| Summary: | 碩士 === 國立成功大學 === 微電子工程研究所碩博士班 === 94 === This work reports, a high electron-mobility transistor (HEMT) using a dilute antimony In0.2Ga0.8As(Sb) channel, grown by the molecular beam epitaxy (MBE) system. The advantages by introducing the surfactant-like Sb atoms during growth of InGaAsN/GaAs quantum well (QW) consist of the suppression of the three-dimensional growth and the improved interfacial quality of the QW heterostructure.
Besides, the present device exhibits better dc characteristics, highly stable thermal and frequency characteristics due to the improvement in the channel layer quality by using an In0.2Ga0.8As(Sb) channel.
Distinguished device characteristics for GaAs/In0.2Ga0.8As(Sb) HEMT and conventional GaAs/In0.2Ga0.8As HEMT, with the gate dimensions of 1.2*200um2, include thermal threshold coefficient (¶Vth/¶T) is low to be -1.54 (-1.77) mV/K, gate-voltage swing (GVS) of 1.17 (1.15) V, peak extrinsic transconductance (gm, max) of 178 (166) mS/mm, and the current drive capability (IDSS) of 171 (157) mA/mm. The microwave characteristics for GaAs/In0.2Ga0.8As(Sb) HEMT and conventional GaAs/In0.2Ga0.8As HEMT, the unity gain cut-off frequency (fT) and the maximum oscillation frequency (fmax) are 25.6 (20.6) GHz and 28.3 (25.6) GHz, respectively.
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