Structural and Electrical Properties of Nanocrystalline Diamond Based Barium Strontium Titanate Varactors


Venkataramanan Gurumurthy, Sathyaharish Jeedigunta, Sam Baylis, Priscila Spagnol, John Bumgarner, Ashok Kumar & Thomas Weller (2008) Structural and Electrical Properties of Nanocrystalline Diamond based Barium Strontium Titanate Varactors, Ferroelectrics, 377:1, 75-85, DOI: 10.1080/00150190802523628


Barium strontium titanate (BST) varactors fabricated on silicon substrates experience reliability and yield issues due to the defects induced in the interdiffusion of the layers in the bottom electrode stack. The structural and electrical properties of BST varactors fabricated on nanocrystalline diamond (NCD) films as the diffusion barrier layer are reported here. The structural properties and the quality of the interfaces were studied along with the electrical properties of the varactors. The varactors fabricated on NCD films displayed improved symmetry of capacitance-voltage (C-V) characteristics and 70% higher quality factor due to better interface stability with reduced bottom electrode losses.

Keywords: Barium strontium titanate, nanocrystalline diamond, interdiffusion, quality factor

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