Study of Dopant Activation in Silicon Employing Differential Hall Effect Metrology (DHEM)

Abstract

Differential Hall Effect Metrology (DHEM) technique was used to characterize highly n-type doped Si epi layers deposited on p-type Si wafers. Total dopant concentration, doping depth profile and post deposition annealing condition were changed for various sample sets and influence of such changes on the resistivity, mobility and carrier concentration depth profiles were studied. It was determined that samples annealed at 900 °C had higher activation compared to those annealed at 700 °C. Gradation in doping depth profiles did not result in similar gradation in resistivity values. Carrier concentration at the near-surface region was found to be lower in all samples. It is shown that electrical properties of films forming ultra-shallow junctions can be studied in detail and correlated with process parameters using DHEM data obtained at sub-nm depth resolution.

Keywords

• Depth profiling
• DHEM
• differential hall effect
• dopant activation
• electrical characterization
• Van der Pauw