Abstract: A method for producing a semiconductor substrate includes the steps of: forming a first patterned mask containing a material having a growth suppressing effect on a substrate; growing a first nitride semiconductor on a portion of the substrate corresponding to an opening portion of the first patterned mask; forming a second patterned mask containing a material having a growth suppressing effect only on a main surface of the first nitride semiconductor which is positioned above the opening portion of the first patterned mask; and growing a semiconductor crystal substantially from the side surface of the first nitride semiconductor so as to form a second nitride semiconductor which integrally includes the first patterned mask and the second patterned mask.

Abstract: The present nitride semiconductor light emitting device includes a nitride semiconductor thick film substrate and a light emitting layered structure including a plurality of nitride semiconductor layers stacked on the substrate. The nitride semiconductor substrate includes at least two layer regions including a first layer region of a high impurity concentration and a second layer region of an impurity concentration lower than the first layer region. The light emitting layered structure is formed on the first layer region of the substrate.

Abstract: A nitride compound semiconductor light emitting device of the present invention includes: a nitride compound semiconductor substrate; and a light emitting device section including a nitride compound semiconductor provided on the nitride compound semiconductor substrate. The nitride compound semiconductor substrate contains a group VII element as an impurity.

Abstract: A light-emitting device has a light-emitting layer of nitride semiconductor containing As, P or Sb and accordingly its emission efficiency or emission intensity is enhanced. The light-emitting device includes a substrate, and further includes n-type and p-type nitride semiconductor layers and a light-emitting layer between the n-type and p-type semiconductor layers that are formed on the substrate. Light-emitting layer includes one or a plurality of well layers formed of nitride semiconductor containing N and element X (element X is As, P or Sb). The nitride semiconductor of the well layer has at most 30% in atomic percent represented by expression {NX/(NN+NX)}×100 where NX represents the number of atoms of element X and NN represents the number of atoms of N. The thickness of the well layer ranges from 0.4 nm to 4.8 nm.

Abstract: There is provided a light emitting device having high luminous efficacy or emission intensity. The device includes a light emitting layer provided between n- and p-type layers of nitride semiconductor formed on a GaN substrate. The light emitting layer is formed of a well layer or a combination of well and barrier layers. The well layer is made of a nitride semiconductor containing an element X, N and Ga, wherein X is As, P or Sb. The ratio of the number of the atoms of element X to the sum of the number of the atoms of element X and N, is not more than 30 atomic percent. The well layer contains Mg, Be, Zn, Cd, C, Si, Ge, Sn, O, S, Se or Te as an impurity for improving the crystallinity of the well layer.

Abstract: A GaN light-emitting device is provided having a low specific contact resistance of an n-type electrode as well as a low threshold voltage or threshold current density. The GaN light-emitting device has an electrode formed on a nitrogen-terminated surface of a GaN substrate. Specifically, the GaN light-emitting device includes the GaN substrate, a plurality of GaN compound semiconductor layers formed on the GaN substrate, and the n-type electrode and a p-type electrode, wherein the semiconductor substrate is of n-type and the n-type electrode is formed on the nitrogen-terminated surface of the semiconductor substrate. The concentration of n-type impurities in the substrate preferably ranges from 1×1017 cm−3 to 1×1021 cm−3.

Abstract: A nitride semiconductor light emitting device includes a worked substrate including grooves and lands formed on a main surface of a nitride semiconductor substrate, a nitride semiconductor underlayer covering the grooves and the lands of the worked substrate and a nitride semiconductor multilayer emission structure including an emission layer including a quantum well layer or both a quantum well layer and a barrier layer in contact with the quantum well layer between an n-type layer and a p-type layer over the nitride semiconductor underlayer, while the width of the grooves is within the range of 11 to 30 &mgr;m and the width of the lands is within the range of 1 to 20 &mgr;m.

Abstract: A method for producing a semiconductor substrate of the present invention, includes the steps: forming a first patterned mask containing a material having a growth suppressing effect on a lower substrate; growing a semiconductor crystal on the lower substrate via the first patterned mask to form a first semiconductor crystal layer; forming a second patterned mask containing a material having a growth suppressing effect on or above the lower substrate, the second patterned mask at least having a surface which is positioned at a level different from a level of a surface of the first patterned mask, with respect to a surface of the lower substrate; and growing a semiconductor crystal on or above the lower substrate via the second patterned mask to form a second semiconductor crystal layer.

Abstract: There is provided a light emitting device having high luminous efficacy or emission intensity. The device includes a light emitting layer provided between n- and p-type layers of nitride semiconductor formed on a GaN substrate. The light emitting layer is formed of a well layer or a combination of well and barrier layers. The well layer is made of a nitride semiconductor containing an element X, N and Ga, wherein X is As, P or Sb. The ratio of the number of the atoms of element X to the sum of the number of the atoms of element X and N, is not more than 30 atomic percent. The well layer contains Mg, Be, Zn, Cd, C, Si, Ge, Sn, O, S, Se or Te as an impurity for improving the crystallinity of the well layer.

Abstract: A nitride semiconductor light emitting device includes a worked substrate including grooves and lands formed on a main surface of a nitride semiconductor substrate, a nitride semiconductor underlayer covering the grooves and the lands of the worked substrate and a nitride semiconductor multilayer emission structure including an emission layer including a quantum well layer or both a quantum well layer and a barrier layer in contact with the quantum well layer between an n-type layer and a p-type layer over the nitride semiconductor underlayer, while the width of the grooves is within the range of 11 to 30 &mgr;m and the width of the lands is within the range of 1 to 20 &mgr;m.

Abstract: There is provided a light emitting device having high luminous efficacy or emission intensity. The device includes a light emitting layer provided between n- and p-type layers of nitride semiconductor formed on a GaN substrate. The light emitting layer is formed of a well layer or a combination of well and barrier layers. The well layer is made of a nitride semiconductor containing an element X, N and Ga, wherein X is As, P or Sb. The ratio of the number of the atoms of element X to the sum of the number of the atoms of element X and N, is not more than 30 atomic percent. The well layer contains Mg, Be, Zn, Cd, C, Si, Ge, Sn, O, S, Se or Te as an impurity for improving the crystallinity of the well layer.

Abstract: A nitride semiconductor laser device having a low threshold current and low noise is provided. The laser device includes n-type and p-type layers made of nitride semiconductor and formed on a substrate, and a light emitting layer between the n-type and p-type layers. The light emitting layer is formed of a well layer or a combination of well and barrier layers. At least the well layer is made of nitride semiconductor containing element X, N and Ga, wherein element is at least one selected from the group consisting of As, P and Sb. The atomic fraction of element X is smaller than that of N. A maximum width through which current is injected into the light emitting layer via the p-type layer is from 1.0 &mgr;m to 4.0 &mgr;m.

Abstract: A nitride semiconductor structure includes: a substrate having a growth surface, a convex portion and a concave portion being formed on the growth surface; and a nitride semiconductor film grown on the growth surface. A cavity is formed between the nitride semiconductor film and the substrate in the concave portion.

Abstract: A nitride semiconductor structure includes: a substrate having a growth surface, a convex portion and a concave portion being formed on the growth surface; and a nitride semiconductor film grown on the growth surface. A cavity is formed between the nitride semiconductor film and the substrate in the concave portion.

Abstract: A method for producing a semiconductor substrate of the present invention, includes the steps: forming a first patterned mask containing a material having a growth suppressing effect on a lower substrate; growing a semiconductor crystal on the lower substrate via the first patterned mask to form a first semiconductor crystal layer; forming a second patterned mask containing a material having a growth suppressing effect on or above the lower substrate, the second patterned mask at least having a surface which is positioned at a level different from a level of a surface of the first patterned mask, with respect to a surface of the lower substrate; and growing a semiconductor crystal on or above the lower substrate via the second patterned mask to form a second semiconductor crystal layer.

Abstract: A nitride semiconductor laser device includes a nitride semiconductor substrate, and a layered portion corresponding to a nitride semiconductor film grown on the nitride semiconductor substrate, the layered portion including an n-type layer and a p-type layer and a light emitting layer posed between the n- and p-type layers, of the n- and p-type layers a layer opposite to the nitride semiconductor substrate with the light emitting layer opposed therebetween serving as an upper layer having a stripe of 1.9 &mgr;m to 3.0 &mgr;m in width, the light emitting layer and the upper layer having an interface distant from a bottom of the stripe by 0 &mgr;m to 0.2 &mgr;m.

Abstract: A nitride compound semiconductor light emitting device includes: a GaN substrate having a crystal orientation which is tilted away from a <0001> direction by an angle which is equal to or greater than about 0.05° and which is equal to or less than about 2°, and a semiconductor multilayer structure formed on the GaN substrate, wherein the semiconductor multilayer structure includes: an acceptor doping layer containing a nitride compound semiconductor; and an active layer including a light emitting region.

Abstract: A method for producing a semiconductor substrate of the present invention, includes the steps: forming a first patterned mask containing a material having a growth suppressing effect on a lower substrate; growing a semiconductor crystal on the lower substrate via the first patterned mask to form a first semiconductor crystal layer; forming a second patterned mask containing a material having a growth suppressing effect on or above the lower substrate, the second patterned mask at least having a surface which is positioned at a level different from a level of a surface of the first patterned mask, with respect to a surface of the lower substrate; and growing a semiconductor crystal on or above the lower substrate via the second patterned mask to form a second semiconductor crystal layer.