| 摘要 |
<p>In one method of producing a semiconductor device, such as an IC including MOS transistors, impurity ions are implanted into a semiconductor substrate (1) provided with an insulating film (2b). The insulating film is electrically charged by the impurity ions and may be destroyed if the electric potential difference between the insulating film and the semiconductor substrate is excessive. The invention shortens the ion implantation time, without risking the destruction of the insulating film, by increasing the ion beam current during the period of ion implantation. An increase is made when with the previous beam current the electric potential difference across the insulating film has fallen and the beam current increase is of a size such that with the new current value the electric potential difference is not increased above the breakdown value for the insulating film and preferably is not above 80-90% of that value. </p> |
