Self-consistent analysis of AlSb/InAs high electron mobility transistor structures

Abstract

The influences of channel layer width, spacer layer width, and δ-doping density on the electron density and its distribution in the AlSb/InAs high electron mobility transistors (HEMTs) have been studied based on the self-consistent calculation of the Schrödinger and Poisson equations with both the strain and nonparabolicity effects being taken into account. The results show that, having little influence on the total two dimensional electron gas (2DEG) concentration in the channel, the HEMT’s channel layer width has some influence on the electron mobility, with a channel as narrow as 100–130 Å being more beneficial. For the AlSb/InAs HEMT with a Te δ-doped layer, the 2DEG concentration as high as 9.1×1012 cm−2 can be achieved in the channel by enhancing the δ-doping concentration without the occurrence of the parallel conduction. When utilizing a Si δ-doped InAs layer as the electron-supplying layer of the AlSb/InAs HEMT, the effect of the InAs donor layer thickness is studied on the 2DEG concentration. To obtain a higher 2DEG concentration in the channel, it is necessary to use an InAs donor layer as thin as 4 monolayer. To test the validity of our calculation, we have compared our theoretical results (2DEG concentration and its distribution in different sub-bands of the channel) with the experimental ones done by other groups and show that our theoretical calculation is consistent with the experimental results.

High sensitivity Hall devices with AlSb/InAs quantum well structures

“…The RMS roughness over a 10 µm×10 µm area was measured to be 2.67 nm. The cracks in the crystallographic orientation, [1][2][3][4][5][6][7][8][9][10] observed on the surface, are attributed to threading dislocations propagating throughout the InAs channel. [9] Figure 4 shows the electron mobility and the sheet electron concentration as a function of the thickness of the InAs channel at room temperature.…”

“…AlSb/InAs QW material system is a very attractive system due to the high electron mobility (30000 cm 2 • V −1 • s −1 at a temperature of 300 K) , the electron saturation velocity (4 × 10 7 cm • s −1 ) of InAs, and the large conduction band offset between InAs and AlSb (1.35 eV). [1][2][3][4][5][6][7] However, a large number of difficulties of material growth must be overcome. The first step is to find a semi-insulating (SI) substrate lattice matched to 6.1-Å materials.…”

Specific Detection of Alpha-Fetoprotein Using AlGaAs/GaAs High Electron Mobility Transistors

“…Nevertheless, current methods including enzyme linked immunosorbent Recently, high electron mobility transistor (HEMT) based biosensors have exhibited their advantages in detecting a variety of chemical and biological substances. Owing to the high sheet concentration of the two-dimensional gas (2DEG) in the channel layer, which is induced by spontaneous and piezoelectric polarization in GaN-based HEMTs [3], [4] and by δ-doping in GaAs, InP, and Sb-based HEMTs [5]- [9], small variation in the charges at the gate area by the presence of the target substance will induce a large change of the current between the source and drain. Using AlGaN/GaN HEMTs, fast detection of DNA, enzyme-based lactic acid, perkinsus marinus, etc., has been reported [10]- [16].…”