Fujitsu Corporation

Sumitomo Electric Device Innovations, Inc.

Other

Fujitsu Optical Components Limited

Eudyna Devices Inc.

Nami Yasuoka

Haruhiko Kuwatsuka

Yoshihiro Yoneda

Kenichi Kawaguchi

Toru Uchida

Haruhisa Soda

Akito Kuramata

Takuya Fujii

Yoshiaki Nakata

Masao Makiuchi

Hiroyasu Yamashita

Takashi Mikawa

Shuichi Miura

An optical semiconductor element includes an optical receiver including a first semiconductor layer, a heater for heating the first semiconductor layer; and a monitor. A first semiconductor layer that absorbs light and generates electric carriers; a heater for heating the first semiconductor layer; and a monitor including a second semiconductor layer in which dark current is changed by heat generated by the heater.

Semiconductor device comprising a monitor including a second semiconductor layer in which dark current is changed by a heater

A semiconductor photodetector element includes a semiconductor substrate having a first conductivity type; a columnar structure formed on a first surface of the semiconductor substrate, the columnar structure being composed of a semiconductor of the first conductivity type; a light absorption layer formed so as to surround the columnar structure; and a semiconductor layer formed so as to surround the light absorption layer.

Semiconductor photodetector element and method

In order to improve reliability by preventing an edge breakdown in a semiconductor photodetector having a mesa structure such as a mesa APD, the semiconductor photodetector comprises a mesa structure formed on a first semiconductor layer of the first conduction type formed on a semiconductor substrate, the mesa structure including a light absorbing layer for absorbing light, an electric field buffer layer for dropping an electric field intensity, an avalanche multiplication layer for causing avalanche multiplication to occur, and a second semiconductor layer of the second conduction type, wherein the thickness of the avalanche multiplication layer at the portion in the vicinity of the side face of the mesa structure is made thinner than the thickness at the central portion of the mesa structure.

Semiconductor photodetector and method for manufacturing the same

In order to improve reliability by preventing an edge breakdown in a semiconductor photodetector having a mesa structure such as a mesa APD, the semiconductor photodetector includes a mesa structure formed on a first semiconductor layer of the first conduction type formed on a semiconductor substrate, the mesa structure including a light absorbing layer for absorbing light, an electric field buffer layer for dropping an electric field intensity, an avalanche multiplication layer for causing avalanche multiplication to occur, and a second semiconductor layer of the second conduction type, wherein the thickness of the avalanche multiplication layer at the portion in the vicinity of the side face of the mesa structure is made thinner than the thickness at the central portion of the mesa structure.

Semiconductor photodetector that causes avalanche multiplication to occur only at photodetector portion located at central portion of mesa structure

A side barrier is provided between columnar dots each constituted by directly stacking respective quantum dots in seven or more layers. Out of respective side barrier layers composing the side barrier, each of the lower side barrier layers (four layers of the undermost layer to the fourth layer from the bottom) is formed as a first side barrier layer into which a tensile strain is introduced, and each of the upper side barrier layers (three layers of the fifth layer to the uppermost layer from the bottom) is formed as a second side barrier layer which has no strain.

Optical semiconductor device and manufacturing method of the same

In order to improve reliability by preventing edge breakdown in a semiconductor photodetector having a mesa structure such as a mesa APD, the semiconductor photodetector includes a mesa structure formed on a first semiconductor layer of the first conduction type formed on a semiconductor substrate, the mesa structure including a light absorbing layer for absorbing light, an electric field buffer layer for dropping an electric field intensity, an avalanche multiplication layer for causing avalanche multiplication to occur, and a second semiconductor layer of the second conduction type, wherein the thickness of the avalanche multiplication layer at the portion in the vicinity of the side face of the mesa structure is made thinner than the thickness at the central portion of the mesa structure.

A semiconductor photodetecting device including a PIN photodiode formed on an SI-InP substrate; a buried optical waveguide portion formed on the SI-InP substrate and including the film thickness continuously increased toward the PIN photodiode and an InP clad layer covering the upper surface and the side surface of the InGaAsP core layer; and a ridge-shaped connection optical waveguide portion formed on the SI-InP substrate between the PIN photodiode and the buried optical waveguide portion and including the InGaAsP core layer and the InP clad layer selectively covering only the upper surface of the InGaAsP core layer.

Semiconductor photodetecting device and method for fabricating the same

A plurality of semiconductor devices are disposed in a line on the surface of a supporting substrate. Each semiconductor device is adapted to generate an electric signal depending on the intensity of incident light. Adjacent semiconductor devices are optically coupled by an interconnecting optical waveguide so that light can pass through the semiconductor device one by one in a direction from a first stage closest to an input end to a last stage. An electric signal transmission line is formed of a pair of conductors connected to the semiconductor devices so that the electric signal generated by the semiconductor devices can propagate. One conductor of the pair of conductors of the electric signal transmission line is formed so as to extend in the air above the supporting substrate between adjacent semiconductor devices.

Semiconductor light receiving device in which optical and electric signal are propagated at matched velocities

A photo sensor is formed in a partial area of the principal surface of a substrate. The photo sensor includes a light reception layer parallel to the principal surface, the light reception layer being made of semiconductor and generating carriers in response to received light. A light waveguide is formed in a partial area of the principal surface of the substrate, the light waveguide propagating light in a direction parallel to the principal surface and introducing light into the light reception layer. A semi-insulating semiconductor film covers side faces of the photo sensor. A pair of electrodes flows current into the light reception layer of the photo sensor in a thickness direction of the light reception layer. A semiconductor light reception device having a structure suitable for high-speed operation and easy to manufacture is provided.

Semiconductor light reception device of end face light incidence type

A photodetector includes a photodiode and an optical waveguide provided adjacent to the photodiode on a common substrate, wherein the optical waveguide includes a plurality of tapered optical waveguide layers separated by an intermediate layer having a uniform thickness, the thickness of the tapered optical waveguide layers increases from a first end surface away from the photodiode toward a second end surface adjacent to the photodiode.

High-speed photodetector

An APD includes a substrate formed of n.sup.+ -type Al.sub.x Ga.sub.1-x Sb or Al.sub.x Ga.sub.1-x Sb.sub.y As.sub.1-y semiconductor, whose aluminum content ratio x is typically within a range from 0.1 to 0.3. A light absorbing layer is formed of an-type GaSb semiconductor on the substrate. An avalanche multiplication layer is formed of n-type Al.sub.x Ga.sub.1-x Sb or Al.sub.x Ga.sub.1-x Sb.sub.y As.sub.1-y semiconduct, whose aluminum content ratio x is from 0.02 to 0.1, typically 0.065, so that an ionization rate ratio of positive and negative carriers is essentially maximized by a resonant impact ionization phenomenon. A p.sup.+ -region is formed as a surface layer of n-type Al.sub.x Ga.sub.1-x Sb or Al.sub.x Ga.sub.1-x Sb.sub.y As.sub.1-y semiconductor on the avalanche multiplication layer or directly in the avalanche multiplication layer so as to form a pn junction. Electrodes are formed on the p-type region and the substrate so as to apply a bias voltage to the APD. A light to be detected is injected through the substrate via an opening in the substrate electrode, while producing no carriers therein, into the light absorbing layer. The avalanche multiplication layer generates resonant impact ionization with only the positive carriers from the light absorbing layer, so that low noise and fast operation of the APD is achieved. Furthermore, the APD structure of the invention allows for easy design of an APD.

Growing community of inventors

Kawasaki, Japan

Nami Yasuoka