# Laser slicing: a thin film lift-off method for GaN-on-GaN technology

## TL;DR

This paper introduces a laser slicing technique using femtosecond laser pulses to lift off thin GaN films with device structures from bulk substrates, enabling transfer onto other substrates without special release layers.

## Contribution

The study demonstrates a novel laser slicing method for GaN that does not require release layers, facilitating efficient film transfer for device applications.

## Key findings

- Successful lift-off of 5 μm GaN films with LED structures
- Electroluminescence demonstrated post-transfer
- No special release layers needed for the process

## Abstract

A femtosecond laser focused inside bulk GaN was used to slice a thin GaN film with an epitaxial device structure from a bulk GaN substrate. The demonstrated laser slicing lift-off process did not require any special release layers in the epitaxial structure. GaN film with a thickness of 5 $\mu$m and an InGaN LED epitaxial device structure was lifted off a GaN substrate and transferred onto a copper substrate. The electroluminescence of the LED chip after the laser slicing lift-off was demonstrated.