Research on a CMOS-MEMS Infrared Sensor with Reduced Graphene Oxide

Abstract

In this research, a new application of reduced graphene oxide (rGO) for a complementary metal-oxide-semiconductor (CMOS)-MEMS infrared (IR) sensor and emitter is proposed. Thorough investigations of IR properties including absorption and emission were proceeded with careful calibration and measurement with a CMOS thermoelectric sensor. The thermocouples of the sensor consist of aluminum and n-polysilicon layers which are fabricated with the TSMC 0.35 μm CMOS process and MEMS post-process. In order to improve the adhesion of rGO, a sensing area at the center of the membrane is formed with an array of holes, which is easy for the drop-coating of rGO material upon the sensing region. To evaluate the performance of the IR sensor with rGO, different conditions of the IR thermal radiation experiments were arranged. The results show that the responsivity of our proposed CMOS-MEMS IR sensor with rGO increases by about 77% compared with the sensor without rGO. For different IR absorption incident angles, the measurement of field of view shows that the CMOS-MEMS IR sensor with rGO has a smaller view angle, which can be applied for the application of long-distance measuring. In addition, characteristics of the proposed thermopile are estimated and analyzed with comparisons to the available commercial sensors by the experiments.

Thermal Sensors for Contactless Temperature Measurements, Occupancy Detection, and Automatic Operation of Appliances during the COVID-19 Pandemic: A Review

“…Furthermore, the IR absorption efficiency, and therefore the responsivity, could be increased by employing different materials for the absorbing membrane. For example, in [ 62 ] reduced graphene oxide (rGO) is deposited by drop-coating on the absorbing area: in this way, the responsivity of the considered thermopile sensor is increased by about 77% with respect to the sensor without the rGO. The considered thermopile sensor is illustrated in Figure 12 .…”

“…Table 2 reports the main characteristics of different thermopile-based thermal detectors. The considered thermopile sensors have been proposed in the referenced papers for various applications: contactless human body temperature measurements [ 15 , 60 ], motion and presence detection [ 63 ], high resolution imaging applications [ 56 ], high-precision IR detection applications [ 54 ], long-distance measuring thanks an intrinsically reduced FOV angle [ 62 ]. Thermopile sensors, therefore, appear particularly well suited for COVID-19 related applications as they are very versatile and can be employed both for contactless fever measurements and for presence and motion detection applications enabling people counting or appliances automation.…”

“… Microphotograph of the thermopile sensor presented in [ 62 ] ( a ) before and ( b ) after rGO drop-coating. …”

A New Macro-Model of Gas Flow and Parameter Extraction for a CMOS-MEMS Vacuum Sensor

“…This development was promoted by mature technology in the semiconductor industry and micro-electro-mechanical systems (MEMS) based on the techniques of microfabrication. Among these, CMOS-MEMS, with its batch fabrication techniques, enables vacuum sensing components to be manufactured with increased performance and reliability, combined with the obvious advantages of low consumed power, and reduced physic size, volume, and weight at a relatively low-cost level [2,3]. It is also easily integrated on the same chip with control or processing circuitry by using a commercial semiconductor device process [2][3][4].…”

“…Among these, CMOS-MEMS, with its batch fabrication techniques, enables vacuum sensing components to be manufactured with increased performance and reliability, combined with the obvious advantages of low consumed power, and reduced physic size, volume, and weight at a relatively low-cost level [2,3]. It is also easily integrated on the same chip with control or processing circuitry by using a commercial semiconductor device process [2][3][4]. Among these studies, thermal MEMS elements are widely used as thermal sensors and heating components, especially thermal-type vacuum sensors (Pirani pressure gauge), which can be used for pressure sensing [5][6][7].…”