Patent ID: 11906727
Assignee: HAMAMATSU PHOTONICS K.K.
Field: Optics (Instruments)
Classification: CPC G  B  H | IPC B  G  H

Claim 0:
1. A method for manufacturing an optical device,
the optical device comprising:
a base,
a movable unit,
an elastic support portion connected between the base and the movable unit, and
an optical function unit disposed on the movable unit,
wherein the base, the movable unit, and the elastic support portion are constituted by a semiconductor substrate including a first semiconductor layer, a second semiconductor layer, and an insulating layer disposed between the first semiconductor layer and the second semiconductor layer,
the base is constituted by the first semiconductor layer, the second semiconductor layer, and the insulating layer,
at least one of the movable unit and the elastic support portion includes a rib portion constituted at least by the first semiconductor layer and disposed on the second semiconductor layer, and
the first semiconductor layer constituting the rib portion is thinner than the first semiconductor layer constituting the base,
the method comprising:
a first step of preparing the semiconductor substrate that includes a portion corresponding to the base, the movable unit, and the elastic support portion;
a second step of forming a first resist layer in a region corresponding to the base on a surface of the first semiconductor layer which is opposite to the insulating layer after the first step;
a third step of forming a depression in the first semiconductor layer by etching the first semiconductor layer up to an intermediate portion in a thickness direction using the first resist layer as a mask after the second step;
a fourth step of forming a second resist layer in a region corresponding to the rib portion on a bottom surface of the depression, a side surface of the depression, and the surface of the first semiconductor layer which is opposite to the insulating layer after the third step; and
a fifth step of forming the rib portion by etching the first semiconductor layer until reaching the insulating layer using the second resist layer as a mask after the fourth step.