Remarkable charge-trapping efficiency of the memory device with (TiO2)0.8(Al2O3)0.1 composite charge-storage dielectric

Abstract

A memory device p-Si/SiO2/(TiO2)0.8(Al2O3)0.1(TAO-81)/Al2O3/Pt was fabricated, in which a composite of two high-k dielectrics with a thickness of 1 nm was employed as the charge-trapping layer to enhance the charge-trapping efficiency of the memory device. At an applied gate voltage of ±9 V, TAO-81 memory device shows a memory window of 8.83 V in its C-V curve. It also shows a fast response to a short voltage pulse of 10−5 s. The charge-trapping capability, the endurance, and retention characteristics of TAO-81 memory device can be improved by introducing double TAO-81 charge-trapping layers intercalated by an Al2O3 layer. The charge-trapping mechanism in the memory device is mainly ascribed to the generation of the electron-occupied defect level in the band gap of Al2O3 induced by the inter-diffusion between TiO2 and Al2O3.

High performance sol–gel spin-coated titanium dioxide dielectric based MOS structures

“…Among various high-κ dielectrics reported so far, titania seems to be a suitable alternative, owing to its exceptional physicochemical and optoelectronic properties [3][4][5][6][7]. In addition, dielectric constant of titania is crystal structure dependent with rutile form exhibited higher values compared to the anatase form (40) [8,9].…”

The roles of the dielectric constant and the relative level of conduction band of high-k composite with Si in improving the memory performance of charge-trapping memory devices

“…The inter-diffusion between two high-k dielectrics introduces a high density of defect states in the high-k composite. 27 Just as expected, the lowest memory window for TAO-05 CTM device shown in Fig.2(a) should be ascribed to the lowest partial composition of TiO 2 in TAO-05 film. With the most effective inter-diffusion between TiO 2 and Al 2 O 3 in TAO-55 composite, the TAO-55 CTM device should have the largest memory window among the three TiAlO CTM devices, whereas the TAO-73 CTM device with the largest partial composition of TiO 2 in TAO-73 film shows the largest memory window.…”

“…20,27 Although many efforts have been made to improve the performance of the CTM devices with different high-k charge-trapping dielectrics, and some of which show excellent charge-storage efficiency, fast P/E speed, good endurance and retention characteristics, the comparative studies on the parameters of high-k dielectric affecting the electric performance of CTM devices have rarely been done. In this paper, we report the CTM devices containing a high-k composite charge-trapping layer (TiO 2 ) x (Al 2 O 3 ) 1-x (TiAlO)(nominal composition x = 0.05, 0.5 and 0.7), in which the dielectric constant of the composite and the band alignment with Si were adjusted by controlling the partial composition of TiO 2 .…”

The effect of the thickness of tunneling layer on the memory properties of (Cu2O)0.5(Al2O3)0.5 high-k composite charge-trapping memory devices

“…[25][26][27][28] Recently, some high-k composite oxides have been employed as the charge-trapping dielectrics to achieve the higher density of trapped charges in CTM devices. [31][32][33] It was reported that the memory structure with a charge-trapping layer of (Al 2 O 3 ) 0.5 (Cu 2 O) 0.5 shows a large memory window and a high density of the trapped charges. 34 In this paper, we report the effect of the thickness of tunneling layer on the memory properties of (Al 2 O 3 ) 0.5 (Cu 2 O) 0.5 CTM device.…”

“…[31][32][33] It was reported that the memory structure with a charge-trapping layer of (Al 2 O 3 ) 0.5 (Cu 2 O) 0.5 (named as CAO) shows a large memory window and a high density of the trapped charges.…”