| 摘要 |
<p>A heterojunction field effect transistor (HFET) having a source (18), drain (19), and channel (13), wherein the channel (13) comprises a quantum well and at least one mono-atomic layer (16a, 16b). The mono-atomic layer (16a, 16b) has a different bandgap than the channel region (13) and serves to modify electron wave function and conduction band energy in the channel region (13), Preferably, an indium arsenide well monolayer (16a) is formed in an InGaAs channel region (13) and functions to move a first quantized energy level E0 closer to the bottom of the channel region quantum well thereby increasing electron concentration by increasing effective band offset potential. Another embodiment uses an aluminum arsenide monolayer as a barrier monolayer (16b) in the InGaAs channel (13). By varying location of the monolayers (16a, 16b), confinement of electrons in the channel (13) is improved. Large bandgap monolayer (16b) can also be used within barrier layer (17) in order to increase the effective Scholtky barrier height and accordingly reduce gate leakage current. <IMAGE></p> |
