The invention relates to a high-frequency and low-
noise gallium nitride transistor structure with high electronic mobility. The structure comprises a substrate, an
aluminium nitride nucleating layer arranged on the substrate and a
gallium nitride cushioning layer arranged on the
aluminium nitride nucleating layer; the substrate, the
aluminium nitride nucleating layer and the
gallium nitride
cushioning layer are sequentially overlapped from bottom to top; the high-frequency and low-
noise gallium nitride transistor structure with the high electronic mobility is characterized in that an InGaN inserting layer for improving roughness of a component interface, an
aluminium nitride inserting layer for improving a potential barrier, an AlGaN isolating layer, an AlGaN electronic providing layer, an AlGaN potential
barrier layer as well as a source
electrode, a grid
electrode and a drain
electrode which are respectively in
ohm connection with the AlGaN potential
barrier layer are sequentially overlapped on the
gallium nitride cushioning layer. The high-frequency and low-
noise gallium nitride transistor structure has the beneficial effects that two-dimensional electronic gas is better bound in a
potential well, therefore, scattering of the two-dimensional electronic gas caused by impurities in a channel layer is reduced, and a saturated rate and a mobility ratio of the two-dimensional electronic gas are increased, and a noise performance of a device is improved, particularly a high-
frequency noise performance.