Hydrogen-terminated polycrystalline diamond MOSFETs with Al2O3 passivation layers grown by atomic layer deposition at different temperatures

Abstract

Metal oxide semiconductor field effect transistors (MOSFETs) with Al2O3 passivation layer grown by atomic layer deposition (ALD) at 200 oC and 300 oC were fabricated on hydrogen-terminated polycrystalline diamond by using gold mask technology. The device with 200 oC grown Al2O3 dielectric shows high output current, low on-resistance, large threshold voltage and high transconductance compared to that with 300 oC grown Al2O3. A maximum drain current of 339 mA/mm has been achieved by the 2-μm device of the former kind, which, as we know, is the best result reported for the diamond MOSFETs with the same gate length except the NO2-adsorbed case. The current-voltage (I-V) of gate diodes of both kinds of devices show the gate forward leakage is dominated by the Frenkel-Poole (FP) emission mechanism at a high electric field, and the gate of the latter device can sustain higher forward bias. The stability of successive I-V measurements of both kinds of devices was proved. We expect that a high performance H-diamond MOSFET with high stability can be achieved by a double-layer dielectric structure with 200 oC grown Al2O3 stacked by another high-quality high κ dielectric.

Analysis of the Mobility-Limiting Mechanisms of the Two-Dimensional Hole Gas on Hydrogen-Terminated Diamond

“…We first observe that, prior to passivating samples A and B, the sheet densities are significantly higher than their passivated counterparts (A' and B'). As reported in other works, a drop in the sheet density after the deposition of Al 2 O 3 is common [4,35], which is attributed to the lower density of surface acceptors in Al 2 O 3 in comparison to air-adsorbates. It is also shown in Fig.…”

Demonstration of Monolithic Polycrystalline Diamond-GaN Complementary FET Technology for High-Temperature Applications

“…In this work, we focused on the monolithic integration method to fabricate a polycrystalline (PC) diamond hole FET and AlGaN/GaN HEMT simultaneously on a single chip to deliver a complementary inverter for high-temperature. Previous work showing that PC diamond hole FET using a PC diamond plate (Element six TM200) with an average grain size between 80 and 100 μm demonstrates comparable performance to the SC diamond hole FET in recent works, − pointing to the validity of our approach. In a separate study, the role of PC diamond as a heat spreader was also discussed, making this combination even more desirable for various applications .…”

Atomic Layer Deposition of Metal Oxides and Chalcogenides for High Performance Transistors

“…Devices fabricated at 200 °C displayed a higher output current, larger V T , and lower onresistance compared with that deposited at 300 °C. [180] In addition, ALD-processed Al 2 O 3 has been also employed as an effective passivation layer to reduce the surface trap density, and thus suppress the threshold voltage hysteresis significantly. [80] Si et al demonstrated enhanced FET performances through the passivation of indium selenide (𝛼-In 2 Se 3 ) by ALD-Al 2 O 3 .…”