A method of manufacturing a semi-floating gate device

Abstract

The invention discloses a method for manufacturing a semi-floating gate device. The remaining silicon near the sidewall of the field oxide layer in the groove channel region is implanted at an oblique angle during the etching process to form a barrier layer of the channel to prevent current flow. Flow along the direction of the remaining silicon between the sidewalls, so that the current can flow along the direction of the groove-shaped channel of the device, thereby reducing the phenomenon of leakage between the source region and the drain region, improving device performance, reducing The small process difficulty makes the semi-floating gate device suitable for high-speed and low-power applications.

Description

technical field [0001] The invention relates to the technical field of semiconductor integrated circuit manufacturing technology, in particular to a method for manufacturing a semi-floating gate device. Background technique [0002] Semiconductor memories are used in various electronic fields. Among them, nonvolatile memory (NonvolatileMemory, NVM) can store data for a long time in the case of power failure. The floating gate transistor (Floating Gate Transistor, FGT) is the mainstream structure of many variants of the non-volatile memory. [0003] FGT is similar to Metal Oxide Semiconductor Field Effect Transistor (MOSFET) in structure, and can be regarded as a single-layer gate dielectric layer in MOSFET changed to a charge storage layer (charge storage layer) embedded in two insulating layers (insulator). ) "sandwich" grid. Among them, the charge storage layer is called a floating gate because it is surrounded by an insulating layer. The amount of charge stored in the...

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Problems solved by technology

However, since this structure will leave silicon on the sidewalls of the field oxide layer during the formation of the U-shaped groove, this will cause part of the current in the device to flow along the direction of the remaining silicon between the sidewalls, resulting in a device that does not have a drain electrode applied. In this case, leakage occurs between the source region and the drain region, and the requirements for key processes such as photolithography and etching are relatively high in the manufacturing process.

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