Abstract: A method of manufacturing a semiconductor integrated circuit device having on the same substrate both a high breakdown voltage MISFET and a low breakdown voltage MISFET is provided. An element isolation trench is formed in advance so that the width thereof is larger than the sum of the thickness of a polycrystalline silicon film serving as a gate electrode of a low breakdown voltage, the thickness of a gate insulating film and an alignment allowance in processing of a gate electrode in a direction orthogonal to the extending direction of the gate electrode and is larger than the thickness of the polycrystalline silicon film in a planar region not overlapping the gate electrode. It is possible to decrease the number of manufacturing steps for the semiconductor integrated circuit device.

Abstract: In an LCD driver, in a high voltage resistant MISFET, end portions of a gate electrode run onto electric field relaxing insulation regions. Wires to become source wires or drain wires are formed on an interlayer insulation film of the first layer over the high voltage resistant MISFET. At this moment, when a distance from an interface between a semiconductor substrate and a gate insulation film to an upper portion of the gate electrode is defined as “a”, and a distance from the upper portion of the gate electrode to an upper portion of the interlayer insulation film on which the wires are formed is defined as “b”, a relation of a>b is established. In such a high voltage resistant MISFET structured in this manner, the wires are arranged so as not to be overlapped planarly with the gate electrode of the high voltage resistant MISFET.

Abstract: A method of manufacturing a semiconductor integrated circuit device having on the same substrate both a high breakdown voltage MISFET and a low breakdown voltage MISFET is provided. An element isolation trench is formed in advance so that the width thereof is larger than the sum of the thickness of a polycrystalline silicon film serving as a gate electrode of a low breakdown voltage, the thickness of a gate insulating film and an alignment allowance in processing of a gate electrode in a direction orthogonal to the extending direction of the gate electrode and is larger than the thickness of the polycrystalline silicon film in a planar region not overlapping the gate electrode. It is possible to decrease the number of manufacturing steps for the semiconductor integrated circuit device.

Abstract: A method of manufacturing a semiconductor integrated circuit device having on the same substrate both a high breakdown voltage MISFET and a low breakdown voltage MISFET is provided. An element isolation trench is formed in advance so that the width thereof is larger than the sum of the thickness of a polycrystalline silicon film serving as a gate electrode of a low breakdown voltage, the thickness of a gate insulating film and an alignment allowance in processing of a gate electrode in a direction orthogonal to the extending direction of the gate electrode and is larger than the thickness of the polycrystalline silicon film in a planar region not overlapping the gate electrode. It is possible to decrease the number of manufacturing steps for the semiconductor integrated circuit device.

Abstract: A method of manufacturing a semiconductor integrated circuit device having on the same substrate both a high breakdown voltage MISFET and a low breakdown voltage MISFET is provided. An element isolation trench is formed in advance so that the width thereof is larger than the sum of the thickness of a polycrystalline silicon film serving as a gate electrode of a low breakdown voltage, the thickness of a gate insulating film and an alignment allowance in processing of a gate electrode in a direction orthogonal to the extending direction of the gate electrode and is larger than the thickness of the polycrystalline silicon film in a planar region not overlapping the gate electrode. It is possible to decrease the number of manufacturing steps for the semiconductor integrated circuit device.

Abstract: In forming a plug 21 of a polycrystalline silicon film in a contact hole 19 to which a bit line BL is connected, the upper surface of the plug 21 is retracted downward from the upper edge of the contact hole 19, and a plug 22 of a laminate of a TiN film 26 and a W film 27 is formed on the plug 21. Then, the W film deposited on the contact hole 19 is patterned to form a bit line BL having a width narrower than the diameter of the contact hole 19. Here, the W film 27 constituting part of the plug 22 in the contact hole 19 is etched, but the TiN film 26 constituting another part of the plug 22 is not almost etched.