Reliability of strained-channel NMOSFETs with SiN capping layer on hi-wafers with a thin LPCVD-TEOS buffer layer

The local strained channel (LSC) technique is proposed to provide tensile strained channel in nMOSFETs. However, the device reliability associated with the strained device owing to the strain, and excess hydrogen and nitrogen incorporation from the deposited SiN layer is an imminent concern. In line with this, the incorporation of a thin LPCVD-TEOS buffer layer to improve the reliability performance has been proposed. In addition, hydrogen annealed wafers (Hi-wafer) have been reported having reduced oxygen defects in Czochralski (CZ) wafers, with improved microroughness and defect on the surface after high hydrogen annealing.