外延薄膜X射线表征方法的新进展

The progress in X-ray characterization techniques for epi-layers

对X射线倒易空间图技术(RSM)及X射线反射技术(XRR)的原理及其在外延薄膜表征方面的应用进行了介绍。RSM主要用于表征外延薄膜的应变、弛豫、马赛克缺陷、倾斜等微观缺陷,因为这些缺陷在倒空间中按不同的方向展宽。而 XRR主要用于模拟薄膜的厚度、粗糙度、密度及深度分布。

The high quality epitaxial thin films and multilayers for future electronic devices demand a full assessment of these materials, especially structural characterization down to micron scale or even lower, which create interesting and complex challenges for modern analysis techniques. X-ray reciprocal space mapping (RSM) and reflectometry were the lastest development of the X-ray techniques. Various effects like mosaicity, strain distributions, lattice parameter spread, layer tilt,etc, can be separated by RSM, as different kinds of imperfections broaden the intensity distribution near an reciprocal lattice point (RLP) in different directions. On the other hand, XRR can provide non-destructive information about density, thickness, surface and interface roughness, and element distribution profile of single- and multi-layer samples. The principle and applications of RSM and XRR for thin films, multilayers, and superlattices and quantum wells were summarized in this paper.