E-mode high electron mobility transistors and methods of manufacturing the same

A method of manufacturing a high electron mobility transistor (HEMT), the method comprising:

• forming a channel layer;
• forming a barrier layer to induce a two-dimensional electron gas (2DEG) in the channel layer, the barrier layer including a first barrier layer on the channel layer and a second barrier layer on the first barrier layer;
• forming a recess in the barrier layer;
• forming a depletion layer to cover a surface of the barrier layer in the recess and to extend onto regions of the barrier layer adjacent to the recess,
• the depletion layer including at least one of a GaN layer, an InN layer, an AlGaN layer, an AlInN layer, an InGaN layer and an AlInGaN layer;
• forming source and drain electrodes on the barrier layer;
• and
• forming a gate electrode on the depletion layer,
• wherein a polarization rate of the second barrier layer is greater than a polarization rate of the first barrier layer.

A method of manufacturing a high electron mobility transistor (HEMT), the method comprising:

• forming a channel layer;
• forming a first barrier layer to induce a two-dimensional electron gas (2DEG) in the channel layer;
• forming a depletion layer pattern on the first barrier layer;
• growing a second barrier layer on the first barrier layer around the depletion layer pattern;
• forming source and drain electrodes on the second barrier layer;
• and
• forming a gate electrode on the depletion layer pattern.