Sanken Electric Co., Ltd.

Shin-etsu Handotai Co., Ltd.

Ken Sato

Hiroshi Shikauchi

Masaru Shinomiya

Kazunori Hagimoto

Keitaro Tsuchiya

Hirokazu Goto

Nobuo Kaneko

Hirotaka Kurimoto

Shoichi Kobayashi

A semiconductor device substrate including: a substrate; a buffer layer which is provided on the substrate and made of a nitride semiconductor; and a device active layer which is formed of a nitride semiconductor layer provided on the buffer layer, the semiconductor device substrate in that the buffer layer includes: a first region which contains carbon and iron; a second region which is provided on the first region and has average concentration of iron lower than that in the first region and average concentration of carbon higher than that in the first region, and the average concentration of the carbon in the second region is lower than the average concentration of the iron in the first region. The semiconductor device substrate which can suppress a transverse leak current in a high-temperature operation of a device while suppressing a longitudinal leak current and can inhibit a current collapse phenomenon is provided.

Semiconductor device substrate, semiconductor device, and method for manufacturing semiconductor device substrate

Semiconductor base including: silicon-based substrate; buffer layer including first and second layers alternately on silicon-based substrate, first layer made of nitride-based compound semiconductor containing first material, second layer made of nitride-based compound semiconductor containing second material having larger lattice constant than first material; channel layer on buffer layer and made of nitride-based compound semiconductor containing second material, buffer layer has: first composition graded layer between at least one of first layers and second layer immediately thereabove, made of nitride-based compound semiconductor whose composition ratio of second material is increased gradually upward, whose composition ratio of first material is decreased gradually upward; second composition graded layer between at least one of second layers and first layer immediately thereabove, made of nitride-based compound semiconductor whose first material is increased gradually upward, whose composition ratio of second material is decreased gradually upward, first composition graded layer is thicker than second composition graded layer.

Semiconductor base having a composition graded buffer layer stack

A substrate for semiconductor device includes a substrate, a buffer layer which is provided on the substrate and made of a nitride semiconductor, and a device active layer which is provided on the buffer layer and composed of a nitride semiconductor layer, wherein the buffer layer contains carbon and iron, a carbon concentration of an upper surface of the buffer layer is higher than a carbon concentration of a lower surface of the buffer layer, and an iron concentration of the upper surface of the buffer layer is lower than an iron concentration of the lower surface of the buffer layer. As a result, the substrate for semiconductor device can reduce a leak current in a lateral direction at the time of a high-temperature operation while suppressing a leak current in a longitudinal direction.

Substrate for semiconductor device, semiconductor device, and method for manufacturing semiconductor device

A semiconductor base substance includes: a substrate; a buffer layer which is made of a nitride semiconductor and provided on the substrate; and a channel layer which is made of a nitride semiconductor and provided on the buffer layer, wherein the buffer layer includes: a first region which is provided on the substrate side and has boron concentration higher than acceptor element concentration; and a second region which is provided on the first region, and has boron concentration lower than that in the first region and acceptor element concentration higher than that in the first region. As a result, the semiconductor base substance which can obtain a high pit suppression effect while maintaining a high longitudinal breakdown voltage is provided.

Semiconductor base substance having a boron containing buffer layer, semiconductor device including the same, and methods for manufacturing the semiconductor base substance and the semiconductor device

A method of manufacturing an epitaxial wafer having an epitaxial layer on a silicon-based substrate, the method of manufacturing the epitaxial wafer including epitaxially growing a semiconductor layer on the silicon-based substrate after applying terrace processing to an outer peripheral portion of the silicon-based substrate. As a result, the method of manufacturing the epitaxial wafer having the epitaxial layer on the silicon-based substrate in which an epitaxial wafer which is completely free from cracks can be obtained, is provided.

Method of manufacturing epitaxial wafer and silicon-based substrate for epitaxial growth

An epitaxial substrate for electronic devices, including: a Si-based substrate; an AlN initial layer provided on the Si-based substrate; and a buffer layer provided on the AlN initial layer, wherein the roughness Sa of the surface of the AlN initial layer on the side where the buffer layer is located is 4 nm or more. As a result, an epitaxial substrate for electronic devices, in which V pits in a buffer layer structure can be suppressed and longitudinal leakage current characteristics can be improved when an electronic device is fabricated therewith, is provided.

Epitaxial substrate for electronic devices, electronic device, method for producing the epitaxial substrate for electronic devices, and method for producing the electronic device

A method for manufacturing a semiconductor substrate, the semiconductor substrate including: a substrate; an initial layer provided on the substrate; a high-resistance layer provided on the initial layer which is composed of a nitride-based semiconductor and contains carbon; and a channel layer provided on the high-resistance layer which is composed of a nitride-based semiconductor, and at a step of forming the high-resistance layer, a gradient is given to a preset temperature at which the semiconductor substrate is heated, and the high-resistance layer is formed such that the preset temperature at the start of formation of the high-resistance layer is different from the preset temperature at the end of formation of the high-resistance layer. It is possible to provide the method for manufacturing a semiconductor substrate, which can reduce a concentration gradient of carbon concentration in the high-resistance layer and also provide a desired value for the carbon concentration.

Method for manufacturing semiconductor substrate, method for manufacturing semiconductor device, semiconductor substrate, and semiconductor device

A silicon-based substrate on which a nitride compound semiconductor layer is formed on a front surface thereof, including a first portion provided on the front surface side which has a first impurity concentration and a second portion provided on an inner side of the first portion which has a second impurity concentration higher than the first impurity concentration, wherein the first impurity concentration being 1&#xd7;10atoms/cmor more and less than 1&#xd7;10atoms/cm. Consequently, there is provided the silicon-based substrate in which the crystallinity of the nitride compound semiconductor layer formed on an upper side thereof can be maintained excellently while improving a warpage of the substrate.

Silicon-based substrate, semiconductor device, and method for manufacturing semiconductor device

A method for producing a semiconductor epitaxial wafer, including steps of: fabricating an epitaxial wafer by epitaxially growing a semiconductor layer on a silicon-based substrate; observing the outer edge portion of the fabricated epitaxial wafer; and removing portions in which a crack, epitaxial layer peeling, and a reaction mark observed in the step of observing are present. As a result, a method for producing a semiconductor epitaxial wafer in which a completely crack-free semiconductor epitaxial wafer can be obtained, is provided.

Method for producing semiconductor epitaxial wafer and semiconductor epitaxial wafer

A semiconductor substrate including a substrate, a buffer layer having a nitride-based semiconductor containing carbon provided on the substrate, a high-resistance layer having a nitride-based semiconductor containing carbon provided on the buffer layer, and a channel layer having a nitride-based semiconductor provided on the high-resistance layer, the high-resistance layer including a first region having carbon concentration lower than that of the buffer layer, and a second region which is provided between the first region and the channel layer, and has the carbon concentration higher than the first region. As a result, it is possible to provide the semiconductor substrate which can reduce a leak current by enhancing crystallinity of the high-resistance layer while maintaining a high resistance of the high-resistance layer, and suppress occurrence of a decrease in electron mobility or current collapse in the channel layer by likewise enhancing crystallinity of the channel layer formed on the high-resistance layer.

Semiconductor substrate and semiconductor device

A silicon-based substrate on which a nitride compound semiconductor layer is formed on a front surface thereof, including a first portion provided on the front surface side which has a first impurity concentration and a second portion provided on an inner side of the first portion which has a second impurity concentration higher than the first impurity concentration, wherein the first impurity concentration being 1&#xd7;10atoms/atomscmor more and less than 1&#xd7;10atoms/cm. Consequently, there is provided the silicon-based substrate in which the crystallinity of the nitride compound semiconductor layer formed on an upper side thereof can be maintained excellently while improving a warpage of the substrate.

Silicon-based substrate having first and second portions

A semiconductor substrate having a silicon-based substrate, a buffer layer provided on the silicon-based substrate and made of a nitride semiconductor containing boron, and an operation layer formed on the buffer layer, wherein a concentration of boron in the buffer layer gradually decreasing toward a side of the operation layer from a side of the silicon-based substrate. Thereby, the semiconductor substrate in which the buffer layer contains boron sufficient to obtain a dislocation suppression effect and boron is not diffused to the operation layer is provided.

Semiconductor substrate, semiconductor device and method of manufacturing the semiconductor device

Semiconductor device including: silicon-based substrate; first buffer layer on silicon-based substrate and is formed of first layer containing Al composition and second layer containing less Al than the first layer, the first and second layers being alternately stacked; second buffer layer on the first buffer layer and is formed of third layer containing Al composition and fourth layer containing less Al than the third layer, the third and fourth layers being alternately stacked; and third buffer layer on the second buffer layer and is formed of fifth layer containing Al composition and sixth layer containing less Al than the fifth layer, the fifth and sixth layers being alternately stacked, wherein the second buffer layer contains more Al than the first and third buffer layers. Thus, the semiconductor device leakage can be suppressed while reducing stress which is applied to buffer layer and can improve flatness of active layer upper face.

Semiconductor device

The invention provides a method for manufacturing a nitride semiconductor device that grows a multilayer film of a III-V group nitride semiconductor in a reaction furnace into which a III group element raw material gas and a V group element raw material gas are introduced, the method including: growing a first nitride semiconductor layer at a first raw material gas flow rate of the V group element raw material gas and a first carrier gas flow rate; and growing a second nitride semiconductor layer at a second raw material gas flow rate of the V group element raw material gas lower than the first raw material gas flow rate and a second carrier gas flow rate higher than the first carrier gas flow rate, wherein the first nitride semiconductor layer and the second nitride semiconductor layer are stacked.

Method for manufacturing nitride semiconductor device

A semiconductor device comprising: an active layer, which has a composition represented by the formula: AlMGaN, wherein x satisfies 0&#x2266;x&#x2266;1, wherein y satisfies 0&#x2266;y&#x2266;1, wherein x+y satisfies 0&#x2266;x+y&#x2266;1, and wherein M contains at least one of In and B; a substrate containing GaN; and a buffer layer provided between the active layer and the substrate, wherein the semiconductor device is operated by electrical current flowing through the active layer in a direction parallel to a face of the substrate, wherein the buffer layer has a composition represented by the formula: AlInN, wherein p satisfies 0&#x2266;p&#x3c;1, and wherein the buffer layer, which has a band gap energy wider than that of the substrate, and which is lattice-matched to the substrate.

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Miyoshi-machi, Japan

Ken Sato