Memory functions of nanocrystalline cadmium selenide embedded ZrHfO high-k dielectric stack

Journal Article · Fri Feb 28 00:00:00 EST 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4867215· OSTI ID:22277972

Lin, Chi-Chou; Kuo, Yue ^[1]

---

1. Thin Film Nano and Microelectronics Research Laboratory, Artie McFerrin Department of Chemical Engineering, Texas A and M University, College Station, Texas 77843-3122 (United States)

Metal-oxide-semiconductor capacitors made of the nanocrystalline cadmium selenide nc-CdSe embedded Zr-doped HfO{sub 2} high-k stack on the p-type silicon wafer have been fabricated and studied for their charge trapping, detrapping, and retention characteristics. Both holes and electrons can be trapped to the nanocrystal-embedded dielectric stack depending on the polarity of the applied gate voltage. With the same magnitude of applied gate voltage, the sample can trap more holes than electrons. A small amount of holes are loosely trapped at the nc-CdSe/high-k interface and the remaining holes are strongly trapped to the bulk nanocrystalline CdSe site. Charges trapped to the nanocrystals caused the Coulomb blockade effect in the leakage current vs. voltage curve, which is not observed in the control sample. The addition of the nanocrystals to the dielectric film changed the defect density and the physical thickness, which are reflected on the leakage current and the breakdown voltage. More than half of the originally trapped holes can be retained in the embedded nanocrystals for more than 10 yr. The nanocrystalline CdSe embedded high-k stack is a useful gate dielectric for this nonvolatile memory device.

• OSTI ID: 22277972
• Journal Information: Journal of Applied Physics, Vol. 115, Issue 8; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
CADMIUM SELENIDES
CAPACITORS
CRYSTALS
DIELECTRIC MATERIALS
DOPED MATERIALS
ELECTRIC POTENTIAL
ELECTRONS
HAFNIUM OXIDES
HOLES
INTERFACES
LEAKAGE CURRENT
NANOSTRUCTURES
P-TYPE CONDUCTORS
SILICON
THIN FILMS
TRAPPING
ZIRCONIUM COMPOUNDS