Low-cost microbolometer infrared detectors utilizing CMOS resistive layers

Download
2017
Öztürk, Hande
This thesis presents the efforts to develop low-cost microbolometer type uncooled infrared detector architectures that utilize standard CMOS layers and components. Various resistance structures of different CMOS technologies are investigated and possible resistors are determined as the active material. In order to figure out potential microbolometer structure, all possible layers in the CMOS technologies are analyzed in terms of mechanical and thermal parameters. Mathematical modeling and computer simulations are realized. In order to obtain experimental data about the CMOS components, two different multi-project wafer CMOS chips are completed that contain various resistances and microbolometer structures. These designs are fabricated in a 0.35 µm and 0.18 µm CMOS processes and characterized in terms of electrical resistivity, temperature coefficient of resistance, thermal conductance, and noise. The characterization results are used to employ two different microbolometer infrared sensors focal plane arrays (FPAs), one with the 40x40 array size and 60 µm pixel size and the other one with the 80x80 array size with 35 µm pixel size. The developed and fabricated sensors are characterized in terms of the detector performance successfully. The outcome of this thesis can be summarized in three items. First of all, it is proven that the CMOS resistive layers can be used as the microbolometer active material, thanks to their very low flicker noise and very high uniformity across the FPA. Secondly, the microbolometer architecture designed in the scope of this thesis formed the fundamentals of the CMOS Infrared (CIR) Technology concept, which enables the fabrication of the infrared sensors in almost any CMOS/MEMS foundries in the world. Thirdly, two different infrared pixel structures developed in the scope of this thesis are employed to develop two different microbolometer FPAs with a team effort of Mikrosens Inc. The 40x40 FPA with 60 µm pixel pitch provides an 237 mK NETD value at 30 fps, in a dewar vacuum conditions with f/1 optics, while the 80x80 FPA with 35 µm pixel pitch provides 150 mK and 68 mK NETD values at 17 fps and 4 fps, respectively, in a dewar vacuum conditions with f/1 optics.

Suggestions

A Low-power capacitive integrated CMOS readout circuitry for high performance MEMS accelerometers
İncedere, Osman Samet; Akın, Tayfun; Eminoğlu, Selim; Department of Electrical and Electronics Engineering (2013)
This thesis presents a low power capacitive integrated CMOS readout circuitry for high performance MEMS accelerometers. It proposes a linearized model of the complete closed loop accelerometer system, which makes easier of designing and analyzing the system. Designed readout circuitry offers low noise, wide dynamic range and high linearity system with very low power consumption. Designed readout circuit includes proportional integral (PI) controller circuit, which significantly decreases the proof mass defl...
Low--‐cost uncooled infrared imaging sensor using mems and a modified standard cmos process
Gülden, Mehmet Ali; Akın, Tayfun; Eminoğlu, Selim; Department of Electrical and Electronics Engineering (2013)
The thesis presents a monolithically integrated low-­‐cost uncooled infrared imaging sensor using a MEMS process and a modified standard CMOS process. The designed sensor has an image format of 160×120 with a pixel pitch of 40 μm. The sensor is implemented with microbolometers that sense the infrared radiation in the 8-­‐12 μm spectral band, where the sensing elements in each pixel are formed with CMOS diodes to sense the temperature variation in the pixel by monitoring the change in the forward bias voltag...
Low-cost uncooled infrared detector arrays in standard CMOS
Eminoglu, S; Tanrikulu, MY; Akın, Tayfun (2003-04-25)
This paper reports the development of a low-cost 128 x 128 uncooled infrared focal plane array (FPA) based on suspended and thermally isolated CMOS p(+)-active/n-well diodes. The FPA is fabricated using a standard 0.35 mum CMOS process followed by simple post-CMOS bulk micromachining that does not require any critical lithography or complicated deposition steps; and therefore, the cost of the uncooled FPA is almost equal to the cost of the CMOS chip. The post-CMOS fabrication steps include an RIE etching to...
CMOS readout electronics for mis-matched and mode-matched MEMS gyroscopes
Yeşil, Ferhat; Akın, Tayfun; Department of Electrical and Electronics Engineering (2015)
This thesis presents the CMOS readout electronics for both mismatched and mode-matched MEMS gyroscopes. A systematic design of MEMS gyroscope's control loop parameters, which is insensitive to sensor parameters and environmental conditions, is necessary for robust and high performance operation. Extra to the systematic design for high performance operation, some special techniques should be used to further increase the performance of the sensor. In this thesis, as a performance increasing technique, mode-ma...
A Small format microbolometer imaging sensor with digital video outputs
Yalçın, Cem; Koç, Seyit Sencer; Department of Electrical and Electronics Engineering (2016)
This thesis presents a small format Readout Integrated Circuit (ROIC) for surface micromachined resistive microbolometer imaging sensors. The imaging sensor is designed to work in the Long Wave Infrared region (8 – 14 um) and is designed with an 80 x80 format with a pixel pitch of 25 um. The ROIC is optimized to perform the readout of MEMS pixels with resistance values around 60 Kohm, where infrared blind reference resistors with similar values are also used to cancel effects of selfheating and high biasi...
Citation Formats
H. Öztürk, “Low-cost microbolometer infrared detectors utilizing CMOS resistive layers,” M.S. - Master of Science, Middle East Technical University, 2017.