摘要
Electrical and reliability characteristics of Ge pMOSFETs with H 2 , NH 3 and NH 3 +H 2 plasma treatments were studied in this work. The GeO x interfacial layer (IL) formation and HfON dielectric deposition were performed in atomic layer deposition (ALD) chamber. H 2 and NH 3 plasma treatments were in-situ performed on GeO x IL in ALD chamber. The equivalent oxide thickness (EOT) can be scaled down by H 2 plasma treatment, and the interface trap density (D it ) is reduced with NH 3 plasma treatment. The enhanced on current of devices with H 2 plasma treatment can be attributed to its lower EOT. Reliability characteristics of devices are improved by H 2 plasma treatment on IL due to effects of H + passivation at GeO 2 /Ge interface. A Ge pMOSFET with an EOT of ∼0.47 nm and a high hole mobility of ∼401 cm 2 /V-s is demonstrated in this work by combining NH 3 and H 2 plasma treatments (NH 3 +H 2 ).