Improved ASM-HEMT GaN device large signal model establishing method

The invention discloses an improved building method of an ASM-HEMT GaN device large signal model, which is characterized in that an improved direct current characteristic model is provided for a wide bandgap semiconductor radio frequency GaN HEMT based on a physical base ASM-HEMT model, the influence of drain-source voltage (Vds) and gate-source voltage (Vgs) on current collapse and kink effect at a low drain-source voltage position of an output characteristic curve is considered, and the large signal model of an ASM-HEMT GaN device is built. And a drain-source current (Ids) formula in the ASM-HEMT is corrected. According to the method, a GaN HEMT device with the single finger gate width of 200 microns and the gate finger number of 6 is tested on a wafer, and direct current characteristic model parameter extraction is carried out. An extraction result shows that the DC characteristic model provided by the invention accurately describes current collapse and the kink effect of the device at a low drain-source v