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US 4,819,036 AGranted
Semiconductor device
AssigneeHitachi, Ltd.
InventorsTakao Kuroda, Akiyoshi Watanabe, Shinji Tsuji, Akio Ohishi, Hiroyoshi Matsumura
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AssigneeHitachi, Ltd.
InventorsTakao Kuroda, Akiyoshi Watanabe, Shinji Tsuji, Akio Ohishi, Hiroyoshi Matsumura
Estimating the term…
A novel method which enables a quaternary III-V group crystal to be readily formed on a III-V group crystal so that the former crystal lattice-matches with the latter crystal. More specifically, it is easy to produce a superlattice structure on a III-V group crystal substrate, the superlattice structure consisting of a first III-V group (hereinafter referred to as "III.sup.1 -V.sup.1 ") binary crystal layer which lattice-matches with the substrate, and a III-V group (III.sup.1 -III.sup.2 -V.sup.2) ternary crystal layer which similarly lattice-matches with the substrate. It is possible to obtain an even more stable superlattice layer by selecting the ratio between the film thickness of the (III.sup.1 -V.sup.1) crystal and the film thickness of the (III.sup.1 -III.sup.2 -V.sup.2) crystal so that, when the superlattice structure is mixed-crystallized spontaneously or by means of impurity doping, the mixed-crystallized composition lattice-matches with the previous crystal.
A semiconductor device comprising a semiconductor layer having a superlattice structure including a first layer of III.sup.1 -V.sup.1 binary crystal and a second layer of III.sup.1 -III.sup.2 -V.sup.2 ternary crystal, which are formed on a III.sup.1 -V.sup.1 binary crystal substrate composed of a III-group element and a V-group element, each of said first and second layers respectively of binary and ternary crystals lattice-matching with said substrate, and wherein the layer, of the first and second layers, having a larger energy band gap has a thickness of at most 25 .ANG..
A semiconductor laser device wherein at least one of the active layer, optical guide layer and cladding layer is defined by a superlattice layer including a first layer of III.sup.1 -V.sup.1 binary crystal and a second layer of III.sup.1 -III.sup.2 -V.sup.2 ternary crystal, which are formed on a III.sup.1 -V.sup.1 binary crystal substrate composed of a III-group element and a V-group element, each of said first layer and second layer respectively of binary and ternary crystals lattice-matching with said substrate, and wherein the layer, of the first and second layers, having a larger energy band gap has a thickness of at most 25 .ANG..
A semiconductor device comprising:
Dependencies are inferred from the claim text.