Abstract: Provided are a transistor of a semiconductor device and method of fabricating the same. The transistor includes: an epitaxy substrate disposed on a semi-insulating substrate and having a buffer layer, a first Si planar doping layer, a first conductive layer, a second Si planar doping layer, and a second conductive layer, which are sequentially stacked, the second Si planar doping layer having a doping concentration different from that of the first Si planar doping layer; a source electrode and a drain electrode diffusing into the first Si planar doping layer to a predetermined depth and disposed on both sides of the second conductive layer to form an ohmic contact; and a gate electrode disposed on the second conductive layer between the source and drain electrodes and being in contact with the second conductive layer. In this structure, both isolation and switching speed of the transistor can be increased.

Abstract: Provided is a power device having a connection structure compensating for a reactance component, in which transistors are arranged and connected to minimize deterioration of transistor properties caused by heat by compensating for a reactance component causing a phase difference due to transmission lines used for connecting a plurality of transistors in parallel such that the power device to be used for a high-frequency power amplifier outputs high power, and transmitting heat generated by high output power to a heat sink to be dissipated.

Abstract: A field effect transistor having a T- or ?-shaped fine gate electrode of which a head portion is wider than a foot portion, and a method for manufacturing the field effect transistor, are provided. A void is formed between the head portion of the gate electrode and a semiconductor substrate using an insulating layer having a multi-layer structure with different etch rates. Since parasitic capacitance between the gate electrode and the semiconductor substrate is reduced by the void, the head portion of the gate electrode can be made large so that gate resistance can be reduced. In addition, since the height of the gate electrode can be adjusted by adjusting the thickness of the insulating layer, device performance as well as process uniformity and repeatability can be improved.

Abstract: Provided are a transistor of a semiconductor device and a method of fabricating the same.

Abstract: Provided is a method of manufacturing a field effect transistor (FET).

Abstract: Provided are a transistor of a semiconductor device and method of fabricating the same. The transistor includes: an epitaxy substrate disposed on a semi-insulating substrate and having a buffer layer, a first Si planar doping layer, a first conductive layer, a second Si planar doping layer, and a second conductive layer, which are sequentially stacked, the second Si planar doping layer having a doping concentration different from that of the first Si planar doping layer; a source electrode and a drain electrode diffusing into the first Si planar doping layer to a predetermined depth and disposed on both sides of the second conductive layer to form an ohmic contact; and a gate electrode disposed on the second conductive layer between the source and drain electrodes and being in contact with the second conductive layer. In this structure, both isolation and switching speed of the transistor can be increased.

Abstract: A high frequency switch device includes an epitaxy substrate that is formed by sequentially stacking an AlGaAs/GaAs superlattic buffer layer, a first Si planar doping layer, an undoped first AlGaAs spacer, an undoped InGaAs layer, an undoped second AlGaAs spacer, a second Si planar doping layer having a doping density greater than that of the first Si planar doping layer, and an undoped GaAs/AlGaAs capping layer on a GaAs semi-insulated substrate. The undoped GaAs/AlGaAs capping layer is formed with a source electrode and a drain electrode that form an ohmic contact with the undoped GaAs/AlGaAs capping layer thereon, and a gate electrode formed between the source electrode and the drain electrode, thereby forming a Schottky contact with the undoped GaAs/AlGaAs capping layer.