Effects of hydrogen on Al/p-Si Schottky barrier diodes

Hydrogen was incorporated into B-doped p-type crystalline silicon in three different ways: boiling the sample in water, exposing the sample to hydrogen plasma, growing silicon in a hydrogen atmosphere. Al-contact Schottky barrier diodes were made on both the hydrogenated and unhydrogenated samples. It was found that the Schottky barrier height (SBH) is increased due to the hydrogenation. The current-voltage measurement showed an increase of 0.06–0.10 eV in the effective SBH and the activation energy measurement revealed an increase of 0.07–0.09 eV in the SBH under a forward bias of 0.15 V. If the silicon grown in a hydrogen atmosphere was thermal annealed at 650 °C to drive out hydrogen before Schottky metallization, then the SBH approached that of the unhydrogenated sample. It is demonstrated that the SBH in Al/p-Si can be increased with hydrogen incorporated in silicon.