论文标题
原位微束表面X射线散射显示在晶体生长过程中交替的步骤动力学
In Situ Microbeam Surface X-ray Scattering Reveals Alternating Step Kinetics During Crystal Growth
论文作者
论文摘要
六边形密闭和相关晶体的堆叠序列通常会导致具有不同生长动力学的交替A和B结构的杂化{0001}表面的步骤。但是，由于很难在实验上确定哪个步骤具有A或B结构，因此无法确定哪种具有更快的Adatom附件动力学。在这里，我们表明，原位微束表面X射线散射可以确定A或B步骤在特定生长条件下是否具有更快的动力学。 We demonstrate this for organo-metallic vapor phase epitaxy of (0001) GaN.在生长过程中执行的X射线测量结果发现，梯田的平均宽度随着生长速率的增加而增加，这表明，与大多数预测相比，步骤的附件速率常数更高。我们的结果对理解GAN生长的原子级机制具有直接的影响，并且可以应用于各种相关晶体。
The stacking sequence of hexagonal close-packed and related crystals typically results in steps on vicinal {0001} surfaces that have alternating A and B structures with different growth kinetics. However, because it is difficult to experimentally identify which step has the A or B structure, it has not been possible to determine which has faster adatom attachment kinetics. Here we show that in situ microbeam surface X-ray scattering can determine whether A or B steps have faster kinetics under specific growth conditions. We demonstrate this for organo-metallic vapor phase epitaxy of (0001) GaN. X-ray measurements performed during growth find that the average width of terraces above A steps increases with growth rate, indicating that attachment rate constants are higher for A steps, in contrast to most predictions. Our results have direct implications for understanding the atomic-scale mechanisms of GaN growth and can be applied to a wide variety of related crystals.
