Fig. 1. (a) Structural diagram of TP65H035WS device, (b) Optical image of TP65H035WS device before decap, (c) Optical image of TP65H035WS device after decap, (d) Structural diagram of INN650D02 device, (e) Optical image of INN650D02 device before decap, (f) Optical image of INN650D02 device after decap (color online)

Fig. 2. Characteristic change curves of GaN HEMT devices with enhancement-mode Cascode structure before and after irradiation with different doses of 5 MeV proton (color online) (a) Transfer characteristic curve, (b) Output characteristic curve, (c) Gate characteristic curve, (d) Electrical parameter change curve

Fig. 3. Electrical characteristic variation curves of GaN HEMT devices with enhancement-mode P-GaN gate structure before and after 5 MeV proton irradiation (color online) (a) Transfer characteristics curve, (b) Output characteristic curve

Fig. 4. Comparison of degradation of electrical parameters after irradiation of two enhancement-mode GaN HEMT devices (color online)

Fig. 5. Variation of normalized current noise power spectral density of GaN HEMT devices before and after 5 MeV proton radiation with frequency (color online) (a) Cascode structure GaN HEMT before irradiation, (b) Cascode structure GaN HEMT after irradiation, (c) P-GaN gate structure GaN HEMT before irradiation, (d) P-GaN gate structure GaN HEMT after irradiation

Fig. 6. (a) An equivalent circuit diagram of Cascode structure GaN HEMT, (b) Schematic diagram of oxide trap and interface state trap resulting from ionization damage of Si MOSFET device (color online)