Time Dependent Dielectric Breakdown of Thin SiO 2 Films

Time dependent dielectric breakdowns (TDDB) of thin SiO 2 films are described. The breakdowns are composed of two logarithmic normal distributions having different mean time to breakdown. One is area dependent and the other is independent. With increasing the area of capacitors the distribution of dielectric breakdowns shifts toward only one logarithmic normal distribution dominated by the area dependent breakdown having the shorter mean time to breakdown. The results are compared with usual voltage ramping method. In addition, electric field acceleration factor is measured 10 2.7 /MV/cm for the area dependent mode and 10 5 /MV/cm for area independent mode. The thickness dependence is also described.