MOS (metal oxide semiconductor) transistor

Abstract

The invention provides an MOS (metal oxide semiconductor) transistor, which is a trench vertical double-diffusion transistor. A metallic layer for leading a source electrode out is filled in a contact hole positioned between two adjacent source regions by means of a metallic plug, and a body contact area in heavy doping is formed below the contact hole. All metals in an MOS transistor structure pass through the metal plug filled in the contact hole to contact with a silicon body, the silicon body contacted by the side walls of the contact hole is a first semiconductor type doped source region, the silicon body contacted by the bottom of the contact hole is the second semiconductor type doped body contact area, and both the areas are heavy doped areas, so that various parasitic effects generated caused by contact of the metals with a light doped silicon body are prevented effectively, and the performance of the MOS transistor is improved. Simultaneously, by the aid of the metallic plug, the bore diameter of the contact hole is greatly reduced, the dimensions of devices are further decreased, and the integration level of the devices is improved.

Description

technical field [0001] The invention relates to a transistor structure, in particular to a trench type vertical double-diffusion transistor structure, which belongs to the technical field of semiconductors. Background technique [0002] In a semiconductor integrated circuit, a circuit based on a double-diffused MOS transistor, referred to as DMOS, uses the difference in the lateral diffusion speed of two impurity atoms to form a self-aligned sub-micron channel, which can achieve high operating frequency and speed. . [0003] Compared with ordinary MOS transistors, DMOS has two main differences in structure: one is that P-type and N-type impurities are sequentially diffused through the same oxide layer window to form a very short channel; A lightly doped N-drift region is added between them, whose doping concentration is much smaller than that of the channel region. This region bears most of the added drain voltage, thereby weakening the short channel effect and increasing ...

AI Technical Summary

Problems solved by technology

Depend on figure 1 As shown, in this structure, the source metal layer 110 is located on the surface of the P-type well region 103, and the part in contact with the silicon body region is the lightly doped P-type well region 103, where the metal-semiconductor contact is easy to cause various Parasitic effects that affect transistor performance

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