Impact of oxide trap passivation by fluorine on the low-frequency noise behavior of gate-last pMOSFETs

The low-frequency noise of gate-last pMOSFETs is studied, with particular attention to the passivation of oxide traps by fluorine. It is shown that the lowest flicker noise power spectral density is obtained after 6 min of exposure to an SF
₆
plasma. At the same time, the dominant 1/f-noise mechanism changes from carrier number fluctuations to mobility fluctuations, indicating the de-activation of the gate oxide traps by the plasma treatment.