Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, a light emitting part, and a p-side electrode. The light emitting part is provided between the n-type and the p-type semiconductor layers, and includes a plurality of barrier layers and a plurality of well layers. The p-side electrode contacts the p-type semiconductor layer. The p-type semiconductor layer includes first, second, third, and fourth p-type layers. The first p-type layer contacts the p-side electrode. The second p-type layer contacts the light emitting part. The third p-type layer is provided between the first p-type layer and the second p-type layer. The fourth p-type layer is provided between the second p-type layer and the third p-type layer. The second p-type layer contains Al and contains a p-type impurity in a lower concentration lower than that in the first concentration.

Abstract: A semiconductor device has an active layer, a first semiconductor layer of first conductive type, an overflow prevention layer disposed between the active layer and the first semiconductor layer, which is doped with impurities of first conductive type and which prevents overflow of electrons or holes, a second semiconductor layer of first conductive type disposed at least one of between the active layer and the overflow prevention layer and between the overflow prevention layer and the first semiconductor layer, and an impurity diffusion prevention layer disposed between the first semiconductor layer and the active layer, which has a band gap smaller than those of the overflow prevention layer, the first semiconductor layer and the second semiconductor layer and which prevents diffusion of impurities of first conductive type.

Abstract: According to one embodiment, a semiconductor light emitting device includes a first semiconductor layer, a second semiconductor layer and a light emitting layer. The second semiconductor layer is provided on a [0001]-direction side of the first semiconductor layer. The light emitting layer includes a first well layer, a second well layer and a first barrier layer. An In composition ratio of the barrier layer is lower than that of the first well layer and the second well layer. The barrier layer includes a first portion and a second portion. The second portion has a first region and a second region. The first region has a first In composition ratio higher than that of the first portion. The second region is provided between the first region and the first well layer. The second region has a second In composition ratio lower than the first In composition ratio.

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting portion. The light emitting portion is provided between the semiconductor layers and includes barrier layers and well layers alternately stacked. An n-side end well layer which is closest to the n-type semiconductor layer contains InwnGa1-wnN and has a layer thickness twn. An n-side end barrier layer which is closest to the n-type semiconductor layer contains InbnGa1-bnN and has a layer thickness tbn. A p-side end well layer which is closest to the p-type semiconductor layer contains InwpGa1-wpN and has a layer thickness twp. A p-side end barrier layer which is closest to the p-type semiconductor contains InbpGa1-bpN and has a layer thickness tbp. A value of (wp×twp+bp×tbp)/(twp+tbp) is higher than (wn×twn+bn×tbn)/(twn+tbn) and is not higher than 5 times (wn×twn+bn×tbn)/(twn+tbn).

Abstract: According to one embodiment, a crystal growth method is disclosed for growing a crystal of a nitride semiconductor on a major surface of a substrate. The major surface is provided with asperities. The method can include depositing a buffer layer on the major surface at a rate of not more than 0.1 micrometers per hour. The buffer layer includes GaxAl1-xN (0.1?x<0.5) and has a thickness of not smaller than 20 nanometers and not larger than 50 nanometers. In addition, the method can include growing the crystal including a nitride semiconductor on the buffer layer at a temperature higher than a temperature of the substrate in the depositing the buffer layer.

Abstract: According to one embodiment, a vapor deposition method is disclosed for forming a nitride semiconductor layer on a substrate by supplying a group III source-material gas and a group V source-material gas. The method can deposit a first semiconductor layer including a nitride semiconductor having a compositional proportion of Al in group III elements of not less than 10 atomic percent by supplying the group III source-material gas from a first outlet and by supplying the group V source-material gas from a second outlet. The method can deposit a second semiconductor layer including a nitride semiconductor having a compositional proportion of Al in group III elements of less than 10 atomic percent by mixing the group III and group V source-material gases and supplying the mixed group III and group V source-material gases from at least one of the first outlet and the second outlet.

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, a light emitting portion, a first layer, a second layer, and an intermediate layer. The semiconductor layers include nitride semiconductor. The light emitting portion is provided between the n-type semiconductor layer and the p-type semiconductor layer and includes a quantum well layer. The first layer is provided between the light emitting portion and the p-type semiconductor layer and includes AlX1Ga1-x1N having first Al composition ratio x1. The second layer is provided between the first layer and the p-type semiconductor layer and includes Alx2Ga1-x2N having second Al composition ratio x2 higher than the first Al composition ratio x1. The intermediate layer is provided between the first layer and the light emitting portion and has a thickness not smaller than 3 nanometers and not larger than 8 nanometers and includes Inz1Ga1-z1N (0?z1<1).

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, a light emitting part, and a p-side electrode. The light emitting part is provided between the n-type and the p-type semiconductor layers, and includes a plurality of barrier layers and a plurality of well layers. The p-side electrode contacts the p-type semiconductor layer. The p-type semiconductor layer includes first, second, third, and fourth p-type layers. The first p-type layer contacts the p-side electrode. The second p-type layer contacts the light emitting part. The third p-type layer is provided between the first p-type layer and the second p-type layer. The fourth p-type layer is provided between the second p-type layer and the third p-type layer. The second p-type layer contains Al and contains a p-type impurity in a lower concentration lower than that in the first concentration.

Abstract: A semiconductor light emitting device has a support substrate, a light emitting element, and underfill material. The light emitting element includes a nitride-based group III-V compound semiconductor layer contacted via a bump on the support substrate. The underfill material is disposed between the support substrate and the light emitting element, the underfill material comprising a rib portion disposed outside of an end face of the light emitting element to surround the end surface of the light emitting element.

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type layer, a p-type layer, and a light emitting unit provided between the n-type layer and the p-type layer and including barrier layers and well layers. At least one of the barrier layers includes first and second portion layers. The first portion layer is disposed on a side of the n-type layer. The second portion layer is disposed on a side of the p-type layer, and contains n-type impurity with a concentration higher than that in the first portion layer. At least one of the well layers includes third and fourth portion layers. The third portion layer is disposed on a side of the n-type layer. The fourth portion layer is disposed on a side of the p-type layer, and contains n-type impurity with a concentration higher than that in the third portion layer.

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type layer, a p-type layer, and a light emitting unit provided between the n-type layer and the p-type layer and including barrier layers and well layers. At least one of the barrier layers includes first and second portion layers. The first portion layer is disposed on a side of the n-type layer. The second portion layer is disposed on a side of the p-type layer, and contains n-type impurity with a concentration higher than that in the first portion layer. At least one of the well layers includes third and fourth portion layers. The third portion layer is disposed on a side of the n-type layer. The fourth portion layer is disposed on a side of the p-type layer, and contains n-type impurity with a concentration higher than that in the third portion layer.

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting portion. The light emitting portion is provided between the semiconductor layers and includes barrier layers and well layers alternately stacked. An n-side end well layer which is closest to the n-type semiconductor layer contains InwnGa1-wnN and has a layer thickness twn. An n-side end barrier layer which is closest to the n-type semiconductor layer contains InbnGa1-bnN and has a layer thickness tbn. A p-side end well layer which is closest to the p-type semiconductor layer contains InwpGa1-wpN and has a layer thickness twp. A p-side end barrier layer which is closest to the p-type semiconductor contains InbpGa1-bpN and has a layer thickness tbp. A value of (wp×twp+bp×tbp)/(twp+tbp) is higher than (wn×twn+bn×tbn)/(twn+tbn) and is not higher than 5 times (wn×twn+bn×tbn)/(twn+tbn).

Abstract: According to one embodiment, a crystal growth method is disclosed for growing a crystal of a nitride semiconductor on a major surface of a substrate. The major surface is provided with asperities. The method can include depositing a buffer layer on the major surface at a rate of not more than 0.1 micrometers per hour. The buffer layer includes GaxAl1-xN (0.1?x<0.5) and has a thickness of not smaller than 20 nanometers and not larger than 50 nanometers. In addition, the method can include growing the crystal including a nitride semiconductor on the buffer layer at a temperature higher than a temperature of the substrate in the depositing the buffer layer.

Abstract: According to one embodiment, a method is disclosed for manufacturing a nitride semiconductor layer. The method can include forming a first nitride semiconductor layer on a substrate in a reactor supplied with a first carrier gas and a first source gas. The first nitride semiconductor layer includes indium. The first carrier gas includes hydrogen supplied into the reactor at a first flow rate and includes nitrogen supplied into the reactor at a second flow rate. The first source gas includes indium and nitrogen and supplied into the reactor at a third flow rate. The first flow rate is not less than 0.07% and not more than 0.15% of a sum of the first flow rate, the second flow rate, and the third flow rate.

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, a light emitting portion, a first layer, a second layer, and an intermediate layer. The semiconductor layers include nitride semiconductor. The light emitting portion is provided between the n-type semiconductor layer and the p-type semiconductor layer and includes a quantum well layer. The first layer is provided between the light emitting portion and the p-type semiconductor layer and includes Alx1Ga1-x1N having first Al composition ratio x1. The second layer is provided between the first layer and the p-type semiconductor layer and includes Alx2Ga1-x2N having second Al composition ratio x2 higher than the first Al composition ratio x1. The intermediate layer is provided between the first layer and the light emitting portion and has a thickness not smaller than 3 nanometers and not larger than 8 nanometers and includes Inz1Ga1-z1N (0?z1<1).

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting part provided therebetween. The light emitting part includes a plurality of light emitting layers. Each of the light emitting layers includes a well layer region and a non-well layer region which is juxtaposed with the well layer region in a plane perpendicular to a first direction from the n-type semiconductor layer towards the p-type semiconductor layer. Each of the well layer regions has a common An In composition ratio. Each of the well layer regions includes a portion having a width in a direction perpendicular to the first direction of 50 nanometers or more.

Abstract: According to one embodiment, a semiconductor light emitting device includes a first semiconductor layer, a second semiconductor layer and a light emitting layer. The second semiconductor layer is provided on a [0001]-direction side of the first semiconductor layer. The light emitting layer includes a first well layer, a second well layer and a first barrier layer. An In composition ratio of the barrier layer is lower than that of the first well layer and the second well layer. The barrier layer includes a first portion and a second portion. The second portion has a first region and a second region. The first region has a first In composition ratio higher than that of the first portion. The second region is provided between the first region and the first well layer. The second region has a second In composition ratio lower than the first In composition ratio.

Abstract: According to one embodiment, in a nitride semiconductor light emitting device, a first clad layer includes an n-type nitride semiconductor. An active layer is formed on the first clad layer, and includes an In-containing nitride semiconductor. A GaN layer is formed on the active layer. A first AlGaN layer is formed on the GaN layer, and has a first Al composition ratio. A p-type second AlGaN layer is formed on the first AlGaN layer, has a second Al composition ratio higher than the first Al composition ratio, and contains a larger amount of Mg than the GaN layer and the first AlGaN layer. A second clad layer is formed on the second AlGaN layer, and includes a p-type nitride semiconductor.

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, and a light emitting part provided therebetween. The light emitting part includes a plurality of light emitting layers. Each of the light emitting layers includes a well layer region and a non-well layer region which is juxtaposed with the well layer region in a plane perpendicular to a first direction from the n-type semiconductor layer towards the p-type semiconductor layer. Each of the well layer regions has a common An In composition ratio. Each of the well layer regions includes a portion having a width in a direction perpendicular to the first direction of 50 nanometers or more.

Abstract: According to one embodiment, a semiconductor light emitting device includes an n-type semiconductor layer, a p-type semiconductor layer, a light emitting portion, a first layer, a second layer, and an intermediate layer. The semiconductor layers include nitride semiconductor. The light emitting portion is provided between the n-type semiconductor layer and the p-type semiconductor layer and includes a quantum well layer. The first layer is provided between the light emitting portion and the p-type semiconductor layer and includes AlX1Ga1-x1N having first Al composition ratio x1. The second layer is provided between the first layer and the p-type semiconductor layer and includes Alx2Ga1-x2N having second Al composition ratio x2 higher than the first Al composition ratio x1. The intermediate layer is provided between the first layer and the light emitting portion and has a thickness not smaller than 3 nanometers and not larger than 8 nanometers and includes Inz1Ga1-z1N (0?z1<1).