z-logo
Premium
Tunable Microwave Device Fabrication on Low‐Temperature Crystallized Ba 0.5 Sr 0.5 TiO 3 Thin Films by an Alternating Deposition and Laser Annealing Process
Author(s) -
Goud Jakkapally Pundareekam,
Kumar Ajeet,
Sandeep Kongbrailatpam,
Ramakanth Suryavamshi,
Ghoshal Partho,
Raju Kanakkappillavila Chinnayya James
Publication year - 2021
Publication title -
advanced electronic materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.25
H-Index - 56
ISSN - 2199-160X
DOI - 10.1002/aelm.202000905
Subject(s) - materials science , thin film , amorphous solid , annealing (glass) , raman spectroscopy , pulsed laser deposition , optoelectronics , fabrication , excimer laser , laser , laser ablation , carbon film , x ray photoelectron spectroscopy , analytical chemistry (journal) , nanotechnology , optics , composite material , chemical engineering , crystallography , medicine , chemistry , physics , alternative medicine , pathology , engineering , chromatography
This article demonstrates a method to fabricate crystalline Ba 0.5 Sr 0.5 TiO 3 (BST) thin films at a lower temperature of ≈300 °C using an excimer laser by an alternating depositing and annealing process. Firstly, a BST thin film with a thickness of ≈120 nm is deposited at 300 °C (laser energy of ≈2 J cm −2 ) and subsequently laser annealed (66 mJ cm −2 ) at 300 °C. This process is repeated five times to obtain thicker device quality films. XRD patterns, TEM, Raman, and UV–Vis–NIR spectroscopy confirm that phase formation of BST thin films has taken place. The band edge value for BST thin films is observed to decrease systematically from 4.65 eV (amorphous, 300 °C) to 3.56 eV (5‐layers, crystalline, 300 °C). A varactor device with a Circular Patch Capacitor (CPC) structure is patterned on the five‐stage laser annealed BST thin films processed at 300 °C, which shows a microwave tunability of 34% at 1 GHz compared to conventionally deposited BST films (prepared at 700 °C). This study provides a way for fabricating ferroelectric thin film based tunable devices at low temperatures, making the process compatible with low melting substrates in flexible electronics and other situations where there is a temperature constraint.

This content is not available in your region!

Continue researching here.

Having issues? You can contact us here