Nanostructure formation during ion-assisted growth of GaN by molecular beam epitaxy
Nanostructure formation during ion-assisted growth of GaN by molecular beam epitaxy
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DOI：
10.1063/1.1897487
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发表时间：
2005-05
影响因子：
3.2
通讯作者：
B. Cui;P. Cohen;A. Dabiran
中科院分区：
文献类型：
--
作者：
B. Cui;P. Cohen;A. Dabiran
离子束辅助分子束外延用于通过使来自喷射池的 Ga 与氨反应，在蓝宝石上生长 GaN。当离子束处于低掠射角和 60-500eV 之间的能量时，可以观察到有或没有生长的周期性纳米级波纹和点。通过改变生长参数，尺寸可以从 40 纳米调整到 800 纳米。根据连续介质模型分析纹波波长。然而，图案形成的时间常数比线性或非线性理论预测的时间常数小几个数量级。计算了移动吸附原子浓度，发现其定量合理，随着净增长率的增加而增加。观察到氮离子束的纹波波长发育良好，但在我们的能量和通量范围内的氩离子则不然。增加生长会减少而不是增加测量的波长。
Ion-beam-assisted molecular beam epitaxy was used to grow GaN on sapphire by reacting Ga from an effusion cell with ammonia. With the ion beam at low glancing angle and energy between 60–500eV, periodic, nanoscale ripple and dots were observed both with and without growth. By changing the growth parameters, the dimensions could be tuned from 40to800nm. The ripple wavelength was analyzed in terms of continuum models. However, the time constant for pattern formation was several orders of magnitude less than that predicted by linear or nonlinear theories. The mobile adatom concentration was calculated and found to be quantitatively reasonable, increasing with increasing net growth rate. The ripple wavelength was observed to be well developed for nitrogen ion beams, but not with Ar ions within our energy and flux range. Adding growth reduced the measured wavelength rather than increasing it.