Plasma-Assisted Atomic Layer Deposition of High-Density Ni Nanoparticles for Amorphous In-Ga-Zn-O Thin Film Transistor Memory

Abstract

For the first time, the growth of Ni nanoparticles (NPs) was explored by plasma-assisted atomic layer deposition (ALD) technique using NiCp2 and NH3 precursors. Influences of substrate temperature and deposition cycles on ALD Ni NPs were studied by field emission scanning electron microscope and X-ray photoelectron spectroscopy. By optimizing the process parameters, high-density and uniform Ni NPs were achieved in the case of 280 °C substrate temperature and 50 deposition cycles, exhibiting a density of ~1.5 × 1012 cm−2 and a small size of 3~4 nm. Further, the above Ni NPs were used as charge storage medium of amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistor (TFT) memory, demonstrating a high storage capacity for electrons. In particular, the nonvolatile memory exhibited an excellent programming characteristic, e.g., a large threshold voltage shift of 8.03 V was obtained after being programmed at 17 V for 5 ms.

Atomic Layer Deposition of Ni-Co-O Thin-Film Electrodes for Solid-State LIBs and the Influence of Chemical Composition on Overcapacity

“…The spectrum for Ni2p ( Figure 1 b) was complex because of the significant overlap of the Ni3d and O2p orbitals, resulting in broad peaks with multiple satellite peaks [ 59 , 60 , 61 ]. However, the shape and position of the maxima showed that all the samples under study contain NiO (854.1 eV) and Ni +3 (Ni 2 O 3 and/or Ni 3 O 4 ), or nickel hydroxide—Ni(OH) 2 .…”

Superior Atomic Layer Deposition Technology for Amorphous Oxide Semiconductor Thin-Film Transistor Memory Devices

“…By means of plasma ALD, high-density Ni nanocrystals were also successfully obtained using NiCp 2 and NH 3 precursors . Similarly, it is demonstrated that the substrate temperature and deposition cycles significantly affect the areal density and size distribution of Ni nanocrystals.…”

“…This is attributed to some key advantages of metal nanocrystals, including a higher density of states around its Fermi level, stronger coupling with the semiconductor conducting channel, a freer selection of metal work function, and smaller energy perturbation because of the carrier confinement effect . Therefore, various metal nanocrystals have been investigated as charge storage mediums for the Si-based flash memory and AOS TFT memory applications, including Ru, Pt, Ni, and Au nanocrystals, etc. ,,,− To obtain metal nanocrystals, different preparation methods can be used, which are roughly classified into colloidal suspension, direct deposition, and ALD. The first one is a chemical wet process, usually being utilized for catalyzers.…”

“…In addition, the sputtering process likely gives rise to underlying surface damage because of energetic particle bombardment, and it is also hard to achieve good spatial controllability for the ion implantation technique, especially for two-dimensional growth of nanocrystals. The ALD technique is the most promising because it can be used to directly grow high-density metal nanocrystals on a solid surface at relatively low temperatures of <350 °C. , For example, Ru nanocrystals can be deposited at 330 °C by thermal ALD with bis­(cyclopentadienyl)ruthenium (RuCp 2 ) and O 2 precursors, exhibiting an areal density of 9 × 10 10 cm –2 on the surface of ALD Al 2 O 3 film. Meanwhile, it is found that surface chemistry on a substrate plays a key role in the deposition of Ru nanocrystals; that is, much denser Ru nanocrystals are deposited on the ALD Al 2 O 3 film than the thermal SiO 2 film, as shown in Figure a and b.…”

Δομή μη πτητικής μνήμης MOS με μεταλλικούς νανοκρυστάλλους ανοπτημένους με laser

“…Όλες αυτές οι παγίδες δρουν σαν μονοπάτια διαρροής για να διαφύγουν εύκολα τα φορτία [11,14,77,99]. Παρόμοια αποτελέσματα έχουν αναφερθεί για πυκνωτές MOS που περιέχουν είτε μεταλλικούς [109,110,111,112] είτε ημιαγώγιμους [113,114,115,116,117] νανοκρυστάλλους. Για να διερευνηθούν και να διαφοροποιηθούν οι επιδράσεις της διεργασίας ανόπτησης με laser χαμηλής εκπομπής (Low Emission-Excimer Laser Annealing, LEM-ELA) σε νανοκρυστάλλους χρυσού και σε παγίδες στο οξείδιο, υιοθετήθηκε μια ανάλυση βασισμένη στην εκφόρτιση, σύμφωνα με παρόμοιες αναλύσεις που αναφέρονται σε παραπλήσιες δομές [11,14].…”