Band offset determination of mixed As/Sb type-II staggered gap heterostructure for n-channel tunnel field effect transistor application

Abstract

Defect assistant band alignment transition from staggered to broken gap in mixed As/Sb tunnel field effect transistor heterostructure J. Appl. Phys. 112, 094312 (2012) The experimental study of the valence band offset (DE v ) of a mixed As/Sb type-II staggered gap GaAs 0.35 Sb 0.65 /In 0.7 Ga 0.3 As heterostructure used as source/channel junction of n-channel tunnel field effect transistor (TFET) grown by molecular beam epitaxy was investigated by x-ray photoelectron spectroscopy (XPS). Cross-sectional transmission electron micrograph shows high crystalline quality at the source/channel heterointerface. XPS results demonstrate a DE v of 0.39 6 0.05 eV at the GaAs 0.35 Sb 0.65 /In 0.7 Ga 0.3 As heterointerface. The conduction band offset was calculated to be $0.49 eV using the band gap values of source and channel materials and the measured valence band offset. An effective tunneling barrier height of 0.21 eV was extracted, suggesting a great promise for designing a metamorphic mixed As/Sb type-II staggered gap TFET device structure for low-power logic applications. V C 2013 American Institute of Physics.

Defect assistant band alignment transition from staggered to broken gap in mixed As/Sb tunnel field effect transistor heterostructure

“…The detailed measurements, measured CL and VB XPS spectra of structure B were reported elsewhere. 13 The CL and VB spectra from each sample of structure C were shown in Figs.…”

“…7,12 Among them, mixed As/Sb based heterostructure namely, GaAs 1Ày Sb y /In x Ga 1Àx As allows a wide range of bandgaps and band alignments depending on the alloy compositions in GaAs 1Ày As y source and In x Ga 1Àx As channel layers. 9,10,13,14 The band alignment at the source/ channel interface determines the effective tunneling barrier, E beff , which is defined as the energy difference between the conduction band minimum of the channel and the valence band maximum of the source. This E beff plays a significant role on the performance of a TFET device, which not only determines the ON-state tunneling rate but also sets the blocking barrier for the OFF-state leakage.…”

DC ANALYSIS OF p-n-p-n TUNNELING FIELD-EFFECT TRANSISTOR BASED ON In0.35Ga0.65As

“…Enhance the current and steep subthreshold swing (below 60 mv/decade) are reliable trait as compared with MOS technology in ultralow voltage and high frequency applications (Vallett, et al, 2010;Ionescu and Riel, 2011). The method of carrier relocation is band--to--band tunneling (BTBT) (Zhu, et al, 2013) model which this phenomena betide between the source region and the channel region (Khayer and Lake, 2009). High ON current (I on ), low OFF current (I off ) and steep subthreshold swing are superior trait that make it distinguished from other devices.…”

Enhanced Characteristics of Square-Shaped Extended Source TFET Via Silicon Carbide Polytype (3C-SiC) and a Dopant Pocket Layer

“…On the other hand, an increase in on-current causes the RF performances of the TFETs to be enhanced. To enhance the TFET on-currents, many efforts have been made including hetero-structures 11,16,17 , bandgap engineering 18,20 , high mobility and low band-gap materials 20,23 , high-k dielectric materials 24,25 , heterogate-dielectric (HG) 26,27 , dual material gate 28,30 and vertical direction tunneling 31,32 .…”