DLTS of defects introduced in Si (and SiGe) by low energy (<5 keV) particles

F. Danie Auret

Department of Physics, University of Pretoria, Pretoria 0002, Republic of South Africa

Prakash N. K. Deenapanray

Department of Electronic Materials Engineering, Research School of Physical Sciences and Engineering, The Australian National University, Canberra 0200 ACT, Australia

Ion implantation and plasma processing techniques are routinely used for the fabrication of semiconductor devices. In particular, these techniques employ low-energy ions, which modify the electrical and optical properties of the semiconductor material, and, consequently, of the devices that are fabricated thereon, by creating defects in the semiconductor lattice. It is, therefore, of both technological and scientific interests to investigate the optical and electrical properties of defects created in low-energy ion bombarded semiconductors. In this paper, we review our investigations of the electrical characterization of defects created in Si by low-energy noble gas ions (He, Ne, and Ar) and hydrogen ions using deep level transient spectroscopy (DLTS). Noble gas ions are of great interests since they are used in plasma processes, and of their ability to form a class of noble-gas-ion-related defects by interacting with the intrinsic I₁ defect in Si. On the other hand, hydrogen possesses the peculiar ability to passivate electrically active defects and dopants. The properties of defects introduced in Si_1-xGe_x during ion etching and electron-beam evaporation of metal contacts are also reviewed.