A study of Fowler-Nordheim injection mechanism for engineered tunnel barrier flash memory devices

Flash memory is a device that is used as a tool to store data electrically. The main advantage of this device is in the non-volatility which can store data without power supply, thus make the device very popular in broad application. Conventional Flash memory generally uses single tunnel oxide with a thickness of 7 nm to 10 nm as a tunnel barrier. In order to obtain good device performance, the thickness of the tunnel barrier must be reduced. If the thickness of the oxide is reduced below than 5 nm, device performance will be better but suffer from problems such as current leakage and data retention. To overcome this problem, a technique identified as Engineered Tunnel Barrier is used to replace the single oxide used in conventional flash memory. The study includes mathematical calculation and computer simulation investigating the device performance criteria such as programming speed, programming tunneling current and programming voltage. The Fowler-Nordheim model is used for mathematical analysis while Technology Computer Aided Designing (TCAD) tool is used for simulating the flash memory device. From both studies, result shows that the performance of the device improve significantly after the engineered tunnel barrier is applied to replace conventional technique Results from this study showed that by using the engineered tunnel barrier techniques the device performance such as programming speed, programming tunneling and programming voltage have increased by 1 )..lS, le1 A/Cm and 12V compared to conventional flash memory that is 1 ms, 1 e·2 A/Cm, and 17V, respectively. From the result, it can be concluded that the Engineered Tunnel Barrier Flash Memory is very promising candidate for the next generation Flash Memory product.