Patent ID: 11959736
Assignee: UNITY SEMICONDUCTOR
Field: Measurement (Instruments)
Classification: CPC G  H | IPC G  H

Claim 0:
1. A method for characterising structures etched in a substrate, comprising, for at least one structure:
an interferometric measurement step, carried out with a low-coherence interferometer positioned on a top surface of said substrate, for measuring with a measurement beam positioned on the at least one structure, at least one depth data relating to a depth of said at least one structure; and
a first adjusting step for adjusting a diameter, at said top surface, of the measurement beam according to at least one top critical dimension (“top-CD”) data relating to a width of said at least one structure;
wherein the diameter of said measurement beam is adjusted to be between 0.3 and 5 times the smallest transverse dimension of the at least one structure.