Chapter 12
Heterostructures
The interface is the device.
H. Kroemer [133]
Abstract Heterostructures are the most important basis for modern devices and are covered regarding
various aspects including heteroepitaxy on planar and patterned substrates, surfactants, heterostructure
band lineup as well as energy levels and recombination in planar confined systems (quantum wells and
two-dimensional electron gases).
12.1 Introduction
Heterostructures consist of (at least two) different materials. The geometry of the interfaces between
the two materials can be complicated. The simplest case is a planar interface, i.e., a layered system.
A metal–semiconductor junction is generally a heterostructure. However, we will use the term mostly
for structures of various semiconductors. Most of the heterostructures discussed here are epitaxial, i.e.,
fabricated by the successive epitaxy of the various layers on a substrate. Another method to fabricate
heterostructures of different (and dissimilar) materials is wafer bonding that is briefly discussed in
Sect. 12.6.
Many modern semiconductor devices rely on heterostructures, such as the heterobipolar transistor
(HBT), the high electron mobility transistor (HEMT), lasers and nowadays also light-emitting diodes.
Shockley had already considered heterostructures in his 1951 patent for pn-junctions. For the development and the realization of heterostructures H. Kroemer and Zh.I. Alferov were awarded the 2000
Physics Nobel Prize. The properties of charge carriers in layers that are part of heterostructures can be
quite different from those in bulk material, e.g., extremely high mobility, high radiative recombination
efficiency or novel states of matter, as revealed in the quantum Hall effects.
© Springer Nature Switzerland AG 2021
M. Grundmann, The Physics of Semiconductors, Graduate Texts in Physics,
https://doi.org/10.1007/978-3-030-51569-0_12
351
Heterostructures
The interface is the device.
H. Kroemer [133]
Abstract Heterostructures are the most important basis for modern devices and are covered regarding
various aspects including heteroepitaxy on planar and patterned substrates, surfactants, heterostructure
band lineup as well as energy levels and recombination in planar confined systems (quantum wells and
two-dimensional electron gases).
12.1 Introduction
Heterostructures consist of (at least two) different materials. The geometry of the interfaces between
the two materials can be complicated. The simplest case is a planar interface, i.e., a layered system.
A metal–semiconductor junction is generally a heterostructure. However, we will use the term mostly
for structures of various semiconductors. Most of the heterostructures discussed here are epitaxial, i.e.,
fabricated by the successive epitaxy of the various layers on a substrate. Another method to fabricate
heterostructures of different (and dissimilar) materials is wafer bonding that is briefly discussed in
Sect. 12.6.
Many modern semiconductor devices rely on heterostructures, such as the heterobipolar transistor
(HBT), the high electron mobility transistor (HEMT), lasers and nowadays also light-emitting diodes.
Shockley had already considered heterostructures in his 1951 patent for pn-junctions. For the development and the realization of heterostructures H. Kroemer and Zh.I. Alferov were awarded the 2000
Physics Nobel Prize. The properties of charge carriers in layers that are part of heterostructures can be
quite different from those in bulk material, e.g., extremely high mobility, high radiative recombination
efficiency or novel states of matter, as revealed in the quantum Hall effects.
© Springer Nature Switzerland AG 2021
M. Grundmann, The Physics of Semiconductors, Graduate Texts in Physics,
https://doi.org/10.1007/978-3-030-51569-0_12
351