Semiconductor Quantum Cascade Lasers (QCLs), in particular mid-IR lasers emitting at wavelengths of about 3-50 μm, are often designed as deep etched buried heterostructure QCLs. The buried heterostructure configuration is favored since the high thermal conductivity of the burying layers, usually of InP, and the low losses guarantee devices high power and high performance. However, if such QCLs are designed for and operated at short wavelengths, a severe disadvantage shows up: the high electric field necessary for such operation drives the operating current partly inside the insulating burying layer. This reduces the current injected into the active region and produces thermal losses, thus degrading performance of the QCL. The invention solves this problem by providing, within the burying layers, effectively designed current blocking or quantum barriers of, e.g. AIAs, InAIAs, InGaAs, InGaAsP, or InGaSb, sandwiched between the usual InP or other burying layers, intrinsic or Fe-doped. These quantum barriers reduce the described negative effect greatly and controllably, resulting in a QCL operating effectively also at short wavelengths and/or in high electric fields.

A method of manufacturing a semiconductor device includes a step of forming a mesa portion including an active layer above a substrate, and an n-type layer above the active layer, a step of forming a current confinement portion on left and right of the mesa portion, the current confinement portion including a p-type current blocking layer, an n-type current blocking layer above the p-type current blocking layer, and an i-type or p-type current blocking layer above the n-type current blocking layer, and a p-type doping step of diffusing p-type impurities into the i-type or p-type current blocking layer, an upper portion of the n-type current blocking layer, and left and right portions of the n-type layer to change the upper portion of the n-type current blocking layer and the left and right portions of the n-type layer to p-type semiconductors.

A semiconductor layer stack, a component made therefrom, a component module, and a production method is provided. The semiconductor layer stack has at least two layers (A, B), which, as individual layers, each have an energy position of the Fermi level in the semiconductor band gap,

[00001]$E_F-E_V<\frac{E_G}{2}$

applying to the layer (A) and

[00002]$E_L-E_F<\frac{E_G}{2}$

applying to the layer (B), with E.sub.F the energy position of the Fermi level, E.sub.V the energy position of the valence band, E.sub.L the energy position of a conduction band and E.sub.L−E.sub.V the energy difference of the semiconductor band gap E.sub.G, the thickness of the layers (A, B) being selected in such a way that a continuous space charge zone region over the layers (A, B) results.

A semiconductor laser diode and a method for manufacturing a semiconductor laser diode are disclosed. In an embodiment a semiconductor laser diode includes an epitaxially produced semiconductor layer sequence comprising at least one active layer and a gallium-containing passivation layer on at least one surface region of the semiconductor layer sequence.

The present invention relates to a diode laser with a current block and, in particular, to a diode laser with a modified “p-n-p” or “n-p-n” structure as a current block for reducing the tunneling probability. A diode laser according to the invention comprises an active layer and a layered current block formed outside the active layer, wherein the current block is made of a material doped in opposition to its surroundings for a spatially selective current injection of the active layer between an n-substrate and a p-contact; wherein the current block is separated from adjacent layers via an intrinsic outer layer.

A semiconductor layer stack, a component made therefrom, a component module, and a production method is provided. The semiconductor layer stack has at least two layers (A, B), which, as individual layers, each have an energy position of the Fermi level in the semiconductor band gap, $E_F-E_V<\frac{E_G}{2}$
applying to the layer (A) and $E_L-E_F<\frac{E_G}{2}$
applying to the layer (B), with E.sub.F the energy position of the Fermi level, E.sub.V the energy position of the valence band, E.sub.L the energy position of a conduction band and E.sub.L−E.sub.V the energy difference of the semiconductor band gap E.sub.G, the thickness of the layers (A, B) being selected in such a way that a continuous space charge zone region over the layers (A, B) results.

A buried semiconductor optical device comprises a semiconductor substrate; a mesa-stripe portion including a multi-quantum well layer on the semiconductor substrate; a buried layer consisting of a first portion and a second portion, the first portion covering one side of the mesa-stripe portion, the second portion covering the other side of the mesa-stripe portion, and the first portion and the second portion covering a surface of the semiconductor substrate; and an electrode configured to cause an electric current to flow through the mesa-stripe portion, the buried layer comprising, from the surface, a first, second, and third sublayer, the first and third sublayer each consisting of semi-insulating InP, the first sublayer and the second sublayer forming a pair structure, the second sublayer being located above the multi-quantum well layer, and the second sublayer consisting of one or more layers selected from InGaAs, InAlAs, InGaAlAs, InGaAsP, and InAlAsP.

A semiconductor layer stack, a component made therefrom, a component module, and a production method is provided. The semiconductor layer stack has at least two layers (A, B), which, as individual layers, each have an energy position of the Fermi level in the semiconductor band gap,

[00001]$E_F-E_V<\frac{E_G}{2}$

applying to the layer (A) and

[00002]$E_L-E_F<\frac{E_G}{2}$

applying to the layer (B), with E.sub.F the energy position of the Fermi level, E.sub.V the energy position of the valence band, E.sub.L the energy position of a conduction band and E.sub.L−E.sub.V the energy difference of the semiconductor band gap E.sub.G, the thickness of the layers (A, B) being selected in such a way that a continuous space charge zone region over the layers (A, B) results.

A buried semiconductor optical device comprises a semiconductor substrate; a mesa-stripe portion including a multi-quantum well layer on the semiconductor substrate; a buried layer consisting of a first portion and a second portion, the first portion covering one side of the mesa-stripe portion, the second portion covering the other side of the mesa-stripe portion, and the first portion and the second portion covering a surface of the semiconductor substrate; and an electrode configured to cause an electric current to flow through the mesa-stripe portion, the buried layer comprising, from the surface of the semiconductor substrate, a first sublayer, a second sublayer, and a third sublayer, the first sublayer, the second sublayer, and the third sublayer each consisting of semi-insulating InP, the first sublayer and the second sublayer forming a pair structure, the second sublayer being located above the multi-quantum well layer from the surface of the semiconductor substrate, and the second sublayer consisting of one or more layers selected from a group of InGaAs, InAAs, InGaAAs, InGaAsP, and InAlAsP.

A semiconductor layer stack, a component made therefrom, a component module, and a production method is provided. The semiconductor layer stack has at least two layers (A, B), which, as individual layers, each have an energy position of the Fermi level in the semiconductor band gap, $E_F-E_V<\frac{E_G}{2}$
applying to the layer (A) and $E_L-E_F<\frac{E_G}{2}$
applying to the layer (B), with E.sub.F the energy position of the Fermi level, E.sub.V the energy position of the valence band, E.sub.L the energy position of a conduction band and E.sub.LE.sub.V the energy difference of the semiconductor band gap E.sub.G, the thickness of the layers (A, B) being selected in such a way that a continuous space charge zone region over the layers (A, B) results.