The Advances of OTP Memory for Embedded Applications in HKMG Generation and Beyond

Abstract

Current need to the development of advanced 28nm and beyond OTP (One-time-Programmable) nonvolatile memory is limited by the compatibility with advanced nodes with particular high-k metal-gate gate stack feature. On the other hand, there is a strong demand for future use in IoT and AI in security applications. In this talk, we will provide a solution on how to develop a unique structure of OTP for the above purpose. A 4kb macro of One Time Programming (OTP) memory, implemented by a new breakdown, named dielectric fuse (dFuse) breakdown, will be demonstrated which is constructed on a foundry pure logic 28nm HKMG CMOS platform. The feature size of a unit cell is 1.5T per cell with 7.5F(2). The experimental results show that dFuse macro exhibits high programming (PGM) speed of 100ns at 4V, read time smaller than 10ns at 0.75V, and excellent data retention under one-month baking at 150 degrees C. More importantly, the program voltage is weakly dependent on the environmental temperature, suitable for automotive applications. This OTP is also expected to be scalable to advanced technology node such as FinFET and provides an ideal and reliable solution for the storage purpose in IoT and 5G era. In particular, it has great potential for embedded applications in MCU, e.g., automotive applications.