Electrical properties of the SiN<i>x</i>/InP interface passivated using H2S

Abstract

Passivation of the electronic defect states at the SiNx/InP interface has been achieved using gaseous H2S treatments of the InP surface. Al/SiNx/InP capacitors, fabricated by depositing silicon nitride films on the H2S-treated InP, exhibit good capacitance-voltage (C-V) characteristics. The SiNx layer is deposited at 200 °C using an electron cyclotron resonance plasma-enhanced chemical vapor deposition (ECR-PECVD) technique. A minimum trap density of 3.5×1011 cm−2 eV−1 is estimated using the high-frequency C-V characteristics. These devices appear to be more uniform and reproducible than ammonium/phosphorous polysulfide-passivated SiNx/InP interfaces.