A semiconductor device including a first P-type well region and an asymmetric second P-type well region each formed in a semiconductor substrate; a gate insulating layer and a gate electrode formed on the substrate; a first N-type source/drain region and a second N-type source/drain region that are formed on respective sides of the gate electrode; and an asymmetric LDD region of N-type formed to extend from the second source/drain region, wherein the asymmetric second P-type well region encompasses the second N-type source/drain region and the asymmetric LDD region, and the first N-type source/drain region both the asymmetric second P-type well region and the substrate, and the asymmetric second P-type well region is formed encompassing the second N-type source/drain region and in contact with the first N-type source/drain region.

The present disclosure discloses a self-aligned silicon carbide MOSFET device with an optimized P.sup.+ region and a manufacturing method thereof. The self-aligned silicon carbide MOSFET device is formed by a plurality of silicon carbide MOSFET device cells connected in parallel, and these silicon carbide MOSFET device cells are arranged evenly. The silicon carbide MOSFET device cell comprises two source electrodes, one gate electrode, one gate oxide layer, two N.sup.+ source regions, two P.sup.+ contact regions, two P wells, one N.sup.- drift layer, one buffer layer, one N.sup.+ substrate, one drain electrode and one isolation dielectric layer. By optimizing the P.sup.+ region, the present disclosure forms a good source ohmic contact, reduces the on-resistance, and also shorts the source electrode and the P well to prevent the parasitic transistor effect of the parasitic NPN and PiN, which may take both conduction characteristics and the breakdown characteristics of the device into consideration, and may be applied to a high voltage, high frequency silicon carbide MOSFET device. The self-aligned manufacturing method used in the present disclosure simplifies the process, controls a size of a channel accurately, and may produce a lateral and vertical power MOSFET.

A semiconductor device including a first P-type well region and an asymmetric second P-type well region each formed in a semiconductor substrate; a gate insulating layer and a gate electrode formed on the substrate; a first N-type source/drain region and a second N-type source/drain region that are formed on respective sides of the gate electrode; and an asymmetric LDD region of N-type formed to extend from the second source/drain region, wherein the asymmetric second P-type well region encompasses the second N-type source/drain region and the asymmetric LDD region, and the first N-type source/drain region both the asymmetric second P-type well region and the substrate, and the asymmetric second P-type well region is formed encompassing the second N-type source/drain region and in contact with the first N-type source/drain region.

A semiconductor device including a first P-type well region and an asymmetric second P-type well region each formed in a semiconductor substrate; a gate insulating layer and a gate electrode formed on the substrate; a first N-type source/drain region and a second N-type source/drain region that are formed on respective sides of the gate electrode; and an asymmetric LDD region of N-type formed to extend from the second source/drain region, wherein the asymmetric second P-type well region encompasses the second N-type source/drain region and the asymmetric LDD region, and the first N-type source/drain region both the asymmetric second P-type well region and the substrate, and the asymmetric second P-type well region is formed encompassing the second N-type source/drain region and in contact with the first N-type source/drain region

A semiconductor device includes an input clock generation circuit able to shift a write command in synchronization with a clock, and generating first and second input clocks. The semiconductor device also includes a write leveling control circuit able to divide a frequency of the clock in response to a write leveling control signal, and generating first to fourth write clocks. The semiconductor device includes a signal transfer circuit able to transfer the first and second input clocks as first and second transfer clocks in a write operation, and transferring the first to fourth write clocks as first to fourth transfer clocks in a write leveling operation.

A semiconductor device includes an input clock generation circuit able to shift a write command in synchronization with a clock, and generating first and second input clocks. The semiconductor device also includes a write leveling control circuit able to divide a frequency of the clock in response to a write leveling control signal, and generating first to fourth write clocks. The semiconductor device includes a signal transfer circuit able to transfer the first and second input clocks as first and second transfer clocks in a write operation, and transferring the first to fourth write clocks as first to fourth transfer clocks in a write leveling operation.

A method for manufacturing a semiconductor device includes providing a substrate, performing an N-type dopant implantation into a first region of the substrate to form an N-well, removing a portion of the substrate to form a first set of fins on the N-well and a second set of fins on a second region of the substrate adjacent the N-well, filling gap spaces between the fins to form an isolation region, and performing a P-type dopant implantation into the second region to form a P-well adjacent the N-well. The N-well and the P-well are formed separately at different times. The loss of the P-type dopant ions due to the diffusion of P-type dopant ions in the P-well into the isolation region can be eliminated, and the damage to the fins caused by N-type dopant ions can be avoided.

In an output amplifier stage of an operational amplifier circuit, the first p-well of the first nMOSFET and the second p-well of the second nMOSFET are connected to the fourth node. Further, the first n-well of the first pMOSFET and the second n-well of the second pMOSFET are connected to the fifth node. At least one of the fourth node and the fifth node is connected to an output terminal VOUT.