2D-Material-Assisted GaN Growth on GaN Template by MOCVD and Its Exfoliation Strategy

Area of Science:

• Materials Science
• Nanotechnology
• Semiconductor Manufacturing

Background:

• Freestanding membranes from 2D materials use van der Waals (vdW) epitaxy, quasi-vdW epitaxy, and remote epitaxy.
• Manufacturing freestanding gallium nitride (GaN) with these methods is challenging due to 2D material damage from high-temperature metal-organic chemical vapor deposition (MOCVD).

Purpose of the Study:

• To develop a stable method for GaN growth and exfoliation on 2D material/GaN templates.
• To overcome the limitations of high-temperature MOCVD damaging 2D materials during GaN synthesis.

Main Methods:

• Graphene and hexagonal boron nitride (h-BN) were transferred onto GaN templates.
• A two-step MOCVD growth process for GaN was performed at 750 °C and 900 °C.
• The 2D materials acted as protective layers during GaN growth.

Main Results:

• The 2D materials effectively protected the underlying GaN template during high-temperature MOCVD.
• Intact 2D materials enabled the successful exfoliation of the grown GaN.
• The study confirmed the feasibility of vdW epitaxy and remote epitaxy principles.

Conclusions:

• This approach enables the production of freestanding GaN membranes by protecting 2D materials during MOCVD.
• The method overcomes previous challenges related to 2D material degradation and GaN exfoliation.
• The findings broaden the applicability of vdW epitaxy and remote epitaxy techniques.