Effect of Bias Voltage on Substrate for the Structure and Electrical Properties of Y:HfO₂ Thin Films Deposited by Reactive Magnetron Co‐Sputtering

Abstract HfO₂ thin film has been widely studied as the most promising candidate material for microelectronic devices. However, low leakage current density is the prerequisite for the excellent performance of devices. Therefore, effects of substrate bias duty ratio and frequency on the roughness and leakage current density are studied for the Y:HfO₂ thin films deposited by reactive magnetron co‐sputtering method. The results illustrate that the substrate bias duty ratio and frequency influence the leakage current density through grain size and roughness of films. An appropriate substrate bias is beneficial to the densification of films and the reduction of leakage current. When the substrate bias duty cycle is 30.1% at the frequency of 19.7 kHz, the roughness and leakage current density of films are reduced to 0.4 nm and 8.8 × 10⁻⁸ A cm⁻², respectively.