Formation of Defects Forming Deep Levels in SiON/AlGaN/GaN Structures.

Autor: Enisherlova, K. L., Mikhaylov, I. A., Seidman, L. A., Kirilenko, E. P., Kolkovsky, Yu. V.
Předmět:
Zdroj: Russian Microelectronics; Dec2023, Vol. 52 Issue 8, p817-826, 10p
Abstrakt: The effect on the electrical parameters of the SiON/AlGaN/GaN structures of treatment of different durations of low-energy nitrogen plasma is studied. The AlGaN surface is subjected to plasma treatment in the working chamber of the plasma-chemical deposition unit before starting the monosilane to form the SiON film. The changes in the transport properties (conductivity and mobility) of the canal and capacitive properties of the structures are evaluated. It is experimentally shown that such treatment leads to a change in the magnitude of polarization charges both at the insulator-AlGN interface and at the AlGaN/GaN interface. With the use of C–V measurements-in the hysteresis mode, it is shown that at the control voltage (U > +4 to +5 V), some of the channel electrons are captured in the deep centers at the SiON–AlGaN interface, and with an increase in the duration of exposure to plasma, a sharp increase is observed in the charge Qit, formed by the electronic boundary states. The use of additional treatment with nitrogen plasma transfers work for nitride structures from the D-mode (Vth = –4 V) to the E-mode (Vth = +0.9 V). Using Auger measurements, it was shown that plasma treatment leads to a change in the amount of oxygen in the SiON layer and in the nanoregions of the barrier layer, and with an increase in the duration of plasma exposure, a sharp decrease in the amount of oxygen in these layers is observed. In addition, when using plasma treatment, Ga and Al is redistributed at the AlGaN–GaN interface, i.e., in the channel area. Using Auger measurements near the SiON–AlGaN interface from the side of the insulator, the localization of nitrogen atoms chemically bonded with silicon N(Si) is detected with the formation of a peak at the interface, the size of which increases with the increasing duration of plasma exposure. [ABSTRACT FROM AUTHOR]
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