| 摘要 |
A Field Effect Transistor (FET) device especially useful in common gate amplifiers of signals in the microwave to millimeter range. The device's input and output are impedence matched to preclude phase cancellation and form a traveling wave amplifier capable of high voltage operation. The channel is formed of gallium arsenide separated from the gate by a layer of aluminum arsenide heteroepitaxial with gallium arsenide layer. The channel is bounded by heavily doped regions which act as inherent sources and drains, and limit electric field strength to avoid sluggish response of heavy mass carriers. The gates are formed by etching trenches in a semi-insulating gallium arsenide layer on the opposite side of the aluminum arsenide layer from the channel, using the aluminum arsenide as an etch stop, oxidizing the exposed aluminum arsenide, and epitaxially growing gallium arsenide to narrow the trench. The resulting gate is disposed on opposite sides of the channel from the source and drain contacts thus significantly improving gate-drain breakdown voltage. The resulting device has an increased power capacity and increased response time, but is simpler to fabricate. In alternate embodiments, several such devices are yoked together in a single monolith, with adjacent sources and drains of adjacent stages being unitary, further simplifying device fabrication, and increasing its dynamic range.
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