Oxide and chalcogenide MOCVD (metal-organic chemical vapour deposition)

The history of II-VI metal-organic chemical vapour deposition (MOCVD) goes back as far as IIII-V MOCVD but has not had the traction in applications for lasers, LEDs and high frequency devices that has been experienced by III-V semiconductors. A new generation of MOCVD equipment can more fully exploit the potential of II-VI semiconductors and explore new oxides and chalcogenides in the exiting areas of III-VIs such as Ga2O3 and 2-D semiconductors such as MoS2. There is now a compelling case for the UK to have state-of-the-art MOCVD equipment for compound semiconductors (CS) covering oxide and chalcogenide materials that are not covered by existing centres such as the National Epitaxy Facility at Sheffield, Cambridge and UCL, and Institute of CS at Cardiff. The UK has a golden opportunity to build on our strengths in CS research that will drive innovation across a range of new opto-electronic and power electronic devices. The need arises from a new generation of functional compound semiconductor materials to capture the unique properties of oxide and chalcogenide compound semiconductors (CSs), complementing III-V compounds and silicon, and opening new application areas in optoelectronics, energy and healthcare.
It is proposed that we buy the Aixtron Close Couple Showerhead (CCS) reactor that has been proven to be the reactor design of choice for GaN deposition and will be the ideal equipment to deposit high quality oxide and chalcogenide compound semiconductor materials. "The UK needs this facility, which it does not have at present. Swansea is an excellent place for it." - Prof. Sir Colin Humphreys (Cambridge). "This proposed research facility will perfectly complement the installation of ~100 production MOCVD reactors leveraged by a £375M investment by IQE Plc over 2018-2022" - Dr Wyn Meredith (CSC, Cardiff). The CCS reactor will be installed in a new building for the Centre for Integrated Semiconductor Materials (CISM) (due for completion in Q1 2021) on the Swansea University Bay Campus. Over 140 m2 of specialist materials laboratory space will be allocated to the MOCVD reactor and complementary materials and characterisation equipment from Professor Irvine's laboratory. This new laboratory will be managed by Professor Irvine's team to provide high quality oxide and chalcogenide CSs to our research partners in Swansea University, other UK universities, industrial partners and to international collaborators. This will put the UK at the forefront of new science and technology using oxide and chalcogenide CSs for applications including high efficiency photovoltaic solar cells, Light harvesting quantum wire opto-electronic devices, piezoelectric energy harvesting, high breakdown voltage power electronic devices and light emitters. This new science and technology will benefit EPSRC priorities of "21st Century Products" and "Sustainable Industries" through enabling smart new products that could be rapidly prototyped through well proven manufacturing capability for MOCVD in the UK and enabling the application of more sustainable materials and reduced materials usage. This exciting opportunity is detailed in the case for support.

In addition to the extensive academic stakeholders who will gain access to the MOCVD reactor, there is significant industry interest to take advantage of new developments in oxide and chalcogenide compound semiconductors. The new equipment will be located at the Swansea University Bay Campus where the £90m joint university-industry centre for integrative semiconductor materials (CISM) will be located and linked to the South Wales cluster in compound semiconductors which is driven by the world leading supplier of epitaxial wafers, IQE. The equipment will enable the compound semiconductor cluster to take advantage of developments in new compound semiconductor materials. The preferred manufacturer, Aixtron Ltd have expressed interest in a collaborative R&D programme for this equipment at Swansea to enable development of new materials based on ZnO, MoS2 and Ga2O3. The Swansea team have also established strong international links with companies such as First Solar in the USA where this MOCVD equipment will be essential to further our collaboration on high performance thin film solar cells. We also have significant opportunities with the application of thin film PV materials for ultra-light-weight solar cells for space where we have worked with SSTL and this MOCVD reactor will enable demonstration of higher performance tandem solar cells that will be needed for eventual deployment.
The rapidly growing industrial cluster in compound semiconductors will require a new generation of MOCVD scientists and engineers and the Aixtron CCS MOCVD reactor will provide an excellent training ground because there will be no established recipes, but PhD students and post-doctoral research staff will need to understand the fundamental processes of MOCVD to produce device quality material.
We expect the impact of this equipment to go far beyond the immediate stakeholders and to inspire a new generation in the exciting opportunities in STEM subjects. We will work with professional institutes such as the RSC, IOP and IOM3, with their STEM ambassadors' schemes for outreach to schools across the UK. Publicity material will be produced to explain the exciting properties and opportunities with these new materials and the fascinating science behind the MOCVD process. This outreach will extend to many local communities to raise awareness of world class opportunities on their doorstep. Outreach opportunities exist with The Swansea Festival of Science and the National Eisteddfod where Swansea University have a major exhibition each year and provides a platform to reach a much wider audience.