Extraction of slow oxide trap concentration profiles in metal–oxide–semiconductor transistors using the charge pumping method

Abstract

The charge pumping technique is shown to be a very efficient method for studying the slow traps in the oxide of metal–oxide–semiconductor (MOS) transistors. The trap concentration is obtained by varying the gate pulse frequency, the other measurement parameters being kept constant. The concentrations measured on virgin devices are in agreement with those generally obtained on state-of-the-art MOS transistors using noise measurements. On virgin and stressed devices, they also agree with those measured using a drain current transient technique. The concentration profiles show an increase of the trap density near the oxide–semiconductor interface.

On the permanent component profiling of the negative bias temperature instability in p-MOSFET devices

“…In fact, more accurate r p (0) should be dependent on temperature involving the multi-phonon process [5,28]. This approximation is based on the well established reports from different research groups regarding the relation between defect depth in the oxide and the CP frequency in thick gate oxide [29][30][31]. Contrarily, Ryan et al [28] conclude that the relationship is more complex than that expected.…”

“…They are obtained for capture cross sections of electrons and holes at the Si/SiO 2 interface r n (0) = 5 . 10 À15 and r p (0) = 10 À16 -cm 2 and m n = m p = 0.5m 0 (details are given in [29]). At f H (500 kHz), we have found that CP-signal, corresponding to fast traps, emanates not only from N it but also from defects located at approximately 5 Å within interfacial oxide layer, even if frequency is increased (for example 1 MHz corresponds to Z = 4.6 Å and 10 MHz to Z = 3.5 Å).…”

On the Si–SiO2 interface trap time constant distribution in metal-oxide-semiconductor transistors

“…Assuming that ⌬F͑K͒ is a step function at K m , where ⌬F͑K͒ = 0.5, the trap concentration profiles are obtained from K m and N t ͑K m ͒ as in Ref. 15 K m = ln͑c n,p ͑0͒t h,l /͓ln͑3͔͒͒…”

Advance in next Century nanoCMOSFET research

“…For high-k device, the Q cp is strongly influenced by the border traps at high frequency and increases with decreasing charge-pumping (CP) frequency. Approximate depth profiles of border traps N bt (x) obtained by adopting the derivative dQ cp /dlog(f) [20] and the related physical parameters are shown in Fig. 4.…”