Abstract

(57) ABSTRACT A semiconductor stack of a FinFET in fabrication includes a bulk silicon substrate, a selectively oxidizable sacrificial layer over the bulk substrate and an active silicon layer over the sacrificial layer. Fins are etched out of the stack of active layer, sacrificial layer and bulk silicon. A conformal oxide deposition is made to encapsulate the fins, for example, using a HARP deposition. Relying on the sacrificial layer having a comparatively much higher oxidation rate than the active layer or substrate, selective oxidization of the sacri ficial layer is performed, for example, by annealing. The presence of the conformal oxide provides structural stability to the fins, and prevents fin tilting, during oxidation. Selec tive oxidation of the sacrificial layer provides electrical isolation of the top active silicon layer from the bulk silicon portion of the fin, resulting in an SOI-like structure. Further fabrication may then proceed to …

Date

2017

Authors

MK Akarvardar, JA Fronheiser, AP Jacob

Inventors

Murat Kerem Akarvardar, Jody A Fronheiser, Ajey Poovannummoottil Jacob

Patent_office

US

Patent_number

9716174

Application_number

13945455