High-k Oxides on Hydrogenated-Diamond for Metal-Oxide-Semiconductor Field-Effect Transistors [Invited]

Thanks to its excellent intrinsic properties, diamond is promising for applications of high-power electronic devices, ultraviolet detectors, biosensors, high-temperature tolerant gas sensors, etc. Here, an overview of high-k oxides on hydrogenated-diamond (H-diamond) for metal-oxide-semiconductor (MOS) capacitors and MOS field-effect transistors (MOSFETs) is demonstrated. Fabrication routines for the H-diamond MOS capacitors and MOSFETs, band configurations of oxide/H-diamond heterointerfaces, and electrical properties of the MOS and MOSFETs are summarized and discussed. High-k oxide insulators are deposited using atomic layer deposition (ALD) and sputtering deposition (SD) techniques. Electrical properties of the H-diamond MOS capacitors with high-k oxides of ALD-Al
₂
O
₃
, ALD-HfO
₂
,ALD-HfO
₂
/ALD-Al
₂
O
₃
multilayer, SD-HfO
₂
/ALD-HfO
₂
bilayer, SD-TiO
₂
/ALD-Al
₂
O
₃
bilayer, and ALD TiO
₂
/ALD-Al
₂
O
₃
bilayer are discussed. Analyses for capacitance-voltage characteristics of them show that there are low fixed and trapped charge densities for the ALD-Al
₂
O
₃
/H -diamond and SD-HfO
₂
/ALD-HfO
₂
/H- diamond MOS capacitors. The k value of 27.2 for the ALD-TiO
₂
/ALD-Al
₂
O
₃
bilayer is larger than those of the other oxide insulators. Drain-source current versus voltage curves show distinct pitch-off and p-type channel characteristics for the ALD-Al
₂
O
₃
/H -diamond, SD- EfO
₂
/ALD-HfO
₂
/H-diamond, and ALD-TiO
₂
/ALD- Al
₂
O
₃
/H-diamond MOSFETs. Understanding of fabrication routines and electrical properties for the high-k oxide/H-diamond MOS electronic devices is meaningful for the fabrication of high-performance H-diamond MOS capacitor and MOSFETs.