Radio-frequency metal-oxide-semiconductor field effect transistor

Abstract

The invention provides a radio-frequency MOS (Metal Oxide Semiconductor) transistor for increasing working speed, reducing noise deterioration caused by a grid parasitic resistor of the radio-frequency MOS transistor, and improving reliability. The radio-frequency MOS transistor comprises a source electrode, a drain electrode, a grid electrode, a substrate, a source metal layer, a drain metal layer and a side grid metal layer, wherein the grid electrode comprises sub grids and a side grid for connecting the sub grids, the source metal layer is used for connecting the source electrode with a source end, the drain metal layer is used for connecting the drain electrode with a drain end, the side grid metal layer is used for connecting the side grid with a grid input end, the source metal layer covers and extends out of the source electrode, a projection of the source metal layer in an active region is not overlapped with the source electrode and the sub grids, the side grid metal layer covers and extends out of the side grid, a projection of the source metal layer is not overlapped with the source electrode and the drain electrode; and in the source metal layer, the drain metal layer and the grid metal layer, parts formed by metals in the same layer are not crossed.

Description

technical field [0001] The invention belongs to the field of integrated circuits, in particular to a radio frequency Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET, Metal-Oxide-Semiconductor Field Effect Transistor). Background technique [0002] With the increasing application of CMOS technology in the field of radio frequency (RF), the high frequency performance of RF MOS tubes has attracted increasing attention. In the case of high frequency, the parasitic resistance and parasitic capacitance of the RF MOS tube usually have an adverse effect on the performance of the RF circuit. For example, the higher the parasitic resistance, the greater the noise of the RF circuit; the higher the parasitic capacitance, the lower the cut-off frequency of the RF MOS tube. The lower the frequency, the lower the working speed of the radio frequency circuit. [0003] figure 1 It is a schematic structural diagram of a partial layout (not including the substrate) of a radio frequ...

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Problems solved by technology

[0007] The inventors of the present application have obtained through analysis that in the radio frequency MOS transistor with the above structure, the main source metal layer covers all the sub-gates 11 and drains 13, on the one hand, the area of ​​the overlapping region between the source and drain and between the gate and source is increased, The larger the area of ​​the overlapping area, the greater the parasitic capacitance of the RF MOS tube, so the parasitic capacitance of the RF MOS tube with the above structure is larger, thereby reducing the working speed of the RF MOS tube; on the other hand, because the gate is usually high Therefore, when the source signal is transmitted on the source metal layer, it will inevitably interfere with the high-frequency signal of each sub-grid 11 covered by it, reducing the reliability of the RF MOS tube.

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