.45 Nm, Of Nor Flash Production Validation

Flash memory, as the chip to store data and applications, is now widely used in mobile phones, storage cards, industrial equipments, digital products etc. In 1984, Fujio Masuoka from Toshiba, was the first one to create an idea of Flash memories. The feature of Flash includes non-volatile and fast speed. Also, it can endure 1 million program and erase cyclings with a data storage period as long as 10 years.Flash can be divided into NOR and NAND. NOR is usually used to store applications and it is useful in mobile phone, automobile electronics and networking while NAND is targeted for storage devices including SD card, USB sticks, etc.With the development of FAB process, the NOR Flash has entered a new era of 45nm from 65nm. As the first 45nm NOR Flash in the industry, it will bring us great challenges during the qualification process. To begin with an immature process and to end with the capability of running mass production, much improvement has to be made in between. Among the methods of making improvements, Failure Analysis (FA) is an effective one. And also even if the product has been running in mass production stage, failure analysis is still the main method in dealing with customer returns. It provides technical support to the requirement of continuous improvement.The qualification before mass production usually follows below steps: First of all is to set the quality and reliability goal. Then to collect data and analyze the failures, report to upstream departments such as FAB about the analysis result. Let them make the corresponding actions to improve the quality and reliability of the products. Thus, finally achieve the goal and make it possible for the production.The thesis is devided into 4 chapters. At first, it introduces the basic of NOR Flash, the 45nm new technology and the corresponding changes. Then it summarizes the failure analysis done before achieving production for 45nm NOR Flash in order to demonstrate how to apply the basic principles of failure analysis to the new technology. Failure analysis helps to solve 3 major issues during qualification:low yield, high DPM (Defects Per Million) and rejects in the package level reliability stress. Through the methods of failure analysis, the failing reasons of each issue have been found and corresponding corrective actions have been defined. After implementation of these corrective actions, the effectiveness of these actions has been proved through the final data collection. Eventually, the product demonstrates good yield, quality and reliability. Thus, the requirement of mass production has been met.