Design and implementation of perforation on high fill factor structures for uncooled infrared sensors

Date

2016

Author

Çetin, Ramazan

Metadata

Show full item record

Item Usage Stats

203
views

0
downloads

This thesis presents the design and implementation of the perforation on high fill factor structures; e.g., umbrella structures, for uncooled infrared detectors. The study is mostly focused on the effect of the perforation on the absorption performance of the sensor pixels. The introduction of the perforation to the umbrella structure is expected to improve the absorption performance which can be degraded due to a trending issue nowadays, the pixel size reduction. In literature, perforation is also proposed to decrease the thermal time constant, to relieve the low vacuum requirements and to ease the etching of the underneath layers. Within the scope of this study, a canonical topology including only the perforated umbrella structure, but still resembling to the full pixel case, is designed, optimized and fabricated successfully. The canonical topology is used for the optimization of the perforated structures to have a high enough, broadband absorption rate in the LWIR (Long Wave Infrared, 8μm-12μm) range using the Cascaded Transmission Line (CTL) technique and the commercial High Frequency Structural Simulator (HFSS) program. The LWIR is the optimized infrared range to get images of the objects having a body temperature around 300 Kelvin. Through these optimizations, a perforation ratio of 50%; i.e., the ratio of the perforation size to the period size is equal to 0.5, is advised to be the optimized value both to have a good absorption performance and also to benefit from other improvements that the perforation offers. The Frequency Transform Infrared (FTIR) spectroscopy results of a successful implementation of perforation on high performance pixels is presented, an average of 90% absorption rate is obtained in the LWIR range. Additionally, a contactless and non-destructive characterization of the absorbing Nichrome (NiCr) layer is presented. Also an improvement by more than 10% with the thermal time constant with the introduction of the perforation is proved through thermal simulations.

Subject Keywords

Microbolometers., Infrared technology., Microelectromechanical systems.

URI

http://etd.lib.metu.edu.tr/upload/12620423/index.pdf
https://hdl.handle.net/11511/25939

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Design and implementation of high fill factor structures on low-cost uncooled infrared sensors Ertürk, Ozan; Akın, Tayfun; Department of Electrical and Electronics Engineering (2015) This thesis presents the design and implementation steps of high fill factor structures for existing SOI diode low-cost microbolometer FPAs. Advancements in uncooled infrared detectors enable high performance military grade uncooled microbolometers as well as ultra-low-cost infrared imagers for civilian applications. The trend in uncooled microbolometers to reduce the pixel pitch has become increasingly significant to lower the cost of detector and system integration due to optics, and increase spatial reso...
Design and implementation of low leakage MEMS microvalves Yıldırım, Ender; Külah, Haluk; Arıkan, Mehmet Ali Sahir; Department of Mechanical Engineering (2011) This thesis presents analysis, design, implementation, and testing of electrostatically actuated MEMS microvalves. The microvalves are specifically designed for lab-on-a-chip applications to achieve leakage ratios below 0.1 at pressure levels in the order of 101 kPa. For this purpose, two different microvalves are presented in the study. In the proposed designs, electrostatic actuation scheme is utilized to operate the microvalves in normally open and normally closed modes. Characterization of normally open...
Design and optimization of nanooptical couplers based on photonic crystals involving dielectric rods of varying lengths Yazar, Şirin; Ergül, Özgür Salih (2022-1-01) This study presents design and optimization of compact and efficient nanooptical couplers involving photonic crystals. Nanooptical couplers that have single and double input ports are designed to obtain efficient transmission of electromagnetic waves in desired directions. In addition, these nanooptical couplers are cascaded by adding one after another to realize electromagnetic transmission systems. In the design and optimization of all these nanooptical couplers, the multilevel fast multipole algorithm, w...
Analysis and characterization of an electrostatically actuated in-plane parylene microvalve Yıldırım, Ender; Külah, Haluk (IOP Publishing, 2011-10-01) This paper presents analysis and implementation of a simple electrostatic microvalve designed for use in parylene-based lab-on-a-chip devices. The microvalve utilizes an in-plane collapsing diaphragm. To investigate the pull-in behavior of the diaphragm and flow characteristics, a thorough analysis is carried out using the finite element method. Microvalves with different diaphragm radii are fabricated using surface micromachining techniques. Pull-in tests are carried out under the no-flow condition with ai...
Design and development of a complex shear modulus measurement setup for viscoelastic materials Özgen, Gökhan Osman (2005-01-01) Details of the design and development study of a complex shear modulus measurement setup for viscoelastic materials have been presented in this paper. The new setup is specifically designed for measuring the complex shear modulus of pressure sensitive adhesives. The setup consists of a rigid block that is connected to a rigid fixture through two identical shear specimens of the viscoelastic material to be tested. The rigid block and the shear specimens resemble a single degree of freedom system. Once the fr...

Citation Formats

R. Çetin, “Design and implementation of perforation on high fill factor structures for uncooled infrared sensors,” M.S. - Master of Science, Middle East Technical University, 2016.