Mosfet provided with substrate source contact and its manufacture

PURPOSE: To provide a means and method of improvement for a MOSFET provided with a back side source contact. CONSTITUTION: This MOSFET (105) provided with the source contact (94) on a back side, a gate (108) on a top side and a drain contact (168) is brought by constitution composed of layered N + (97), N - (96), P - (95) and N + (92) regions arranged between the peak surface (99) and bottom surface (93) of a semiconductor die. In a desirable execution example, two trenches (100 and 108) are etched from the peak surface (99) to the interface of P - (95) and N + (92). The short- circuit of the embedded P - (95) and N + (92) is brought by one trench (108) and a gate dielectric (102) and a gate electrode (104) are brought by covering the area of the P - (95) of a side wall exposed in the other trench (100). It forms a vertical type MOSFET and the substrate of the N + (92) is short-circuited by a P - body region (95) for which a channel (106) is produced by the gate (104) and forms a source region. COPYRIGHT: (C)1992,JPO