Patent ID: 6621116
Filing Date: 2003-09-16
Classification: H01L

Abstract:
An EPROM cell comprising:a P-type semiconductor substrate having a P well located therein to form a surface active area having a predefined periphery, the active area includes; at least a first P base region located at the predefined periphery at a surface of the substrate; a poly gate region located across the surface active area and extending over the at least first P base region; lightly doped first and second regions aligned with the poly gate region; oxide spacers at the sides of the poly gate region above portions of the lightly doped first and second regions; and, heavily doped source and drain regions provided at the surface active area with the source region being over at least a portion of the lightly doped first region and in alignment with a first one of the oxide spacers and the drain region being over at least a portion of the lightly doped second region and in alignment with a second one of the oxide spacers, the source and drain regions being separated by a channel region located beneath the poly gate; a second P base region located at a portion of the predefined periphery opposite the location of the first P base region and the poly gate including a first end over the first P base region and a second end over the second P base region; and the lightly doped first region being positioned at the predefined periphery at a first location and extending towards the center region from the predefined periphery and being position not to contact either the first P base or second P base regions and lightly doped second region being positioned at the predefined periphery at a second location opposite from the first location and extending towards the center region from the predefined periphery and being position not to contact either first or second P base regions.