Method to perform selective drain engineering with a non-critical mask

Abstract

A method of producing an asymmetrical semiconductor device with ion implantation techniques and semiconductor devices constructed according to this method in which a barrier of ion absorbing material of height h is positioned beside a structure on a semiconductor surface. The barrier is located at a maximum distance d from one side of the structure, and an angled ion implant is directed at the side of the structure. The maximum distance d of the barrier from the side of the structure is equal to the height of the barrier h divided by the tangent of the angle of the ion implant so that the side of the structure is shadowed from the ion implant. A second ion implant is directed to the opposite side of the structure on the semiconductor surface, thereby forming a desired implant and producing the asymmetrical semiconductor device.