An uncooled microbolometer infrared focal plane array in standard CMOS

Tezcan, Ds
Eminoglu, S
Akar, Os
Akın, Tayfun
This paper reports implementation of a low-cost microbolometer focal plane array using n-well layer in a CMOS process as the microbolometer material. N-well microbolometer structures are suspended for thermal isolation by postetching of fabricated CMOS dies using silicon bulk-micromachining techniques. Although n-well has a moderate TCR of 0.5-0.65 %/K at 300 K, it still provides a reasonable performance due to its single crystal structure which contributes low 1/f noise. Detailed thermal simulations in ANSYS were performed to obtain an optimized structure. Various prototype FPAs with 16x16 array sizes have been implemented with 80 mu mx80 mum and 50 mu mx50 mum pixel sizes. The measurements and calculations show that the n-well microbolometers can provide a responsivity of 8.5x10(6) V/W, a detectivity of 5.5x10(9) cmHz(1/2)/W, and an NETD of 260 mK at 30 frames per second using a simple, fully-serial readout approach with an integrator output. The performance of the array can be increased with advanced readout techniques and improved pixel structures. The CMOS n-well microbolometer approach seems very cost-effective to produce large focal plane arrays for uncooled infrared imaging with reasonable performance.


A CMOS n-well microbolometer FPA with temperature coefficient enhancement circuitry
Eminoglu, S; Tezcan, DS; Akın, Tayfun (2001-04-20)
This paper reports the development of a low-cost CMOS microbolometer focal plane array with a new temperature coefficient enhancement readout circuit. We have recently reported an uncooled microbolometer detector that uses the CMOS n-well layer as the active material, where the suspended and thermally isolated n-well structure is obtained by silicon bulk micromachining of fabricated CMOS dies. In addition, we have successfully fabricated a 16x16 n-well microbolometer FPA. Although n-well is single crystal s...
A low-cost 128x128 uncooled infrared detector array in CMOS process
Eminoglu, Selim; Tanrikulu, Mahmud Yusuf; Akın, Tayfun (2008-02-01)
This paper discusses the implementation of a low-cost 128 x 128 uncooled infrared microbolometer detector array together with its integrated readout circuit (ROC) using a standard 0.35 mu m n-well CMOS and post-CMOS MEMS processes. The detector array can be created with simple bulk-micromachining processes after the CMOS fabrication, without the need for any complicated lithography or deposition steps. The array detectors are based on suspended p(+)-active/n-well diode microbolometers with a pixel size of 4...
A low-cost small pixel uncooled infrared detector for large focal plane arrays using a standard CMOS process
Eminoglu, S; Tanrikulu, MY; Tezcan, DS; Akın, Tayfun (2002-04-03)
This paper reports the development of a low-cost, small pixel uncooled infrared detector using a standard CMOS process. The detector is based on a suspended and thermally isolated p(+)-active/n-well diode whose forward voltage changes due to an increase in the pixel temperature with absorbed infrared radiation. The detector is obtained with simple post-CMOS etching steps on dies fabricated using a standard n-well CMOS process. The post-CMOS process steps are achieved without needing any deposition or lithog...
A CMOS visible image sensor array using current mirroring integration readout circuitry
Akbay, Selim Sermet; Bircan, A.; Akın, Tayfun (null; 2000-08-30)
This paper reports the development of a CMOS visible sensor array using a high performance readout circuit called Current Mirroring Integration (CMI). The sensor element is a photodiode implemented using n-well and p+ -active layers available in any CMOS process. The current generated by optical excitation is mirrored and integrated in an off-pixel capacitor using the CMI readout circuit, which provides high injection efficiency, low input impedance, almost-zero and stable detector bias, and a high dynamic ...
A low cost uncooled infrared microbolometer focal plane array using the CMOS n-well layer
Tezcan, DS; Eminoglu, S; Akar, OS; Akın, Tayfun (2001-01-25)
This paper reports a low-cost, 256-pixel uncooled infrared microbolometer focal plane array (FPA) implemented using a 0.8 mum CMOS process where the n-well layer is used as the active microbolometer material. The suspended n-well structure is obtained by simple front-end bulk etching of the fabricated CMOS dies, while the n-well region is protected from etching by electrochemical etch-stop technique within a TMAH solution. Electrical connections to the suspended n-well are obtained with polysilicon intercon...
Citation Formats
D. Tezcan, S. Eminoglu, O. Akar, and T. Akın, “An uncooled microbolometer infrared focal plane array in standard CMOS,” 2001, vol. 4288, Accessed: 00, 2020. [Online]. Available: