Isotropic atomic layer etch for silicon and germanium oxides
US9431268B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 5, 2015 |
| Grant date | Aug 30, 2016 |
| Priority date | — |
| Expiry date | Jan 5, 2035 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J37/32715
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Methods for controlled isotropic etching of layers of silicon oxide and germanium oxide with atomic scale fidelity are provided. The methods make use of a reaction of anhydrous HF with an activated surface of an oxide, with an emphasis on removal of water generated in the reaction. In certain embodiments the oxide surface is first modified by adsorbing an OH-containing species (e.g., an alcohol) or by forming OH bonds using a hydrogen-containing plasma. The activated oxide is then etched by a separately introduced anhydrous HF, while the water generated in the reaction is removed from the surface of the substrate as the reaction proceeds, or at any time during or after the reaction. These methods may be used in interconnect pre-clean applications, gate dielectric processing, manufacturing of memory devices, or any other applications where accurate removal of one or multiple atomic layers of material is desired.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.