Scanning tunneling microscopy analysis of ultrafast laser damage of single crystal silicon

Abstract

Laser processing is useful for topographical and band structure modification of semiconductors. We used a Scanning Tunneling Microscope (STM) to map topography and spectra around hydrofluoric acid etched silicon (100) damaged with an ultrafast pulsed Yb:KGW laser at 1030nm with duration of 70fs in high vacuum. STM uses an atomically sharp tip and feedback loop controlled piezoelectric crystals to characterize conductive surfaces with atomic resolution. With this, we have observed periodic surface structures. This information can then be used to understand the laser damage process better and eventually can be used to characterize defect formation without the presence of topographical change.