Diffusion of Iron into GaAs from a Spin‐on Source

Abstract

Iron was diffused from a spin‐on glass film into n‐type wafers at temperatures of 700°–900°C. The observed diffusion depths can be explained by a model with exhaustible diffusion sources. The diffusion coefficient of iron in has been estimated to be in this temperature range. The resistivity of the diffused layer was in the order of 104 Ω cm. The activation energy of the introduced levels was 0.53 eV for the diffusion at 700° and 800°C, which agrees well with the acceptor level of iron. The current‐voltage characteristics of mesa diodes made of the diffused wafers showed no excess leakage current, which ensures that high‐resistivity, p‐type, iron‐diffused regions can be used for junction isolation in integrated circuits.