Electron Transport in Modulation-Doped InAlAs/InGaAs/InAlAs Heterostructures in High Electric Fields

Abstract

The following peculiarities of electron transport in In0.53Ga0.47As/In0.52Al0.48As quantum wells with δ-Si-doped In 0.52 Al 0.48 As barriers at high electric fields are discovered: (1) an enhancement of electron mobility by inserting the InAs phonon wall into the In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As quantum well, as well as increasing the InAs content in the modulation-doped In 0.8 Ga 0.2 As/In 0.7 Al 0.3 As heterostructure; (2) a large decrease in electron mobility and a change of electron density with increasing electric field in the range of 1-4 kV/cm; (3) a magnetic field dependence of the threshold electric field for intervalley scattering of electrons; and (4) microwave current oscillations in high electric fields.

Electron transport in modulation-doped InAlAs/InGaAs/InAlAs and AlGaAs/InGaAs/AlGaAs heterostructures

“…The engineering of electron interaction with polar optical (PO) and interface (IF) phonons by inserting thin semiconductor layers into a quantum well (QW), which could reflect PO and IF phonons, is a functional tool for controlling electron transport and photoelectric properties of semiconductor heterostructures [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. In particular, it is essential to increase electron mobility in In 0.52 Al 0.48 As/ In 0.53 Ga 0.47 As/In 0.52 Al 0.48 As channels of high electron mobility transistors (HEMTs) that in turn are the basic elements of microwave electronics in the frequency range up to 100 GHz, and are intended for detection and generation of electromagnetic radiation in the terahertz frequency range [16][17][18][19].…”

“…The field F ⊥ collects free electrons in the QW at the interface barrier, and electron interaction with IF phonons increases. In modulation-doped InAlAs/InGaAs structures at 300 K, electron scattering by IF phonons is a dominant scattering mechanism [12,14,15].…”

“…Regulation of electron-interface phonon scattering rate by changing composition of In x Al 1-x As/ In y Ga 1-y As and Al x Ga 1-x As/In y Ga 1-y As QWs An electron-IF phonon scattering rate is a function of IF phonon frequencies, which are determined by a composition of interface semiconductor materials. Calculations of the electron-IF phonon scattering rate show that the rate can be reduced several times by increasing InAs content x in the In x Al 1-x As barrier layer at the In 0.53 Ga 0.47 As QW, as well as by decreasing AlAs content x in the Al x Ga 1-x As barrier layer at the In 0.2 Ga 0.8 As QW [12,14,15]. The maximal decrease of the electron-IF phonon scattering rate is achieved for InAs content x around 0.8 [11] and AlAs content x = 0 [14].…”