The goal of this work is to study the transient electrical features of metal/high-k interface in MOS stacks. To this aim, electrons are injected from the gate of TaN/Al2O3/SiO2/p-Si capacitors in pulsed regime. The displacement current flowing during the pulse front is detected, and the capacitance is extracted. As a result, for the first time, a flat-band instability related to electron trapping in states near the metal/high-k interface is measured on a millisecond timescale. A picture of the time evolution of the charge density inside the oxide bulk is drawn, with the aid of a finite-element simulator. Reliability of the metal/high-k interface is also investigated by performing stress experiments in pulsed conditions. It is shown that after a certain number of pulses, the creation of new traps at the top interface of the MOS stack becomes relevant.
Electron-Related Phenomena at the TaN/Al2O3 Interface / Rao, Rosario; Lorenzi, Paolo; G., Ghidini; Palma, Fabrizio; Irrera, Fernanda. - In: IEEE TRANSACTIONS ON ELECTRON DEVICES. - ISSN 0018-9383. - 57:3(2010), pp. 637-643. [10.1109/ted.2009.2039100]
Electron-Related Phenomena at the TaN/Al2O3 Interface
RAO, ROSARIO;LORENZI, PAOLO;PALMA, Fabrizio;IRRERA, Fernanda
2010
Abstract
The goal of this work is to study the transient electrical features of metal/high-k interface in MOS stacks. To this aim, electrons are injected from the gate of TaN/Al2O3/SiO2/p-Si capacitors in pulsed regime. The displacement current flowing during the pulse front is detected, and the capacitance is extracted. As a result, for the first time, a flat-band instability related to electron trapping in states near the metal/high-k interface is measured on a millisecond timescale. A picture of the time evolution of the charge density inside the oxide bulk is drawn, with the aid of a finite-element simulator. Reliability of the metal/high-k interface is also investigated by performing stress experiments in pulsed conditions. It is shown that after a certain number of pulses, the creation of new traps at the top interface of the MOS stack becomes relevant.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.