Hello Logout


Study of tantalum pentoxide as a dielectric in MOS Structures

Ta2O5 was studied as a dielectric for DRAM applications. Optimization of the dielectric formation process to get high K, low leakages and low dielectric relaxation effects are the highlights of this study. A model for dielectric relaxation effect on dielectric constant has been developed to determine the frequency range within which the deposited dielectric would give constant performance. Thermally oxidized Ta films studied over a wide oxidation temperature from 300-1000°C for a time of 1-3 h, showed that at temperatures 300-400°C, there is improper oxidation of Ta. At temperatures higher than the crystallization temperature of Ta2O5 (600 °C), though dielectric constants are high, leakages are also high. Films formed at 550°C/3 h showed good electrical properties, with a dielectric constant of 23, Ileak= 2.2 X 10-7 A/cm2 at 1 MV/cm and tan d=0.001 at 1 kHz. Dielectric relaxation studies showed 10 kHz as the frequency range in which this dielectric could be used without dielectric relaxation effects. More Info

Tags :
Your rating: None Average: 5 (1 vote)