Calculations of Thickness Uniformity in Molecular Beam Epitaxial Growth

MBE 장치에 의한 에피 성장 두께 균일도 계산

The growth thickness uniformity of epitaxial layers deposited using a moiecular beam epitaxy system is calculated from the arrangement of molecular beam source and the substrate and the geometric dimensions of the crucible in order to predict the optimum design conditions of the prototype MBE system. The thickness uniformity better than 5% over a 3-inch wafer can be obtained by keeping the distance between the substrate and the crucible's orifice longer than 20cm, the tapering angle of the crucible larger than 6$^{\circ}$, and the angle between the normal to the substrate at the center and the crucible axis as larger as possible. In addition, the growth yield decreases to below 51% as the distance between the substrate and the orifice becomes longer than 25cm.