Study of the Etching Mechanism of Heavily Doped Si in HF
| Periodical | Solid State Phenomena (Volume 187) |
|---|---|
| Main Theme | Ultra Clean Processing of Semiconductor Surfaces X |
| Edited by | Paul Mertens, Marc Meuris and Marc Heyns |
| Pages | 41-44 |
| DOI | 10.4028/www.scientific.net/SSP.187.41 |
| Citation | Nick Valckx et al., 2012, Solid State Phenomena, 187, 41 |
| Online since | April, 2012 |
| Authors | Nick Valckx, Daniel Cuypers, Rita Vos, Harold Philipsen, Jens Rip, Geert Doumen, Paul W. Mertens, Marc M. Heyns, Stefan de Gendt |
| Keywords | ICP-MS, Si Etching, USJ |
| Price | US$ 28,- |
Following Moores scaling law, the transistor source and drain area become shallower and higher doped regions. As a consequence the limitations of substrate and dopant loss during cleaning become more stringent. For a better understanding, highly B, As and P doped blanket substrates, either prepared by ion implantation or by EPI growth, are studied. Substrate and dopant loss as a function of time and different HF etching conditions is monitored by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and additional techniques like Spectroscopic Ellipsometry (SE), .... It is shown that in general, the Si etching is dependent of the position of the Fermi level. More remarkably, the junction (4 nm) of a non-annealed heavily As or P doped substrate is completely removed after less than 20 min of etching in HF. This process is related to enhanced etch rates because of the amorphization of the substrate.
