Charging characteristics of Au nanocrystals embedded in metal-oxide-semiconductor structures

Abstract

The charging characteristics of metal-oxide-semiconductor ͑p-type͒ structures containing Au nanocrystals in SiO 2 gate oxide were studied. The Au nanocrystals of 2-3 nm in diameter are self-assembled from the agglomeration of an ultrathin Au layer embedded in SiO 2 matrix by annealing at 600°C. A large hysteresis loop is found in the capacitance-voltage ͑C-V͒ relation even at a low operating voltage ͑2 V͒, indicating its significant charge storage effect. Different charging rates for two kinds of trapped carriers ͑electron and hole͒ were found from C-V measurement under various scan rates. The relatively stable retention characteristic for holes trapped in the Au nanocrystals at room temperature was also demonstrated.

Study of tunneling mechanism of Au nanocrystals in HfAlO matrix as floating gate memory

“…Owing to the charging effects of Au NCs, a significant threshold voltage shift has been obtained and the memory window up to 10.0 V and stored charge density up to 1 ϫ 10 14 / cm 2 has been achieved. FowlerNordheim tunneling mechanism is used to analyze the capacitance-voltage characteristics of the trilayer memory structure, and it is found that higher density and smaller size of the Au NCs result in a higher tunneling coefficient and a larger memory window.…”

“…10,11 However, there is not much emphasis being put on comparing the experimental results of memory characterizations with the F-N tunneling mechanisms, and hence optimizing the formation of the Au NCs in the trilayer floating gate memory. In fact, the tunneling mechanism is not well addressed yet in such floating gate memory system.…”

Improved performance of non-volatile memory with Au-Al2O3 core-shell nanocrystals embedded in HfO2 matrix

“…In the past decade, tremendous efforts have been invested into research of nanocrystal (NC) memories from materials and structures. Semiconductor nanocrystals such as Si, 1 Ge, 2 metal nanocrystals such as Al, 3,4 Ag, 5 Ni, 6 W, 7-9 Pt, 10 Au, [11][12][13][14] Ru, 15 Co, 16,17 ,Ir, 18 and oxide nanocrystals such as IrO x , 19 RuO (Ref. 20) have been reported.…”

Memory characteristics of Au nanocrystals embedded in metal–oxide–semiconductor structure by using atomic-layer-deposited Al2O3as control oxide

“…In recent years, metal-oxide-semiconductor (MOS) structures embedded with semiconductor or metal nanocrystals as floating gate have been widely studied due to their superior physical properties for application in nonvolatile memory devices of next generation [1][2][3][4][5][6][7][8][9]. Compared with conventional flash memories, the nanocrystal-based-nonvolatile-memory allows more aggressive scaling of the tunnel oxide and exhibits superior characteristics in terms of operation voltage, write/erase speed and endurance [2,4].…”