The degradation and recovery properties of AlGaN/GaN high-electron mobility transistors under direct current reverse step voltage stress

Abstract

Direct current (DC) reverse step voltage stress is applied on the gate of an AlGaN/GaN high-electron mobility transistor (HEMT). Experiments show that parameters degenerate under stress. Large-signal parasitic source/drain resistance (R S /R D ) and gate-source forward I-V characteristics are recoverable after breakdown of the device under test (DUT). Electrons trapped by both the AlGaN barrier trap and the surface state under stress lead to this phenomenon, and surface state recovery is the major reason for the recovery of device parameters.

Low-leakage-current AlGaN/GaN HEMTs on Si substrates with partially Mg-doped GaN buffer layer by metal organic chemical vapor deposition

“…AlGaN/GaN HEMTs are excellent candidates for power electronics and radio frequency (RF) devices due to their superior properties in high-power, high frequency and hightemperature applications. [1][2][3][4][5] Although sapphire and SiC are commonly used substrates for the growth of AlGaN/GaN HEMTs, silicon is emerging as a promising alternative because of its low cost, large size, as well as its potential for integration with advanced Si electronics. However, the growth of high quality GaN HEMTs on Si is more challenging than that on sapphire or SiC because of the larger mismatches in lattice and thermal expansion coefficient, resulting in a higher density of dislocations and cracks.…”

Different influences of Schottky metal on the strain and relative permittivity of barrier layer between AlN/GaN and AlGaN/GaN heterostructure Schottky diodes

“…Thus, it is of great importance to investigate the influences of Schottky metal on the strain and relative permittivity of AlN barrier layer in AlN/GaN diode. Since the AlN/GaN and AlGaN/GaN heterostructures are both main-stream materials for microwave devices and digital circuits, [8] a comparison of the influence of Schottky metal on the strain and relative permittivity of barrier layer between AlN/GaN diode and Al-GaN/GaN diodes is of great importance to further improve the performance and reliability of GaN-based frequency devices and the digital circuit.…”

The degradation mechanism of an AlGaN/GaN high electron mobility transistor under step-stress

“…[5][6][7] Meneghini et al [8] found that for sufficient long stress time, the degradation occurs even below the "critical voltage", and demonstrated that before permanent degradation the gate current would become noisy, indicating an increase in defect concentration. Recent reports [9,10] suggested that the degradation of some device parameters is recoverable, arising from the high field-induced electron detrapping beyond a critical voltage or the recovery of surface state after the step-stress.…”