A Study Of Biased Target Ion Beam Deposited Dielectric Oxides

Open Access
Author:
Aronovich, Felix
Area of Honors:
Engineering Science
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Mark William Horn, Thesis Supervisor
  • Bernhard R Tittmann, Honors Advisor
  • Judith A Todd, Faculty Reader
Keywords:
  • Biased Target Ion Beam Deposition
  • Dielectric oxides
  • I-V
  • TFT
Abstract:
Biased Target Ion Beam Deposition (BTIBD) is a novel sputtering system that combines ion-beam deposition and sputtering deposition. This work investigated the deposition of silicon dioxide (SiO2) and hafnium dioxide (HfO2) for micro-electronic purposes. This is the first report examination of dielectric oxides deposited using the BTIBD. The purpose of this study was to find an optimal “recipe” for the deposition of the aforementioned thin-films. As low temperature sputtering of dielectric oxides is important for thin-film-transistors and in display applications, there exists a need for this kind of sputtering method. The following parameters of sputtering were investigated: target voltage, oxygen flow method, oxygen partial pressure, gun voltage and deposition time. In addition, different post deposition anneals were carried out to study their effect on the quality of the oxides. The characterization techniques included ellipsometry (thickness and refractive index measurements) and formation of metal oxide semiconductor (MOS) capacitors for the evaluation of leakage current densities. The as-deposited silicon dioxide films demonstrate a leakage current density of 1x10-5 A/cm2 (reported at 2 MV/cm) and dielectric breakdown in the ranges of 9-12 MV/cm. Oxygen annealed SiO2 films demonstrate leakage current density of 2.7x10-9 A/cm2 (at 2MV/cm) with a breakdown field of 12 MV/cm. HfO2 leakage current density was measured to be 7.7 x 10-8 A/cm2 (at 2 MV/cm) after a rapid thermal anneal in oxygen.