Parasitic channel induced by an on-state stress in AlInN/GaN HEMTs

Abstract

In this paper, we have highlighted that an on-state stress can induce a parasitic channel in AlInN/GaN HEMTs. The devices have been stressed during 216 h with a drain-to-source voltage (VDS) of 20 V and a gate-to-source voltage (VGS) of 0 V. A decrease in the drain current (IDS max) of 43%, an increase in the access resistance (RON) of 100%, and a drop in the maximum extrinsic transconductance (gm max) from 234 mS/mm down to 144 mS/mm have been observed after the ageing test. Moreover, a double peak feature is shown in the gm (VGS) characteristic 4 months after the end of the on-state stress. Consequently, we can conclude that a parasitic channel has been created by the on-state stress in the AlInN/GaN transistors. At the same time, no degradation of the Schottky contact has been highlighted after the ageing test.

The role of SiN/GaN cap interface charge and GaN cap layer to achieve enhancement mode GaN MIS-HEMT operation

“…The formation of the parasitic channel at the interface between these two layers is due to increase of the potential applied on the drain [53]. Experimental work confirms the presence of a parasitic channel induced by the on-state stress, originating from applied external fields, which occurs after ageing the device for many hours [54]. The location of the parasitic channel is assumed to be between the gate and the source but not under the gate.…”

Analysis of Trapping Effects on AlInN/GaN High Electron Mobility Transistors with Pulsed Electrical Measurements Under Visible and Infrared Illumination

“…It can be done immediately after the fabrication of the devices or electrical stresses under operational conditions and/or in a radiation environment. [7,[11][12][13][14][15][16][17] Thus, the characterization of trapping or detrapping phenomena can be investigated by various techniques such as capacitance deep-level transient spectroscopy, [18] drain-current deep-level transient spectroscopy, [9] gate and drain lag measurements, [19] double pulse measurements, [20] photoionization spectroscopy, [21] electroluminescence techniques, [22] and deep-level optical spectroscopy. [23] All these techniques can provide information on the trapping effects responsible for the electrical performance degradation of GaN-based devices.…”