|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Materials Processing Fundamentals
||Gallium Evaporation Behavior for Purification in Molecular Beam Epitaxy (MBE)
||Kyungjean Min, David Johnson, Kevin Trumble
|On-Site Speaker (Planned)
The electron mobility in GaAs/AlGaAs heterostructures has been shown to correlate with the purity of the Ga source material in the Molecular Beam Epitaxy (MBE). Distillation of Ga was performed in the MBE to reduce impurities before growing AlGaAs/GaAs heterostructures at Purdue University and higher electron mobility was achieved after distillation compared to the initial 7N (99.99999%) Ga. During distillation and growth, 25% of the initial Ga was spent and the impurity concentration of Ge in the residual Ga was measured by ICP-MS to decrease from 690 ppb to 65 ppb. The evaporated amounts of Ga and impurities are analyzed by the Langmuir-Knudsen equation, as well as active oxidation of Ge. Geometric effects of evaporation from the crucible are analyzed using Clausing’s theory for the flux of angular distribution in evaporation from an area source in a cylindrical crucible.
||Planned: Stand-alone book in which only your symposium’s papers would appear (indicate title in comments section below)