Tailoring bolometric properties of a TiOx/Ti/TiOx tri-layer film for integrated optical gas sensors

被引：13

作者：

Shim, Joonsup ^{[1
]}

Lim, Jinha ^{[1
]}

Geum, Dae-Myeong ^{[1
]}

Kim, Bong Ho ^{[1
]}

Ahn, Seung-Yeop ^{[1
]}

Kim, SangHyeon ^{[1
]}

机构：

[1] Korea Adv Inst Sci & Technol KAIST, Sch Elect Engn, 291 Daehak Ro, Daejeon 34141, South Korea

来源：

OPTICS EXPRESS | 2021年 / 29卷 / 12期

关键词：

WAVE-GUIDE PLATFORM; MIDINFRARED PHOTONICS; ROOM-TEMPERATURE; THIN-FILM; MU-M; SILICON; GERMANIUM; MICROBOLOMETER;

D O I：

10.1364/OE.427147

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

In this paper, we systematically investigated tailoring bolometric properties of a proposed heat-sensitive TiOx/Ti/TiOx tri-layer film for a waveguide-based bolometer, which can play a significant role as an on-chip detector operating in the mid-infrared wavelength range for the integrated optical gas sensors on Ge-on-insulator (Ge-OI) platform. As a proof-of-concept, bolometric test devices with a TiOx single-layer and TiOx/Ti/TiOx tri-layer films were fabricated by varying the layer thickness and thermal treatment condition. Comprehensive characterization was examined by the scanning transmission electron microscopy (STEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses in the prepared films to fully understand the microstructure and interfacial properties and the effects of thermal treatment. Quantitative measurements of the temperature- and time-dependent resistance variations were conducted to deduce the minimum detectable change in temperature (Delta T-min) of the prepared films. Furthermore, based on these experimentally obtained results, limit-of-detection (LoD) for the carbon dioxide gas sensing was estimated to demonstrate the feasibility of the proposed waveguide-based bolometer with the TiOx/Ti/TiOx tri-layer film as an on-chip detector on the Ge-OI platform. It was found that the LoD can reach similar to 3.25 ppm and/or even lower with the Delta T-min of 11.64 mK in the device with the TiOx/Ti/TiOx (47/6/47 nm) tri-layer film vacuum-annealed at 400 degrees C for 15 min, which shows great enhancement of similar to 7.7 times lower value compared to the best case of TiOx single-layer films. Our theoretical and experimental demonstration for tailoring bolometric properties of a TiOx/Ti/TiOx tri-layer film provides fairly useful insight on how to improve LoD in the integrated optical gas sensor with the bolometer as an on-chip detector. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

引用

页码：18037 / 18058

页数：22