A novel detection system for defects and chemical contamination in semiconductors based upon the Scanning Kelvin Probe

A novel wafer scale detection system for defects and chemical contamination in semiconductors based upon the Scanning Kelvin Probe (SKP) is presented. It incorporates traditional work function (phi) topography with high resol ution (<0.1 meV). surface photovoltage (SPV) measurement and surface photov oltage-deep level transient spectroscopy (SPV-DLTS). This permits quasi-sim ultaneous determination of surface charge, surface potential and carrier li fetime, as well as the characterisation of deep level defects. The SKP system is introduced and the SPV and SPV-DLTS measurement modes are discussed. Surface charge measurements on clean and Fe-contaminated p-type Si(100) wafers show that iron induces negative charge in both native and t hermally grown oxide layers. SPV-DLTS is demonstrated on defects in thermal ly oxidised Si. The system is both non-contact and non-destructive. requires no wafer prepa ration, and can be applied in both ambient and vacuum environments. (C) 199 9 Published by Elsevier Science B.V. All rights reserved.