Nucleation mechanism of SPIMOX (separation by plasma implantation of oxygen)

Abstract

Buried oxide layers in Si were fabricated using the SPIMOX (separation by plasma implantation of oxygen) technique. The implantation was carried out by applying a negative bias to a Si substrate wafer immersed in an oxygen plasma. An implantation time of 2–3 min was required to implant the oxygen at doses ranging from 1 × 1017 atoms cm−2−3 × 1017 atoms cm−2. At a lower ion dose (1 × 1017 atoms cm−2), buried oxide precipitates were observed. At a higher dose (3 × 1017 atoms cm−2), a continuous buried oxide layer could be obtained, as indicated by cross section transmission electron microscopy (XTEM) and Rutherford backscattering spectrometry (RBS). By optimizing the concentration ratio of O+ and O2+ in the plasma and the implantation fluence, a double oxide layer (Si/oxide/Si/oxide/Si) structure could be produced in a single implantation step.