SR-stimulated etching and OMVPE growth for semiconductor nanostructure fabrication

Synchrotron radiation- (SR-)stimulated etching and selective area growth by organometallic vapor phase epitaxy were performed to form an ordered array of InP crystals on SiO2-patterned InP (001) substrate. The SR-stimulated e tching was used to pattern the SiO2 film, because photochemical reaction us ing SR was expected to provide smooth surfaces, vertical side walls and fin e patterning. In the first place, we investigated the basic properties of t he SR-stimulated etching by using a mm-size pattern of SiO2 mask. The etche d depth was observed to increase linearly with the irradiation dose. It was found that the etching depth was controlled very accurately. Next, we used mu m-size patterns of SiO2 masks for fabricating the ordered array of InP crystals. In a atomic force microscope image of the sample after etching, a steep side wall was observed. However, the etched surface was not smooth, contrary to our expectation. Moreover, some dust were observed on the surfa ce. From this dust it was found that the SR-stimulated etching had a resolu tion of less than or equal to 100 nm at most. (C) 2000 Elsevier Science S.A . All rights reserved.