Terheiden Barbara, Hensen Jan, Wolf Andreas, Horbelt Renate, Plagwitz Heiko, Brendel Rolf
Institut für Solarenergie Forschung Hameln (ISFH), Am Ohrberg 1, 31860 Emmerthal, Germany.
Materials (Basel). 2011 May 23;4(5):941-951. doi: 10.3390/ma4050941.
We demonstrate for the first time the successful layer transfer of an epitaxially grown monocrystalline Si film from a purely chemically etched porous Si substrate of 150 mm diameter to a glass carrier. The surface conditioning for all Si layer transfer processes based on porous Si has been, up to now without exception, carried out by electrochemical etching. In contrast, our chemical stain etching process uses an aqueous HF-rich HF/HNO₃ solution. The porosity increases with increasing doping concentration of the Si substrate wafer and with increasing porous layer thickness. In contrast to the electrochemically etched double layers, the porosity profile of the stain etched substrates is highest at the original wafer surface and lowest at the interface between the porous layer and the Si bulk. The epitaxy process is adapted to the high porosity at the surface with regard to the reorganization of the porous layer.
我们首次展示了将外延生长的单晶硅膜从直径为150毫米的纯化学蚀刻多孔硅衬底成功转移到玻璃载体上。到目前为止，所有基于多孔硅的硅层转移工艺的表面处理无一例外都是通过电化学蚀刻进行的。相比之下，我们的化学腐蚀蚀刻工艺使用富含氢氟酸的HF/HNO₃水溶液。孔隙率随着硅衬底晶圆掺杂浓度的增加以及多孔层厚度的增加而增大。与电化学蚀刻的双层结构不同，腐蚀蚀刻衬底的孔隙率分布在原始晶圆表面最高，在多孔层与硅块体之间的界面处最低。外延工艺针对多孔层的重组对表面的高孔隙率进行了调整。
