Antimony and arsenic segregation at Si-SiO2interfaces

The behavior of shallow Sb and As implants has been investigated in the vicinity of the Si-SiO2interface. The implants were performed through thin typically 10-nm oxides and then subjected to inert ambient annealing between 900 and 1000°C. It has been found that the diffusing dopants have an essentially unity sticking coefficient at the SiO2interface, until ∼ 2 × 10¹⁴/cm²is segregated. All indications are that the segregated Sb/As forms a single monolayer at the interface. The dopants in this layer are electrically inactive. Such a loss of active dopants must be taken into account in the design of submicrometer devices.