Temperature Dependence of the l/f Noise in Heat-Treated Films of Al And Al-Cu

Abstract

AbstractThe 1/f noise in heat-treated Al and AI-Cu thin films was investigated at a current density of 20 mA/μm2 from approximately RT to 200 C. The results were consistent with the Dutta-Dimon-Hom model, i.e., the noise is the result of a collection of two-state systems. From the temperature dependence of the noise, a modified Dutta-Dimon-Hom model was used to extract the energy of formation, ΔHf, and the energy of migration, ΔHm, of the noise process. The development as well as simulations of this model will be discussed. It will be shown that ΔHm can be determined through investigation of the temperature at which the noise magnitude peaks for many frequencies. It will also be shown that ΔHf can be determined by investigation of the temperature at which the noise magnitude peaks and the temperature at which a, the negative of the logarithmic slope of the power spectral density, passes through 1. For both the Al and Al-Cu films, ΔHm was approximately 0.7 eV. The results also indicated that ΔHf was ≤ 0.1 eV for the Al films, and only slightly higher, i.e., 0.1 - 0.2 eV, for the Al-Cu films. The temperature at which cx passes through I was similar for both the Al and AI-Cu films. These results strongly suggest that the l/f noise is caused by the motion of Al atoms along the grain boundaries.