Metal oxide semiconductor field effect transistor

Abstract

The invention discloses a metal oxide semiconductor field effect transistor which comprises a semiconductor substrate, a grid insulation dielectric layer which is arranged on the surface of the semiconductor substrate, a grid which is piled on the grid insulation dielectric layer and a source electrode area and a drain electrode area which are arranged in the surface area of the semiconductor substrate at two sides of the grid and are separated by a channel region. A first part of the grid insulation dielectric layer is close to the drain electrode area, a second part thereof is close to the source electrode area, and the thickness of the first part is thicker than the thickness of the second part. The thickness of the second part near the source electrode area of the metal oxide semiconductor field effect transistor is thinner, thereby improving the control capacity of the grid on the channel, increasing saturation current, improving the drive capacity of the apparatus and also reducing the area of the apparatus. The thickness of the first part near the drain electrode area is thicker, thereby controlling leakage current caused by GIDL effect.

Description

technical field [0001] The invention relates to a semiconductor device, in particular to a metal oxide semiconductor field effect transistor. Background technique [0002] The application environment of metal-oxide-semiconductor field-effect transistors (MOSFETs) is increasingly complex and needs to work under different voltage conditions. For example, in memory peripheral circuits, it is often necessary for a MOSFET drain to withstand a higher voltage in the "off" state. Voltage (such as 12V), while in the "on" state, the gate and drain only bear the normal operating voltage (such as 3.3V). When a high voltage is applied to the drain, due to the gate-induced-drain leakage (GIDL) effect, the drain will generate a large leakage current, which will increase the power consumption of the device and affect the working life of the device. [0003] The magnitude of the leakage current caused by the GIDL effect is directly related to the thickness of the gate insulating dielectric ...

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Problems solved by technology

However, this method has obvious disadvantages, that is, when the thickness of the gate insulating dielectric layer of the MOSFET becomes larger, the control ability of the gate to the channel becomes worse, and the threshold voltage increases, resulting in a decrease in the saturation current of the device.

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