Characterization of defects in Si and SiO[sub 2][minus]Si using positrons

• Published in: Journal of applied physics 1994-11, Vol.76:9
• Main Authors: Asoka-Kumar, P., Lynn, K.G., Welch, D.O.
• Format: Article
• Language: English
• Subjects: 360605 - Materials- Radiation Effects; 665300 - Interactions Between Beams & Condensed Matter- (1992-); ANNIHILATION; ANTILEPTONS; ANTIMATTER; ANTIPARTICLES; BASIC INTERACTIONS; CHALCOGENIDES; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DEFECTS; DOPPLER BROADENING; ELECTROMAGNETIC INTERACTIONS; ELECTROMAGNETIC RADIATION; ELEMENTARY PARTICLES; ELEMENTS; FERMIONS; GAMMA RADIATION; INTERACTIONS; INTERFACES; IONIZING RADIATIONS; LEPTONS; LINE BROADENING; MATERIALS SCIENCE; MATERIALS TESTING; MATTER; NONDESTRUCTIVE TESTING; OXIDES; OXYGEN COMPOUNDS; PARTICLE INTERACTIONS; PHYSICAL RADIATION EFFECTS; POSITRONS; RADIATION EFFECTS; RADIATIONS; SEMIMETALS; SILICON; SILICON COMPOUNDS; SILICON OXIDES; TESTING; TRAPPING
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.357207

In the past few years, there has been rapid growth in the positron annihilation spectroscopy (PAS) of overlayers, interfaces, and buried regions of semiconductors. There are few other techniques that are as sensitive as PAS to low concentrations of open-volume-type defects. The characteristics of the annihilation gamma rays depend strongly on the local environment of the annihilation sites and are used to probe defect concentrations in a range inaccessible to conventional defect probes, yet which are important in the electrical performance of device structures. We show how PAS can be used as a nondestructive probe to examine defects in technologically important Si-based structures. The discussion will focus on the quality of overlayers, formation and annealing of defects after ion implantation, identification of defect complexes, and evaluation of the distribution of internal electric fields. We describe investigations of the activation energy for the detrapping of hydrogen from SiO[sub 2][minus]Si interface trap centers, variations of interface trap density, hole trapping at SiO[sub 2][minus]Si interfaces, and radiation damage in SiO[sub 2][minus]Si systems. We also briefly summarize the use of PAS in compound semiconductor systems and suggest some future directions.