rus
Issue #4/2020
N. A. Kulchitsky, A. V. Naumov, V. V. Startsev
Infrared Focal Plane Array Detectors: «Post Pandemic» Development Trends. Part II
Infrared Focal Plane Array Detectors: «Post Pandemic» Development Trends. Part II
DOI: 10.22184/1993-7296.FRos.2020.14.4.320.330
The first part of the review (see Photonics Russia.2020; 14(3): 234–244) deals with infrared detectors of thermal imaging technology. The devices are in demand in systems and complexes of civil and medical thermography, security and fire surveillance, personal night vision and security systems. The second part of the review deals with cooled APDs for the spectral range of 3–5 microns, 8–12 microns, uncooled APDs. A comparison of thermal detectors of various types by different world manufacturers is presented. An expert forecast of changes in market growth dynamics and trends of its post-pandemic development is given.
The first part of the review (see Photonics Russia.2020; 14(3): 234–244) deals with infrared detectors of thermal imaging technology. The devices are in demand in systems and complexes of civil and medical thermography, security and fire surveillance, personal night vision and security systems. The second part of the review deals with cooled APDs for the spectral range of 3–5 microns, 8–12 microns, uncooled APDs. A comparison of thermal detectors of various types by different world manufacturers is presented. An expert forecast of changes in market growth dynamics and trends of its post-pandemic development is given.
Infrared Focal Plane Array Detectors: «Post Pandemic» Development Trends. Part II
N. A. Kulchitsky 1, 2, A. V. Naumov 3, V. V. Startsev 3
Moscow Technological University (Moscow Institute of Radio, Electronics and Automatics, MIREA), Moscow, Russia
State Scientific Center of the Russian Federation, NPO ORION JSC, Moscow, Russia
Astron Design Bureau JSC, Lytkarino, Moscow Region, Russia
The first part of the review (see Photonics Russia.2020; 14(3): 234–244) deals with infrared detectors of thermal imaging technology. The devices are in demand in systems and complexes of civil and medical thermography, security and fire surveillance, personal night vision and security systems. The second part of the review deals with cooled APDs for the spectral range of 3–5 microns, 8–12 microns, uncooled APDs. A comparison of thermal detectors of various types by different world manufacturers is presented. An expert forecast of changes in market growth dynamics and trends of its post-pandemic development is given.
Received on: 08.04.2020
Accepted on: 20.04.2020
COOLED APDs FOR IR RANGE
A decrease in the pixel pitch and an increase in the array format leads to a significant increase in the range of recognition of objects by optoelectronic systems [5–7].
Cooled APDs for the spectral range of 3–5 µm
Array photodetectors (APDs) considered in the first part of the review (see Photonics Russia. 2020; 14(3): 234–244) are mass-produced widely presented on the world market. The main format is 640 × 512 pixels, the transition to 1280 × 1024 pixels. Advances in technology of IR sensors allowed increasing the size of the arrays and reducing the size of pixels to obtain megapixel arrays. Materials for their creation are InSb, КРТ, InAsSb.
Cooled APDs for the spectral range of 8–12 µm
APDs presented in table 3, are also mass-produced by leading manufacturers and are widely represented in the world market. The main formats are 320 × 256, 384 × 288, and 640 × 512; samples of megapixel APDs are developed. Materials for their creation are КРТ, QWIP.
Dual-spectrum and multispectral APDs
Almost all leading companies actively develop dual-spectrum and multi-spectral APDs. Their use in optoelectronic systems increases the probability of target detection and recognition. High information content and achieved at the same time compact devices are the driving forces for the development of this direction. In the next decade, dual-spectrum APDs will become commercially available infrared photoelectronics products. For the implementation of dual-spectrum APDs sensitive in the ranges 3–5 and 8–12 μm, SRT‑based technologies are mainly used. An example of images in two ranges (Fig. 9), obtained using a dual-spectrum APDs, gives an idea of the degree of detailed study of the scene.
UNCOOLED APDs
Compared to photon, thermal detectors in the second half of the twentieth century were used less frequently. The reason lies in the fact that they worked relatively slowly (response time t > 5 ∙ 10–2 s) and their sensitivity was lower. However, over the past two decades we have seen significant progress in creating uncooled infrared thermal detectors. Their threshold characteristics are close to the characteristics of photon detectors, and note – at a much lower cost. The cost of APDs based on bolometers in industrial production is two orders of magnitude lower than the cost of arrays based on HgCdTe, InSb [2–4].
Radiation is recorded when heat is accumulated in the volume of the receiver from the action of radiation energy during the frame. To this end, the sensitive element is maximally insulated from the substrate in the design. Thermal insulation is realized through the use of MEMS technology. It is based on deep dry etching of silicon using “sacrificial” layers (up to three). On the surface in this way create membrane structures with a thickness of less than 1 micron. A pair of microbeams (supporting consoles) holds them above the substrate at a distance of ~ 2 μm, a photosensitive element is placed on them – a thin-film structure (Fig. 10).
Figure 11 shows a roadmap for the development of uncooled arrays of thermal IR detectors [4]. It can be seen that with an improvement in the characteristics and an increase in the density of pixels (a decrease in their size), it can significantly expand the number of their applications. Thermal arrays have already become widely used in everyday night driving devices. For such purposes, we use arrays with the number of pixels in the array 2 ∙ 105 and the value NETD = 100 mK (NETD – Noise Equivalent Temperature Difference). In helmet-mounted devices, rifle scopes, sensors of ground-based security devices, arrays are widely used, in which the pixel pitch is reduced to 10–17 μm with the number of pixels >106. If the goals of such a program are achieved (NETD <10 mK), then the areas of application of such thermal uncooled arrays can be expanded even more. So far, technical difficulties are getting in the way of implementation.
Currently, vanadium oxide and doped α-Si: H are most widely used to create thermal imaging devices. Vanadium oxide VOx has high values of the temperature coefficient of resistance (TCR = 2–3%). Based on this material, arrays of 2 048 × 1 536 format with a pixel size of 17 μm were created [4–6]. However, vanadium oxide is a non-standard material for CMOS technology. The manufacture of vanadium oxide in the form of thin films is difficult to control the process. The reason lies in the too narrow range of technological parameters within which it is possible to ensure the stability and optimality of the characteristics of the oxide. In addition, the presence of hysteresis leads to problems in constructing thermal images of hot objects. The thermal conductivity of such films is an order of magnitude higher than the values of this parameter for semiconductors (usually 0.05 W / cmK). α-Si: H‑based bolometers have high resistance, but this material is unstable during heat treatments and under the influence of ultraviolet radiation. This material has two phases: stable and metastable, which are separated by potential barriers, which prevents the formation of an equilibrium state.
Currently, the attention of the developers is focused in the field of technological problems of compatibility of the manufacturing process of bolometric arrays with CMOS technology, as well as in the field of optimization of material resistance, TCR, thermal conductivity and other characteristics of the device. Silicon carbide SiC bolometers have high TCR values (4–6%). However, to stabilize the material properties, annealing is required at temperatures of about 1 000 °C, which is incompatible with CMOS technology [6, 7].
Another development direction was the creation of array arrays of photosensitive elements with a step of elements reduced up to 5 μm (Fig. 12).
However, we see a new interest in the technology of creating microbolometers. It is associated with their use in high-speed cameras. When imaging, a fast response is required from the detector. In this case, the limiting factor is the value of the thermal response time constant τth. Today, for typical bolometers with a step of 17 μm, the value τth = 12 ms is reached. By optimizing the design of the bolometer, τth can be reduced to values less than 3 ms. Reducing the thermal time constant can provide improved image quality (Fig. 13).
MICROBOLOMETER MARKET
According to the analytical agency Yole Development, the main production of microbolometers today is concentrated in the USA and France. Also, manufacturers are available in Israel, China, Japan, and other countries of Southeast Asia (Fig. 14). These products are mass-produced by world manufacturers and are widely represented on the world market [6, 8]. In the table. 4 shows the characteristics of uncooled PDs of various manufacturers.
SITUATION IN THE USSR AND RUSSIA
A number of enterprises of Shvabe JSC and Roselectronika JSC, the Russian Academy of Sciences, and private enterprises are developing photodetectors for various purposes in Russia. The main suppliers are NPO Orion JSC and MZ Sapfir JSC, members of Shvabe JSC, as well as a private enterprise Astrohn DB JSC. NPO Orion JSC develops and produces refrigerated and uncooled photodetectors. MZ Sapphire JSC produces cooled and uncooled APDs based on Si, Ge, InSb, CdHgTe. NII Polyus JSC is developing uncooled InGaAs-based APDs and the production of photosensitive semiconductor structures. The enterprises of Roselectronika JSC specialize in the development and production of visible-range arrays based on silicon, cooled by APDs based on quantum wells, the Schottky barrier from platinum silicide, and cooled PDs based on impurity silicon (NPP Pulsar JSC, CRI Electron JSC, CRI Cyclone JSC, NPP Vostok JSC). The Institute of Semiconductor Physics of the Siberian Branch of the Russian Academy of Sciences is developing semiconductor materials science and multifunctional devices based on CdHgTe, InAs, microbolometers and quantum wells. Astrohn DB JSC (Lytkarino, Moscow Region) designs and manufactures civil thermal imaging devices based on uncooled APDs of its own production, as well as cooled APDs based on CdHgTe in conjunction with IFP SB RAS.
NPO Orion JSC started mass production of the medium-wave range APDs. Astrohn DB JSC has begun serial production of a array photodetector module in the long wavelength range based on a cooled KRT / Si array (manufactured by the Institute of Physics and Technology of the Siberian Branch of the Russian Academy of Sciences) and Astrohn-MKS500 own microcooling system. Astrohn-MKS500 operates on a closed reverse thermogasdynamic Stirling regenerative cycle with internal heat recovery; ultrapure helium gas is used as a working fluid. The results achieved are close in their indicators to the world level.
The first attempts to create microbolometric arrays were started in 1994–1995 at the NPO Orion (Moscow) [1, 3]. In the early 2000s, the company began developing devices of the 320 × 240 format on vanadium oxide on a silicon nitride substrate. However, the emerging market for civilian and security applications required large-scale production of microbolometers. Until recently, domestic equipment was provided with thermal imaging systems as part of a purchase or joint production with foreign co-contractors. The need for the development and serial production of domestic uncooled APDs became especially urgent after the ban on their supplies from abroad.
Since 2016, Astrohn DB JSC has mastered the production of multifunction devices with a sensitivity of up to 40 mK Astrohn‑38425-1 and Astrohn‑64025-1 with the size of sensitive elements of the array 25 μm and 17 μm. APD is made on the basis of a array of microbolometers with an electronic reading subsystem, and packed in a ceramic case. The APD has an array of microbolometers in the form of a two-dimensional array of elementary detectors located in the focal plane, consisting of 384 × 288 elements (PD ASTROHN‑38417-1), and 640 × 480 (PD ASTROHN‑64017-1). Microbolometers are made of vanadium oxide according to the bridge circuit. The APD delivers a raw image in analog format at speeds up to 60 frames per second. The electronic subsystem is controlled via a serial data bus. The pixel size is 17 × 17 μm.
The APD is made in the LCC (Leadless chip Carrier) case made of vacuum-tight ceramic (Fig. 15). The topology of microbolometric detectors of different manufacturers is shown in Fig. 16 [6]. Work on the creation of microbolometric arrays based on vanadium oxides is also underway at the Institute of Physics and Technology of the Siberian Branch of the Russian Academy of Sciences (Novosibirsk) [4, 6, 7].
MAIN DEVELOPMENT TRENDS
In the last decade, a number of new directions and trends have been outlined in infrared photoelectronics. They are associated with increasing the resolution of systems, improving methods for recording ultra-weak optical signals, creating high-speed and multispectral systems, forming infrared 3D images, etc.:
CONCLUSION
The consequences of the pandemic and restrictions lead to the emergence of short-term and long-term factors influencing the market of IR APDs. Short-term can be attributed to everything that is directly related to medical thermography. This primarily relates to uncooled thermal detectors. The low response time in the case of inexpensive “looking” thermal imaging systems is practically insignificant, especially for medical applications when measuring the thermal fields of stationary objects or objects moving with small angular velocities. In general, the entire industry will experience a recovery (especially noticeable against the background of a possible slowdown in the global economy as a whole). Moreover, this trend can move from short-term to long-term phase.
With regard to long-term trends, it is highly likely that the epidemiological threat will occupy in the public mind the same place as the terrorist threat after the terrorist attacks in New York in 2001. It is impossible to exclude the appearance of biometric control at airports in addition to the existing aviation security protocols, new protocols for passing border crossing points, etc. All this will require a sharp increase in production volumes and lower manufacturing costs. Technologies of even larger series production in a single technical process of multi-pixel arrays with low defectiveness, as well as their hybridization with readout circuits will be in demand. In the medium term, a thermal imager will turn from a rather exotic and expensive device into an almost household device.
The ideas of using metamaterials, graphene, and other 2D structures in photoelectronics are being put into practice. Together with the “traditional” thermal imaging, they unusually widely push the boundaries and technical capabilities. We expect a significant expansion of the prospects for improvement and the creation of new infrared optoelectronic systems.
REFERENCES
Ponomarenko V. P., Filachev A. M. Infrakrasnaya tekhnika i elektronnaya optika. Stanovlenie nauchnyh napravleniya. – M.: Fizmatkniga. 2016. 417.
Filachev A. M., Taubkin I. I., Trishenkov M. A. Tverdotel’naya fotoelektronika. Fotorezistory i fotopriemnye ustrojstva. – M.: Fizmatkniga. 2012, 368.
Ponomarenko V. P. Tellurid kadmiya – rtuti i novoe pokolenie priborov infrakrasnoj fotoelektroniki. UFN. 2003; 173(6): 649–665.
Sizov F. F. IK‑fotoelektronika: fotonnye ili teplovye detektory? Perspektivy. Sensor Electronics and Microelectronics Technologies. 2015;12(1): 26–53.
Rogalski А. Next decade in infrared detectors. Proc. SPIE10433. ElectroOptical and Infrared Systems: Technology and Applications XIV (9–10 October2017). 2017; 10433:104330L1–104330L25. DOI: 10.1117 / 12.2300779.
Kul’chickij N. A., Naumov A. V., Starcev V. V. Neohlazhdaemye mikrobolometry infrakrasnogo diapazona-sovremennoe sostoyanie i tendencii razvitiya. Nanoi mikrosistemnaya tekhnika. 2018; 20(10): 613–624.
Samvelov A. V., YAsev S. G., Moskalenko A. S., Starcev V. V., Pahomov O. V. Integral Microcryogenic Stirling Systems As A Part Of Cryostatting Photoreceiving Modules Based On Long IR Region Matrix. Photonics Russia. 2019; 13(1): 58–64. DOI: 10.22184 / FRos.2019.13.1.58.64.
Ivanov S. D., Koscov E. G. Priemniki teplovogo izlucheniya neohlazhdaemyh megapiksel’nyh teplovizionnyh matric (obzor). Uspekhi Prikladnoj fiziki. 2017; 5(2): 136–154.
ABOUT AUTHORS
Kulchitsky Nikolai Alexandrovich, Doctor of Technical Sci., e-mail: n.kulchitsky@gmail.com, Professor, Moscow Technological University (MIREA), Chief Specialist, SSC RF, JSC Orion Scientific-Production Association, Moscow, Russia.
ORCID ID: 0000-0003-4664-4891
Naumov Arkady Valerievich, engineer-analyst, ASTROHN Technology Ltd,
https://astrohn.ru, Lytkarino, Moscow region, Russia.
ORCID: 0000-0001-6081-8304
Startsev Vadim Valerievich, Cand. of Technical Sciences, ASTROHN Technology Ltd, https://astrohn.ru, Lytkarino, Moscow region, Russia.
ORCID ID: 0000-0002-2800-544X
N. A. Kulchitsky 1, 2, A. V. Naumov 3, V. V. Startsev 3
Moscow Technological University (Moscow Institute of Radio, Electronics and Automatics, MIREA), Moscow, Russia
State Scientific Center of the Russian Federation, NPO ORION JSC, Moscow, Russia
Astron Design Bureau JSC, Lytkarino, Moscow Region, Russia
The first part of the review (see Photonics Russia.2020; 14(3): 234–244) deals with infrared detectors of thermal imaging technology. The devices are in demand in systems and complexes of civil and medical thermography, security and fire surveillance, personal night vision and security systems. The second part of the review deals with cooled APDs for the spectral range of 3–5 microns, 8–12 microns, uncooled APDs. A comparison of thermal detectors of various types by different world manufacturers is presented. An expert forecast of changes in market growth dynamics and trends of its post-pandemic development is given.
Received on: 08.04.2020
Accepted on: 20.04.2020
COOLED APDs FOR IR RANGE
A decrease in the pixel pitch and an increase in the array format leads to a significant increase in the range of recognition of objects by optoelectronic systems [5–7].
Cooled APDs for the spectral range of 3–5 µm
Array photodetectors (APDs) considered in the first part of the review (see Photonics Russia. 2020; 14(3): 234–244) are mass-produced widely presented on the world market. The main format is 640 × 512 pixels, the transition to 1280 × 1024 pixels. Advances in technology of IR sensors allowed increasing the size of the arrays and reducing the size of pixels to obtain megapixel arrays. Materials for their creation are InSb, КРТ, InAsSb.
Cooled APDs for the spectral range of 8–12 µm
APDs presented in table 3, are also mass-produced by leading manufacturers and are widely represented in the world market. The main formats are 320 × 256, 384 × 288, and 640 × 512; samples of megapixel APDs are developed. Materials for their creation are КРТ, QWIP.
Dual-spectrum and multispectral APDs
Almost all leading companies actively develop dual-spectrum and multi-spectral APDs. Their use in optoelectronic systems increases the probability of target detection and recognition. High information content and achieved at the same time compact devices are the driving forces for the development of this direction. In the next decade, dual-spectrum APDs will become commercially available infrared photoelectronics products. For the implementation of dual-spectrum APDs sensitive in the ranges 3–5 and 8–12 μm, SRT‑based technologies are mainly used. An example of images in two ranges (Fig. 9), obtained using a dual-spectrum APDs, gives an idea of the degree of detailed study of the scene.
UNCOOLED APDs
Compared to photon, thermal detectors in the second half of the twentieth century were used less frequently. The reason lies in the fact that they worked relatively slowly (response time t > 5 ∙ 10–2 s) and their sensitivity was lower. However, over the past two decades we have seen significant progress in creating uncooled infrared thermal detectors. Their threshold characteristics are close to the characteristics of photon detectors, and note – at a much lower cost. The cost of APDs based on bolometers in industrial production is two orders of magnitude lower than the cost of arrays based on HgCdTe, InSb [2–4].
Radiation is recorded when heat is accumulated in the volume of the receiver from the action of radiation energy during the frame. To this end, the sensitive element is maximally insulated from the substrate in the design. Thermal insulation is realized through the use of MEMS technology. It is based on deep dry etching of silicon using “sacrificial” layers (up to three). On the surface in this way create membrane structures with a thickness of less than 1 micron. A pair of microbeams (supporting consoles) holds them above the substrate at a distance of ~ 2 μm, a photosensitive element is placed on them – a thin-film structure (Fig. 10).
Figure 11 shows a roadmap for the development of uncooled arrays of thermal IR detectors [4]. It can be seen that with an improvement in the characteristics and an increase in the density of pixels (a decrease in their size), it can significantly expand the number of their applications. Thermal arrays have already become widely used in everyday night driving devices. For such purposes, we use arrays with the number of pixels in the array 2 ∙ 105 and the value NETD = 100 mK (NETD – Noise Equivalent Temperature Difference). In helmet-mounted devices, rifle scopes, sensors of ground-based security devices, arrays are widely used, in which the pixel pitch is reduced to 10–17 μm with the number of pixels >106. If the goals of such a program are achieved (NETD <10 mK), then the areas of application of such thermal uncooled arrays can be expanded even more. So far, technical difficulties are getting in the way of implementation.
Currently, vanadium oxide and doped α-Si: H are most widely used to create thermal imaging devices. Vanadium oxide VOx has high values of the temperature coefficient of resistance (TCR = 2–3%). Based on this material, arrays of 2 048 × 1 536 format with a pixel size of 17 μm were created [4–6]. However, vanadium oxide is a non-standard material for CMOS technology. The manufacture of vanadium oxide in the form of thin films is difficult to control the process. The reason lies in the too narrow range of technological parameters within which it is possible to ensure the stability and optimality of the characteristics of the oxide. In addition, the presence of hysteresis leads to problems in constructing thermal images of hot objects. The thermal conductivity of such films is an order of magnitude higher than the values of this parameter for semiconductors (usually 0.05 W / cmK). α-Si: H‑based bolometers have high resistance, but this material is unstable during heat treatments and under the influence of ultraviolet radiation. This material has two phases: stable and metastable, which are separated by potential barriers, which prevents the formation of an equilibrium state.
Currently, the attention of the developers is focused in the field of technological problems of compatibility of the manufacturing process of bolometric arrays with CMOS technology, as well as in the field of optimization of material resistance, TCR, thermal conductivity and other characteristics of the device. Silicon carbide SiC bolometers have high TCR values (4–6%). However, to stabilize the material properties, annealing is required at temperatures of about 1 000 °C, which is incompatible with CMOS technology [6, 7].
Another development direction was the creation of array arrays of photosensitive elements with a step of elements reduced up to 5 μm (Fig. 12).
However, we see a new interest in the technology of creating microbolometers. It is associated with their use in high-speed cameras. When imaging, a fast response is required from the detector. In this case, the limiting factor is the value of the thermal response time constant τth. Today, for typical bolometers with a step of 17 μm, the value τth = 12 ms is reached. By optimizing the design of the bolometer, τth can be reduced to values less than 3 ms. Reducing the thermal time constant can provide improved image quality (Fig. 13).
MICROBOLOMETER MARKET
According to the analytical agency Yole Development, the main production of microbolometers today is concentrated in the USA and France. Also, manufacturers are available in Israel, China, Japan, and other countries of Southeast Asia (Fig. 14). These products are mass-produced by world manufacturers and are widely represented on the world market [6, 8]. In the table. 4 shows the characteristics of uncooled PDs of various manufacturers.
SITUATION IN THE USSR AND RUSSIA
A number of enterprises of Shvabe JSC and Roselectronika JSC, the Russian Academy of Sciences, and private enterprises are developing photodetectors for various purposes in Russia. The main suppliers are NPO Orion JSC and MZ Sapfir JSC, members of Shvabe JSC, as well as a private enterprise Astrohn DB JSC. NPO Orion JSC develops and produces refrigerated and uncooled photodetectors. MZ Sapphire JSC produces cooled and uncooled APDs based on Si, Ge, InSb, CdHgTe. NII Polyus JSC is developing uncooled InGaAs-based APDs and the production of photosensitive semiconductor structures. The enterprises of Roselectronika JSC specialize in the development and production of visible-range arrays based on silicon, cooled by APDs based on quantum wells, the Schottky barrier from platinum silicide, and cooled PDs based on impurity silicon (NPP Pulsar JSC, CRI Electron JSC, CRI Cyclone JSC, NPP Vostok JSC). The Institute of Semiconductor Physics of the Siberian Branch of the Russian Academy of Sciences is developing semiconductor materials science and multifunctional devices based on CdHgTe, InAs, microbolometers and quantum wells. Astrohn DB JSC (Lytkarino, Moscow Region) designs and manufactures civil thermal imaging devices based on uncooled APDs of its own production, as well as cooled APDs based on CdHgTe in conjunction with IFP SB RAS.
NPO Orion JSC started mass production of the medium-wave range APDs. Astrohn DB JSC has begun serial production of a array photodetector module in the long wavelength range based on a cooled KRT / Si array (manufactured by the Institute of Physics and Technology of the Siberian Branch of the Russian Academy of Sciences) and Astrohn-MKS500 own microcooling system. Astrohn-MKS500 operates on a closed reverse thermogasdynamic Stirling regenerative cycle with internal heat recovery; ultrapure helium gas is used as a working fluid. The results achieved are close in their indicators to the world level.
The first attempts to create microbolometric arrays were started in 1994–1995 at the NPO Orion (Moscow) [1, 3]. In the early 2000s, the company began developing devices of the 320 × 240 format on vanadium oxide on a silicon nitride substrate. However, the emerging market for civilian and security applications required large-scale production of microbolometers. Until recently, domestic equipment was provided with thermal imaging systems as part of a purchase or joint production with foreign co-contractors. The need for the development and serial production of domestic uncooled APDs became especially urgent after the ban on their supplies from abroad.
Since 2016, Astrohn DB JSC has mastered the production of multifunction devices with a sensitivity of up to 40 mK Astrohn‑38425-1 and Astrohn‑64025-1 with the size of sensitive elements of the array 25 μm and 17 μm. APD is made on the basis of a array of microbolometers with an electronic reading subsystem, and packed in a ceramic case. The APD has an array of microbolometers in the form of a two-dimensional array of elementary detectors located in the focal plane, consisting of 384 × 288 elements (PD ASTROHN‑38417-1), and 640 × 480 (PD ASTROHN‑64017-1). Microbolometers are made of vanadium oxide according to the bridge circuit. The APD delivers a raw image in analog format at speeds up to 60 frames per second. The electronic subsystem is controlled via a serial data bus. The pixel size is 17 × 17 μm.
The APD is made in the LCC (Leadless chip Carrier) case made of vacuum-tight ceramic (Fig. 15). The topology of microbolometric detectors of different manufacturers is shown in Fig. 16 [6]. Work on the creation of microbolometric arrays based on vanadium oxides is also underway at the Institute of Physics and Technology of the Siberian Branch of the Russian Academy of Sciences (Novosibirsk) [4, 6, 7].
MAIN DEVELOPMENT TRENDS
In the last decade, a number of new directions and trends have been outlined in infrared photoelectronics. They are associated with increasing the resolution of systems, improving methods for recording ultra-weak optical signals, creating high-speed and multispectral systems, forming infrared 3D images, etc.:
- transition to a full megapixel format of 1 024 × 1 280 elements with a simultaneous decrease in the step of elements, the creation of super-large format arrays;
- increase the functionality of APDs (3D, avalanche amplification, etc.);
- creation of dual-spectrum and multispectral APDs;
- expansion of applications of the short-wave infrared APDs;
- introduction of digital preprocessing in LSI readout;
- creation of ultra-long-wavelength APDs with a boundary wavelength of more than 14 microns;
- search for new principles for detecting infrared radiation and new photosensitive materials (graphene, other 2D structures, etc.).
CONCLUSION
The consequences of the pandemic and restrictions lead to the emergence of short-term and long-term factors influencing the market of IR APDs. Short-term can be attributed to everything that is directly related to medical thermography. This primarily relates to uncooled thermal detectors. The low response time in the case of inexpensive “looking” thermal imaging systems is practically insignificant, especially for medical applications when measuring the thermal fields of stationary objects or objects moving with small angular velocities. In general, the entire industry will experience a recovery (especially noticeable against the background of a possible slowdown in the global economy as a whole). Moreover, this trend can move from short-term to long-term phase.
With regard to long-term trends, it is highly likely that the epidemiological threat will occupy in the public mind the same place as the terrorist threat after the terrorist attacks in New York in 2001. It is impossible to exclude the appearance of biometric control at airports in addition to the existing aviation security protocols, new protocols for passing border crossing points, etc. All this will require a sharp increase in production volumes and lower manufacturing costs. Technologies of even larger series production in a single technical process of multi-pixel arrays with low defectiveness, as well as their hybridization with readout circuits will be in demand. In the medium term, a thermal imager will turn from a rather exotic and expensive device into an almost household device.
The ideas of using metamaterials, graphene, and other 2D structures in photoelectronics are being put into practice. Together with the “traditional” thermal imaging, they unusually widely push the boundaries and technical capabilities. We expect a significant expansion of the prospects for improvement and the creation of new infrared optoelectronic systems.
REFERENCES
Ponomarenko V. P., Filachev A. M. Infrakrasnaya tekhnika i elektronnaya optika. Stanovlenie nauchnyh napravleniya. – M.: Fizmatkniga. 2016. 417.
Filachev A. M., Taubkin I. I., Trishenkov M. A. Tverdotel’naya fotoelektronika. Fotorezistory i fotopriemnye ustrojstva. – M.: Fizmatkniga. 2012, 368.
Ponomarenko V. P. Tellurid kadmiya – rtuti i novoe pokolenie priborov infrakrasnoj fotoelektroniki. UFN. 2003; 173(6): 649–665.
Sizov F. F. IK‑fotoelektronika: fotonnye ili teplovye detektory? Perspektivy. Sensor Electronics and Microelectronics Technologies. 2015;12(1): 26–53.
Rogalski А. Next decade in infrared detectors. Proc. SPIE10433. ElectroOptical and Infrared Systems: Technology and Applications XIV (9–10 October2017). 2017; 10433:104330L1–104330L25. DOI: 10.1117 / 12.2300779.
Kul’chickij N. A., Naumov A. V., Starcev V. V. Neohlazhdaemye mikrobolometry infrakrasnogo diapazona-sovremennoe sostoyanie i tendencii razvitiya. Nanoi mikrosistemnaya tekhnika. 2018; 20(10): 613–624.
Samvelov A. V., YAsev S. G., Moskalenko A. S., Starcev V. V., Pahomov O. V. Integral Microcryogenic Stirling Systems As A Part Of Cryostatting Photoreceiving Modules Based On Long IR Region Matrix. Photonics Russia. 2019; 13(1): 58–64. DOI: 10.22184 / FRos.2019.13.1.58.64.
Ivanov S. D., Koscov E. G. Priemniki teplovogo izlucheniya neohlazhdaemyh megapiksel’nyh teplovizionnyh matric (obzor). Uspekhi Prikladnoj fiziki. 2017; 5(2): 136–154.
ABOUT AUTHORS
Kulchitsky Nikolai Alexandrovich, Doctor of Technical Sci., e-mail: n.kulchitsky@gmail.com, Professor, Moscow Technological University (MIREA), Chief Specialist, SSC RF, JSC Orion Scientific-Production Association, Moscow, Russia.
ORCID ID: 0000-0003-4664-4891
Naumov Arkady Valerievich, engineer-analyst, ASTROHN Technology Ltd,
https://astrohn.ru, Lytkarino, Moscow region, Russia.
ORCID: 0000-0001-6081-8304
Startsev Vadim Valerievich, Cand. of Technical Sciences, ASTROHN Technology Ltd, https://astrohn.ru, Lytkarino, Moscow region, Russia.
ORCID ID: 0000-0002-2800-544X
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