| 摘要 |
PROBLEM TO BE SOLVED: To stably form a low resistance ohmic electrode by successively depositing a first layer made of a compound of a first metal and N, and a second layer made of the first metal on a GaN based compound semiconductor layer to form an intermediate layer between an electrode metal and the semiconductor layer. SOLUTION: An n-type GaN layer 101 is epitaxially grown on a sapphire wafer to purify the surface thereof. Setting the wafer in a main chamber of an electron beam(EB) vacuum deposition device, the chamber is vented in a high-vacuum manner. Thereafter, heating treatment is performed until the temperature of the wafer becomes around 200 deg.C, followed by forming a Zr nitride layer 102 and a Zr layer 103 by an EB vacuum deposition method. Like this, by using the Zr nitride layer 102 as an electrode which is in direct contact with the n-type GaN layer 101, contact resistance is reduced, and the dispersion of characteristics can be controlled. Further, bonding strength at each of the interfaces between the layers is so high that the mechanical strength of the entire electrode structure can be kept in high level. |
