High voltage tolerance element and producing method thereof

Abstract

The invention discloses a high-voltage resistant element which comprises a semi-conductive substrate and a gate electrode. The semi-conductive substrate comprises a first doping zone with a first conduction type, a second doping zone with a second conduction type, a third doping zone with a second conduction type, a fourth doping zone surrounding the third doping zone and with a second conduction type, and a fifth doping zone surrounding the third doping zone and with a second conduction type. The gate electrode is adjacently equipped between two clearance walls, and divides the second doping zone from the third doping zone to control the communication between the second doping zone and the third doping zone. The high-voltage resistant element utilizes the fifth doping zone to surround the third doping zone, so as to strengthen the encapsulation of the third doping zone, improve the uniformity of ion concentration at the bottom of the third doping zone, and reduce the drain current thereof.

Description

technical field [0001] The present invention relates to a high voltage resistant element and its manufacturing method, especially to a high voltage resistant metal oxide semiconductor transistor (High Voltage Metal-Oxide-Semiconductor Transistor: HVMOS transistor) and its manufacturing method, the high voltage resistant metal Oxide semiconductor transistors are particularly suitable for protection circuits against electrostatic discharge (ESD). Background technique [0002] In the manufacture and use of integrated circuits (ICs), ESD problems are often encountered. With the increasing demand for high computing speed and wireless broadband communication product ICs, and the current IC technology is rapidly entering 80 nanometers or even below 65 nanometers, the internal components of ICs are very small, so they are easily damaged by instantaneous electrostatic discharge . Therefore, ESD has a great impact on the quality of IC, and with the continuous improvement of IC techn...

AI Technical Summary

Problems solved by technology

3 (a) and 3 (b) leakage current problem is because when forming the double diffused drain structure of FIG. The lightly doped drain 14 is relatively large, and its diffusion degree is relatively strong after the thermal annealing process, resulting in uneven ion concentration of the NB (refer to FIG. 2 ) at the bottom of the heavily doped drain 13, that is, the The lightly doped drain 14 has poor coverage for the bottom NB, so that when the HVNMOS transistor 1 withstands a VDS greater than 12V, the following situations occur: (1) hot carrier effect (hot carrier effect) lead to body current I sub High leakage current (refer to Fig. 3(a) and 3(b)): and (2) said HVNMOS transistor 1 has obvious leakage current on its drain side even when it is turned off (refer to Fig. 7 Curve F)

When the HVNMOS transistor 1 is used in the ESD protection circuit, because the ion concentration uniformity of the bottom NB is not good, when an electrostatic discharge pulse occurs, it will first cause damage to the bottom NB, and then cause the ESD protection circuit fail

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