Patent ID: 6097078
Filing Date: 2000-08-01
Classification: H01L

Abstract:
A triple well structure of a semiconductor device, in which a semiconductor substrate of a first conductive type has a first well of the first conductive type, a second well of the first conductive type, a first well of a second conductive type, and a second well of the second conductive type enclosing the second well of the first conductive type in order to separate the first well of the first conductive type from the second well of the first conductive type, the second well of the second conductive type having sidewall regions extending below the surface of the substrate to a region having a first depth and a base region overlapping with lower portions of the sidewall regions and formed at a second depth below the surface of the substrate, the device having been formed by a method comprising the steps of:forming the base region of the second well of the second conductive type and the second well of the first conductive type via ion implantation using the same ion implantation mask pattern.