查看文章

Passivation/encapsulation of III–V electronic and photonic circuits and devices is often performed using plasma-enhanced chemical vapor deposited Si x N y with a standard high frequency excitation of 13.56 MHz. The hypothesis of a possible higher passivation process efficiency for low frequency Si x N y deposition on GaAs has been suggested by comparison with published work on high frequency. In this work, we report a direct experimental demonstration of the effect of the RF plasma source frequency on electronic properties of GaAs/Si x N y interfaces during a passivation process. GaAs substrates from the same wafer are processed in the same reactor using the same plasma conditions except for the plasma excitation frequency and MIS structures are fabricated to probe interface electronic properties. Comparing interfaces obtained with a plasma source frequency below or over the ion transit frequency (∼ 2 …