Transverse field effect transistor and preparation method thereof

The invention provides a transverse field effect transistor and a preparation method thereof, and relates to the technical field of semiconductors, a grid electrode bonding pad and a source electrode bonding pad arranged in a passive region of the transverse field effect transistor extend to the surface of a substrate from the first surface of a device function layer, the grid electrode bonding pad is insulated and isolated from the device function layer and the substrate, and the source electrode bonding pad is insulated and isolated from the first surface of the device function layer. The source pad is in short circuit with the substrate, so that the grid pad forms a capacitor structure through the source pad which is in short circuit with the substrate, and the grid-source capacitance C of the device formed between the grid pad and the source pad can be increased, thereby effectively relieving generated oscillation, reducing the loss of the power device, and avoiding mistaken opening of the transverse fiel