Gated-diode characterization of the back-channel interface on irradiated SOI wafers

Effect of Radiation on Interface Traps of SOI NMOSFETs by the Direct-Current Current-Voltage Technique

“…The superiority of DCIV technique over conventional methods is that the method has access to the energy distribution of interface trap density nearby midgap besides interface trap density and its equivalent energy level [18], [19]. Therefore, the direct-current current-voltage (DCIV) technique has been often used for the characterization of interface traps in many issues related to reliability [20]- [22]. In DCIV measurements, enough electrons and holes are guaranteed by surface potential near the Si/SiO 2 interface.…”

“…The interface trap density is detected by measuring the bulk current related to the interface traps as recombination centers of electron and hole [15], [23], [24]. Several works [20], [22] have reported that an increase in the peak value of DCIV current is indicative of interface-states formation. Details of the DCIV theory will be presented in the next section.…”

“…Several works [22], [25]- [27] have reported that the buildup of radiation-induced interface traps. E. X. Zhang et al [26] have estimated radiation-induced interface trap density (N it ) from the charge pumping data but the energy level distribution of interface traps in his work is not involved.…”

“…S. Bonaldo et al [27] have inspected the spatial distribution of interface traps in irradiated pMOSFETs and found a high density of interface traps in the lateral source/drain extension regions by static DC and charge pumping measurements. R. K. Lawrence et al [22] have calculated quantificationally the interfaced trap density (N it ) at different dose by DCIV method regardless of the energy distribution of interface traps. Several works have reported the energy distribution of interface traps under bias temperature instability (BTI) stress by conductance method [20] and under hot carrier damage by DCIV technique [7], [18].…”

Probing proton damage in SOI CMOS technology by using lateral bipolar action

“…The induced change of the characteristics, however, is often very small, making the identification of radiation-induced charges difficult, primarily because of the thin gate oxide found in modern devices. On the other hand, the gate-controlled base current or gate-diode current can be used to measure the recombination current due to the interface traps generated at the interface during fabrication, under stress, or after radiation, when an MOSFET is operated as a lateral bipolar transistor [1]- [5] or as a gated diode (body to source/drain) [6]- [8]. Electrical properties of the interface traps, including their energy levels and density, can be derived from the gate bias dependence of the recombination current [9]- [11], an analysis technique which can be dated back to the early 1960s [12], [13].…”