Over the past decades Optical Lithography has become increasingly complex and expensive. As a consequence frequency multiplication techniques have been explored and have already been implemented in manufacturing. Directed self-assembly (DSA) based on block co-polymer (BCP) chemistry has been identified as a promising candidate for effective frequency multiplication at very small dimensions. DSA is based on the property of BCP materials to give spontaneous micro-phase separation resulting in lamella, cylinder or sphere type structures. These can be used to define line/space or hole patterns, which are the primary features in chip designs.
Poly(styrene-b-methylmethacrylate) BCP systems have been the work horse for initial DSA studies. However, the resolution of this material is limited to ~25nm pitch due to the relatively low c-value of this system. BCP systems with higher c-values are under development, but much needs to be learned about processing of these systems.
As your main activity, you will work with the DSA flows as implemented at imec and further develop them to make them amenable for high-c material processing. You will also explore how various process parameters influence its performance. After a process meets initial standards you will explore how defects are formed in high-c BCP materials and explore methods for defect reduction. The objective is to determine the parameters that need to be controlled for high fidelity pattern formation. Your work will consist of setting up experiments, running them in our clean room and analyzing the acquired data.
You will work together with a team of lithography specialists within an international environment using advanced tools at the leading edge technology. Also the interaction with the material suppliers for formulation of dedicated DSA chemistries, equipment suppliers for processing or metrology and partnering universities will be part of your work. Your experimental work will be carry out in a modern 300 mm semiconductor cleanroom using the lithography clusters to coat and expose silicon wafers and metrology tools for material characterization. The results of your research will be presented to the imec partners, and are either published at international conferences, in peer reviewed journals or filed for patent.
Chemistry, chemical engineering, nano-technology, materials science.
Type of work:
50% for preparation and execution of experiments, 30% for data analysis, 20% for literature study.
Supervisor: Stefan De Gendt or Guido Groeseneken
Daily advisor: Paulina Rincon
When you apply for this PhD project, mention the following reference code in the imec application form: ref. STS 1704-15.