Selective growth and texturing of VO2(B) thin films for high-temperature microbolometers

Abstract

Vanadium oxides exhibit a broad spectrum of physical properties due to their ability to form various compounds and polymorphs. To utilise a particular property, it is essential to selectively synthesise a desired phase. Herein, we demonstrate a method to selectively and reproducibly grow (00l)-textured VO2(B) thin films using an amorphous SrTiO3 buffer layer by sputtering at 350 degrees C, which enables their direct integration with read-outintegrated-circuits (ROICs), glass, and polymer substrates. The VO2(B) films exhibit high temperature-coefficient-of-resistances (TCRs) ( -3.5%/K at 25 degrees C and >-1.5%/K at 95 degrees C) and low electrical resistivities (similar to 5 10(-1) Omega cm at 25 degrees C and < 1 x 10(-1) Omega cm at 95 degrees C), which are favourable for realising highly-sensitive, lownoise, and high-temperature microbolometers. A robust thermal stability of these VO2(B) thin films at ambient pressure will provide new opportunities to incorporate thermal sensing functions to various electronics.