Electrical, dielectric and interface-state characterization of Al-Doped ZrO₂/p-Si (MOS) structures by sol–gel dip-coating: the role of Al incorporation on barrier height, series resistance and trap passivation
Journal of Materials Science: Materials in Electronics, cilt.37, sa.22, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 37 Sayı: 22
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s10854-026-18206-8
- Dergi Adı: Journal of Materials Science: Materials in Electronics
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Applied Science & Technology Source, Chemical Abstracts Core, Compendex, INSPEC, MEDLINE, Engineering Source (EBSCO), Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Erciyes Üniversitesi Adresli: Evet
Özet
Undoped and Al-doped (1, 5, and 10%) zirconium dioxide (ZrO2) thin films were deposited on p-type Si (111) substrates via a low-cost sol–gel dip-coating route using zirconium(IV) ethoxide and aluminum nitrate precursors. Al/Al:ZrO2/p-Si metal–oxide–semiconductor (MOS) structures were fabricated by the thermal evaporation of Al contacts. X-ray diffraction (XRD) of the undoped film revealed a mixed monoclinic–tetragonal nanocrystalline structure with a dominant tetragonal (101) peak. X-ray diffraction (XRD) analysis of the undoped film revealed a mixed monoclinic–tetragonal nanocrystalline structure with a dominant tetragonal (101) reflection. Because direct structural characterization was not performed on the Al-doped films, possible Al-induced phase stabilization, crystallite-size reduction, and lattice contraction are discussed only as literature-supported mechanisms rather than experimentally demonstrated structural changes. The oxide thickness increased monotonically from 83 nm (undoped) to 103 nm (10% Al) after the oxidation process. Room-temperature current–voltage (I-V) data were analyzed using thermionic emission theory, the Norde function, and two Cheung functions. The energy distribution of the interface state density (Nss) was obtained from the forward I-V data using the Card–Rhoderick effective barrier height formalism: With increasing Al content the ideality factor decreased from 4.55 to 3.39, the zero-bias barrier height increased from 0.620 to 0.778 eV, and Nss at accumulation bias fell from ~ 1.15 × 1013 to ~ 4.2 × 1012 cm−2 eV−1 without any post-deposition passivation. Frequency-dependent capacitance–voltage (C–V) and conductance–voltage (G–V) measurements at 100 and 500 kHz independently confirmed this trend: Al doping reduced the peak conductance by more than one order of magnitude, markedly suppressed C–V frequency dispersion, and lowered the Hill–Coleman trap density by a factor of ~ 4.5. The electrical and dielectric trends are interpreted using a literature-supported model involving possible Al-related modification of oxygen-vacancy and dangling-bond-type defect populations at the oxide/semiconductor interface; however, direct structural and chemical confirmation of this mechanism remains necessary.