NSCore, Inc. is a semiconductor intellectual property (IP) provider specializing in the field of nonvolatile memory (NVM)technology.
As an IP provider, NSCore provides a complete package of licenses, design parameters, macro databases and foundry proven yield and reliability data . The customers can benefit from nonvolatile memory functions in their own products with lowest cost and shortest development turnaround time.

Lifetime_100513 v31

Retention lifetime is a major issue when developing non-volatile memories using a new mechanism. PermSRAM® technology utilizes hot-carrier effects to program. The generated electrons are mainly trapped in the Si3N4 layer in the sidewall spacer. In non-volatile memories using trapping mechanism, including SONOS, it is known that the Poole-Frenkel current dominates the de-trapping and determine the lifetime [1, 2]. This paper describes the methodology of retention lifetime estimation and activation energy calculation for memory cells in PermSRAM technology from NSCore. In this methodology, we consider statistical variation to predict lifetime in different temperatures. When we set our design criteria, we assume the cell failure rate is less than 1ppb, which is equivalent to 100ppm for a 100-Kb memory macro.


Since the invention of NAND Flash memory in the 1980’s, non-volatile memory (NVM) has touched all aspects of our daily life. Applications for NVM is growing everyday from handy data storage devices like a USB Flash Drive to High Definition Multimedia Interface (HDMI) and its high-bandwidth digital content protection (HDCP) encryption algorithms to firmware storage in a variety of digital devices like digital cameras and mobile phones.