A new in-situ optical probing method with an atomic-scale resolution in heteroepitaxial growth is proposed. The experimental set-up of the method is very similar to another optical probing method called surface photo-absorption (SPA), but the principle is quite different. The new method is named surface photo-interference (SPI) because it is essentially concerned with photo-interference in the heteroepilayer. The principle of the SPI is as follows: the complex refractive indices of the atomic or molecular layers, which alternately appear on top of the surface during epitaxial growth of compound semiconductors, greatly affect the total phase shift of probing light during propagation in the epilayer, resulting in a change in the photo-interference signal intensity. One of the features of the SPI is that, unlike in the case of SPA, fairly low energy photons which are transparent for the epilayer can also be used as probing light. This is very preferable for studying the growth kinetics and/ or surface reaction in photo-excited epitaxial growth of widegap II-VI compounds, because the effect of photocatalytic growth-rate enhancement can be avoided when using such low energy photons as probing light.
ASJC Scopus subject areas
- 化学 (全般)