STRUCTURAL-ANALYSIS OF ION-IMPLANTED CHEMICAL-VAPOR-DEPOSITED DIAMONDBY TRANSMISSION ELECTRON-MICROSCOPE

A transmission electron microscope (TEM) study of ion-implanted chemic al-vapor-deposited (CVD) diamond is presented. CVD diamond used for tr ansmission electron microscope observation was directly deposited onto Mo TEM grids. As-deposited specimens were irradiated by C (100 keV) i ons at room temperature with a wide range of implantation doses (10(12 )-10(17)/cm(2)). Transmission electron diffraction (TED) patterns indi cate that there exists a critical dose (D-c) for the onset of amorphiz ation of CVD diamond as a result of ion induced damage and the value o f critical dose is confirmed to be about 3 x 10(15)/cm(2). The ion-Ind uced transformation process is clearly revealed by high resolution ele ctron microscope (HREM) images. For a higher dose implantation (7 X 10 (15)/cm(2)) a large amount of diamond phase is transformed into amorph ous carbon and many tiny misoriented diamond blocks are found to be le ft in the amorphous solid. The average size of these misoriented diamo nd blocks is only about 1-2 nm. Further bombardment (10(17)/cm(2)) alm ost kills all of the diamond phase within the irradiated volume and mo reover leads to local formation of micropolycrystalline graphite.