Format

Send to

Choose Destination
Sensors (Basel). 2019 Feb 7;19(3). pii: E672. doi: 10.3390/s19030672.

In-Situ Temperature Measurement on CMOS Integrated Micro-Hotplates for Gas Sensing Devices.

Author information

1
Materials Center Leoben Forschung GmbH, Roseggerstrasse 12, 8700 Leoben, Austria. marco.deluca@mcl.at.
2
Materials Center Leoben Forschung GmbH, Roseggerstrasse 12, 8700 Leoben, Austria. robert.wimmer-teubenbacher@mcl.at.
3
Materials Center Leoben Forschung GmbH, Roseggerstrasse 12, 8700 Leoben, Austria. lisa.mitterhuber@mcl.at.
4
ams AG, Tobelbader Strasse 30, 8141 Premstaetten, Austria. johanna.mader@ams.com.
5
ams AG, Tobelbader Strasse 30, 8141 Premstaetten, Austria. karl.rohracher@ams.com.
6
Materials Center Leoben Forschung GmbH, Roseggerstrasse 12, 8700 Leoben, Austria. marco.holzer@mcl.at.
7
Materials Center Leoben Forschung GmbH, Roseggerstrasse 12, 8700 Leoben, Austria. anton.koeck@mcl.at.

Abstract

Metal oxide gas sensors generally need to be operated at elevated temperatures, up to and above 400 °C. Following the need for miniaturization of gas sensors and implementation into smart devices such as smartphones or wireless sensor nodes, recently complementary metal-oxide-semiconductor (CMOS) process-based micro electromechanical system (MEMS) platforms (micro-hotplates, µhps) have been developed to provide Joule heating of metal oxide sensing structures on the microscale. Heating precision and possible spatial temperature distributions over the µhp are key issues potentially affecting the performance of the overall gas sensor device. In this work, we use Raman spectroscopy to directly (in-situ and in-operando) measure the temperature of CMOS-based µhps during the application of electric current for Joule heating. By monitoring the position of the Raman mode of silicon and applying the theoretical framework of anharmonic phonon softening, we demonstrate that state-of-the-art µhps are able to reach the set temperature with an error below 10%, albeit with significant spatial temperature variations on the hotplate. This work demonstrates the potential of Raman spectroscopy for in-situ and in-operando temperature measurements on Si-based devices, an aspect of high relevance for micro- and nano-electronic device producers, opening new possibilities in process and device control.

KEYWORDS:

MEMS; Raman spectroscopy; gas sensors; micro-hotplates; silicon

Supplemental Content

Full text links

Icon for Multidisciplinary Digital Publishing Institute (MDPI) Icon for PubMed Central
Loading ...
Support Center