Abstract. The current slump of different recipes of SiN_x passivated AlGaN/GaN high electron mobility transistors (HEMTs) is investigated. The dc and pulsed current-voltage curves of AlGaN/GaN HEMTs using different recipes are analyzed. It is found that passivation leakage has a strong relationship with NH₃ flow in the plasma-enhanced chemical vapor phase deposition process, which has impacted on the current collapse of SiN_x passivated devices. We analyze the pulsed I_DS – V_DS characteristics of different recipes of SiN_x passivation devices for different combinations of gate and drain quiescent biases (V_GS0, V_DS0) of (0, 0), (−6, 0), (−6, 15) and (0, 15)V. The possible mechanisms are the traps in SiN_x passivation capturing the electrons and the surface states at the SiN_x/AlGaN interface, which can affect the channel of two-dimensional electron gas and cause the current collapse.

PACS numbers: 71.55.Eq, 71.55.Ak

Print publication: Issue 11 (November 2009)
Received 24 April 2009