Remote Plasma Atomic Layer Deposition of SiNx Using Cyclosilazane and H2/N2 Plasma

Abstract

Silicon nitride (SiNx) thin films using 1,3-di-isopropylamino-2,4-dimethylcyclosilazane (CSN-2) and N2 plasma were investigated. The growth rate of SiNx thin films was saturated in the range of 200–500 °C, yielding approximately 0.38 Å/cycle, and featuring a wide process window. The physical and chemical properties of the SiNx films were investigated as a function of deposition temperature. As temperature was increased, transmission electron microscopy (TEM) analysis confirmed that a conformal thin film was obtained. Also, we developed a three-step process in which the H2 plasma step was introduced before the N2 plasma step. In order to investigate the effect of H2 plasma, we evaluated the growth rate, step coverage, and wet etch rate according to H2 plasma exposure time (10–30 s). As a result, the side step coverage increased from 82% to 105% and the bottom step coverages increased from 90% to 110% in the narrow pattern. By increasing the H2 plasma to 30 s, the wet etch rate was 32 Å/min, which is much lower than the case of only N2 plasma (43 Å/min).

Review—Silicon Nitride and Silicon Nitride-Rich Thin Film Technologies: State-of-the-Art Processing Technologies, Properties, and Applications

“…Front-end-of-line (FEOL) portion of IC device manufacturing Gate spacers in DRAM and logic devices, charge trap layer in NAND flash devices Cho et al 28 Glow discharge ALD IC devices Silicon-nitrogen nanostructures Ezhovskii et al 72 Thermal and PE-ALD DRAM devices, 3D-NAND flash devices, FinFETs Spacers in DRAM, charge trap layers in 3D-NAND devices, gate spacers in FinFETs, stoppers in (CMP) in a self-aligned multiple patterning process when forming fins in FinFETs Ovanesyan et al 73 Table V. Summary of recent sputtered SiN x work.…”

“…18,41,67,70 • Gate spacers and sidewall spacers in DRAM. 28 • Charge trap layers in 3D-NAND flash devices. 73 2.…”

“…27 • In the second report, CSN-2 was employed in a three-step remote plasma ALD (RP-ALD process consisting of: (i) CSN-2 pulsing step, (ii) H 2 plasma pulsing step, and (iii) N 2 plasma pulsing step. 28 The authors argue for the use of H 2 plasma due to the fact that N radicals exhibit an exceptionally short lifetime vs H radicals and/or O radicals. As a result, recombination loss occurs, and ligands are not completely removed from the adsorbed precursor, leading to deterioration in film quality.…”

Silicon Nitride and Hydrogenated Silicon Nitride Thin Films: A Review of Fabrication Methods and Applications

“…In these processes, the thin film is formed on the substrate by atomic layers using chemical reactions in the gas atmosphere. For the deposition of SiNx thin films that are thermal [ 32 , 33 , 34 ], plasma-assisted (PA), and plasma-enhanced (PE) [ 35 , 36 , 37 , 38 ], ALD are the method most often used. Considering the growing scientific interest ALD methods are receiving in recent years, we discuss them separately from other CVD methods.…”

Role of an Al2O3 Passivation Layer during Annealing of 2D-SnS2 Thin Films Grown by Atomic Layer Deposition

“…Recently, adding more steps have also been used to deposit ternary or quaternary compunds, so called ALD super-cycle. 39,40 We used tetrakis (dimethylamino) tin (TDMASn; [(CH 3 ) 2 N] 4 Sn) as a Sn source and H 2 S gas as a S source to deposit SnS 2 thin films. The durations of T 1 , T 2 , T 3 , and T 4 were 1 s, 40 s, 3 s, and 50 s, respectively.…”