Channeling of aluminum in silicon

Abstract

A systematic study of channeling of aluminum in the silicon crystal is reported. Depth distributions measured by secondary ion mass spectrometry are reported for 40-, 75-, and 150-keV aluminum channeled in the 〈100〉 and 〈110〉 directions of silicon. The profile dependence on alignment angle is shown for 150-keV aluminum in the 〈110〉 of silicon. Aluminum has low electronic stopping in silicon and corresponding deep channeled profiles are observed for aligned implants and deep channeling tails are observed on random implants. The maximum channeling range for 150-keV Al in 〈100〉 silicon is about 2.8 μm and is about 6.4 μm in 〈110〉 silicon. Some ions will reach the maximum channeling range even for 2° misalignment. Many of the deep channeling tails and ‘‘supertails’’ reported in earlier literature can be explained by the normal channeling of aluminum in silicon.