Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
A low-power robust humidity sensor in a standard CMOS process
Date
2007-11-01
Author
Okcan, Burak
Akın, Tayfun
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
262
views
0
downloads
Cite This
This paper presents a low-cost thermal-conductivity-based humidity sensor implemented using a 0.6-mu m CMOS process, where suspended p-n junction diodes are used as the humidity-sensitive elements. The measurement method uses the difference between the thermal conductivities of air and water vapor at high temperatures by comparing the output voltages of two hea ted and thermally isolated diodes; one of which is exposed to the environment and has a humidity-dependent thermal conductance, while the other is sealed and has a fixed thermal conductance. Thermal isolation is obtained by a simple front-end bulk silicon etching process in a TMAH solution, while the diodes are protected by the electrochemical etch-stop technique. The suspended diodes are connected to an on-chip circuit using polysilicon interconnect layers in order to increase their thermal resistance to be able to heat them with less power. Due to the high electrical resistance and positive temperature coefficient of resistance of the polysilicon, temperature sensitivities of the diodes are reduced to - 1.3 mV/K at a 100-mu A bias level. The diodes and the readout circuit are monolithically integrated using a standard 0.6-mu m CMOS process. Characterization results show that humidity sensitivity of the sensor is 14.3, 26, and 46.9 mV/%RH for 20 degrees C, 30 degrees C, and 40 degrees C, respectively, with a nonlinearity less than 0.3%. Hysteresis of the sensor is less than 1%. The chip measures 1.65 mm x 1.90 mm, operates from a 5-V supply, and dissipates only 1.38-mW power.
Subject Keywords
Micro-electromechanical system (MEMS) humidity sensor
,
Humidity sensor
,
CMOS humidity sensor
URI
https://hdl.handle.net/11511/47054
Journal
IEEE TRANSACTIONS ON ELECTRON DEVICES
DOI
https://doi.org/10.1109/ted.2007.907165
Collections
Department of Electrical and Electronics Engineering, Article
Suggestions
OpenMETU
Core
A thermal conductivity based humidity sensor in a standard CMOS process
Okean, B; Akın, Tayfun (2004-01-29)
This paper presents a low-cost, thermal conductivity based humidity sensor implemented using a 0.6 mum CMOS process where suspended p-n junction diodes are used as the humidity sensitive elements. In this method, the difference between the thermal conductivities of air and water vapor at high temperatures is used. Humidity sensing idea is to compare the output voltages of two heated and thermally isolated diodes one of which is exposed to the environment and has a humidity dependent thermal conductance whil...
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...
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 laterally resonating gravimetric sensor with uniform mass sensitivity and high linearity
Eroglu, D.; Bayraktar, E.; Külah, Haluk (2011-09-01)
In this paper, a laterally resonating gravimetric sensor with high linearity and uniform mass sensitivity is presented for biochemical sensor applications including rare-cell detection. The sensor utilizes symmetrically placed, balanced, folded spring beam structures to ensure lateral motion of the proof mass and limit the displacement difference between the proof mass center and edges. The dynamic mass sensitivity range of the resonator is increased by using the above mentioned properties of the resonators...
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...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
B. Okcan and T. Akın, “A low-power robust humidity sensor in a standard CMOS process,”
IEEE TRANSACTIONS ON ELECTRON DEVICES
, pp. 3071–3078, 2007, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/47054.