SRIM Tutorial 2 - Mixing and Sputtering

. Tutorial #2 – Target Mixing and Sputtering The previous Tutorials has covered how to setup TRIM, determine which ion and energy to specify for a n-well implantation, and how to evaluate the damage during the implantation. This Tutorial will show other effects of ion/solid interactions. . Interface Mixing and Sputtering Interface Mixing is the transport of atoms from one layer of a target into another layer. This is usually an undesirable effect. We have seen how ions can transfer significant energy to recoil atoms, and these can move long distances and create significant collision cascades (see Tutorial #4). When a recoil atom crosses from one target layer to another, the second layer is contaminated. However, there are special cases where recoil mixing is used to modify materials on purpose, and this process is called “recoil implantation”. This technique is used for materials which are either difficult or dangerous to handle. An example is the fabrication of materials containing radioactive substances. For example, a thin layer of calcium may be deposited on a target of silicon, and then it is placed in a nuclear reactor to convert the calcium to a radioactive isotope. The silicon is then placed in an ion implanter, and a high dose of Xe ions are implanted into the calcium layer. The Xe atoms knock some of the radioactive material into the silicon, where it is trapped. After removing any remaining surface Ca, the silicon with implanted ...