Suppression of surface crystallization on borosilicate glass using RF plasma treatment

Abstract Surface crystallization on a commercial grade borosilicate glass wafer, Borofloat ® 33, is effectively prevented against 3 h of thermal reflow process at 850 °C. Surface plasma treatment with three different reactive gases, CF 4 , SF 6 , and Cl 2 , has been performed prior to the annealing. The effect of plasma treatment on surface ion concentration and nucleation of cristobalite were examined through optical microscope and x-ray photoemission spectroscopy. The dominant cause that suppresses crystallization was verified to be the increase of surface ion concentration of alumina during the plasma treatment. Both CF 4 and SF 6 treatment of no less than 30 s showed significant efficacy in suppressing crystallization by a factor of more than 112. Average surface roughness and the optical transparency were also enhanced by a factor of 15 and 3, respectively, compared to untreated sample.