Self-aligned silicon carbide MOSFET device and preparation method thereof

The invention provides a self-aligned silicon carbide MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) device and a preparation method thereof. Through a completely self-aligned mask forming mode, the alignment deviations of the base region, the source region, the body region and the channel region of the silicon carbide MOSFET device are all 0, and the cellular size of the planar silicon carbide MOSFET device can be effectively reduced, so that the cellular density of the planar silicon carbide MOSFET device is improved. The silicon carbide MOSFET device obtained according to the preparation method has the JFET region of which the width is gradually widened along with the increase of the depth, so that the on resistance of the JFET region is reduced, and the current conduction capability of the device is enhanced. 本发明提供了一种自对准的碳化硅MOSFET器件及其制备方法。本发明通过一种完全自对准的掩膜形成方式，使碳化硅MOSFET器件的基区、源区、体区、沟道区的对准偏差均为0，可有效缩减平面型碳化硅MOSFET器件的元胞尺寸，从而提高其元胞密度。根据此制备方法得到的碳化硅MOSFET器件具有宽度随着深度增加而逐渐变宽的JFET区，从而降低了JFET区的导通电阻，增强器件导通电流的