TY - GEN
T1 - Properties of Si / SiO2 interfaces in vertical trench MOSFETs
AU - Suliman, Samia A.
PY - 2006
Y1 - 2006
N2 - We report on the study of the Si/SiO2 interface of vertical U-shaped trench-gated n+ - polycrystalline Si / oxide / Si (UMOS) capacitor gate structure using capacitance-deep level transient spectroscopy (c-DLTS) and capacitance-voltage (CV). The oxide of a UMOS capacitor is three-dimensional- thermally-grown at different temperature 900°C - 1175°C, on sidewall and base of a reactive-ion etched silicon surface. High-density mid-gap Si/SiO 2 interfacial traps (∼1011 eV-1 cm -2) are observed with both holes and electron trapping. The amphoteric nature of traps is argued to arise from the Pb- dangling Si bond defect center. Moreover, a study of UMOSFET channel region using constant-amplitude charge pumping (CP), measurements coupled with electrical stressing of the gate oxide in the Fowler-Nordheim (FN) regime, have shown that the oxide edge adjacent to the drain and the oxide/silicon interface therein are the most susceptible regions to damage. SEM revealed non-uniformity in oxide thickness. Finally, enhanced UMOSFETS channel characteristics are observed for rounded-comer trench-bottom geometry in contrast with sharp-corner trench-bottom geometry.
AB - We report on the study of the Si/SiO2 interface of vertical U-shaped trench-gated n+ - polycrystalline Si / oxide / Si (UMOS) capacitor gate structure using capacitance-deep level transient spectroscopy (c-DLTS) and capacitance-voltage (CV). The oxide of a UMOS capacitor is three-dimensional- thermally-grown at different temperature 900°C - 1175°C, on sidewall and base of a reactive-ion etched silicon surface. High-density mid-gap Si/SiO 2 interfacial traps (∼1011 eV-1 cm -2) are observed with both holes and electron trapping. The amphoteric nature of traps is argued to arise from the Pb- dangling Si bond defect center. Moreover, a study of UMOSFET channel region using constant-amplitude charge pumping (CP), measurements coupled with electrical stressing of the gate oxide in the Fowler-Nordheim (FN) regime, have shown that the oxide edge adjacent to the drain and the oxide/silicon interface therein are the most susceptible regions to damage. SEM revealed non-uniformity in oxide thickness. Finally, enhanced UMOSFETS channel characteristics are observed for rounded-comer trench-bottom geometry in contrast with sharp-corner trench-bottom geometry.
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M3 - Conference contribution
AN - SCOPUS:34250191086
SN - 1424400473
SN - 9781424400478
T3 - Extended Abstracts of the Sixth International Workshop on Junction Technology, IWJT '06
SP - 225
EP - 228
BT - Extended Abstracts of the Sixth International Workshop on Junction Technology, IWJT '06
T2 - Extended Abstracts of the 6th International Workshop on Junction Technology, IWJT '06
Y2 - 15 May 2006 through 16 May 2006
ER -