Effects of Proton Irradiation on Hole Carrier Transport in Hydrogen-Terminated Diamond Surfaces

TL;DR

This study investigates how 2 MeV proton irradiation affects the electrical properties of hydrogen-terminated diamond surfaces, revealing degradation in hole mobility and providing first data on proton tolerance for such surfaces.

Contribution

It presents the first data on proton irradiation effects on hydrogen-terminated diamond surfaces, analyzing mobility degradation and surface charge effects at different fluences.

Findings

Hole conductivity decreases with higher proton fluence.

Mobility reduction is due to enhanced hole scattering.

Both passivated and unpassivated surfaces show similar degradation.

Abstract

In this letter, we report the effects of irradiating hydrogen-terminated diamond surfaces with protons. We study the electrical behavior of the two-dimensional hole gas that forms on the diamond surface as a result of hydrogen-termination. Four diamond samples, two of which were passivated with Al2O3 and the other two unpassivated, were irradiated with 2 MeV protons at two fluences, 0.5x10^14 and 1.0x10^14 /cm^2. The hole conductivity degraded at a higher proton fluence, which is attributed to the reduction of the mobility caused by enhanced hole scattering. Both passivated and unpassivated samples exhibited a reduction in the mobility, which can be explained by charging effects of the Al2O3 (for the passivated samples) and degradation of the hydrogen-terminated surface (for the unpassivated samples). To our knowledge, this is the first reported data on 2 MeV proton tolerance of hydrogen-terminated diamond surfaces.