| 摘要 |
PURPOSE:To bring the level measurements of an element isolation region to zero and to contrive high density integration by a method wherein a stepped section is provided by performing an etching on a semiconductor substrate and a field oxide film is formed vertically on the inner wall of the stepped section. CONSTITUTION:The pattern of an Si oxide film 2 of 1mum in thickness is formed on the Si semiconductor substrate 1, a reactive ion etching is performed using the above pattern as a mask and the stepped section 15 of 1mum in depth is formed on the semiconductor substrate 1. Then, after the Si oxide film has been removed, an ion is implanted vertically on a proton and a donor layer 16 is formed on the upper surface of the semiconductor substrate 1 and on the bottom surface of the stepped section 15. Subsequently, when anode formation is performed, no current is applied to the donor layer 16, anode is formed only on P type inner wall 15a of the stepped section 15 and a porous Si layer 17 is formed. Lastly, when a wet thermal oxidization is performed and the thin oxide film formed on the surface is removed by etching, element forming regions 7a-7c which are isolated by a field oxide film 5 can be obtained. |
