H-diamond MOS interface properties and FET characteristics with high-temperature ALD-grown HfO2 dielectric

Zeyang Ren,Jiamin Xu,Dandan Lv,Chunfu Zhang,Qi He,Jinfeng Zhang,Yue Hao,Yufei Xing,Kai Su,Hong Zhang,Jincheng Zhang

doi:10.1063/5.0044004

Abstract

The performance of hydrogen-terminated diamond MOSFETs with a large gate–drain interspace (LGD) was analyzed on a polycrystalline diamond sample. A 300 °C atomic layer deposition grown (ALD-grown) HfO2 dielectric (28 nm) was used the gate dielectric and device passivation layer. The HfO2/H-diamond interfacial valence band offset of 1.98 eV was determined by x-ray photoelectron spectroscopy, indicating that the high temperature grown HfO2 dielectric has great potential for accommodating a high density of holes on the H-diamond surface, and the high dielectric constant of HfO2 is also useful for improving the control capability of the gate on the device channel. A breakdown voltage of 657 V was achieved on the device. Baliga’s figure of merit of the device was calculated to be ∼2.0 MW/cm2, which is comparable to that of the H-diamond FETs with Al2O3 dielectrics that are more than 200 nm thick. The HfO2 dielectric shows great potential for use in H-diamond power devices.

Highlights

Diamond has great potential in high-voltage, high-frequency, and high-power electronics devices due to its outstanding properties.1–4 the high activation energy of p- and n-type dopants has severely hindered the development and application of diamondbased devices.5,6 a possible solution—formation of the 2DHG on the surface of the H-diamond—was identified for this problem.7,8 H-diamond MOSFETs have achieved a maximum output current, cutoff frequency, and microwave output power density of 1.3 A/mm,9 70 GHz,10 and 3.8 W/mm at 1 GHz11 and 182 mW/mm at 10 GHz,12 respectively
The HfO2/H-diamond interfacial valence band offset of 1.98 eV was determined by x-ray photoelectron spectroscopy, indicating that the high temperature grown HfO2 dielectric has great potential for accommodating a high density of holes on the H-diamond surface, and the high dielectric constant of HfO2 is useful for improving the control capability of the gate on the device channel
H-diamond MOSFETs with a high-temperature ALD-grown HfO2 dielectric were obtained on a polycrystalline diamond surface

Summary

INTRODUCTION

Diamond has great potential in high-voltage, high-frequency, and high-power electronics devices due to its outstanding properties. the high activation energy of p- and n-type dopants has severely hindered the development and application of diamondbased devices. a possible solution—formation of the 2DHG on the surface of the H-diamond—was identified for this problem. H-diamond MOSFETs have achieved a maximum output current, cutoff frequency (fT), and microwave output power density of 1.3 A/mm, GHz, and 3.8 W/mm at 1 GHz11 and 182 mW/mm at 10 GHz, respectively. H-diamond pchannel FETs show excellent power operation performance characteristics, with a maximum breakdown voltage, maximum drain current density, and specific on-resistance (RON) of greater than 2 kV, 800 A/cm, and 3.2 mΩ cm respectively, reported for H-diamond vertical-type MOSFETs. H-diamond p-channel MOSFETs have great potential for application in high-power complimentary inverters through the combination with SiC or GaN n-channel power FETs.. There is an urgent need to continue improving H-diamond power MOSFETs. Previously, almost all high breakdown voltage H-diamond MOSFETs used atomic layer deposition grown (ALD-grown) Al2O3 films as the gate dielectric or the passivation layer. The HfO2 film currently reported in Hdiamond devices was grown at a low temperature of 120 ○C, while. The direct current and breakdown characteristics were demonstrated, and the interfacial band configuration of HfO2/H-diamond was studied

EXPERIMENT DETAILS

RESULTS AND DISCUSSIONS

CONCLUSIONS