Optical Detection of Parasitic Channels of Vertically Stacked Ge0.98Si0.02 nGAAFETs

Abstract

The distinct photoresponse of the floating channels and the parasitic channels can be a signature to check the existence of the parasitic channel. The photoresponse of the sole parasitic channel mainly shows the photocurrent ( ${I}_{\text {ph}}$ ), while the photoresponse of the sole floating channels without parasitic channel shows the negative threshold voltage shift ( $\Delta {V}_{\text {T}}$ ) for nFET. The device with both the floating channels and the parasitic channel shows both photocurrent and negative threshold voltage shift under exposure.