No abstract

Highly sensitive and stable pH-sensing properties of an extended-gate field-effect transistor (EGFET) based on the aluminum-doped ZnO (AZO) nanostructures have been demonstrated. The AZO nanostructures with different Al concentrations were synthesized on AZO/glass substrate via a simple hydrothermal growth method at 85°C. The AZO sensing nanostructures were connected with the metal-oxide-semiconductor field-effect transistor (MOSFET). Afterwards, the current-voltage (I-V) characteristics and the sensing properties of the pH-EGFET sensors were obtained in different buffer solutions, respectively. As a result, the pH-sensing characteristics of AZO nanostructured pH-EGFET sensors with Al dosage of 3 at.% can exhibit the higher sensitivity of 57.95 mV/pH, the larger linearity of 0.9998, the smaller deviation of 0.023 in linearity, the lower drift rate of 1.27 mV/hour, and the lower threshold voltage of 1.32 V with a wider sensing range (pH 1 ~ pH 13). Hence, the outstanding stability and durability of AZO nanostructured ionic EGFET sensors are attractive for the electrochemical application of flexible and disposable biosensor.

No abstract

The fabrication of trench-gate power MOSFETs with a SiGe channel region has been proposed to further improve the device performance. A larger Ge mole fraction of Si 1−x Ge x may cause a smaller on-state resistance but more degradation of the blocking voltage. A proper Ge mole fraction of 0.2 may be available, implementing a device with a blocking voltage of 30 V and a specific on-state resistance of about 0.70 cm. On the other hand, a gradually changed Ge mole fraction of the Si 1−x Ge x channel region may be employed to enhance the electric field in the channel region, and a specific on-state resistance of about 0.68 cm can be achieved. Moreover, for this device with a SiGe channel region, a thin n-SiGe layer may be used in the drain near the channel region. This scheme can even yield a specific on-state resistance of only about 0.66 cm which is 10% smaller than that caused by a conventional Si-channel device with the same process parameters.