Thin-Film Ga₂O₃ for Next Generation Deep-UV Sensing

Solar-blind deep-UV (λ < 280 nm) photodetectors enable emerging applications such as flame monitoring, sterilization process control, and label-free surface inspection. Realizing compact and scalable deep-UV imaging systems, however, requires semiconductor technologies that combine intrinsic solar-blind sensitivity with compatibility with large-area manufacturing. Gallium oxide (Ga₂O₃, Eg ≈ 4.4-5.3 eV depending on crystalline structure and doping) is an ultra-wide-bandgap semiconductor that has recently emerged as a promising platform for this purpose. In particular, room-temperature sputtered Ga₂O₃ enables filter-free solar-blind response on a wide variety of substrates, including sapphire, Si/SiO₂, glass, and flexible foils. This PhD aims to establish a CMOS-compatible Ga₂O₃ technology platform and demonstrate fast, low-dark-current photodiodes, ultimately leading to one of the first integrated solar-blind micro-imagers based on sputtered Ga₂O₃. The resulting devices could enable compact UV imaging systems for industrial, environmental, and safety-critical applications operating in harsh and radiation-rich environments.
 

Topic

This PhD is strongly experimental and offers extensive hands-on experience in thin-film deposition, semiconductor device fabrication, and advanced optoelectronic characterization. The successful candidate will develop sputtered Ga₂O₃ thin films using CMOS-compatible processes and investigate how thickness, annealing, crystallinity, and intentional doping influence key detector metrics such as responsivity, dark current, rejection ratio, and response speed. Building on these materials, the candidate will design, fabricate, and characterize solar-blind photodiodes using imec's state-of-the-art microfabrication facilities. Optimized device stacks and DUV-transparent top contacts will be developed to achieve high performance and reliability under UV exposure and harsh environmental conditions.
 

Beyond individual photodiodes, the project will culminate in application-oriented demonstrators, including flame detection and a first integrated deep-UV imaging system. This offers a rare opportunity to contribute to a technology spanning the entire innovation chain, from materials development and device fabrication to functional imaging systems. The candidate will collaborate closely with imec experts in thin-film materials, semiconductor processing, reliability, and ROIC design, leveraging world-class cleanroom and characterization facilities to achieve ambitious targets in dark current, responsivity, rejection ratio, and bandwidth, while charting a path toward BEOL-compatible integration.
 

The candidate

We are looking for a curious and motivated PhD researcher who enjoys hands-on experimentation and is excited by the prospect of developing next-generation optoelectronic technologies. You hold a Master's degree in semiconductor physics, electrical engineering, materials/nano-engineering, or a related field. You are eager to deepen your expertise in thin-film optoelectronic devices and enjoy working at the intersection of materials science, device physics, and semiconductor technology. Interest in semiconductor processing, thin-film deposition, optoelectronic devices, or electrical and optical characterization is highly valued. Whether your background is primarily in materials, devices, fabrication, characterization, or modeling, you are enthusiastic about learning new skills and applying them to cutting-edge research.

You combine a hands-on mindset with creativity in problem solving and data analysis. You communicate clearly, enjoy collaborating in a multidisciplinary and multicultural environment, and are motivated to present and discuss your work with both academic and industrial partners. Given the international character of imec, an excellent command of English is required