Research Projects

• Rationale of the research Some recent literature reports indicate the amazing potential of inorganic resists for advanced lithography. More importantly, India is focusing on establishing fab line for advanced electronic chip fabrication. Hence, given the rapid growth in photoresist market, development of sensitive and scalable inorganic resists is an emerging area with a lot of room for scientific and technological innovation. • Hypothesis and scientific objectives The present proposal aims to innovate through the development of bi-functional inorganic photoresists for sub-12 nm dense patterning using lithography tools including electron beam, helium ion beam and extreme ultraviolet lithography. Next, we aim to optimize the lithography process for energy-efficient edge computing and fabricating devices for strategic needs. • Main experiments to be carried out The proposal is formulated with the following two functions: Function 1: Inorganic resists for lithography patterning 1st Approach: Soluble molecular cages clusters containing many organometallic metal centres. Our approach would be to tune the structural features of the cages/clusters through appropriate organic linkers bearing suitable functionality. We already have got some interesting preliminary results with novel tin-clusters. 2nd Approach: We recently patented an approach for mitigating the issue of film shrinkage of inorganic resists through introduction of robust matrix into resist composition. However, the sensitivity of the composition was still on lower side. Our recent preliminary results indicate that the structure tuning of the matrix as well as inorganic components may improve the sensitivity. The matrix design will focus on bulky molecular systems bearing polymerizable units at the periphery. 3rd Approach: N-Heterocyclic carbene (NHC) based organometallic molecular and macromolecular species have rarely been explored as photosensitive inorganic resist compositions. We have designed a number of NHC-based organometallic species which we believe will show good solubility and would be interesting inorganic resists for nanopatterning. Resist formulation, thin film and lithography: Following parameters will be considered: surface levelling agent, under layer treatment, macroscale and nanoscale defects, quality of thin film, pre-exposure bake, film stability, spin time, spin speed, film uniformity, exposure dose, post-application bake, developer selection, developing time, pattern inspection. • An estimate of the significance to the field of research Resist compositions with the following properties:  Thin film: 15-20 nm  EBL sensitivity: 50 µC/cm2  EUVL sensitivity: 20-30 mJ/cm2  Resolution: 12 nm or below dense features Function 2: Exploration of developed resist for device applications • Devices This research focuses on developing bifunctional inorganic resists integrated with ultra-thin high-k dielectric layers for energy-efficient and edge computing applications. These hybrid materials will serve dual roles: enabling high-resolution patterning through advanced lithography techniques and functioning as high-performance dielectric insulators. The use of high-k dielectrics may address the key challenges in traditional semiconductor materials such as SiOx by allowing thinner gate insulators, reducing power consumption, and minimizing gate leakage. High-k dielectrics support neuromorphic computing by enabling efficient modulation of synaptic weights and stable resistance switching in memristors, mimicking biological synapses. The proposed fabrication process uses a bottom-gate-top-contact (BGTC) structure on glass substrates, involving sequential steps for gate, insulator, semiconductor, and electrode patterning. Electrical characterization of the fabricated TFTs will extract parameters like mobility, threshold voltage, subthreshold swing, and ON/OFF current ratio. The developed resists will be used for space-worthy device fabrication at SAC.