PhD

Process Technology

• Ge and III-V CMOS scaling
• Post-CMOS nano
• Reliability research at imec
• Memories
• Power devices
• GaN Power Converters
• Nanoscale properties of new materials for emerging memory de
• Ion-solid interactions
• Probing semiconductor devices on the atomic scale
• Packaging and interconnection
• SiGe-based MEMS
• RF-MEMS
• Advanced lithography
• Simulation of wafer plating uniformity
• Superfilling of 3D via structures with alternative metals
• Diamond bit cutting for metal bonding

Probing semiconductor devices on the atomic scale

Advanced concepts such as vertical transistors, SOI-based devices (gate all-around, dual gate,…) as well as deep submicron devices (70, 50, 35 nm…) can be viewed as the technology of the next 5-10 years. They all involve extremely complex processing and detailed engineering of the dopant distributions and use short time anneals, laser activation, outdiffusion from silicides, selective epi-growth as technological processes to cope with the demands of ultra shallow junctions, extremely high activation, controlled underdiffusion etc.. Unfortunately most of these processes are not very well understood and their description/ incorporation in process simulators is rather primitive. The latter has led to a strong need for characterization of these distributions in 1,2, (3) dimensions with extreme spatial resolution (< 1 nm?), sensitivity and quantification accuracy. Techniques emerging for these applications are based on Atomic Force Microscopy (Scanning Capacitance Microscopy, Scanning Spreading Resistance Microscopy, Nanopotentiometry, Conductive tunneling AFM,..) and Transmission Electron Microscopy. Each of these techniques represents a potential route towards satisfying the industrial needs but at the same time contains numerous challenges with respect to their fundamental aspects and basic understanding, practical implementation, data interpretation and impact on our basic understanding of process technology. Research topics suited for a Ph.D-thesis are related to the development of these concepts and encompass:

• fundamental studies of nm-sized point contacts (based on heterojunctions such as doped diamond/Si),
• basic modeling of the various measurement concepts (calculations of 2/3D-current or field, capacitance or potential distributions),
• basic studies of interaction mechanisms (how does a nm-sized point contact influence the potential distribution when one is imaging the potential distribution on an operational device),
• development and implementation of concepts such as force/time multiplexed AFM-measurements and their interpretation,
• development of a (Si-micromachining) based technology to fabricate AFM-tips with nm-sized contacts using doped diamond and extremely hard metals (including challenging concepts such as a dual probe/cantilever system) and
• basic studies of electron holography (TEM).

Responsible scientist: Wilfried Vandervorst