ION-IMPLANTATION INTO HEATED SODA-LIME GLASS SUBSTRATES

Soda-lime silicate glass substrates have been implanted with 55 keV copper, gallium and silver ions. For each ion, implants were done with the substrate at room temperature, 373, 498, 623 and 873 K. The ion distributions varied greatly with temperature. Ion exchange between the silver and sodium ions was observed for temperatures at 498 K and above; a similar process occurred for the copper at 873 K only. Those four implants formed single-mode enhanced-index waveguides. Migration of sodium and calcium ions was also observed: sodium was sputtered from the surface but, at 623 K and above, was replaced from within the bulk; conversely, at the same temperatures, the calcium at the surface migrated deeper into the glass. The calcium movement was induced by an electric field at the surface caused by the implantation process. The depletion of the sodium and calcium from the surface left a silica-rich layer. Overall the data emphasise that ion implantation into a heated multi-element silicate glass produces more complex changes than those predictable by normal ion-range theories.