| abstract |
By utilizing a fluorine-containing gaseous compound in a plasma etching process, isotropic etching of monocrystalline silicon (48) and doped or undoped polycrystalline silicon (54) is achieved. The etching processes, which are applicable, for example, to pattern delineation in the processing of semiconductor wafers, are substantially free of any proximity effects and are characterized by a high etching rate at relatively low power levels, high selectivity (with respect to, for example, silicon dioxide) and excellent uniformity. By mixing other gases (for example, chlorine) with the fluorine-containing gas, the amount of undercutting achieved during the etching process can be selectively controlled. |