| abstract |
The method allows formation of buried cavities in a wafer (25) of monocrystalline semiconductor material. Initially, at least one cavity (21) is formed in a substrate (10) of monocrystalline semiconductor material, by timed TMAH etching silicon, then the cavity is covered with a material inhibiting epitaxial growth (22); finally, a monocrystalline epitaxial layer (26) is grown above the substrate (10) and the cavities (21). Thereby, the cavity (21) is completely surrounded by monocrystalline material. Starting from this wafer, it is possible to form a thin membrane (52). The original wafer (25) must have a plurality of elongate cavities or channels (21), parallel and adjacent to one another. Trenches (44) are then excavated in the epitaxial layer (26), as far as the channels (21), and the dividers between the channels are removed by timed TMAH etching. <IMAGE> <IMAGE> <IMAGE> |