Oxidation of silicon surfaces by CO2 lasers

Abstract

We report for the first time, the use of a focussed CO₂ laser beam and a controlled oxygen atmosphere to induce localized oxidation on the surface of a silicon wafer. These thin oxide films have been compared by infrared spectrometry with thin furnace‐grown layers. We conclude that the laser‐grown oxides are compositionally similar to conventional layers, and can be described by the formula SiO₂. In contrast the half‐width of the Si‐O stretching vibration at 1070 cm⁻¹ was found to be consistently less than for furnace‐grown oxides. By fabricating simple Al‐SiO₂‐Si‐Al diodes, the dielectric properties of the films have been studied.