| 摘要 |
PURPOSE:To obtain an integrated circuit device with a high yield by forming elements at the rear surface of semiconductor substrate forming an epitaxial layer. CONSTITUTION:A window is provided to an SiO2 film 2 formed on the N type Si substrate 1 and a high concentration P type region 3 and N type region 4 are selectively formed in such a manner that they are not in contact each other. At this time, this SiO2 film 2' is removed and the stepped part 5 with difference in height of 1-1.5mum is formed by the etching with the remaining SiO2 film 2 used as the mask so that the surface of diffused regions 3, 4 becomes lower than the main surface of semiconductor substrate 1. Next, the SiO2 film 2 is removed from the entire part and a P type epitaxial layer 6 is formed. Thereafter, the N type Si substrate 1 is polished from the rear surface 7 up to the desired thickness. Then, P type impurity is implanted and thereby the element isolating regions 9-9'' are formed. At this time, the stepped part 5' is used for alignment. Then, impurity regions 10, 11 are formed at the rear surface 7' and thereby an element such as transistor can be formed. |
