**Meet the editor**

Dr. A. G. Unil Perera, obtained his bachelor's degree (Physics Special, 1st Class Honors) from the University of Colombo, Sri Lanka and MS and PhD from the University of Pittsburgh in 1987. He is a Professor & the Associate Chair of the Department of Physics & Astronomy and also the Graduate Director of the Physics program at the Georgia State University (GSU). His research on

developing various multi band and terahertz detectors was continuously funded by various federal agencies since 1990. Dr. Perera has published over 150 refereed technical articles, and book chapters, edited several books and and has 5 patents granted. He has given many invited talks at international conferences all over the world and has won numerous awards. His work was featured in various Professional magazines such as "Laser Focus World, Photonics Spectra, and the Reviews of Modern Physics". He is a Life Fellow of the American Physical Society (APS), Fellow of The Institute of Electrical and Electronics Engineers (IEEE), and also a Life Fellow of the Society of Photo-Instrumentation Engineers (SPIE).

Contents

**Preface IX** 

**Part 1 Bolometer Materials 1** 

Chapter 1 **Group IV Materials for Low Cost** 

and Andrey Kosarev

Chapter 3 **Noise Limitations of** 

Béla Szentpáli

Chapter 5 **Lens-Antenna Coupled** 

Lei Liu

Chapter 4 **Cold-Electron Bolometer 77**  Leonid S. Kuzmin

**Part 3 Advances and Trends 135** 

Chapter 6 **Detection of Terahertz Radiation** 

**and High Performance Bolometers 3**  Henry H. Radamson and M. Kolahdouz

Mario Moreno, Alfonso Torres, Roberto Ambrosio

**Miniature Thermistors and Bolometers 53** 

**Superconducting Hot-Electron Bolometers for Terahertz Heterodyne Detection and Imaging 107** 

**from Submicron Plasma Waves Transistors 137** 

Y. M. Meziani, E. Garcia, J. Calvo, E. Diez, E. Velazquez, K. Fobelets and W. Knap

Chapter 7 **Bolometers for Fusion Plasma Diagnostics 151**  Kumudni Tahiliani and Ratneshwar Jha

**Germanium-Silicon (a-GexSiy:H) Thermo-Sensing Films 23** 

Chapter 2 **Un-Cooled Microbolometers with Amorphous** 

**Part 2 Bolometer Types and Properties 51** 

## Contents

## **Preface XI**

**Part 1 Bolometer Materials 1**  Chapter 1 **Group IV Materials for Low Cost and High Performance Bolometers 3**  Henry H. Radamson and M. Kolahdouz Chapter 2 **Un-Cooled Microbolometers with Amorphous Germanium-Silicon (a-GexSiy:H) Thermo-Sensing Films 23**  Mario Moreno, Alfonso Torres, Roberto Ambrosio and Andrey Kosarev **Part 2 Bolometer Types and Properties 51**  Chapter 3 **Noise Limitations of Miniature Thermistors and Bolometers 53**  Béla Szentpáli Chapter 4 **Cold-Electron Bolometer 77**  Leonid S. Kuzmin Chapter 5 **Lens-Antenna Coupled Superconducting Hot-Electron Bolometers for Terahertz Heterodyne Detection and Imaging 107**  Lei Liu **Part 3 Advances and Trends 135**  Chapter 6 **Detection of Terahertz Radiation from Submicron Plasma Waves Transistors 137**  Y. M. Meziani, E. Garcia, J. Calvo, E. Diez, E. Velazquez, K. Fobelets and W. Knap Chapter 7 **Bolometers for Fusion Plasma Diagnostics 151**  Kumudni Tahiliani and Ratneshwar Jha

X Contents

Chapter 8 **Smart Bolometer: Toward Monolithic Bolometer with Smart Functions 171**  Denoual Matthieu, de Sagazan Olivier, Attia Patrick and Allègre Gilles

## Preface

Although the Infrared region covers a very small fraction of the full electromagnetic spectrum, the importance of the region has led to a vast amount of publications covering detectors,emitters and applications in this region. From Astronomy to Zoology Infrared detectors are used in various different fields. Started as a niche field for the defense industry, now it has usefull applications in medicine, home land security, environmental, industry to name a few. Far infrared or terahertz region is becoming more and more important due to the ability to pass through clothes and other material without damaging living cells. Replacing the X-ray scanners at the airports with T- Ray scanners (terahertz) has already begun in ernst. Sir Frederick William Herschel, an astronomer discovered infrared by accident in 1800. Infra which means "beyond" ,was used to name the rays which was not visible to the naked eye but heated the thermometers placed beyond the red light region of the spectrum. His four publications in Transactions of Royal Society ( London) Volume 90, Pt 11 (pages 255, 284, 293, 437) in 1800 provided details of his experiments which led to the discovery of Infrared radiation. Detecting infrared rays has been studied for a long time. In general, the detection is done by converting the infrared rays in to a current. This is done mainly in two different ways, one is due to an electronic transition, that is an excitation of a carrier from one energy level to the other by absorbing the infrared photon energy. When the excited carrier gets collected recorded as a current, an intrinsically fast photon detector is developed. The absorbed photons will have a quantized photon energy giving rise to a spectrum of the detector. By absorbing infrared (heat) if a property of the material such as the resistivity is changed, then a change in the current can be observed under a bias voltage. This current change will give rise to a thermal detector which does not differentiate the photon energy in the incoming infrared photon. The thermal detectors usually respond in time scales very much slower than photon detectors.

 There are large number of books and book chapters written on photon detectors, however, a very limited number of publications discuss thermal detectors. E. Scott Barr in an article published in American Journal of Physics Vol. 28(1), Pp 42-54 in 1960 presented a historical survey of the early development of the infrared spectral region. In early 90s, intersubband transition related infrared detectors, specifically quantum well infrared photodetectors (QWIPs) came into existence. World Scientific publication

#### X Preface

"The Physics of Quantum Well Infrared Photodetectors" , by K.K. Choi in 1997, gives an in depth description of the Physics of QWIPs . Semiconductor optical and Electro Optical Devices" second of a five volume "Hand book of Thin Film Devices" edited by M. H. Francombe, A. G. Unil Perera and H.C. Liu discuss several types of thin film based infrared detectors. Another world scientific publication "Intersubband Infrared Photodetecors" by V. Ryzhii in 2003 covers several other Infrared Detectors. Published in 2011, semiconductors and semimetals series Vol. 84 edited by S.D. Gunapala, D. R. Rhiger and C. Jagadish covers several types of infrared detectors in " Advances in Infrared Photodetectors." An Elsevier publication in 2011, "Comprehensive Semiconductor Science and Technology (sixth of a nine-volume set)" edited by P. Bhattacharya, discuss various types of infrared and terahertz detectors.

Preface XI

MODFETs transistors. Chapter seven from Kumudni Tahiliani & Ratneshwar Jha (Institute for Plasma Research, India) describes bolomters for plasma diagnostics. Last but not least, chapter eight presented by Denoual Matthieu and co-workers (University of Rennes, France) discuss *a* monolithically integrated, futuristic smart

We hope that this book will fill the need for bolometer publications and will be useful for engineers and scientists interested in learning about or developing bolometers. In addition this can be used as a text book for Physics and Engineering advanced undergraduate and graduate students interested in learning about infrared detectors.

**Prof. A. G. Unil Perera**

USA

Department of Physics and Astronomy, Georgia State University, Atlanta,

bolometer.

Somehow, only very few chapters are about bolometers in those publications. Ward and Wormster in an article "Description and properties of Various Thermal Detectors" published in proceedings of the IRE Vol. 47, PP 1508-1513, 1959 presented an account of early thermal detectors. Chapter 5 of the Antoni Rogalski's book 'Infrared detectors' was devoted to Bolometers, which was published in 2000 by CRC Press.

Hence it is timely to have a book devoted to bolometers to be published. This book consists of three sections, (i) Bolometer Materials, (ii) Types and Properties and (iii) Applications and Trends. The first section has two chapters describing bolometer materials. The second section chapters 3-5, describe nosie properties of miniature bolometers and different types of bolometers. The third section consisting of chapters 6 to 8 describes the applications and trends in bolometer research.

In the first chapter written by Henry H. Radamson (KTH Royal Institute of Technology, Sweeden) and Kolahdouz (University of Tehran, Iran) discuss the benefits and the drawbacks of group IV materials as thermistor material in bolometers. Multiple quantum well, multiple quantum dot and schottky barrier structures are discussed as bolometers. Mario Moreno and co-workers (National Institute of Astrophysics, Optics and Electronics, and Universidad Autonoma de Ciudad Juarez, Mexico) discuss micro-bolometers with amorphous germanium-silicon (a-GexSiy:H) films operating at room temperature in the second chapter.

Miniature bolometers allow high speed operation, requiring broader bandwidths which in turn change the noise properties. Béla Szentpáli (Hungarian Academy of Sciences,) in chapter three describe the noise limitations in miniature bolometers giving rise to performance limits*.* Leonid Kuzmin (Chalmers University, Sweeden) describes Cold-Electron Bolometers in the fourth chapter. Dr. Liu Lei (University of Notre Dame, USA) in chapter five describe hot electron Bolometers and the use of those as remote sensors for the terahertz region.

In chapter six, Y.M. Meziani group (Universidad de Salamanca, Spain), K. Fobelets (Imperial College, UK) and W. Knap (Université Montpellier, France) report on the detection of terahertz radiations by plasma wave oscillations in strained Si/SiGe nMODFETs transistors. Chapter seven from Kumudni Tahiliani & Ratneshwar Jha (Institute for Plasma Research, India) describes bolomters for plasma diagnostics. Last but not least, chapter eight presented by Denoual Matthieu and co-workers (University of Rennes, France) discuss *a* monolithically integrated, futuristic smart bolometer.

X Preface

"The Physics of Quantum Well Infrared Photodetectors" , by K.K. Choi in 1997, gives an in depth description of the Physics of QWIPs . Semiconductor optical and Electro Optical Devices" second of a five volume "Hand book of Thin Film Devices" edited by M. H. Francombe, A. G. Unil Perera and H.C. Liu discuss several types of thin film based infrared detectors. Another world scientific publication "Intersubband Infrared Photodetecors" by V. Ryzhii in 2003 covers several other Infrared Detectors. Published in 2011, semiconductors and semimetals series Vol. 84 edited by S.D. Gunapala, D. R. Rhiger and C. Jagadish covers several types of infrared detectors in " Advances in Infrared Photodetectors." An Elsevier publication in 2011, "Comprehensive Semiconductor Science and Technology (sixth of a nine-volume set)" edited by P.

Somehow, only very few chapters are about bolometers in those publications. Ward and Wormster in an article "Description and properties of Various Thermal Detectors" published in proceedings of the IRE Vol. 47, PP 1508-1513, 1959 presented an account of early thermal detectors. Chapter 5 of the Antoni Rogalski's book 'Infrared detectors'

Hence it is timely to have a book devoted to bolometers to be published. This book consists of three sections, (i) Bolometer Materials, (ii) Types and Properties and (iii) Applications and Trends. The first section has two chapters describing bolometer materials. The second section chapters 3-5, describe nosie properties of miniature bolometers and different types of bolometers. The third section consisting of chapters

In the first chapter written by Henry H. Radamson (KTH Royal Institute of Technology, Sweeden) and Kolahdouz (University of Tehran, Iran) discuss the benefits and the drawbacks of group IV materials as thermistor material in bolometers. Multiple quantum well, multiple quantum dot and schottky barrier structures are discussed as bolometers. Mario Moreno and co-workers (National Institute of Astrophysics, Optics and Electronics, and Universidad Autonoma de Ciudad Juarez, Mexico) discuss micro-bolometers with amorphous germanium-silicon (a-GexSiy:H)

Miniature bolometers allow high speed operation, requiring broader bandwidths which in turn change the noise properties. Béla Szentpáli (Hungarian Academy of Sciences,) in chapter three describe the noise limitations in miniature bolometers giving rise to performance limits*.* Leonid Kuzmin (Chalmers University, Sweeden) describes Cold-Electron Bolometers in the fourth chapter. Dr. Liu Lei (University of Notre Dame, USA) in chapter five describe hot electron Bolometers and the use of

In chapter six, Y.M. Meziani group (Universidad de Salamanca, Spain), K. Fobelets (Imperial College, UK) and W. Knap (Université Montpellier, France) report on the detection of terahertz radiations by plasma wave oscillations in strained Si/SiGe n-

Bhattacharya, discuss various types of infrared and terahertz detectors.

was devoted to Bolometers, which was published in 2000 by CRC Press.

6 to 8 describes the applications and trends in bolometer research.

films operating at room temperature in the second chapter.

those as remote sensors for the terahertz region.

We hope that this book will fill the need for bolometer publications and will be useful for engineers and scientists interested in learning about or developing bolometers. In addition this can be used as a text book for Physics and Engineering advanced undergraduate and graduate students interested in learning about infrared detectors.

> **Prof. A. G. Unil Perera** Department of Physics and Astronomy, Georgia State University, Atlanta, USA

**Part 1** 

**Bolometer Materials** 

**Part 1** 

**Bolometer Materials** 

**1** 

*1Sweden 2Iran* 

**Group IV Materials for Low Cost** 

Henry H. Radamson1 and M. Kolahdouz2

*Royal Institute of Technology, Kista* 

*University of Tehran, Tehran,* 

**and High Performance Bolometers** 

*1School of Information and Communication Technology, KTH* 

*2Thin Film Laboratory, Electrical and Computer Engineering Department,* 

Infrared (IR) imaging has absorbed a large attention during the last two decades due to its application in both civil and military applications (Per Ericsson et al., 2010; Lapadatu et al., 2010; Sood et al., 2010). Thermal detector is presently revolutionizing the IR technology field and it is expected to expand the market for cameras. These detectors are micro-bolometers and are manufactured through micro-maching of a thermistor material. Since these detectors demand no cryogenic cooling, they provide the opportunity for producing compact, light-weight, and potentially low-cost cameras. The preferred functioning wavelength regions for these detectors are usually 8–12 μm due to the high transparency of

Micro-bolometers function through absorption of infrared radiation on a cap layer which warms the bolometer's body and raises the temperature. This temperature change is sensed by a thermistor material integrated in the bolometer, i.e. a a material whose resistivity changes with temperature variation. The whole detector body consists of a thin membrane which is thermally isolated and is fastened to the wafer via two thin legs. The legs are connected to a CMOS-based read-out integrated circuit (ROIC). A thin oxide or nitride layer is deposited to ensure the stability of the legs in contact to the ROIC body (see Fig. 1). The whole detector is vacuum encapsulated to reduce effectively the thermal conductance. Signal processing is obtained and multiplexing electronics (CMOS) is integrated within the silicon substrate. All the membranes are in form of pixels which are bonded to a read-out circuit to amplify the generated signal (Kvisterøy et al., 2007; J. Källhammer et al., 2006; F.

This chapter will present the benefits and drawbacks of group IV thermistor materials in bolometers. The proposed structures are composed of multi-quantum wells (MQWs) or dots (MQDs), structures of Si(C) (barrier)/SiGe(C) (quantum well layer) and their combination

Niklaus, Kälvesten, & G. Stemme, 2001; F. Niklaus, Vieider, & Jakobsen, 2007).

**1. Introduction** 

the atmosphere in these regions.

with a Schottky diode.
