Visible photoluminescence from Tb/sup 3+/ ions implanted into a SiO/sub 2/ film on Si at room temperature

摘要

Visible photoluminescence (PL) from Tb/sup 3+/ ions in SiO/sub 2/ has been investigated at room temperature. The Tb ions were implanted into a 200 nm thick SiO/sub 2/ layer on a Si wafer. Since the PL of rare-earth ions is sensitive to their concentration, a uniform depth profile of Tb ions is important for reliable results. To achieve it, multiple implantations were conducted at 50, 100, 190 keV to a total dose of 8.8/spl times/10/sup 14/-1.3/spl times/10/sup 16/ ions/cm/sup 2/. The PL spectrum consists of sharp lines due to 4f-4f transitions of Tb/sup 3+/ ions and a broad band due to defects of SiO/sub 2/. The PL lines from the /sup 5/D/sub 4/ level of Tb/sup 3+/ increase superlinearly with Tb concentration up to 1 at%. and are dominant over the defect band. The residual defect band is reduced by H/sub 2//N/sub 2/ annealing at 900/spl deg/C. Then the defect-free PL from Tb:SiO/sub 2/ is attained.