Tunable EOT Scaling Down to 0.55 nm for HfO₂-Based Gate-Stacks on Ge Substrate by In Situ H₂ Plasma Treatment

We propose a continuous fabrication method for HfO 2 -based gate stacks on a Ge bulk p-type metal–oxide–semiconductor capacitor (pMOSCAP) with HfGeO x interfacial layer by H 2 plasma treatment through in situ plasma-enhanced atomic layer deposition. The electrical characteristics showed that the proper hydrogen plasma treatment could obtain an aggressively scaled equivalent oxide thickness of approximately 0.55 nm and a relatively low gate leakage current of 8 × 10 −4 A cm −2 under PMA 500 °C.