Electron transport in Al _x Ga_1−x As based double quantum well modulation doped field effect transistor structure: effect of non-square potential profile

Abstract

The importance of non-square quantum well potential profile on the electron mobility µ of coupled double quantum well based modulation doped field effect transistor (MOD-FET) structure is studied. We consider non-square cubic structure potential, V DS (z) α z 3 , where z denotes the position coordinate from the center of the well. The cubic double quantum well (CD-QW) is made of Al x Ga 1−x As alloy in which both the side barriers are δ-doped with Si. We consider ionized impurity (imp-) and alloy disorder (al-) scatterings for the calculation of µ. We investigate the variation of the structure parameters, such as well width, barrier width, alloy concentration and doping concentration on µ. The nonlinear behavior of µ can be achieved by properly tuning the structure parameters, mostly controlled by imp-scatterings. We show that under suitable structure parameters µ is enhanced in CD-QW as compared to that of a conventional SD-QW structure. Our analysis will help improve the channel conductivity in QW based MOD-FETs.

Asymmetric doping induced nonlinear electron mobility in double V-shaped quantum well based FET structure under external electric field

“…The shape of the potential manipulates the energy levels and wave functions which can be applied to specific devices. Study of electronic as well as optical properties of NS-QW systems has been made to explore their use in novel electro-optic devices [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Parabolic quantum wells have been shown to provide a small leakage current for infrared detector applications [1].…”