HIGH VOLTAGE SEMICONDUCTOR DEVICE AND FABRICATING METHOD THEREOF

摘要

PURPOSE: A high voltage device is provided to enhance the reliability thereof by increasing a withstand junction breakdown voltage and improving a snap-back characteristic. CONSTITUTION: An n-type well region(310) is formed in a semiconductor substrate(300). A plurality of active regions(301a) are defined in the n-type well region(310) for forming a source/drain of a high voltage device. A field plate(306) is formed on an upper surface of a filed oxide layer(301b) and an upper portion of a gate electrode(302). An electric field is distributed by applying a ground voltage or a voltage below the ground voltage to the field plate(306). The field plate(306) is formed to cover an edge portion of the field oxide layer(301b), and therefore a junction of a drain(303a) is apart from the field oxide layer(301b) in a predetermined distance. Accordingly, a drift layer(304) sufficiently encloses the drain region(303a), and thereby preventing steep junction profile caused by the contact between the drain region(303a) and the n-type well(310).