Characterization of MOS Devices by Scanning Thermal Microscopy (SThM)

Abstract

Temperature measurements on passivated electronic devices and the determination of the local thermal conductivity using the Scanning Thermal Microscope demonstrate promising possibilities to use this system as a tool for thermal diagnostics as well as for the failure analysis. Since doping concentration affects the thermal conductivity (κ) due to the free carriers introduced, we propose the SThM as a potential dopant-profiling tool. To correlate doping concentration and thermal conductivity, we have mapped out the thermal conductivity of decreasing Boron-doped and Phosphorus-doped staircase silicon substrates and compared these data to the corresponding doping profile from 1D Secondary ion mass spectroscopy (SIMS). To demonstrate the ability of the SThM technique to analyze both thermal features - temperature distribution and quantitative thermal conductivity - of an electronic device, we investigated properties of an NMOS device.