6533b838fe1ef96bd12a4cd8

RESEARCH PRODUCT

Innovative electronic lithography using self-assembly films in order to modify material surfaces at nanometric scale

subject

description

The concept of electon beam decomposition has been developed in order to create smaller patterns than those achieved by conventional lithographic methods. This work aimed to go further about this concept through a separation of the involved mechanisms in order to better understand them and thus reach a better control of process.A device was designed and a protocol was defined where the first stage is the adsorption at cryogenic temperature of metal-carbonyl compounds. The adsorbate is then decomposed by a focused electron beam and fragmentation residues are removed through annealing allowing the deposit reorganization. The study of the different steps of the elaboration method was followed through the "surface science" approach because such a way offers the opportunity to study the processes involved by analytical techniques sensitive to material chemistry.Thus, this work has highlighted that the adsorption at cryogenic temperature of Mo(CO)6 and W(CO)6 on metal or oxide surfaces does not induce any significant changes in their molecular structure demonstrating that this step is reversible. Moreover, it was shown that low energy electrons ( <150 eV ) cause dissociation of these molecules by a one-electron process. Moreover, it is possible to decompose adsorbed molecules with a focused electron beam, leading to the formation of a stable deposit at room temperature. Annealing treatment can complete the decomposition. Besides, the final morphology is related to the electron dose as well as the initial amount of adsorbed molecules.