Atomic layer deposition of ZrO2 and HfO2 on deep trenched and planar silicon

Conformal ZrO2 and HfO2 thin films were grown by atomic layer deposition using novel liquid cyclopentadienyl precursors at 300 °C or 350 °C on planar Si wafers and deep trenched Si with an aspect ratio of 60:1. The crystal growth and phase content in as-deposited films depended on the precursor, film thickness, and the material grown. The structural and electrical behaviour of the films were somewhat precursor-dependent, revealing better insulating properties in the films grown from oxygen-containing precursors. Also the HfO2 films showed lower leakage compared to ZrO2.