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: 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: An electrode pad for e 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 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 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 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 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 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 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 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.