SEMICONDUCTOR DEVICE AND MANUFACTURE THEREOF

PURPOSE:To provide a semiconductor device with a layer insulating film which is adequately flat and high quality by forming a coating film on an insulating film of two layers each made of a different material formed on a semiconductor substrate having a difference in height formed on its surface and then etching the whole surface of each of the coating film and the insulating film of the upper layer. CONSTITUTION:A first insulating film 3A and a second insulating film 4 made of the different material from that of the first insulating film 3A are formed in sequence on a semiconductor substrate having a difference in height on the surface. Next, a coating film 5 is formed on the second insulating film 4, and then the whole surface of the coating film 5 is etched to expose the highest part of the second insulating film 4. Next, the etching of the whole surface is conducted on the condition that the rate at which the second insulating film 4 is etched is higher than that at which the coating film 5 is etched to expose the first insulating film 3A under the second insulating film 4 which is exposed. And after that, for example, after the coating film is separated, a second silicon oxide 3B is deposited by a plasma CVD method to some degree that it has a necessary film thickness for a layer insulating film on a wiring 2.