| 摘要 |
PURPOSE:To make it possible to do reactive ion etching (RIE) stably and precisely, by a method in which, after impurities are implanted in a substrate to depth required to be etched, it is detected whether or not there exists luminescence in the plasma owing to gas impurities in order to detect the etching end. CONSTITUTION:Through a thermal oxidizing film 2 which is formed on a substrate 1, openings 3 are formed above regions to form element separating grooves. Next, when impurity ion implantation 4 is done over the entire face of the semiconductor substrate 1, impurities 5 are implanted only into the element separating groove forming regions on the semiconductor substrate 1 through the openings 3 passing through the thermal oxidizing film 2. At this time, by controlling the accelerating voltage for the ion implantation, the impurities 5 are implanted to depth necessary for the element separating grooves 6 to be ditched. In the case where the semiconductor substrate 1 is etched by a RIE apparatus, the etching reaching to the predetermined depth would result in a state in which there does not exist impurities 5, so that an impurity gas detector 17 no longer can detect the impurity gas, ending the etching. |
