Patent ID: 11881408
Assignee: PAUL SCHERRER INSTITUT
Field: Semiconductors (Electrical engineering)
Classification: CPC H  B  G  C  Y | IPC B  C  G  H

Claim 0:
1. A method for fabricating photonic device elements by means of metal assisted chemical etching in gas phase, the method comprising the following steps:
(a) providing a semiconductor substrate and a patterned metal layer on the semiconductor substrate;
(b) exposing the semiconductor substrate and the patterned metal layer to reactants in gas phase, the reactants including an oxidant gas and an etchant gas;
the oxidant gas comprising air and the etchant gas comprising hydrofluoric acid;
supplying the reactants in a continuous or pulsed flow to the semiconductor substrate and the patterned metal layer on the semiconductor substrate;
locally increasing a concentration of oxygen in the oxidant gas by decomposing H2O2 on a platinum surface, being a solid piece containing platinum immersed in a liquid solution containing H2O2, with a decomposition of H2O2 in the liquid phase on the platinum surface producing O2 in gas phase; and

wherein the liquid solution is placed in a container and the liquid is not in contact with the semiconductor substrate and the patterned metal on the semiconductor substrate.