Cell structure of one-time programmable memory (OTP) device and manufacturing method and operating method of cell structure

Abstract

The invention discloses a cell structure of a one-time programmable memory (OTP) device. The cell structure is characterized in that silicon dioxides (16) are arranged at the two sides of a gate oxide (13); silicon nitride side walls (17) are arranged on the silicon dioxides (16); and a lightly doped region (15) is arranged below only one side of a polysilicon gate (14). By removing the lightly doped region (15) at the other side, the generation probability and quantity of hot electrons are improved and the hot electrons penetrate through the barriers of the silicon dioxides (16) and are captured by the silicon nitride side walls (17), thus implementing programming by using a channel hot electron injection (CHE) mechanism. In the cell structure, the polysilicon gate (14) is used as a wordline, an n-type heavily doped region (18a) adjacent to the n-type lightly doped region (15) is used as a bit line; and an n-type heavily doped region (18b) not adjacent to the n-type lightly doped region (15) is used as the programming terminal. The invention also discloses a manufacturing method and an operating method of the cell structure of the OTP device. The cell structure has small area and is applicable to the condition of thinner gate oxide.

Description

technical field [0001] The invention relates to an OTP (one-time programmable memory, one-time programmable memory) device, in particular to a unit structure of the OTP device. Background technique [0002] There are currently two representative types of unit structures for OTP devices. [0003] see Figure 1a , Figure 1b , the unit structure of the first type of OTP device consists of a transistor 1b and a floating gate capacitor 1a, where the transistor 1b performs the programming function, the floating gate capacitor 1a performs the charge storage function, and the polysilicon gate of the transistor 1b extends to the floating gate capacitor 1a. Above, the floating gate capacitor 1a is a plate capacitor formed by the extended polysilicon and the silicon below it. Chinese Invention Patent Application Publication CN1627525A (published on June 15, 2005) and Chinese Invention Patent Application Publication CN1627526A (published on June 15, 2005) both disclose the unit struc...

AI Technical Summary

Problems solved by technology

Due to the existence of the floating gate coupling capacitor 1a, the unit structure area of ​​this OTP device is too large, which is not conducive to the application of high-density integrated circuits

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