Conduction in Al[sub 2]O[sub 3] Films and Charge Storage in MAOS Structures

Abstract

The conduction characteristics of aluminum oxide films deposited by rf sputtering on silicon substrates and ranging from 400-600A in thickness were measured over a range of temperatures. It was found that the current transport is essentially bulk limited and independent of the film thickness, the electrode material, and the polarity of the electrode. The three processes which affect the conduction through these films were found to be: Poole-Frenkel emission, field ionization, and trap hopping. The various parameters such as temperature and gate electrode affecting the charge storage in MAOS memory elements, were investigated using an automatic measurement set up and were related to the conduction characteristics of the two insulating layers. The memory elements consisted of 400-600A thick A1203 films deposited by rf sputtering on thermally grown SiO2 layers 50A thick. The charging and memory retention characteristics of the MAOS structure were also investigated. The effect of charge transport across the silicon dioxide on the surface state density at the Si-SiO2 interface was also observed.

Electrical Breakdown: II . During the Anodic Growth of Aluminum Oxide

“…Avalanche properties were examined in the manner described for tantalum pentoxide. We found that trapping by 1.35 eV deep traps (12) does not affect conduction band electrons at fields of anodization and the hole mobility was estimated to be larger than 3.10-s cm2/Vsec. The temperature pulse produced by an avalanche was calculated to be 15~ Equation [21a] of Part I (1) for the rate of breakdown could not be fitted to the experimental results of Fig.…”

“…Measurements of the barrier at the aluminum-CVD aluminum oxide interface resulted in energies of 3-3.5 eV (9)(10)(11). Conduction experiments at high fields in CVD films were interpreted with trapping of injected electrons roughly 1.35 eV below the conduction bandedge (12). Observations indicated deep trapping of holes, but quantitative data were not obtained (13).…”

Efficient spin injection through a crystalline AlOx tunnel barrier prepared by the oxidation of an ultra-thin Al epitaxial layer on GaAs

“…This method is not used for III-V compound semiconductors because group-V elements, such as As and P, have high vapor pressures. Other methods, the low-temperature plasma anodic oxidation 11 , metal-organic chemical vapor deposition 12 , sputtering 13 , electron beam evaporation 14 , and atomic layer deposition 15 , have been studied with the aim to obtain high quality AlO x layers, but layers obtained from those methods have suffered from a large numbers of interface traps. Density of the interface traps is ∼10 13 cm -2 eV -1 for the AlO x /GaAs systems 16 , which is much higher than that (∼10 9 cm -2 eV -1 ) in the SiO 2 /Si system.…”

The Deformation of Anodic Films during the Plasma Anodization of Al‐Si Structures

“…Memory action in metal A120~-Si FET's has also been observed (4). The A1203 film can be deposited in a variety of ways, e.g., pyrohydrolysis of A1C13 (4), decomposition of Al-alkoxides (5), pyrolytic deposition from AIB3 (6), rf sputtering (7), and plasma anodization (1,3). The latter method is considered here and results are presented indicating that severe deformation of the anodic oxide film can occur during anodization.…”