US 5,629,534 AGranted

Semiconductor device

AssigneeNippondenso Co., Ltd.

InventorsHajime Inuzuka, Naomi Awano, Takeshi Hasegawa, Masahito Mizukoshi

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Abstract

There is provided a monolithic photocoupler which is easy to integrate. An SOI structure is formed by providing a first insulation layer on a silicon substrate. The semiconductor single crystal region is further divided by trench insulation layers into separate regions. Light emitting elements are formed on one of the separated semiconductor single crystal region and light receiving elements are formed on the other semiconductor single crystal region. The light emitting elements are obtained by forming light emitting diodes made of GaAs or the like on the substrate using a heterogeneous growth process. An optical waveguide made of a material which is optically transparent and electrically insulative such as a TiO.sub.2 film on each pair of light emitting and light receiving elements. The insulation layers constituted by SiO.sub.2 layers have a refractive index smaller that of the active layer of the substrate. Thus, the light emitted by the light emitting elements is almost entirely reflected without leaking out, and the light which has entered the optical waveguides reaches the light receiving elements without leaking out except those components which have entered perpendicularly or at an angle close thereto.

Claims15

Dependent claims

A semiconductor device comprising:

a substrate;
a semiconductor single crystal region constituted by a single crystal semiconductor formed on said substrate;
a plurality of channels formed on said semiconductor single crystal region, each of said plurality of channels comprising:
a light emitting element for emitting light in response to an input electrical signal,
a light receiving element for receiving light emitted by said light emitting element and for outputting an output electrical signal, and
an optical waveguide formed across said light emitting element and said light receiving element for optically coupling said light emitting element and said light receiving element;
and
a crosstalk preventing structure disposed to prevent crosstalk between said plurality of channels by reflecting and absorbing light emitted by said light emitting element constituting a particular one of said plurality of channels that is directed to another one of said plurality of channels adjacent to said particular one of said plurality of channels, said crosstalk preventing structure comprising:
a first portion of at least one of an insulator and a dielectric disposed in said semiconductor single crystal region between said plurality of channels,
a second portion of at least one of an insulator and a dielectric disposed in said semiconductor single crystal region between said plurality of channels, and
a third portion of a semiconductor substance disposed between said first portion and second portion,
said first portion and said second portion reflecting light,
said third portion absorbing light which passes at least one of said first portion and said second portion.

10 more elements

A semiconductor device comprising:

a substrate;
a first single crystal semiconductor region in which a first light emitting element is formed, disposed on said substrate;
a second single crystal semiconductor region in which a second light emitting element is formed, disposed on said substrate;
a third single crystal semiconductor region in which a first light receiving element is formed, disposed on said substrate;
a fourth single crystal semiconductor region in which a second light receiving element is formed, disposed on said substrate;
a first optical waveguide optically coupling said first light emitting element and said first light receiving element;
a second optical waveguide optically coupling said second light emitting element and said second light receiving element;
a first isolation region of an insulation substance having a first refractive index smaller than a second refractive index of said first single crystal semiconductor region, said first isolation region enclosing said first single crystal semiconductor region at sides and bottom thereof;
a second isolation region of said insulation substance having a third refractive index smaller than a fourth refractive index of said second single crystal semiconductor region, said second isolation region enclosing said second single crystal semiconductor region at sides and bottom thereof;
a third isolation region of an insulation substance having a fifth refractive index smaller than a sixth refractive index of said third single crystal semiconductor region, said third isolation region enclosing said third single crystal semiconductor region at sides and bottom thereof;
and
a fourth isolation region of an insulation substance having a seventh refractive index smaller than a eighth refractive index of said fourth single crystal semiconductor region, said fourth isolation region enclosing said fourth single crystal semiconductor region at sides and bottom thereof;
at least said first single crystal semiconductor region and said second single crystal semiconductor region being further surrounded at sides thereof by semiconductor portions, respectively, to absorb light coming out through said first isolation region and said second isolation region to said semiconductor portions.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/691,416Filed 2 Aug 1996 · continuation
Priority: JP 6-07985823 Mar 1994
Granted: 13 May 1997
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H10F 55/255
Wherein the radiation-sensitive devices and the electric light source are all semiconductor devices: formed in, or on, a common substrate
H04B 10/802
Using optical interconnects, e.g. light coupled isolators, circuit board interconnections: for isolation, e.g. using optocouplers
H10F 39/107
Integrated devices: having multiple elements covered by H10F30/00 in a repetitive configuration, e.g. radiation detectors comprising photodiode arrays
H10F 39/198
Image sensors: contact-type image sensors [CIS]