Ion beam induced charge collection (IBICC) microscopy of ICs: relation to single event upsets (SEU)

Abstract

Single event upset (SEU) imaging is a new diagnostic technique recently developed using Sandia's nuclear microprobe. This technique directly images, with micron resolution, those regions within an integrated circuit which are susceptible to ion-induced malfunctions. Such malfunctions are an increasing threat to space-based systems which make use of current-generation 1C designs. A complementary technique to SEU imaging involves measurement of the charge collection volumes within integrated circuits; charge collection is the underlying physical process responsible for single event phenomena. This technique, which we term ion beam induced charge collection (IBICC), has been used here and elsewhere to generate micron resolution maps of the charge collection response of integrated circuits. In this paper, we demonstrate the utility of combining the SEU imaging and IBICC techniques in order to gain a better understanding of single event upset phenomena. High resolution IBICC images are used to extract more detailed information from charge collection spectra than that obtained from conventional broad-area ion exposures, such as from radioactive sources. Lastly, we suggest the application of IBICC as a replacement for electron beam induced conduction/current (EBIC) measurements. As reductions in circuit feature size continue in the submicron regime, IBICC could certainly prove to be a technologically valuable replacement for EBIC and an important business opportunity for all nuclear microprobe facilities.