SPP 2253: Nano Security

From Nanoelectronics to Safe Systems

Physically Unclonable Functions (PUF) and True Random Number Generation (TRNG) are two components that are widely used today to generate random bit streams in security applications. In the past decade, the use of portable consumer electronics has increased dramatically, making wireless communication security one of the most important requirements in microelectronic technology. It is therefore of great interest to develop an implementation of security components which meet the following properties: low-power operation, high integration density and compatibility with CMOS processes. According to the "More than Moore" Approach (increasing performance through multifunctionality), such characteristics can be achieved. For example, resistive RAM memories (RRAM) have been investigated as promising future candidates for non-volatile memory (NVM) in recent years. In addition, the mechanisms of switching processes in RRAM components are intrinsically stochastic. Therefore, the RRAM technology is seen as a suitable solution for the implementation of the future PUF and TRNG components. The study proposed in this project includes an interdisciplinary research activity to achieve the following three objectives: 

  1. Development of a CMOS-compatible RRAM-based component that can implement both PUFs and TRNGs functionalities
  2. Development of a suitable operational algorithm that is able to convert the physical randomness of RRAM devices into real random digital bits
  3. Finding out how the randomness of the proposed solution is composed of fundamental physical and chemical processes

In order to understand the basic physical mechanisms of the properties required for TRNGs and PUFs applications, extensive material and electrical characterizations are carried out. All RRAM-based structures that are required for these characterizations are based on the known TiN/HfO2/Ti/TiN structure, whereby process parameters are specifically modified in order to achieve the objectives of the project. The knowledge gained about the material properties through the electrical characterizations improves the switching and conduction mechanisms in RRAM components from the macroscopic perspective. In order to explain these properties through physical and chemical atomic interactions, a complementary approach is required: the simulation of atomistic models. Ultimately, a detailed statistical analysis of the electrical results generated by the resistive switching components is essential.