Physical model to explain anomalous Hall coefficient in band conduction in heavily Al-doped 4H-SiC

What is it about?

As an excellent high-power semiconductor device, very low resistivity p-type 4H-SiC is required to fabricate 4H-SiC n-channel insulated-gate bipolar transistors, the on-resistance of which is considerably lower than that of commercially available 4H-SiC n-channel metal-oxide-semiconductor field-effect transistors. Understanding the underlying conduction mechanisms is essential for reducing the resistance of these materials. This article examined the band conduction region to uncover why the Hall coefficient in heavily Al-doped 4H-SiC epilayers becomes negative at low temperatures.

Featured Image

Photo by Axel R. on Unsplash

Photo by Axel R. on Unsplash

Why is it important?

Because the substitutional Al in 4H-SiC behaves as an acceptor, Al-doped 4H-SiC is a p-type semiconductor, indicating that the Hall coefficient should be positive. This article proposes a physical model to explain the negative Hall coefficient at low temperatures in the band conduction region for heavily doped p-type wide bandgap semiconductors.

Perspectives