Nanostructured surfaces

 Electric properties of layered SiOx-Al-SiOx structure obtained by ion-plasma sputtering

Bratus O.L.1, Evtukh A.A.1, Ilchenko V.V.2, Antonin S.V.1, Pylypova O.V.2, Gorbanyuk T.I.1, Voitovych M.V.1
1V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine,
Kyiv, Ukraine. E-mail: o.l.bratus@gmail.com

2Taras Shevchenko Kyiv National University, Institute of High Technologies,
Kyiv, Ukraine. 

Non-volatile memory cells based on metallic nanocrystals as a floating gate are of interest due to their potential in overcoming the boundaries of ordinary memory elements. Metal nanocrystals can be used to make non-volatile memory devices by using as localized traps, due to their properties as a Coulomb blockade effect and controlled size. In the trend overview of memory devices, most researchers focused on the study of semiconductor nanocrystals in metal-oxide-semiconductor (MOS) structures. Nevertheless, metal nanocrystals as the basis of memory devices are considered more advantageous in many respects, compared with semiconductor nanocrystals. The use of metal nanocrystals allows for lower operating voltages, resulting in increased data storage time and improved write / erasure speeds [1].
In our investigations we studied the electron transport and charge capture in MIS structures with SiOx-Al-SiOx gate dielectric. The SiOx and Al films were deposited on a p-type silicon wafer using an ion-plasma sputtering (IPS) method. The mechanism of electrical conductivity of this structure depends on the electric field. The value of the electrical conductivity of the film increases with increasing the termal annealing of the structure (Fig. 1). The effect of electric charge accumulation was detected, the magnitude of captured charge increases with increasing the amplitude and length of the voltage pulse.
		
	Fig. 1. Typical I-V characteristics of MIS structure with SiOx-Al-SiOx gate dielectric. Arrow shows the direction of temperature growth.	
1. Park, B. et al. (2007). Memory characteristics of Al nanocrystals embedded in Al2O3 layers. Microelectronic engineering, 84(5-8), 1627-1630.