Correlating Local Defects to Global Wafer Properties in Next Generation Semiconductor Platforms

Societal recognition of the criticality of semiconductor-technology arises from national initiatives, public debate around sovereign supply and the central role of the sector in delivering net zero. This joint Leeds-Swansea University PhD project in collaboration with Industry partners (Tescan, the National Physics Laboratory and the companies of the South Wales CSconnected Cluster) will focus on characterising semiconductors at the wafer-scale using new advanced electron microscopy capabilities.

It will investigate defects, interfacial epitaxies, doping profiles/distributions and lateral uniformities in devices and seeks to correlate these defects with reliability and failure modes, so developing metrology methods and enhancing data integration.

This studentship will be part of an exciting new Doctoral Training Initiative called UK Semiconductor Industry Future Skills or UK-SIFS for short. UK-SIFS will provide valuable and highly practical skills of substantial relevance to the UK semiconductor industry such as formal cleanroom fabrication training, vacuum systems maintenance and operation, process control (six sigma) in semiconductor manufacturing, semiconductor supply chains and export control, semiconductor packaging, and technology translation in the semiconductor sector.

The Initiative will create two cohorts of students in 2024 and 2025 across Swansea University and the University of Leeds and is a collaboration between the two universities, the Royce Institute, and industry partners such as KLA, QinetiQ, IQE, NSG Pilkington, Renishaw, Edwards Vacuum, Space Forge, Paragraph, Tescan, Vishay Maxpower, National Physical Laboratory, Paragraf and many others. Our partners will co-deliver the DTI training content, plus co-supervise PhD research projects, plus there will also be a programme of secondments at industry partner sites.

UK-SIFS provides not only the considerable benefits of research training and collaboration across a multidisciplinary cohort working in areas such as power electronics, clean energy, bioelectronics and sensing, THz devices, optoelectronics, molecular semiconductors, quantum technology, electronic glass and advanced heterogeneous integration, but is also a unique opportunity for those students who may want to connect closely with the semiconductor and related industries for their PhD and aspire to be the future leaders of the sector in the UK and beyond.

This project is equipment intensive in terms of the use of the Electron Microscopy and Cleanroom Facilities at both Leeds and at Swansea. Of particular importance are the new Leeds Nanotechnology Cleanroom, the adjacent Royce Institute multi-chamber materials deposition system, III-V semiconductor MBE growth facilities, as well as extensive microscopy and materials characterisation capabilities including Leeds Electron Microscopy and Spectroscopy (LEMAS) Centre.

In a collaboration with a European instrument manufacturer TESCAN, the LEMAS Centre are currently testing a new electron microscope (one of only two in the world) - a dedicated scanning transmission electron microscope (STEM) capable of chemical mapping and combined diffractive imaging (so called 4D STEM) at the nanometre scale. This allows the detailed correlated imaging and mapping of crystal structure and strain (measured by electron diffraction) and its relationship to variations in chemical composition (measured by X-ray spectroscopy) in nanostructured materials and devices.

This information allows to understand how the fabrication and subsequent processing of semiconductor materials is linked to the ultimate functional properties of the device.