or more openings defining a plurality of island-shaped portions, and the first layer further including a portion as a continuous layer covering the second region, forming a catalyst layer an a portion(s) of the main surface exposed in the openings by plating, forming a second layer to cover a portion of the catalyst layer adjacent to a boundary between the first and second regions and expose a portion of the catalyst layer spaced apart from the boundary, and etching the substrate in a presence of the catalyst layer and the second layer.

Claims15

Dependent claims

An etching method comprising:

forming a first layer on a substrate, the substrate containing a semiconductor material and having a main surface, the main surface including a first region and a second region adjacent to each other, the first layer covering the first region and the second region, a portion of the first layer covering the first region being provided with a plurality of openings or one or more openings defining a plurality of island-shaped portions, and a portion of the first layer covering the second region being a continuous layer;
forming a catalyst layer containing a noble metal on a portion(s) of the main surface exposed in the plurality of openings or the one or more openings by a plating method;
forming a second layer to cover a portion of the catalyst layer adjacent to a boundary between the first region and the second region and expose a portion of the catalyst layer spaced apart from the boundary;
and
etching the substrate with an etching agent containing an oxidizer and hydrogen fluoride in a presence of the catalyst layer and the second layer.

2 more elements

An etching method comprising:

forming a mask layer on a substrate, the substrate containing a semiconductor material and having a main surface, the main surface including a first region and a second region adjacent to each other, the mask layer including a first portion and a second portion, the first portion covering the first region and being provided with a plurality of openings or one or more openings defining a plurality of island-shaped portions, the second portion being a continuous layer covering the second region, and a height of the second portion at a position adjacent to a boundary between the first region and the second region with reference to the main surface being higher than a height of the first portion with reference to the main surface;
forming a catalyst layer containing a noble metal on a portion(s) of the main surface exposed in the plurality of openings or the one or more openings by a plating method;
and
etching the substrate with an etching agent containing an oxidizer and hydrogen fluoride in a presence of the catalyst layer and the mask layer.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 17/473,418Filed 13 Sep 2021
Priority: JP 2021-04488718 Mar 2021
Published: US 2022/0301877 A122 Sep 2022
Granted: 13 Feb 2024
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

H10P 50/642
Of semiconductor materials: chemical etching
H10P 50/644
Chemical etching: anisotropic liquid etching
H10D 64/01
Electrodes of devices having potential barriers: manufacture or treatment
H10D 64/01306
Characterised by the conductor: the conductor comprising a layer of silicon contacting the insulator, e.g. polysilicon