One time programmable (OTP) unit and array as well as programming and reading method thereof

Abstract

The invention discloses a one time programmable (OTP) unit which comprises a storage element, a first NMOS transistor and a second NMOS transistor, wherein the storage element can break down a gate oxide medium, the first end of the storage element is connected with a first voltage end, and the second end of the storage element is connected with a first NMOS drain electrode; a first NMOS grid electrode is connected with a second voltage end; and a first NMOS source electrode is connected with a second NMOS drain electrode, a second NMOS grid electrode is connected with a row selection end, and a second NMOS source electrode is connected with a column selection end.The invention also discloses a one time programmable (OTP) array which comprises M rows of row lines, N rows of column lines and M X NOTP units. The invention also discloses a one time programmable (OTP) array programming method which comprises the following steps: applying a constant first voltage on the first voltage end; applying a constant second voltage to the second voltage end; applying a row selective voltage on each row line; and applying a column selective voltage on each column line. The OTP unit and array as well as the programming method thereof provided by the invention have the advantages that high-voltage decoding is not needed, the process requirements are low, the cost is lower and the application ranged is enlarged.

Description

technical field [0001] The present invention relates to one-time programmable memory cells and arrays made of these cells, more specifically to one-time programmable memory cells and arrays made of these cells, as well as their programming and reading method. Background technique [0002] One-time programmable technology is widely used in practice. At present, there are one-time programmable arrays realized by gate oxide breakdown phenomenon, such as patents CN03135903.5, CN03135904.3, and CN03135905.1 which disclose the use of gate oxide breakdown One-time programmable array realized by phenomenon and corresponding programming method. [0003] The following takes the patent CN03135903.5 as an example to illustrate, the one-time programmable array disclosed by this invention is as figure 1 As shown, it includes a large number of row lines, column lines, at least one source line, and one-time programmable memory cells located at the intersections of row lines and column lin...

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Problems solved by technology

[0004] Through this example, it can be seen that during the programming process of the one-time programmable unit, two voltages of 7V high voltage or 0V low voltage are applied to the column line according to whether it is selected. The principle of the one-time programmable array disclosed in the above-mentioned other patents is basically the same as this example The same, that is, during the programming process of the one-time programmable array, a high voltage is applied to the selected column line, and a low voltage is applied to the unselected column line, so the high voltage needs to be decoded, but the high voltage decoding will lead to complicated circuit design, or need Special process manufacturing for high-voltage decoding increases manufacturing difficulty and cost. In addition, due to the need for high-voltage decoding, it will affect the high-voltage amplitude applied to the selected column lines, thereby limiting its application.

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