Abstract: A layer comprising cobalt (Co) is formed on a p+ layer by vapor deposition, and a layer comprising gold (Au) is formed thereon. The two layers are alloyed by a heat treatment to form a light-transmitting electrode. The light-transmitting electrode therefore has reduced contact resistance and improved light transmission properties, and gives a light-emitting pattern which is stable over a long time. Furthermore, since cobalt (Co) is an element having a large work function, satisfactory ohmic properties are obtained.

Abstract: A GaN type semiconductor layer having a new structure is provided which incorporates a substrate having surface which is opposite to a GaN type semiconductor layer and which is made of Ti.

Abstract: An AlN layer having a surface of a texture structure is formed on a sapphire substrate. Then, a growth suppressing material layer is formed on the AlN layer so that the AlN layer is partially exposed to the outside. Then, group III nitride compound semiconductor layers are grown on the AlN layer and on the growth suppressing material layer by execution of an epitaxial lateral overgrowth method. Thus, a group III nitride compound semiconductor device is produced. An undercoat layer having convex portions each shaped like a truncated hexagonal pyramid is formed on a substrate. Group III nitride compound semiconductor layers having a device function are laminated successively on the undercoat layer.

Abstract: A group III nitride compound semiconductor device is produced according to the following manner. A separation layer made of a material which prevents group III nitride compound semiconductors from being grown thereon is formed on a substrate. Group III nitride compound semiconductors is grown on a surface of the substrate uncovered with the separation layer while keeping the uncovered substrate surface separated by the separation layer.

Abstract: A method for manufacturing a light-emitting device which using group III nitride group semiconductors and a quantum well structure, comprising forming a well layer (e.g. an InGaN layer), forming a cap layer on the well layer, the cap layer having almost the same compositions as the well layer at a temperature similar to that at which the well layer was formed. Further, and the cap layer is formed at a crystal growth rate which is faster than the crystal growth rate of the well layer and removing the cap layer using a thermal cracking (or decomposition) process during the temperature ramp up associated with the formation of the next group III nitride compound semiconductor layer. After the cap layer is removed, the group III nitride compound semiconductor layer is formed on the exposed well layer.

Abstract: An electrode pad for a Group III nitride compound semiconductor having p-type conduction includes a triple layer structure having first, second, and third metal layers, formed on an electrode layer. A protection film with a window exposing a central portion of the third metal layer is formed by etching on the third metal layer and covers the sides of the first, second, and third metal layers. The second metal layer is made of gold (Au). The first metal layer is made of an element which has ionization potential lower than gold (Au). The third metal is made of an element which has adhesiveness to the protection film stronger than that of gold (Au). Consequently, this structure of the electrode pad improves the adhesive strength between the protection layer and the third meal layer and prevents the etching of the sides of the protection film. Furthermore, the contact resistance between the semiconductor and the electrode pad is lowered and, thus, ohmic characteristic of the electrode pad is improved.

Abstract: A GaN type semiconductor layer having a structure is provided which incorporates a substrate having surface which is opposite to a GaN type semiconductor layer and which is made of Ti.

Abstract: A group III nitride compound semiconductor device has a substrate, a group III nitride compound semiconductor layer having a device function, and an undercoat layer formed between the substrate and the group III nitride semiconductor layer. The undercoat layer has a surface which has a texture structure, or which is trapezoid shaped in section or which is pit shaped. In addition, a reflection layer made of nitride of at least one metal selected from the group consisting of titanium, zirconium, hafnium and tantalum may be formed on a surface of the undercoat layer. Also the surface of the reflection layer is formed as a texture structure, a trapezoid shape in section or a pit shape.

Abstract: A layer comprising cobalt (Co) is formed on a p+ layer by vapor deposition, and layer comprising gold (Au) is formed thereon. The two layers are alloyed by a heat treatment to form a light-transmitting electrode. The light-transmitting electrode therefore has reduced contact resistance and improved light transmission properties, and gives a light-emitting patten which is stable over a long time. Furthermore, since cobalt (Co) is an element having a large work function, satisfactory ohmic properties are obtained.

Abstract: A light-emitting semiconductor device (10) consecutively includes a sapphire substrate (1), an AlN buffer layer (2), a silicon (Si) doped GaN n+-layer (3) of high carrier (n-type) concentration, a Si-doped (Alx3Ga1-x3)y3In1-y3N n+-layer (4) of high carrier (n-type) concentration, a zinc (Zn) and Si-doped (Alx2Ga1-x2)y2In1-y2N emission layer (5), and a Mg-doped (Alx1Ga1-x1)y1In1-y1N p-layer (6). The AlN layer (2) has a 500 Å thickness. The GaN n+-layer (3) has about a 2.0 &mgr;m thickness and a 2×1018/cm3 electron concentration. The n+-layer (4) has about a 2.0 &mgr;m thickness and a 2×1018/cm3 electron concentration. The emission layer (5) has about a 0.5 &mgr;m thickness. The p-layer 6 has about a 1.0 &mgr;m thickness and a 2×1017/cm3 hole concentration. Nickel electrodes (7, 8) are connected to the p-layer (6) and n+-layer (4), respectively. A groove (9) electrically insulates the electrodes (7, 8).

Abstract: A layer comprising cobalt (Co) is formed on a p+ layer by vapor deposition, and a layer comprising gold (Au) is formed thereon. The two layers are alloyed by a heat treatment to form a light-transmitting electrode. The light-transmitting electrode therefore has reduced contact resistance and improved light transmission properties, and gives a light-emitting pattern which is stable over a long time. Furthermore, since cobalt (Co) is an element having a large work function, satisfactory ohmic properties are obtained.

Abstract: A digital watermarking system capable of making a digital watermark even in an input image of few colors. An image input section inputs an object image in which a digital watermark is to be made and transforms or develops the image into digital data of the format of the system. In a texture database section, texture patterns in each of which the digital watermark is previously made are registered. And in a color conversion table section, information for coordinating original colors used in the input image with the textures is registered. An image composing section creates a watermarked image in which the original colors of the input image are replaced with the textures of the texture database as designated in the color conversion table. An image output section retains the watermarked image to be outputted from the image composing section and outputs the watermarked image.

Abstract: A light-emitting semiconductor device (10) consecutively includes a sapphire substrate (1), an AlN buffer layer (2), a silicon (Si) doped GaN n+-layer (3) of high carrier (n-type) concentration, a Si-doped (Alx3Ga1−x3)y3In1−y3N n+-layer (4) of high carrier (n-type) concentration, a zinc (Zn) and Si-doped (Alx2Ga1−x2)y2In1−y2N emission layer (5), and a Mg-doped (Alx1Ga1−x1)y1In1−y1N p-layer (6). The AlN layer (2) has a 500 Å thickness. The GaN n+-layer (3) has about a 2.0 &mgr;m thickness and a 2×1018/cm3 electron concentration. The n+-layer (4) has about a 2.0 &mgr;m thickness and a 2×1018/cm3 electron concentration. The emission layer (5) has about a 0.5 &mgr;m thickness. The p-layer 6 has about a 1.0 &mgr;m thickness and a 2×1017/cm3 hole concentration. Nickel electrodes (7, 8) are connected to the p-layer (6) and n+-layer (4), respectively. A groove (9) electrically insulates the electrodes (7, 8).

Abstract: A LED has a thin highly resistive or insulative layer formed below an electrode pad in order to divert current flow from the region below an electrode pad, which region does not contribute to light emission, to another region which does. Consequently, better current efficiency is obtained. Further, diverting current flow from the region below the electrode pad where mechanical damages are expected deters deterioration of the region. Consequently, the LED lasts longer and is a better quality product.

Abstract: The invention combines a closed-end loop antenna and an open-end loop antenna in a conformal antenna on the rear window glass of an automotive vehicle above the defogging heater grid. The loops are adapted to receive Digital Audio Broadcasting (DAB) signals in both L band and Band-III frequency bands with maximum sensitivity to vertically polarized signals while requiring minimal space on the window glass. The antenna uses one substantially continuous trace between a pair of antenna feedpoints to achieve low manufacturing cost.

Abstract: An electrode for a Group III nitride compound semiconductor having p-type conduction that has a double layer structure. The first metal electrode layer comprising, for example, nickel (Ni) and the second metal electrode layer comprising, for example, gold (Au). The Ni layer is formed on the Group III nitride compound semiconductor having p-type conduction, and the Au layer is formed on the Ni layer. Heat treatment changes or reverses the distribution of the elements Ni and Au. Namely, Au is distributed deeper into the Group III nitride compound semiconductor than is Ni. As a result, the resistivity of the electrode is lowered and its ohmic characteristics are improved as well as its adhesive strength.

Abstract: A base layer of electode made of at least a metal selected from V, Nb, and Zr, or an alloy containing such metal on an n-type GaN compound semiconductor layer. Further, a main electrode layer made of other metal is formed on the base layer. Then, an n electrode is formed by subjecting the semiconductor layer, the base layer, and the main electrode layer to a heat treatment.

Abstract: A GaN type semiconductor layer having a new structure is provided which incorporates a substrate having surface which is opposite to a GaN type semiconductor layer and which is made of Ti.

Abstract: A wafer is diced up to a depth of 15 .mu.m from the surface of a sapphire substrate along a dicing line set in the center of a processed region between electrodes for respective devices by using a blade having a width narrower than the width of the processed region, so that separation grooves are formed. In the present invention, the first contact layer, the second contact layer, the p layer, the light-emitting layer and the n layer are arranged in a region between a side surface of the blade and a side wall of the electrode formation region. Accordingly, stress is concentrated into an intersection line of the electrode formation region and the side wall which is erected so as to be L-shaped. Thus, cracks generated at the time of dicing are formed-toward the intersection line. As a result, the cracks never enter into the electrode formation region and, accordingly, never enter into the lower portion of the electrode.

Abstract: A double-hetero structure light emitting diode using group III nitride compound semiconductor is disclosed- The diode has a first electrode connected to a first semiconductor layer and a second electrode connected to a second semiconductor layer. In one aspect of the invention, the first electrode is also connected to the second semiconductor layer. In another aspect of the invention, a resistance is disposed between the first electrode and the second semiconductor layer. In another aspect of the invention, a diode in a reverse direction and in parallel to the light emitting diode is disposed between the first and second electrodes.