| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that the influence of the crystallinity of an n-GaN substrate on the electric characteristic of a Schottky contact is unknown and that the necessity of the quality degree of the n-GaN substrate is not clear. SOLUTION: Ni Schottky contacts are formed on four kinds of n-GaN wafers whose electron mobilities are different, and their I-V characteristic is measured at room temperature. In the I-V characteristic of a sample A and a sample B whose electron mobilities are at 100 cm2/Vs or less, their leakage current is large, and a sample C whose electron mobility is at 107 cm2/Vs displays a good characteristic. The I-V characteristic of a sample D whose electron mobility is by three times larger than that of the sample C, and whose dislocation density is at 1/3 or less is not different from that of the sample C. That is to say, when the electron mobility is at 100 cm2/Vs or more, the Schottky contact can be formed on the n-GaN wafers irrespective of the dislocation density. Consequently, it is possible to select the n-GaN wafers which are low- cost. |
