High Performance GaAs Mutiple-Function Field-Effect Transistors Grown by Metalorganic Chemical Vapor Deposition
| Autor: | Chang-Luen Wu, 吳昌崙 |
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| Rok vydání: | 1993 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 84 Four-terminal MESFET and MODFET-like GaAs mutiple-function transistors (MFTs) with salient negative differential resistance (NDR) characteristics have been implemented by low- pressure metalorganic chemical vapor deposition (LP-MOCVD). The vertical GaAs negative resistance field-effect transistor (NERFET) with a delta-doped channel based on real-space transfer (RST) shows superior NDR characteristics to those with a homogeneously doped channel. Moreover, the delta-doped GaAs NERFET with an InGaAs channel shows improved NDR behaviors than that without an InGaAs channel. The present devices possess advantages of : (i) ease of growth and fabrication, (ii) very large (up to 432,000) and adjustable peak-to-valley current ratio (PVR) at room temper- ature,(iii) very sharp charge injection, (iv) very broad current valley range (> 5 V), (v) very high switching transconductance (> 24 S/mm), and (vi) very high power handling capability (> 950 mA/mm). We have also considered theoretically the basic physical processes underlying the operation of the NERFET. Our treatment is based on the electron temperature (Te) approximation for the energy distribution of electrons in the two-dimensional electron gas (2DEG) channel. By using ohmic recesses, planar field-effect transistors (FETs) characteristics with high extrinsic transconductance, large gate voltage swing, high current driving capability, and high Schottky voltage are also demonstrated in the present devices simultane- ously. In addition, we also observed pronounced NDR behavior and negative transconductance at field gate fields in delta-doped GaAs/ InGaAs FET by tunneling real-space transfer (TRST). |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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