Double diffusion drain metal oxide semiconductor field effect transistor (DDDMOS) and manufacturing method thereof

Abstract

The invention discloses a double diffusion drain metal oxide semiconductor field effect transistor (DDDMOS). In the DDDMOS, a lightly doped region of the drain of the traditional DDDMOS is changed into an annular lightly doped region, so that a heavily doped region of the drain directly contacts with a trap. When the DDDMOS serves as an electrostatic protection structure of a high-voltage circuit, voltage breakdown occurs between the heavily doped region of the drain and the trap. The invention also discloses a manufacturing method of the DDDMOS. In the manufacturing method, a mask or a barrier layer of an annular ion implantation window is exposed in the process of ion implantation of the lightly doped region of the drain. The DDDMOS has the advantages that: the breakdown voltage and thetrigger conduction voltage are small; and early failure is avoided.

Description

technical field [0001] The invention relates to a semiconductor integrated circuit device and a manufacturing method thereof, in particular to a DDDMOS and a manufacturing method thereof. Background technique [0002] DDDMOS (Double Diffusion Drain MOSFET, double diffused drain MOS transistor) is usually used as a working structure and / or electrostatic protection (ESD) structure of a high voltage circuit. [0003] see figure 1 , which is a schematic diagram of an existing DDDMOS, using n-type DDDMOS as an example. On the p-type substrate 10 is a p-well 11 . There are n-type lightly doped regions 12 and field oxygen isolation structures 131 , 132 and 133 in the p-well 11 . Above the p-well 11 is a gate 14 . Two sides of the gate 14 are sidewalls 15 . In the p-well 11 and between the field oxygen isolation structures 131 and 132 is a p-type heavily doped region 161 . In the p-well 11 and between one side of the side wall 15 and the field oxygen isolation structure 132 is...

AI Technical Summary

Problems solved by technology

[0007] Second, when the parasitic triode is turned on, the figure 2 In the position B shown, that is, the contact between the lightly doped region 12 of the drain and the side wall 15, there is a relatively large electric field and current, and the early damage of the parasitic triode is easy to occur at this position when it is turned on.

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