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In this paper, we report reliability evaluation results for nanomixed amorphous ZrAlxOy and symmetrically or asymmetrically stacked ZrO2/Al2O3/ZrO2 dielectric thin films grown by atomic layer deposition method in cylindrical metal-insulator-metal capacitor structure. Clear distinctions between their I-V asymmetry and breakdown behavior were correlated with the differences in compositional modification of bottom interface, defect density, and conduction mechanism of the film stacks. The thermochemical molecular bond breakage model was found to explain the dielectric constant dependent breakdown field strength and electric field acceleration parameter of lifetime very well

Essential techniques that allow W h e r scaling of trench DRAMs beyond 100 nm have been developed. (1) A1203 was implemented as high-k node dielectric in silicon-insulatorsilicon trench capacitors. A1203 films were deposited by ALD with excellent step coverage at aspect ratios of up to AR --60. Even.after thermal stressing at 1050 "C an effective oxide thickness ( = capacitance equivalent thickness) of to, = 3.6 nm and a leakage current of well below 1 fA/cell were obtained. (2) Both selective and non-selective HSG Si was formed inside high-aspect ratio straight and bottled trenches. On fully integrated 0.17 pm trench DRAMs, a storage capacitance of 45 fF/cell with acceptable leakage current was achieved. Both the aluminum oxide node dielectric and the HSG silicon have thus been proven to withstand the high thermal budget required for integration into trench DRAMs. (3) In addition, a silicon etch process was developed that allows trench aspect ratios of AR = 60 at critical dimensions of CD = 80 nm.

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