Boosted growth rate using discrete reactant feeding method and novel precursor of indium oxide by atomic layer deposition

Abstract

This paper proposes the introduction of a novel Pentylcyclopentadienyl indium(I) precursor, named PeCpIn, which remains in a liquid state at room temperature. Alongside introducing the new precursor, we propose a different deposition method called the 'Discrete Reactant Feeding (DRF)' method, distinct from the conventional single reactant feeding (SRF) method. Through the new DRF method, In2O3 films exhibited an exceptionally high growth rate exceeding 2.2 Angstroms/cycle over a broad temperature range of 200–400 ℃, in contrast to the 1.3 Angstroms/cycle of the traditional SRF method. The In2O3 films produced by the DRF method showed negligible low carbon impurities detected by XPS below the detection limit at all temperatures, achieving high-quality In2O3 films with an O/In ratio close to ideal In2O3. Due to the unique mechanism of DRF, consistent crystallinity, low oxygen defects, and few hydrogen impurities below 1% were observed at all temperatures. Additionally, the high step coverage of over 95%, demonstrated in trench structures with a high aspect ratio of 40:1, underscores the suitability of In2O3 films produced using the DRF method for application in the semiconductor industry.