# Application of UV Laser for Ohmic Contact Formation on 4H-SiC

## TL;DR

A new method using UV lasers and silver adhesive creates efficient ohmic contacts on 4H-SiC without high-temperature steps.

## Contribution

A simplified, low-temperature process for ohmic contact formation on 4H-SiC using UV laser and silver adhesive.

## Key findings

- Laser processing significantly improves contact interface and enables linear I–V characteristics.
- Surface amorphization from laser treatment eliminates the Schottky barrier in SiC.
- The method allows rapid prototyping of SiC devices without high-temperature annealing.

## Abstract

In this paper, we demonstrate a simplified method for fabricating ohmic contacts on 4H-SiC substrates using pulsed UV laser surface modification followed by application of a silver-based conductive adhesive. Even a small number of laser passes significantly improved the contact interface, while ten or more repetitions produced linear I–V characteristics with low voltage drops. SEM analysis revealed surface ablation and an expanded effective area of the contact. Raman spectroscopy proved that laser processing leads to surface amorphization of the SiC sample. DFT simulations showed that the amorphous SiC layer is a material with no band gap, explaining the elimination of the Schottky barrier. Our approach enables the manufacturing of reliable, low-resistive contacts without high-temperature annealing and offers a practical route for rapid SiC device prototyping.