Comparative study on atomic layer deposition of HfO₂via substitution of ligand structure with cyclopentadiene

Abstract

Theoretical and experimental studies were investigated on the growth characteristics and electrical properties of HfO2 films using Hf(N(CH3)2)4 and CpHf(N(CH3)2)3.

High-Throughput Growth of HfO2 Films Using Temperature-gradient Laser Chemical Vapor Deposition

“…To improve the measurement accuracy, the HfO2 film was divided into eight specimens fabricated at 1250-1600 K using a single growth process. The Rdep of the HfO2 film prepared by HT-LCVD reached a maximum of 362 μm/h at Tdep = 1600 K, which was 10 2 -10 4 times higher than that obtained using existing methods, such as MOCVD [9][10][11], TCVD [12] and ALD [13][14][15][16][17]. Using the infrared temperature-measurement program, the microstructure of the HfO2 film was found to change from columnar to cluster-like at approximately 1420 K. A phase transition temperature above 1300 K was measured at atmospheric pressure [6].…”

“…announced that HfO2, a high-k inorganic material with an ultrahigh melting point (3085 K) [5], a sufficient electrical breakdown field (3.9-6.7 MV/cm) [6], low thermal conductivity (~2.55 W•K -1 •m -1 ), and four times the density (9.68 g/cm 3 ) of SiO2 (2.26 g/cm 3 ) [7], as the most promising dielectric layer material to replace the traditional SiO2 layer for a new generation of supercomputers [8]. for HfO2 films grown using different methods, such as metal-organic CVD (MOCVD) [9][10][11], thermal CVD (TCVD) [12], atomic layer deposition (ALD) [13][14][15][16][17], sol-gel [18][19][20], radio frequency magnetron sputtering (RFMS) [21] and pulsed laser deposition (PLD) [22]. As a result of the extremely low deposition rate of HfO2 films, only a few scholars have studied the growth of films with thicknesses below 100 nm over the last decade, such that HfO2 films have not been exploited at the micron scale.…”

Recent Advances in Theoretical Development of Thermal Atomic Layer Deposition: A Review

“…Another study used DFT to design an aluminum ALD precursor by substituting one methyl in TMA and se- [166] compared two different hafnium precursors for ALD. DFT was used to predict that the cyclic precursor would result in a lower growth rate compared with the alkylamide precursor due to the low probability of final chemical adsorption of the bulky cyclic ligand on the surface [166]. When a decision needs to be made between two similar precursors, DFT can be used to compare different ALD precursors without performing any experiments.…”

“…They proposed a Cu-based reducing agent in case a co-deposition happened, which would be desirable as copper was still deposited [ 48 ]. In addition to Cu ALD [ 48 , 75 , 174 ], other materials have been studied through DFT, e.g., platinum [ 148 ], aluminum oxide [ 76 , 146 , 147 ], hafnium oxide [ 74 , 166 , 167 ], titanium oxide [ 77 , 169 ], and zirconium oxide [ 80 , 171 ]. Another study used DFT to design an aluminum ALD precursor by substituting one methyl in TMA and selectively decorating Pt nanoparticles by AlO x via ALD [ 76 ].…”

“…Yang et al [ 76 ] showed that dimethylaluminum isopropoxide (DMAI) could be used as an ALD precursor, and they predicted the decomposition mechanism of DMAI with DFT [ 76 ]. Recently, Park et al [ 166 ] compared two different hafnium precursors for ALD. DFT was used to predict that the cyclic precursor would result in a lower growth rate compared with the alkylamide precursor due to the low probability of final chemical adsorption of the bulky cyclic ligand on the surface [ 166 ].…”