Accurate Modelling of Average Phosphorus Diffusivities in Germanium after Long Thermal Anneals

In summary, phosphorus diffusivities in germanium were measured after long anneals at temperatures between 600degC and 800degC. The diffusivities are extrinsic (i.e., D ~ (n/n_i)²) but are slower than recently reported extrinsic diffusivities and a slightly larger activation energy is also measured in this work than the previous work. Using a diffusion model that includes a segregation term between the cap oxide and the germanium combined with a peak solid solubility of 3times10¹⁹ cm^-3 good fits to the experimental profiles were obtained