| 摘要 |
PURPOSE:To form an impurity area for separation with effective self matching by a method wherein a nitride film is selectively formed on an oxide film on a substrate by utilizing the 1st and 2nd resist masks and after a high impurity concentration area is formed between nitride films in the substrate, a selective oxidation processing is performed. CONSTITUTION:A heat oxide SiO2 film 2 is formed on the surface of a P type Si substrate 1, and after the 1st resist pattern 12 is installed on the surface thereof, a Si3N4 film 3 is formed with a low temperature CVD. Next thereto, the 2nd resist pattern 13 is installed so that it may include a part not to form an oxide film for separation between elements and a segment of the 1st resist part. The exposed Si3N4 film part is removed by etching. After a P<+> type area 5 is formed with an ion injection, a resist is removed and taking a residual Si3N4 film 3 as a mask, a heat oxide SiO2 film 6 for the separation use is formed. With this, a P<+> type area for the separation use can be formed with effective accuracy by means of a self matching. |
