Renewal and Extension of an MOVPE System for III-Nitride and 2D Semiconductors

• Subject Area: Electrical Engineering and Information Technology
• Term: Funded in 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 583379146

In addition to the massive penetration of the lighting market with gallium nitride (GaN) LEDs, electronic components made from nitride semiconductors are already widely established in the mass market today: High-efficiency portable DC-DC converters are based on GaN transistors and GaN transistors in high-frequency technology already enable systems with watt-level output up to 100 GHz. In the future, high-voltage transistors with an operating voltage of 800 V will also be used in data centers and on-board chargers in e-mobility. The THz spectrum enables promising applications, but there is a lack of powerful and efficient sources as well as low-noise detectors that exceed the limitations of today's transistors. In the department Components for High Frequency Electronics, resonant tunneling diodes (RTD) have been successfully established in the indium phosphide (InP) material system and applied in the THz range. Based on these results, the development of a GaN RTD on non-polar surfaces is approached in order to exceed the power limit of the emitted THz radiation observed in InP RTDs. In the future, new materials and heterostructures will also be investigated. The 2D material hexagonal boron nitride (h-BN) is of interest for components in several applications: With a band gap of 5–6 eV, high thermal conductivity, high chemical resistance, and good mechanical stability, it is suitable as a dielectric for passivating components. It also belongs to the category of 2D materials that can be stacked vertically via weaker van der Waals bonds. E. g., h-BN can be used to passivate epitaxially grown graphene in order to increase electron mobility. Alternatively, h-BN can be used as a dielectric to develop a field-effect transistor based on 2D materials. However, the large-area deposition of h-BN poses a challenge, with metal organic vapor phase epitaxy (MOVPE) showing the best results. h-BN layers grown in this way on GaN/sapphire can be used as an integration platform for 2D materials, with the advantage of an electrically insulating substrate for high-frequency applications. These current and future research projects require an overhaul and expansion of the existing nitride MOVPE system. For both topics—the development of new heterostructures, e.g., tunnel structures with nm-thick barriers, and large-area 2D material deposition for integrated high-frequency chips—the uniformity of the layers is a critical aspect. To achieve this, the process gas supply to the reactor chamber must be upgraded (gas mixture manifold and showerhead) and new material sources have to be integrated. In addition, a reliable operation of the 2010 installed nitride MOVPE system for the next 10-15 years requires the replacement of key components that have reached the end of their economic life.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Erneuerung und Erweiterung einer MOVPE-Anlage für III-Nitrid und 2D-Halbleiter
• Instrumentation Group: 0920 Atom- und Molekularstrahl-Apparaturen
• Applicant Institution: Universität Duisburg-Essen
• Leader: Professor Dr. Nils Weimann