Junction-modulated type tunneling field effect transistor and manufacturing method thereof

Abstract

The invention discloses a junction-modulated type tunneling field effect transistor and a manufacturing method of the junction-modulated type tunneling field effect transistor, and belongs to the field of field effect transistor logic devices and circuits in CMOS ultra large scale integration (ULSI) circuits. According to the junction-modulated type tunneling field effect transistor, a PN junction provided by a highly-doped source region enclosed on three sides in a vertical channel region is utilized so that the channel region can be effectively used up, a surface channel energy band below a grid can be increased, a device can obtain a steeper energy band and a smaller tunneling barrier width compared with a traditional TFET when subjected to band-band tunneling, the effect of a steep tunnel junction doping density gradient is achieved equivalently, as a result, the subthreshold property of the traditional TFET is improved substantially, and breakover currents of the device are increased at the same time. According to the junction-modulated type tunneling field effect transistor and the manufacturing method of the junction-modulated type tunneling field effect transistor, under the condition that the junction-modulated type tunneling field effect transistor is compatible with an existing CMOS process, the bipolar breakover effect of the device is restrained effectively, parasitic tunneling currents at corners of a source junction with a small size also can be restrained, and the effect of steep source junction doping density can be achieved equivalently.

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 junction modulation type tunneling field effect transistor 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 leakage-induced barrier reduction, band-band tunneling and other effects make the off-state leakage current of the device continuously increase. At the same time, the sub-threshold slope of the traditional MOSFET is limited by the thermoelectric potential and cannot be reduced synchronously with the shrinking of the device size, thus increasing device power consumption. The power consumption problem has become the most severe problem limiting ...

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Problems solved by technology

TFET has many excellent characteristics such as low leakage current, low subthreshold slope, low operating voltage, and low power consumption. However, due to the limitation of source junction tunneling probability and tunneling area, TFET faces the problem of small on-state current, far It is not as good as traditional MOSFET devices, which greatly limits the application of TFET devices

In addition, TFET devices with a steep subthreshold slope are also difficult to realize experimentally, because it is difficult to achieve a steep doping concentration gradient at the source junction so that the electric field at the tunnel junction is not large enough when the device is turned on. This causes the subthreshold slope of the TFET to degrade from the theoretical value

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