Thermally Annealed Molecular Layer‐Deposited Indicone: Structural Analysis and Area Selective Deposition Application

Abstract

A half pitch can be decreased by increasing numerical aperture (N.A.), immersion lithography, decrement of the k-value, and multiple patterning using an ArF source. [2] However, since the remaining ArF source for lithography dramatically increases the cost of device fabrication, lithography using an extreme ultraviolet (EUV) source was introduced for high volume manufacturing. However, a number of requirements including a pellicle, photoresist (PR), and numerical aperture for the EUV process have to be developed. In addition, as the device structure becomes smaller and more complicated, the number of vias exceeds billions and the probability of failure during the top-down process for device fabrication increases. Area selective deposition (ASD) as a bottom-up process is a patterning method used to deposit a thin film only in a desired area, which can complement the disadvantages of the topdown process by simplifying the process, attaining errorless alignment, increasing yield, and reducing the cost and probability of failure. [3] In the manufacturing process of semiconductor devices, a number of ASD processes have been devised such as self-aligned gate, contact and via, fully self-aligned via (FSAV), and self-aligned blocking.For realizing a bottom-up process, area selective atomic layer deposition (AS-ALD) has been researched vigorously using chemistry. [4] The ALD process has principles based on the surface chemistry. [5] At least two kinds of precursors are sequentially injected to the reactor and form a monolayer via a self-limited reaction. The precursors chemically adsorb and react on the functional groups of the surface, generating a thin film with repeated cycles. Because of the self-limiting reaction and surface reaction, the ALD process is advantageous for depositing a conformal and uniform film over 3D structures and a large area, exhibiting excellent thickness control on the nanoscale, and allowing various kinds of thin films such as metals, oxides, nitrides, and sulfides. The film growth through ALD depends on the surface chemistry, where the characteristic chemical reaction occurs with a specific chemical state of the surface. In other words, AS-ALD can be induced by modulating the precursors, reactants, surface constitution, and functional groups of the surface. [6] However, it is still deliberated how ASD should be employed during the production of semiconductor devices in thousands of processes.Semiconductor devices have become smaller, more complicated, and structuralized in three dimensions. Area selective deposition is one of the promising bottom-up process techniques for self-alignment or improved overlay to achieve errorless alignment. The surface chemistry is crucial to adjust precursor adsorption. In this research, graphitic carbon fabricated by molecular layer deposition is utilized for inhibiting precursor adsorption. An indicone film, which has an indium-based metalcone structure, is fabricated using bis(trimethysily)-amidodiethylindium and hydroquinone. The structure of the indicone ...

Review of molecular layer deposition process and application to area selective deposition via graphitization

“…When the HOPG surface, manufactured by the annealing of aromatic metalcone was exposed to H 2 O, the energy diagram of reaction site formation due to adsorption could be calculated using DFT calculations, as shown in Figs. 10(a)-10(b) 174) The states of various surface defects that were generated on the HOPG surface were reviewed. The activation energy increased under the states of single vacancies (SV) and Stone-Wales (SW) defects, and perfect graphene (PG) flakes in an ideal state were compared.…”