Fabrication of Metal–Oxide–Diamond Field-Effect Transistors with Submicron-Sized Gate Length on Boron-Doped (111) H-Terminated Surfaces Using Electron Beam Evaporated SiO2 and Al2O3

Journal of Applied Physics

Liao

Imura

et al. 2013

Atomic layer deposited (TiO2)x(Al2O3)1−x/In0.53Ga0.47As gate stacks for III-V based metal-oxidesemiconductor field-effect transistor applications Appl. Phys. Lett. 100, 062905 (2012); 10.1063/1.3684803 Energy-band alignment of Al 2 O 3 and HfAlO gate dielectrics deposited by atomic layer deposition on 4 H -SiC Appl. Phys. Lett. 96, 042903 (2010); 10.1063/1.3291620Band alignments and improved leakage properties of ( La 2 O 3 ) 0.5 ( SiO 2 ) 0.5 / SiO 2 / GaN stacks for hightemperature metal-oxide-semiconductor field-effect transistor applications Impact of a γ -Al 2 O 3 ( 001 ) barrier on LaAlO 3 metal-oxide-semiconductor capacitor electrical propertiesIn order to search a gate dielectric with high permittivity on hydrogenated-diamond (H-diamond), LaAlO 3 films with thin Al 2 O 3 buffer layers are fabricated on the H-diamond epilayers by sputtering-deposition (SD) and atomic layer deposition (ALD) techniques, respectively. Interfacial band configuration and electrical properties of the SD-LaAlO 3 /ALD-Al 2 O 3 /H-diamond metaloxide-semiconductor field effect transistors (MOSFETs) with gate lengths of 10, 20, and 30 lm have been investigated. The valence and conduction band offsets of the SD-LaAlO 3 /ALD-Al 2 O 3 structure are measured by X-ray photoelectron spectroscopy to be 1.1 6 0.2 and 1.6 6 0.2 eV, respectively. The valence band discontinuity between H-diamond and LaAlO 3 is evaluated to be 4.0 6 0.2 eV, showing that the MOS structure acts as the gate which controls a hole carrier density. The leakage current density of the SD-LaAlO 3 /ALD-Al 2 O 3 /H-diamond MOS diode is smaller than 10 À8 A cm À2 at gate bias from À4 to 2 V. The capacitance-voltage curve in the depletion mode shows sharp dependence, small flat band voltage, and small hysteresis shift, which implies low positive and trapped charge densities. The MOSFETs show p-type channel and complete normally off characteristics with threshold voltages changing from À3.6 6 0.1 to À5.0 6 0.1 V dependent on the gate length. The drain current maximum and the extrinsic transconductance of the MOSFET with gate length of 10 lm are À7.5 mA mm À1 and 2.3 6 0.1 mS mm À1 , respectively. The enhancement mode SD-LaAlO 3 /ALD-Al 2 O 3 /H-diamond MOSFET is concluded to be suitable for the applications of high power and high frequency electrical devices. V C 2013 AIP Publishing LLC.

supporting

confidence: 61%

Interfacial band configuration and electrical properties of LaAlO3/Al2O3/hydrogenated-diamond metal-oxide-semiconductor field effect transistors

Journal of Applied Physics

Liao

Imura

et al. 2013

“…7 Alternatively, in order to further improve the drain current density and reduce the threshold voltage, the enhancement of the capacitive coupling between the gate and the semiconductor channel is also crucial. Up to now, in addition to the gate insulators such as SiO 2 and AlN, 8,9 Al 2 O 3 is the mostly utilized insulator on H-diamond surface for MOSFETs. 5 As previously disclosed, a gate insulator with high dielectric constant (high-k) could control high carrier densities even at small electric fields.…”

mentioning

confidence: 99%

Assembly of a high-dielectric constant thin TiOx layer directly on H-terminated semiconductor diamond

Zhao

Applied Physics Letters

Sang

et al. 2016

A high-dielectric constant (high-k) TiO x thin layer was fabricated on hydrogen-terminated diamond (H-diamond) surface by low temperature oxidation of a thin titanium layer in ambient air. The metallic titanium layer was deposited by sputter deposition. The dielectric constant of the resultant TiO x was calculated to be around 12. The capacitance density of the metal-oxide-semiconductor (MOS) based on the TiO x /H-diamond was as high as 0.75 µF/cm 2 contributed from the high-k value and the very thin thickness of the TiO x layer. The leakage current was lower than 10-13 A at reverse biases and 10-7 A at the forward bias of-2 V. The MOS field-effect transistor based on the high-k TiO x /H-diamond was demonstrated. The utilization of the high-k TiO x with a very thin thickness brought forward the features of an ideally low subthreshold swing slope of 65 mV per decade and improved drain current at low gate voltages. The advantages of the utilization high-k dielectric for diamond MOSFETs are anticipated.

“…Several gate insulators such as SiO 2 , AlN, Al 2 O 3 , and CaF 2 have been deposited on the H-diamond for fabricating the MISFETs12131415. However, the k values of them are not large.…”

mentioning

confidence: 99%

Low on-resistance diamond field effect transistor with high-k ZrO2 as dielectric

Liao

Imura

et al. 2014

Sci Rep

118

Although several high-k insulators have been deposited on the diamond for metal-insulator-semiconductor field effect transistors (MISFETs) fabrication, the k values and current output are still not fully satisfactory. Here, we present a high-k ZrO2 layer on the diamond for the MISFETs. The k value for ZrO2 is determined by capacitance-voltage characteristic to be 15.4. The leakage current density is smaller than 4.8 × 10−5 A·cm−2 for the gate voltage ranging from −4.0 to 2.0 V. The low on-resistance MISFET is obtained by eliminating source/drain-channel interspaces, which shows a large current output and a high extrinsic transconductance. The high-performance diamond MISFET fabrication will push forward the development of power devices.