Investigation of the gate oxide leakage current of low temperature formed hafnium oxide films

Verrelli, E.; Tsoukalas, D.

Abstract

In this work, low temperature physically deposited hafnium oxide films are investigated in terms of their electrical properties through measurements and analysis of leakage currents in order to understand the defects behavior in this dielectric material. Two extreme conditions will be presented and discussed: the first one concerns the use of a nearly trap-free hafnium oxide layer, while the second one concerns the use of a hafnium oxide film with a very large amount of electrically active traps. Particular emphasis is given to the detection and comparison of the shallow and deep traps that are responsible for the room temperature leakage of these films. It is shown that by modifying the amount of traps in the hafnium oxide layer, achieved by changing the deposition conditions, the traps energy location is heavily influenced. The nearly trap-free sample exhibits Ohmic conduction at low fields (with activation energies in the range 16-33 meV for low temperatures and 0.13-0.14 eV for higher than ambient temperatures), Poole-Frenkel conduction at high fields (trap depth in the range 0.23-0.38 eV), while at low temperatures and high fields, the Fowler-Nordheim tunneling is identified (estimated barrier height of 1.9 eV). The charge-trap sample on the other hand exhibits Ohmic conduction at low fields (activation energies in the range 0.26-0.32 eV for higher than ambient temperatures), space charge limited current conduction at intermediate fields (exponent n 3), while at high fields the Poole-Frenkel conduction appears (trap depth in the range 1.63-1.70 eV). © 2013 American Institute of Physics.

Citation

Verrelli, E., & Tsoukalas, D. (2013). Investigation of the gate oxide leakage current of low temperature formed hafnium oxide films. Journal of applied physics, 113(11), Article 114103. https://doi.org/10.1063/1.4795278

• Journal Article Type: Article
• Acceptance Date: Feb 28, 2013
• Online Publication Date: Mar 18, 2013
• Publication Date: Mar 21, 2013
• Deposit Date: Apr 1, 2022
• Journal: Journal of Applied Physics
• Print ISSN: 0021-8979
• Publisher: American Institute of Physics
• Peer Reviewed: Peer Reviewed
• Volume: 113
• Issue: 11
• Article Number: 114103
• DOI: https://doi.org/10.1063/1.4795278
• Public URL: https://hull-repository.worktribe.com/output/700992