Viscosity-dependent drain current noise of AlGaN/GaN high electron mobility transistor in polar liquids

Abstract

The drain current fluctuation of ungated AlGaN/GaN high electron mobility transistors (HEMTs) measured in different fluids at a drain-source voltage of 0.5 V was investigated. The HEMTs with metal on the gate region showed good current stability in deionized water, while a large fluctuation in drain current was observed for HEMTs without gate metal. The fluctuation in drain current for the HEMTs without gate metal was observed and calculated as standard deviation from a real-time measurement in air, deionized water, ethanol, dimethyl sulfoxide, ethylene glycol, 1,2-butanediol, and glycerol. At room temperature, the fluctuation in drain current for the HEMTs without gate metal was found to be relevant to the dipole moment and the viscosity of the liquids. A liquid with a larger viscosity showed a smaller fluctuation in drain current. The viscosity-dependent fluctuation of the drain current was ascribed to the Brownian motions of the liquid molecules, which induced a variation in the surface dipole of the gate region. This study uncovers the causes of the fluctuation in drain current of HEMTs in fluids. The results show that the AlGaN/GaN HEMTs may be used as sensors to measure the viscosity of liquids within a certain range of viscosity.

Modification of Dopant Concentration Profile in a Field-Effect Heterotransistor for Modification Energy Band Diagram

“…At the same time one can find increasing integration rate of integrated circuits [1][2][3]5,7]. In this situation dimensions of elements of integrated circuits decreases.…”

“…The parameter γ is integer and usually could be varying in the following interval γ ∈ [1,3]. The parameter describes quantity of charged defects, which interacting (in aver-age) with each atom of dopant.…”

“…Development of solid state electronic leads to increasing performance of the appropriate electronic devices [1][2][3][4][5][6][7][8][9][10][11]. At the same time one can find increasing integration rate of integrated circuits [1][2][3]5,7].…”

On Optimization of Manufacturing Planar Double-Base Heterotransistors To Decrease Their Dimensions

“…where D L (x,y,z,T) is the spatial (due to presents several layers in heterostructure) and temperature (due to Arrhenius law) dependences of dopant diffusion coefficient; P (x,y,z,T) is the limit of solubility of dopant; parameter γ depends on properties of materials and could be integer in the following interval γ ∈ [1,3] [13]; V (x,y,z,t) is the spatio-temporal distribution of concentration of radiation vacancies; V * is the equilibrium distribution of concentration of vacancies. Concentrational dependence of dopant diffusion coefficient has been described in details in [13].…”

“…One way to increase performance of the solid state electronic devices is searching materials with higher charge carriers mobility [1][2][3]. Another way to increase the performance is development of new or optimization of existing technological processes [4][5][6][7].…”