Nippon Soken, Inc.

Nippondenso Co., Ltd.

Denso Corporation

Takashi Taguchi

Yoshiki Ueno

Tadashi Hattori

Susumu Sato

Kazuoki Matsugatani

Koichi Hoshino

Teruaki Kohara

A semiconductor device includes a semi-insulating substrate. A channel layer is formed on the semi-insulating substrate. An electron supply layer is formed on the semi-insulating substrate for generating a two-dimensional electron gas. The electron supply layer includes a doped superlattice layer. The superlattice layer includes layers of In.sub.X Al.sub.1-X As and layers of In.sub.Y Al.sub.1-Y As which alternate with each other, where 0.ltoreq.X.ltoreq.1.0 and 0.ltoreq.Y.ltoreq.1.0, and X differs from Y.

InP-based HEMT with superlattice carrier supply layer

A pseudomorphic HEMT of a structure which prevents the distribution of 2DEG in the channel layer from being concentrated near the hetero-interface relative to a doping layer and which, at the same time, enables the thickness of the channel layer to which distortion is imparted to be decreased. In an n-InAlAs/InGaAs pseudomorphic structure grown on an InP substrate 1, an InGaAs spacer layer 4 having an In composition ratio smaller than that of an InGaAs channel layer 3 is inserted in an InAlAs/InGaAs hetero-interface. The InGaAs channel layer 3 has an In composition ratio of 0.80 to exhibit a high mobility. Another InAlAs buffer layer 2, spacer layer 5 and doping layer 6 have an In composition ratio of 0.52 which is in lattice-match with the substrate, and InGaAs spacer layer 4 and cap layer 7 have an In composition ratio of 0.53 which is in lattice-match with the substrate. This constitution makes it possible to control the two-dimensional electron gas and to further increase the mobility.

Compound semiconductor substrate having a hetero-junction and a

A compound semiconductor device including a semiconductor substrate having (100) plane as a crystal growth plane, a first semiconductor layer as an electron traveling layer and a second semiconductor layer for supplying electrons to the electron traveling layer. The first semiconductor layer is formed on the semiconductor substrate and has a different lattice constant from the semiconductor substrate so that a first strain is applied in the first semiconductor layer in a first strain direction. The second semiconductor layer is formed on the first semiconductor layer and has a different lattice constant from the first semiconductor layer to thereby apply a second strain to the second semiconductor layer. The second strain has a direction that is inverse to the first strain direction. In addition, the thickness of the semiconductor layer is defined so as to compensate for the first strain applied to the first semiconductor layer by the second strain applied to the second semiconductor.

Compound semiconductor device for reducing the influence of resistance

A heat-blocking glass comprising: a first layer of infrared rays-blocking film of any thickness formed on a substrate; a plurality of intermediate layers from a second to a (2n+2)th layer (n: positive integral) stacked on said first layer, the optical thickness of each intermediate layer being .lambda./4 (.lambda.: design wavelength); and an uppermost (+3)th layer of a .lambda./8 optical thickness. The refractive index of the first layer is smaller than the refractive index of the second layer. The refractive index of each layer from the second layer to the uppermost layer is arranged so that high-refractive-index layers and low-refractive-index layers are alternately stacked, the second layer being disposed as a high-refractive-index layer.

Heat-blocking glass

Heat reflection film

A heat rays reflecting film composed of dielectric thin layers (n.sub.H layers) having a relatively high refractive index and dielectric thin layers (n.sub.L layers) having a relatively low refractive index which are alternately piled on one another, is disclosed. The first layer of the heat rays reflecting film, which contacts with the air is n.sub.L layer and the undermost layer which contacts with the window glass is n.sub.H layer. The optical thickness of the first layer is less than .lambda./4 while that of the other layers is .lambda./4. And the thickness of each layer is expressed by the formula: optical thickness/nv wherein nv is the refractive index for visible rays.

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Anjo, Japan

Takashi Taguchi