Junction-free field-effect transistor and preparation method thereof

Abstract

A surrounding gate field-effect transistor combined with a vertical channel (4) and a junction-free structure comprises a surrounding semiconductor channel in the vertical direction, a surrounding gate electrode (6), a surrounding gate dielectric layer (5), a source region (2), a drain region (3) and a semiconductor substrate (1), wherein the source region (2) is located at the bottom of the vertical channel (4) and connected with the substrate (1), the drain region (3) is located at the top of the vertical channel (4), and the gate dielectric layer (5) and the gate electrode (6) surround the vertical channel (4) circularly. The impurities of the same type and concentration are doped into the source region (2), the drain region (3) and the vertical channel (4). The same impurities are doped into source and drain channels of the transistor, so that heat budget is greatly reduced, the impurity diffusion and abrupt junction forming problems are eliminated, process requirements are simplified, integration machining photo-etching ultimate limit is broken through by utilizing the vertical channel and a surrounding gate structure, and the integration degree is improved.

Description

technical field [0001] The invention belongs to the field of field effect transistor logic devices and circuits in CMOS ultra large integrated circuits (ULSI), and in particular relates to a ring gate field effect transistor combined with a vertical channel and a junctionless structure and a preparation method thereof. Background technique [0002] Driven by Moore's Law, the feature size of traditional MOSFETs has been shrinking, and now it has entered the nanometer scale. As a result, the negative effects of short-channel effects on devices have become more serious. The effects of leakage-induced barrier reduction and band-band tunneling increase the off-state leakage current of the device. In the research on new device structures, the source-drain doped Gate All Around transistor (GAA) structure is currently the most concerned one. GAA devices have better gate control characteristics, which can meet the sharpest characteristic requirements, so as to meet the needs of devi...

AI Technical Summary

Problems solved by technology

In addition, the introduction of nanowires makes the source and drain design of GAA more complex than planar devices and multi-gate devices

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