About Plessey
We’re building the hardware foundation for next-era computing.
Plessey is a world-leading technology company driving the next generation of photonic devices and systems. With over 70 years of innovation, we combine research, materials science, process engineering, and manufacturing under one roof. We’re recognised as a global authority in microLED displays, optical computing, and optical interconnects.
Join us to work on breakthrough technologies shaping the future of light-based technology and computing.
Our values
Lead
We don’t follow industry trends; we create them, pushing boundaries and setting standards others aspire to. Every team member has the power to make decisions, drive change, and deliver excellence. We support each other, challenge one another for the best solutions, and lead by example. Together, we build industries and technologies that shape the future and scale toward our vision of the next era of computing.
Grow
We expand our capabilities every day — deepening our expertise, improving how we work, and pushing the boundaries of what’s possible. Curiosity fuels us: we question assumptions, explore new ideas, and innovate with light-based technologies. By investing in and empowering our people, we strengthen Plessey’s impact and help shape the future of optical technology.
Trust
We operate like a family—honest, reliable, and supportive. We have each other’s backs, own our actions, and uphold the highest standards of integrity and safety. We trust each other to deliver, our customers to challenge us, and our expertise to guide the way. Together, trust enables the collaboration essential for breakthrough innovation and lasting impact.
Location
Located at our head office and state-of-the-art fabrication facility in Plymouth.
About the Role
The Thin Film Ellipsometry Process Engineer is responsible for developing, optimising, and controlling thin-film optical measurement and characterisation processes to support high-yield, high-performance semiconductor device fabrication. This role focuses on ellipsometry-based metrology for deposited thin films across development and production environments.
Key Responsibilities
* Develop, qualify, and optimise ellipsometry measurement processes for thin films (thickness, refractive index n/k, composition, and uniformity).
* Support R&D and new materials development by providing accurate thin-film characterisation, measurement development, and data analysis.
* Own and maintain ellipsometry process recipes, optical models, and control strategies.
* Provide accurate metrology feedback to thin-film deposition processes (e.g., PVD, CVD, ALD).
* Analyse film properties including thickness mapping, optical constants, and process-induced variation.
* Develop and refine optical models for multilayer thin-film stacks.
* Utilise statistical process control (SPC) to monitor tool performance and process stability.
* Conduct root cause analysis for measurement drift, model instability, or yield excursions related to film properties.
* Collaborate with equipment and process engineering teams to maintain and improve metrology tool performance.
* Support new product introduction (NPI) through film characterisation, DOE planning, and process transfer.
* Generate technical reports and present findings to engineering and management teams.
* Ensure compliance with safety and cleanroom protocols.
Skills, Knowledge and Expertise
* Bachelor’s or Master’s degree in Materials Science, Physics, Electrical Engineering, or related field.
* 3–7+ years of experience in semiconductor or advanced thin-film processing environments.
* Strong hands-on experience with spectroscopic ellipsometry.
* Solid understanding of thin-film optics, dispersion modelling, and multilayer analysis.
* Experience correlating ellipsometry data with complementary techniques (e.g., XRD, AFM, profilometry).
* Strong data analysis and problem-solving skills.
* Strong ownership mentality with the ability to work independently in a fast-paced environment.
* Adaptable and comfortable with evolving priorities and rapid change.
* Excellent cross-functional collaboration skills (working effectively with process, equipment, R&D, and manufacturing teams).
* Clear and confident communicator, able to present technical findings to both technical and non-technical audiences.
* Experience with compound semiconductor or dielectric thin films would be an advantage.