In this study, we investigate the low frequency current noise in 2.5 nm MOSFETs undergoing soft breakdown. Statistic experiments show that gate current noise belongs to low frequency 1/f(gamma) noise, where 1.5 < gamma < 2. The soft breakdown shows fractal properties, and its fractal dimension is obtained as 1.5 < D-b < 1.75. An improved dynamic percolation with trap inhomogeneous distribution is introduced to describe the low frequency current noise. In addition, the effects of voltage and temperature on the power-law exponent gamma are given, and also the Weibull statistics distribution of power-law exponent gamma is given. (C) 2003 Elsevier Science Ltd. All rights reserved.