| 摘要 |
<p>A non-linear element (such as a diode) which includes an oxide semiconductor and has a favorable rectification property is provided. In a transistor including an oxide semiconductor in which the hydrogen concentration is 5×1019/cm3 or lower, a work functionφms of a source electrode in contact with the oxide semiconductor, a work functionφmd of a drain electrode in contact with the oxide semiconductor, and electron affinityχof the oxide semiconductor satisfyφms≰χ<φmd, and an area of contact between the drain electrode and the oxide semiconductor is larger than an area of contact between the source electrode and the oxide semiconductor. By electrically connecting a gate electrode and the drain electrode in the transistor, a non-linear element having a favorable rectification property can be achieved.</p> |
