Temperature-accelerated dielectric breakdown in ultrathin gate oxides

Temperature-accelerated effects on dielectric breakdown of ultrathin gate o xide with thickness ranging from 8.7 to 2.5 nm are investigated and analyze d. Although superior reliability for ultrathin gate oxide at room temperatu re has been reported in recent literatures, a strong temperature-accelerate d degradation of oxide reliability is observed in this study. Experimental results show that both charge-to-breakdown (Q(bd)) and breakdown field (E-b d) characteristics are greatly aggravated for ultrathin oxide at elevated t emperature. The Arrhenius plot also confirms that the activation energies o f Q(bd) and E-bd increase significantly as oxide thickness decreases, expla ining the higher sensitivity to temperature for thinner oxides. (c) 1999 Am erican Institute of Physics. [S0003-6951(99)02024-0].