Ion Implantation and Synthesis of Materials - Studium

182 13 Ion-Induced Atomic Intermixing at the Interface: Ion Beam MixingFig. 13.3. An example of mass and dose effects in the ion mixing of Pt/Si. Mixing increaseswith both increasing mass of the incident ion and increasing dose φ. The mixing rate for allirradiating ions is proportional to φ 1/2 (from Tsaur et al. 1979)critical temperature the mixing is very temperature-dependent. This behavior canbe seen in Fig. 13.4 for the case of Cr/Si irradiated with 300 keV Xe ions to a doseof 1 × 10 16 cm −2 . For temperatures below 0°C, the amount of mixing that occursis relatively insensitive to the sample temperature during irradiation; thistemperature interval is known as the temperature-independent ion mixing regime.However, as the sample temperature is increased to above ~100°C, the mixingrate changes rapidly with temperature and is observed to increase with increasingtemperature; this temperature interval is known as the temperature-dependent ionmixing regime.13.2 Ballistic MixingThe interaction of an energetic ion with a solid involves several processes. As an ionpenetrates a solid, it slows down by depositing energy both to the atoms and tothe electrons of the solid. During the nuclear collision portion of this process, target