Abstract
The invention provides a semiconductor device. The device comprises a substrate, an epitaxial layer formed thereon and electrodes, including a drain electrode, a source electrode and a gate electrode, formed on the epitaxial layer. The gate electrode with a symmetric, enclosed geometry is entirely disposed within an active region without crossing an isolation region. Because the gate electrode is disposed in a way which avoids crossing the isolation region, the breakdown voltage and reliability of the semiconductor device are improved.