In situ UHV contactless C–V and XPS characterization of surface passivation process for InP using a partially nitrided Si interface control layer

A totally in situ surface passivation process of InP consisting of growth of an ultrathin Si interface control layer Si ICL. and its subsequent partial nitridation is described. The process was characterized and optimized by in situ ultrahigh vacuum UHV.contactless capacitance–voltage C–V.measurements and X-ray photoelectron spectroscopy XPS.measurements. An electron cyclotron resonance ECR.-N2 plasma process and a nitrogen radical process were compared for partial nitridation of Si ICL. In situ XPS measurements provided useful information on the thickness and composition of the nitrided surface layer. UHV C–V measurements showed that the nitridation process using ECR-N2 plasma was more favorable, realizing a full swing of Fermi level almost over the entire bandgap. A metal–insulator–semiconductor MIS. capacitor was fabricated by further depositing a thick Si3N4 layer on the ECR plasma processed structure. Conventional MIS C–V measurements confirmed an excellent interface property, proving the effectiveness of the in situ passivation process. q2000 Elsevier Science B.V. All rights reserved