Charge trapping properties and retention time in amorphous SiGe/SiO2 nanolayers

In this paper, we report on the electrical properties of metal–oxide–semiconductor (MOS) capacitors containing a well-confined 8 nm-thick SiGe amorphous layer (a-SiGe) embedded in a SiO2 matrix grown by RF magnetron sputtering at a low temperature (350 ºC). Capacitance–voltage measurements show that the introduction of the SiGe layer leads to a significant enhancement of the charge trapping capabilities, with the memory effect and charge retention time larger for hole carriers. The presented results demonstrate that amorphous floating-gate SiGe layers embedded in SiO2 may constitute a suitable alternative for memory applications.This study was partially funded by: (i) European COST Actions MP0901-NanoTP and MP0903-NanoAlloy; (ii) FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology in the framework of the Strategic Project PEST-C/FIS/UI607/2011; (iii) the transnational access framework of the ANNA Eu Project (Contract No 026134-RII3) through the funding of the ANNA_TA_UC9_RP006 proposal. EMFV is grateful for financial support through the FCT and POPH of the grant SFRH/BD/45410/2008. JMS is grateful for financial support through the Spanish CSIC JAE-DOC-070/01 program co-funded by FSE. The authors would also like to thank Engineer Jose Santos for technical support at the Thin Film Laboratory.The authors would also like to thank Engineer José Santos for technical support at the Thin Film Laboratory