# Amorphization after Ion Implantation

| The picture below shows the boundary between crystalline Si, and Si that has been rendered amorphous by an ion implantation (the ion beam came from the right). The picture is slightly remarkable because it was the first high resolution transmission electron microscopy (HRTEM) picture ever taken from damage after ion implantation.
|  | There is indeed an amorphous Si (a-Si) layer. (Think a minute how you could ascertain that without transmission electron microscopy).
|  | There is a pretty abrupt, if somewhat wavy boundary between the amorphous and the crystalline Si.
|  | There seems to be little disturbance in the Si lattice - it looks pretty perfect.

| Quick glances at HRTEM pictures may be deceiving, however.
|  | A lot of point defects may be contained in the lattice - they would not clearly show in this picture
|  | Looking a bit more closely at some greater depth (to the left of the above picture), a high density of dislocations is found. An example is shown below; the ending lattice planes are indicated with yellow lines.
|  | Note that not all dislocations will show up in this kind of imaging mode.

With frame

6.4.2 Ion Implantation

© H. Föll (Electronic Materials - Script)