WAVELENGTH DEPENDENCE OF LASER-ENHANCED OXIDATION OF SILICON.

THE THERMAL OXIDATION RATE OF SI IN DRY OXYGEN IS INCREASEDBY ILLUMINATION WITH LOW-POWER VISIBLE AND ULTRAVIOLET LASER LIGHT AND IS SHOWN TO BE A FUNCTION OF THE WAVELENGTH OF THE LASER RADIATION. VISIBLE LASER RADIATION INCREASES THE THERMAL OXIDATION RATE OF SI BY APPROXIMATELY 40P, AND ULTRAVIOLET RADIATION AT 350 NM BY 60P, OVER THE TEMPERATURE RANGE OF 770-900 D. C. A LASER-INDUCED RATE INCREASE OF 40P IS ALSO OBSERVED IN WET (H//2O + O//2) THERMAL OXIDATION. HOWEVER,NO SIGNIFICANT WAVELENGTH DEPENDENCE IS SEEN IN THIS CASE. IT MAY BE CONCLUDED FROM THESE DATA THAT ULTRAVIOLET LASER LIGHT AFFECTS SOME COMPONENT OF THE DRY OXYGEN REACTION THAT IS NOT PRESENT (OR NOT IMPORTANT) IN WET THERMAL OXIDATION. THERE APPEARS TO BE A THRESHOLD ENERGY OF 3. 0 TO 3. 5 EV FOR THIS OBSERVED OPTICAL EFFECT. POSSIBLE MECHANISMS FOR THE OPTICAL INTERACTION ARE DISCUSSED.