• Journal of Sensor Science and Technology
• /
• v.16 no.2
• /
• pp.104-109
• /
• 2007

In this paper, we have fabricated on extended-gate field effect transistor (EGFET)-type protein sensor for the application to a CRP detection. We used the self-assembled monolayer (SAM) to adhere or entrap biomolecules, namely CRP antibodies. The experimental result shows that the proposed SAM is well immobilized on the gold gate surface. So the drain current was varied by antigen-antibody interactions on the gate surface because of the CRP charge. Experimental results related to the formation of SAM, antibody, antigen were obtained by measuring the electrical characteristics of the EGFET device.

• Journal of Sensor Science and Technology
• /
• v.20 no.3
• /
• pp.156-161
• /
• 2011

We fabricated a schottky barrier metal oxide semiconductor field effect transistor(SB-MOSFET) by applying indium-tin-oxide(ITO) to the source/drain on a highly resistive GaN layer grown on a silicon substrate. The MOSFET, with 10 ${\mu}M$ gate length and 100 ${\mu}M$ gate width, exhibits a threshold gate voltage of 2.7 V, and has a sub-threshold slope of 240 mV/dec taken from the $I_{DS}-V_{GS}$ characteristics at a low drain voltage of 0.05 V. The maximum drain current is 18 mA/mm and the maximum transconductance is 6 mS/mm at $V_{DS}$=3 V. We observed that the spectral photo-response characterization exhibits that the cutoff wavelength was 365 nm, and the UV/visible rejection ratio was about 130 at $V_{DS}$ = 5 V. The MOSFET-type UV detector using ITO, has a high UV photo-responsivity and so is highly applicable to the UV image sensors.

• Journal of Korea Society of Industrial Information Systems
• /
• v.19 no.4
• /
• pp.33-39
• /
• 2014

In this paper, a new on-chip aging sensing circuit based on flip-flops is proposed to detect a circuit failure of MOSFET digital circuits casued by aging phenomenon such as HCI and BTI. The proposed circuit uses timing windows to warn against a guardband violation of sequential circuits, and generates three warning bits right before circuit failures occur. The generated bits can apply to an adaptive self-tuning method for reliable system design as control signals. The aging sensor circuit has been implemented using 0.11um CMOS technology and evaluated by $4{\times}4$ multiplier with power gating structure.

• Journal of Sensor Science and Technology
• /
• v.30 no.4
• /
• pp.236-242
• /
• 2021

In this paper, we report the fabrication of the tip-on-gate of a field-effect-transistor (ToGoFET) probe using a standard complementary metal-oxide-semiconductor (CMOS) process and the performance evaluation of the fabricated probe. After the CMOS process, I-V characteristic measurement was performed on the reference MOSFET. We confirmed that the ToGoFET probe could be operated at a gate voltage of 0 V due to channel ion implantation. The transconductance at the operating point (Vg = 0 V, Vd = 2 V) was 360 ㎂/V. After the fabrication process was completed, calibration was performed using a pure metal sample. For sensitivity calibration, the relationship between the input voltage of the sample and the output current of the probe was determined and the result was consistent with the measurement result of the reference MOSFET. An oxide sample measurement was performed as an example of an application of the new ToGoFET probe. According to the measurement, the ToGoFET probe could spatially resolve a hundred nanometers with a height of a few nanometers in both the topographic image and the ToGoFET image.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.876-879
• /
• 2012

In this paper we studied the radiation detection technology which described the radiation level distribution in high radiation area with remotely and safely. The designed radiation mapping system was composed of radiation nodes and radiation station. The radiation nodes could sense the radiation dose values with pMOSFET radiation sensors and transmit them to the radiation station. At the radiation station the received radiation values were merged with a geometric information and visualized at the virtual graphic location. For the functional verification of the above system, we attached the radiation nodes to each corner in our laboratory, executed the mapping tests, and confirmed the designed functions finally.

• Journal of the Korea Computer Industry Society
• /
• v.3 no.2
• /
• pp.141-148
• /
• 2002

In this paper, brushed servo control system for industrial robot is realized under GUI environment. Brushed servo motor has 400W capacities, 1000ppr optic encoder and electric brake load. Especially, driving unit is composed of full-bridge MOSFET semiconductors with 9540 and 540 FET ICs. Control unit has PIC 16C74 microprocessor［l,2,3], RS-232 communication ports, URD current sensor, and GAL 16R8ACN. Servo control system is controlled by PID control method[5,8］ with varying control parameters and load capacities. Brushed servo control systems which are proposed in this raper are applied to industrial robot control system.

• Journal of Sensor Science and Technology
• /
• v.10 no.3
• /
• pp.173-179
• /
• 2001

The currently used semiconductor pressure sensors are piezoresistive and capacitive type. Especially, semiconductor micro pressure sensors have a great deal of attention because of their small size. However, its fabrication processes are difficult, so that its yield is poor. For the purpose of resolving the drawbacks of the existing silicon pressure sensors, we demonstrate a new type of pressure sensor using PSFET(pressure sensitive field effect transistor) and investigate its operational characteristics. We used PZT(Pb(Zr,Ti)$O_3$) as a pressure sensing material. PZT thin films were deposited on a gate oxide of MOSFET by an rf-magnetron sputtering method. To abtain the stable phase, perovskite structure, furnace annealing technique have been employed in PbO ambient. The sensitivity of the PSFET was 0.38 mV/mmHg.

• Journal of Sensor Science and Technology
• /
• v.18 no.4
• /
• pp.274-279
• /
• 2009

In this paper, a wide dynamic range active pixel sensor(APS) with output voltage feedback structure has been designed by a 2-poly 4-metal 0.35 $\mu$m standard CMOS technology. We presented a novel APS with output voltage feedback, which exhibits a wide dynamic range. The dynamic range increases at the cost of an additional diode and an additional MOSFET. The output voltage feedback structure enables the control of the output voltage level by itself, as incident light power varies. It is confirmed that the light level which the output voltage level of proposed APS is saturated is about 120,000 lux, which is higher than that of a conventional 3-transistor APS.

• Journal of Sensor Science and Technology
• /
• v.25 no.5
• /
• pp.320-325
• /
• 2016

In this paper, we propose an AlGaN/GaN-based extended-gate metal-insulator-semiconductor high electron mobility transistor (MISHEMT)-type biosensor for detecting streptavidin-biotin complexes. We measure the drain current of the fabricated sensor, which varies depending on the antibody-antigen reaction of streptavidin with biotin molecules. To confirm the immobilization of biotin polyethylene glycol (PEG) thiol, we analyze the Au surface of a GaN sample using X-ray photoelectron spectroscopy (XPS). The proposed biosensor shows higher sensitivity than Si-based extended-gate metal oxide semiconductor field effect transistor (MOSFET)-type biosensor. In addition, the proposed AlGaN/GaN-based extended-gate MISHEMT-type biosensor exhibits better long-term stability, compared to the conventional AlGaN/GaN-based MISHEMT-type biosensor.

• Journal of Sensor Science and Technology
• /
• v.11 no.5
• /
• pp.255-262
• /
• 2002

Human retina is able to detect the edge of an object effectively. We designed a CMOS vision chip by modeling cells of the retina as hardwares involved in edge detection. There are several fluctuation factors which affect characteristics of MOSFETs during CMOS fabrication process and this effect appears as output offset of the vision chip which is composed of pixel arrays and readout circuits. The vision chip detecting edge information from input image is used for input stage of other systems. Therefore, the output offset of a vision chip determine the efficiency of the entire performance of a system. In order to eliminate the offset at the output stage, we designed a vision chip by using CDS(Correlated Double Sampling) technique. Using standard CMOS process, it is possible to integrate with other circuits. Having reliable output characteristics, this chip can be used at the input stage for many applications, like targe tracking system, fingerprint recognition system, human-friendly robot system and etc.