Patent DE-102007043943-A1 (DE)
Title: Dynamic coating of substrates with doped layers of silicon and/or germanium in vacuum coating chamber, comprises transferring the substrate into the chamber by transport system and over evaporation source with the coating material
Inventor: REINHOLD EKKEHART
IPC: C23C14/56
Filed: 2007-09-14
Abstract: The method for dynamic coating substrates (2) with doped layers of semiconducting elements such as silicon and/or germanium by vaporization in a vacuum coating chamber (1), comprises transferring the substrate into the vacuum coating chamber by a transport system (12) and over an evaporation source (3) with the coating material (7), heating the coating material in the evaporation source by an energy input, evaporating doping materials (13, 14) in a linear effusion cell arranged beside the evaporation source, and aligning the particle stream of the doping material by the effusion cell. The method for dynamic coating substrates (2) with doped layers of semiconducting elements such as silicon and/or germanium by vaporization in a vacuum coating chamber (1), comprises transferring the substrate into the vacuum coating chamber by a transport system (12) and over an evaporation source (3) with the coating material (7), so that the substrate side is located in an opposite direction of the surface of the coating material, heating the coating material in the evaporation source by a suitable energy input, at which a part of the coating material is present in the gaseous phase and condensed on the substrate, evaporating doping materials (13, 14) in a linear effusion cell arranged beside the evaporation source, and aligning the particle stream of the doping material by the effusion cell. The vaporous doping material is mixed in a defined area of the spatial distribution of steam, a steam cloud and the coating material and is condensed as mixture on the substrate. The coating takes place by the evaporation source, whose distance from the surface of the coating material to the substrate is constant during the coating of a wide substrate or a defined number of substrates or a defined substrate section of a band-shaped substrate. The evaporation of the coating material takes place by the symmetrical distribution of sources of the vaporous coating material transverse to the substrate transportation direction. The coating material is heated by the concentrated electron-beam and the distribution of steam sources is produced by the electron-beam figures, which are formed on the surface of the coating material by defined motion of the electron-beam. The effusion cell is arranged at a right-angle to the substrate transportation direction and comprises a linear dimension, which corresponds to the width of the substrate. The evaporation temperature of the doped material is regulated in the effusion cell in a segment-wise manner. A part of coating material steam is mixed with the steam of the doped material and is separated and another part of coating material steam is condensed in an undoped manner. Two different dopings are produced by the two effusion cells, which are arranged with a different distance and/or different orientation of the particle steam. The particle steam is spatially limited by a suitable screen in such a manner that it changes in a vaporization area of the composition of the steam cloud in a substrate transportation direction in a discontinuous manner. An additional energy is applied into the substrate before and/or during the coating. A base and doped unexpanded layer is applied to a back surface field in the vacuum coating chamber. An independent claim is included for a device for coating of substrates with doped layers.