Delta-doped quantum well structures grown by molecular beam epitaxy

Abstract

Delta doping in quantum well structures has been studied. The quantum wells consist of a strained InGaAs layer sandwiched between two GaAs layers. The layers were undoped except for a sheet of Si dopants deposited in the middle of the quantum well. Structures with various doses and quantum well thicknesses were studied and compared. Capacitance voltage measurements were carried out to determine the carrier distribution. A very narrow carrier profile with a full width at half maximum of only 12 Å has been achieved. This is the narrowest carrier profile ever reported for any growth technique.

Reduction of DX Centers in Superlattice Alloy‐Like Material High Electron Mobility Transistors

“…Further separation of the Si donors from A1 atoms reduces the atomic displacements responsible for the formation of the 0.43 eV DX centers. The general trend of this result and the lack of total elimination of DX centers may be explained by the in-and outdiffusions of Si dopants (15,16) toward the A1As/GaAs interfaces and into AlAs layers during MBE growth.…”

Hydrogenic donor impurities in $\delta$ -doped cylindrical quantum dots under intense laser field

“…From magneto-transport measurements they find that an increase in the mobility/mean free path by %40 and an increase in the phase coherence length by %25 could be achieved [13]. In addition, many novel heterostructures based on δ-doped structures were exper imentally performed by using crystal growth techniques [14][15][16][17][18][19][20][21]. It has been found that, by using the δ-doping technique it is possible to obtain higher electronic mobility in semiconductors.…”

A delta-doped quantum well system with additional modulation doping

“…Such a technique, termed delta-doping, can be used to prepare structures which are of great potential applications. For example, many novel structures based on delta-doped structures [ 2 - 10 ] can be experimentally realized using very simple fabrication techniques. It is found that delta-doped quantum wells may suffer from surface depletion and carrier freeze-out, which compromise their performances, thereby limiting their potential applications.…”