Abstract: In an avalanche photodiode provided with a substrate including a first electrode and a first semiconductor layer, formed of a first conductivity type, which is connected to the first electrode, the configuration is in such a way that, at least an avalanche multiplication layer, a light absorption layer, and a second semiconductor layer having a bandgap that is larger than that of the light absorption layer are layered on the substrate; a second conductivity type conductive region is formed in the second semiconductor layer; and the second conductivity type conductive region is arranged so as to be connected to a second electrode. With the foregoing configuration, an avalanche photodiode having a small dark current and a high long-term reliability can be provided with a simple process.

Abstract: An avalanche photodiode has improved low-noise characteristics, high-speed response characteristics, and sensitivity. The avalanche photodiode includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, a semiconductor multiplication layer interposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, and a semiconductor light-absorbing layer interposed between the semiconductor multiplication layer and the second conductivity type semiconductor layer. The avalanche photodiode further comprises a multiplication suppressing layer which suppresses multiplication of charge carriers in the semiconductor light-absorbing layer, located between the semiconductor light-absorbing layer and the second conductivity type semiconductor layer.

Abstract: An objective is to provide an avalanche photodiode that is excellent in device characteristics such as reliability. An avalanche photodiode is provided, which includes a substrate 1 formed with a light receiving region 3 on a multiplication layer 119, and formed with layers of differing semiconductor type with the multiplication layer 119 intervening, a ring-shaped groove 7 formed on the end face of the substrate 1 on its light-receiving-region side, in such a way that the groove surrounds the light receiving region 3, and one or more steps 5 provided on a side wall of the ring-shaped groove 7, in a range of from ¼ to ¾ of the depth of the groove.

Abstract: An avalanche photodiode has improved low-noise characteristics, high-speed response characteristics, and sensitivity. The avalanche photodiode includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, a semiconductor multiplication layer interposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, and a semiconductor light-absorbing layer interposed between the semiconductor multiplication layer and the second conductivity type semiconductor layer. The avalanche photodiode further comprises a multiplication suppressing layer which suppresses multiplication of charge carriers in the semiconductor light-absorbing layer, located between the semiconductor light-absorbing layer and the second conductivity type semiconductor layer.

Abstract: The present invention provides an avalanche photodiode capable of raising productivity. An n-type InP buffer layer, an n-type GaInAs light absorption layer, an n-type GaInAsP transition layer, an n-type InP electric field adjusting layer, an n-type InP avalanche intensifying layer, an n-type AlInAs window layer and a p-type GaInAs contact layer are grown in order on an n-type InP substrate. Next, Be is ion-injected into an annular area along the outer periphery of a light receiving area which is activated by heat treatment so as to form an inclined joint, to obtain a p-type peripheral area for preventing an edge break down. Further, Zn is selectively diffused thermally into the light receiving area until it reaches the n-type InP avalanche intensifying layer so as to form a p-type conductive area.

Abstract: An avalanche photodiode has improved low-noise characteristics, high-speed response characteristics, and sensitivity. The avalanche photodiode includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, a semiconductor multiplication layer interposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, and a semiconductor light-absorbing layer interposed between the semiconductor multiplication layer and the second conductivity type semiconductor layer. The avalanche photodiode further comprises a multiplication suppressing layer which suppresses multiplication of charge carriers in the semiconductor light-absorbing layer, has a thickness of 0.6 ?m or less, and is located between the semiconductor light-absorbing layer and the second conductivity type semiconductor layer. The thickness of the semiconductor light-absorbing layer is 0.5 ?m or more.

Abstract: A semiconductor device has a structure reducing resistances to a high frequency current. The semiconductor device includes a semi-insulating substrate, a first n-type layer made of a compound semiconductor, and a first p-type layer made of a compound semiconductor in which a signal current flows in a lateral direction, parallel to the semi-insulating substrate. The first p-type layer is sandwiched between the semi-insulating substrate and the first n-type layer. A second n type layer made of a compound semiconductor is between the semi-insulating substrate and the first p type layer. An alternating current component of the signal current flows through the second n type layer.

Abstract: A waveguide type photoreceptor device of the present invention comprises a waveguide 16a disposed on a Fe-doped InP substrate, the waveguide including an n-cladding layer connected to an n-electrode, an n-light guide layer, a light absorption layer, a p-light guide layer, and a p-cladding layer connected to a p-electrode, laminated onto one another over the Fe-doped InP substrate, and the ratio of the layer thickness of the thicker one of the n-light guide layer and the p-light guide layer to that of the thinner one being between 1.3 and 5 both inclusive.

Abstract: Composition wavelengths of materials of cladding layers and optical guide layers are 0.92 ?m and 1.2 ?m respectively. When the thickness of optical guide layers, corresponding to an extreme value in which inclination of a sensitivity curve to 1.3 ?m-wavelength light and to 1.55 ?m-wavelength light with respect to a change in the thickness of each of both optical guide layers changes from positive to negative, are defined as d1 and d2, respectively, the thickness, dg, of optical guide layers of a light detecting element satisfies 0.75d1?dg?1.25d2.

Abstract: A semiconductor light detecting device includes an n-contact layer selectively disposed on an Fe—InP substrate. An optical waveguide layer is disposed on the n-contact layer and includes an n-cladding layer, a light absorption layer, and a p-cladding layer, laminated on one another, over the n-contact layer, in that order. An Fe—InP current blocking layer is disposed on the n-cladding layer such that sides of the optical waveguide layer are buried in the Fe—InP current blocking layer. A p-electrode includes a contact electrode electrically connected to the p-cladding layer of the optical waveguide layer, a lead-out electrode portion extending on a side wall of the current blocking layer from the contact electrode and extending on the Fe—InP substrate, and an electrode pad disposed on a surface of the Fe—InP substrate, with an SiN film between the electrode pad and the surface of the Fe—InP substrate and connected to the lead-out electrode portion.

Abstract: An avalanche photodiode has improved low-noise characteristics, high-speed response characteristics, and sensitivity. The avalanche photodiode includes a first conductivity type semiconductor layer, a second conductivity type semiconductor layer, a semiconductor multiplication layer interposed between the first conductivity type semiconductor layer and the second conductivity type semiconductor layer, and a semiconductor light-absorbing layer interposed between the semiconductor multiplication layer and the second conductivity type semiconductor layer. The avalanche photodiode further comprises a multiplication suppressing layer which suppresses multiplication of charge carriers in the semiconductor light-absorbing layer, has a thickness of 0.6 ?m or less, and is located between the semiconductor light-absorbing layer and the second conductivity type semiconductor layer. The thickness of the semiconductor light-absorbing layer is 0.5 ?m or more.

Abstract: A semiconductor devices has a structure reducing resistances to a high frequency current. The semiconductor device includes a semi-insulating substrate, a first n-type layer made of a compound semiconductor, and a first p-type layer made of a compound semiconductor in which a signal current flows in a lateral direction, parallel to the semi-insulating substrate. The first p-type layer is sandwiched between the semi-insulating substrate and the first n-type layer. A second n type layer made of a compound semiconductor is between the semi-insulating substrate and the first p type layer. An alternating current component of the signal current flows through the second n type layer.

Abstract: An objective is to provide an avalanche photodiode that is excellent in device characteristics such as reliability. An avalanche photodiode is provided, which includes a substrate 1 formed with a light receiving region 3 on a multiplication layer 119, and formed with layers of differing semiconductor type with the multiplication layer 119 intervening, a ring-shaped groove 7 formed on the end face of the substrate 1 on its light-receiving-region side, in such a way that the groove surrounds the light receiving region 3, and one or more steps 5 provided on a side wall of the ring-shaped groove 7, in a range of from ¼ to ¾ of the depth of the groove.

Abstract: An avalanche photodiode according to this invention include a light receiving region 101 surrounded by a ring-shaped trench 13, a first electrode 11 formed on the light receiving region 101, a second electrode 12 formed on the periphery of the ring-shaped trench 13 surrounding the light receiving region, a first semiconductor layer lying just under the first electrode 11, and a second semiconductor layer lying just under the second electrode 12. Conductivity types of the first semiconductor and the second semiconductor are identical.

Abstract: A waveguide type photoreceptor device of the present invention comprises a waveguide 16a disposed on a Fe-doped InP substrate, the waveguide including an n-cladding layer connected to an n-electrode, an n-light guide layer, a light absorption layer, a p-light guide layer, and a p-cladding layer connected to a p-electrode, laminated onto one another over the Fe-doped InP substrate, and the ratio of the layer thickness of the thicker one of the n-light guide layer and the p-light guide layer to that of the thinner one being between 1.3 and 5 both inclusive.

Abstract: Composition wavelengths of materials of cladding layers and optical guide layers are 0.92 ?m and 1.2 ?m respectively. When the thickness of optical guide layers, corresponding to an extreme value in which inclination of a sensitivity curve to 1.3 ?m-wavelength light and to 1.55 ?m-wavelength light with respect to a change in the thickness of each of both optical guide layers changes from positive to negative, are defined as d1 and d2, respectively, the thickness, dg, of optical guide layers of a light detecting element satisfies 0.75d1?dg?1.25d2.

Abstract: A waveguide photodiode includes an n-type cladding layer, an n-type light confining layer, an i-type light absorption layer, a p-type light confining layer, and a p-type cladding layer buried in an Fe—InP blocking layer on a semiconductor substrate. At least one of the p-type light confining layer and the p-type cladding layer contains a p-type impurity selected from Be, Mg, and C. An undoped layer is preferably located between the i-type light absorption layer and the p-type light confining layer.

Abstract: A waveguide photodiode of the present invention is configured such that an n-type cladding layer 8, an n-type light confining layer 9, an i-type light absorption layer 10, a p-type light confining layer 11, and a p-type cladding layer 12 are buried in a Fe-InP blocking layer 14 in that order over a semiconductor substrate 2. At least one of the p-type light confining layer 11 and the p-type cladding layer 12 contains as a p-type impurity a material selected from a group consisting of Be, Mg, and C. An undoped layer is preferably formed between the i-type light absorption layer 10 and the p-type light confining layer 11.