Vasquez M R, Flauta R E, Wada M
Department of Engineering Sciences, College of Engineering, University of the Philippines, Diliman, Quezon City, Philippines.
Rev Sci Instrum. 2008 Feb;79(2 Pt 2):02B910. doi: 10.1063/1.2816965.
Monte Carlo simulations were conducted to study the formation of gallium-nitride (GaN) layer on liquid gallium (Ga) sputtering target immersed in nitrogen (N(2)) plasma. In the simulation model, N ions were assumed to possess energy equal to the bias voltage applied to the sputtering target with respect to the plasma. The results showed the surface morphology of GaN changed from a relatively smooth GaN on Ga surface at 50 eV N ion energy to a rough surface with GaN dendrites on liquid Ga at 500 eV ion energy. Further increase in N ion energy up to 1 keV resulted in smaller density of GaN dendrites on surface. Increasing surface coverage of Ga by GaN substantially reduced the sputtering yield of Ga from the target. These simulation results were correlated with previously reported experimental observations on liquid Ga surface immersed in the nitrogen plasma of a plasma-sputter-type ion source.
进行了蒙特卡罗模拟，以研究浸没在氮气（N₂）等离子体中的液态镓（Ga）溅射靶上氮化镓（GaN）层的形成。在模拟模型中，假设N离子具有的能量等于相对于等离子体施加到溅射靶上的偏置电压。结果表明，GaN的表面形态从50 eV N离子能量下Ga表面相对光滑的GaN，变为500 eV离子能量下液态Ga上带有GaN枝晶的粗糙表面。N离子能量进一步增加至1 keV，导致表面GaN枝晶密度减小。GaN对Ga表面覆盖率的增加显著降低了靶材上Ga的溅射产率。这些模拟结果与先前报道的关于浸没在等离子体溅射型离子源的氮等离子体中的液态Ga表面的实验观察结果相关。
