Fast-IV Measurement Investigation of the Role of TiN Gate Nitrogen Concentration on Bulk Traps in HfO2 Layer in p-MOSFETs

Abstract

This letter investigates the role of the TiN gate's nitrogen concentration on bulk traps in the HfO2 layer in p-MOSFETs using fast I-V measurement. During negative bias temperature instability, the holes trapped in the HfO2 layer will induce Vth degradation. The fast I-V double sweep confirms the holes are trapped in process-related pre-existing defects. These defects are interstitial-type, influenced by the nitrogen in the TiN gate diffusing to the HfO2 layer when the device undergoes thermal annealing. Moreover, these nitrogen interstitials increase with increasing TiN gate nitrogen concentration, which induces more holes being trapped in the HfO2 layer.