Abstract: A method includes forming a multi-layer stack over a semiconductor substrate, the multi-layer stack comprising a plurality of sacrificial layers that alternate with a plurality of channel layers, forming a dummy gate stack over a top surface and sidewalls of the multi-layer stack, forming first spacers on sidewalls of the dummy gate stack, growing an epitaxial source/drain region that extends through the plurality of sacrificial layers and the plurality of channel layers, forming a metal-semiconductor alloy region on first portions of the epitaxial source/drain region, forming a coating layer on the metal-semiconductor alloy region, wherein during the forming of the metal-semiconductor alloy region and the coating layer, a residual layer is formed on sidewalls of the first spacers, and performing a wet clean process to selectively etch the residual layer from the sidewalls of the first spacers.

Abstract: A FinFET includes a semiconductor substrate, a semiconductor fin, a gate structure, and an isolation structure. The semiconductor fin protrudes from the semiconductor substrate. The gate structure is disposed across a first segment of the semiconductor fin. The isolation structure interrupts a continuity of a second segment of the semiconductor fin. The isolation structure has a first portion and a second portion stacked on the first portion. Sidewalls of the first portion are inclined and sidewalls of the second portion are straight. A top surface of the first portion is coplanar with a top surface of the gate structure.

Abstract: A sensing method, comprising steps of causing a first molecule to be adjacent to one of a plurality of first nanoparticles spacedly disposed on a detachable chip; adding a target object to contact the first molecule; and measuring a spectral signal, wherein a variation of the spectral signal of the plurality of first nanoparticles occurs when the target object demonstrates a first specific binding with the first molecule.