METHOD FOR FORMING WELL OF SEMICONDUCTOR DEVICE TO IMPROVE CHARACTERISTICS OF JUNCTION LEAKAGE CURRENT, INVERSE NARROW WIDTH EFFECT AND NARROW WIDTH EFFECT

摘要

PURPOSE: A method for forming a well of a semiconductor device is provided to improve characteristics of a junction leakage current, an inverse narrow width effect and a narrow width effect by forming a well having impurity ions of a uniform doping density. CONSTITUTION: A trench is formed in a semiconductor substrate(11) by using a pad nitride layer as an etch mask such that the pad nitride layer is patterned to open a field region. An oxide layer is formed along the surface of the trench. An additional ion implantation process is performed to form an additional ion implantation layer on the sidewall of the trench. The trench is filled with an insulation material to form a field oxide layer(17). After the pad nitride layer is removed, a well(210) is formed in the semiconductor substrate by a well ion implantation process and an annealing process.