Hydrogen sulfide plasma passivation of indium phosphide
The electrical properties of the SiO2-InP interface are improved using in-situ H2S plasma pretreatments as a reliable method of sulfidizing the InP surface prior to film deposition. High frequency (1 MHz) and quasi-static capitance-voltage measurements on metal-insulator-semiconductor structures show reduced interface trap densities. X-ray photoemission spectroscopy analysis indicates that prior to film deposition, sulfur is bonded to phosphorus at the surface; but after film deposition, very little sulfur remains. Spectroscopic ellipsometry measurements confirm that the interface does remain modified even after film deposition, and photoluminescence data show increased signal intensity for thin SiO2 film on InP with H2S pretreatments as compared to untreated samples.