| Summary: | 碩士 === 逢甲大學 === 電子工程所 === 96 === This work reports, high electron mobility transistors (HEMTs) using a dilute antimony In0.2Ga0.8AsSb channel, grown by molecular beam epitaxy (MBE) system. Introducing the surfactant-like Sb atoms during growth of the InGaAs/GaAs quantum well (QW) was devised to effectively improve the channel confinement capability and the interfacial quality within the InGaAsSb/GaAs QW heterostructure, resulting in enhanced carrier transport property and superior device performances.
In comparison, without passivation (sample A), the proposed devices employing with silicon nitride (SiNx) surface passivation (sample B), or sulfur (NH4)2Sx passivation (sample C) have been investigated. Sample A (B/C) has demonstrated superiorly the maximum extrinsic trans-conductance (gm, max) of 183 (205/221) mS/mm, the drain saturation current density (IDSS) of 174 (190/205) mA/mm, the gate-voltage swing (GVS) of 1.482 (1.28/1.105) V, and the P.A.E. characteristic 13 (21.4/30.4) % at 300 K, with the gate dimensions of 1 × 200 µm2.
From experimental results, the gate passivation exhibited the better high-frequency performance and the minimum noise. Besides, the (NH4)2Sx treatment passivation showed the lowest output conductance, the highest voltage gain, the best linearity, breakdown voltage, and power performances. Consequently, the InGaAsSb/GaAs PHEMTs with sulfur passivation is suitable for high-power with good linearity MMIC applications.
|
|---|
