A new preparation method for large area electron-transparent silicon samples

A technique for the preparation of large area (several millimetres in diameter) samples is described, which can be applied to both low and high voltage transmission electron microscopy (TEM). The procedure starts with chemical thinning down to 2-10 mu m from one side of a whole silicon wafer. From the thinned wafer, discs of a diameter suitable for the TEM examinations are chemically separated by a photoresist step and are fastened onto a metal ring adapted for the TEM sample holder. For low voltage electron microscopy these silicon discs must be thinned to less than 1 mu m in a further chemical treatment.