Patent ID: 8710551
Filing Date: 2014-04-29
Classification: H01L

Abstract:
1. A high electron mobility transistor (HEMT), comprising: a semiconductor layer, which has a semiconductor bandgap; a barrier layer, which is formed on the semiconductor layer, and has a barrier bandgap; a piezoelectric layer, which is formed on the barrier layer, and has a piezoelectric bandgap, wherein each one of the semiconductor bandgap, the barrier bandgap, and the piezoelectric bandgap partially but not entirely overlaps the other two bandgaps; a gate, which is formed on the piezoelectric layer for receiving a gate voltage; and a source and a drain, which are formed at two sides of the gate respectively; wherein a two dimensional electron gas (2DEG) is formed in a portion of a junction between the semiconductor layer and the barrier layer but not below at least a portion of the piezoelectric layer, and the 2DEG is electrically connected to the source and the drain.