| 摘要 |
PURPOSE:To reduce interfacial level and also to prevent occurrence of cracking on a final protective film, by annealing an inorganic insulating film by using NH3 plasma. CONSTITUTION:A gate oxide film 5' and a gate electrode 6' are prepared on the surface of a P type Si substrate 4 which was separated by a field oxide film 1 and a channel cut 2. It is covered with SiO28 by difusing an N<+> layer 7, provided with an Al electrode 9 by opening a hole and covered with an Si3N410. At this time, interfacial level is formed on the oxide film 5'. And then, when the substrate is put into a bell jar, exposed to NH3 plasma and the gate oxide film 5' is annealed by high frequency, noncombined Si atoms are combined with activated H2, etc., and interfacial density becomes extremely low, and therefore, MOSFET having a stable threshold voltage becomes obtainable. Further, since temperature of the substrate rises very little during the annealing process, it is possible to prevent the Si3N4 film 10 from occurrence of fine cracks. |
