Skip to Main Content
 

Global Search Box

 
 
 
 

Files

ETD Abstract Container

Abstract Header

ReRAM based platform for monitoring IC integrity and aging

Abstract Details

2019, PhD, University of Cincinnati, Engineering and Applied Science: Electrical Engineering.
This dissertation reports the work done on MgO based Resistive Random-Access Memory (ReRAM) devices to be used in conjunction with CMOS circuitry to develop a platform capable of monitoring the age and integrity of IC components. The dissertation starts by providing insights into the basic operation of ReRAM devices, hardware security, and other research work performed in this field. A short background introduction of ReRAM devices is provided along with a review of widely accepted switching mechanisms and theory behind them. Thereafter, a short introduction into the increased need for hardware security, some of the current solutions and their pitfalls are discussed. The dissertation then discusses reasons behind why MgO is an excellent candidate for a switching oxide in ReRAM devices. A fabrication process for MgO materials consisting of a systematic optimization of RF magnetron sputtering and Rapid Thermal Annealing (RTA) is presented and supported with experimental results. The process integration of MgO in ReRAM devices involved development of new masks along with the optimization of etch process for thin films of SiN, MgO, Ru, Ti, and W which is discussed in detail. Scanning Electron Microscopy (SEM) images are presented for fabricated devices which demonstrated the success in fabricating the intended ReRAM devices. The compositional analysis of the stack was performed using Energy Dispersive X-Ray Spectroscopy (EDX) and crystallographic structure of MgO with various annealing and deposition conditions was studied using X-Ray Diffraction (XRD). The Process Voltage Temperature (PVT) characteristics, aging, and temperature sensitivity of MgO-ReRAM devices were experimentally studied and modeled to capture resistance distributions and temperature-based modalities. These studies demonstrated excellent temperature sensing and aging modalities with simultaneous storage of sensed temperature and age as a change in the resistive state. A novel read strategy was developed by integrating an Axon-Hillock circuit (AHC) to convert the change in resistive state of the ReRAM device into a measurable spiking frequency using 180 nm CMOS technology. 180nm feature sizes were chosen so these circuits can be fabricated in-house within the US in a trusted foundry. Temporal changes in temperature of underlying CMOS circuit were captured by instantaneous change in resistive state of ReRAM with local temperature fluctuations which translated to a change in the read circuit output. Due to the additive integration of the ReRAM devices and associated circuitry, this approach for aging and integrity monitoring (AIM) ensures large spatial coverage and accurate temporal monitoring of the underlying CMOS die with minimal loss of the functional chip area for these added security features. These circuits were extensively studied through simulations first and were then fabricated through MOSIS/TSMC 180nm CMOS process and tested. Results from the circuit testing and ReRAM integration are presented in detail discussing every component and its specific function. Since ReRAM resistance states and material composition are unique for every device, it is difficult to read the age by reverse engineering or tampering of the devices. This makes these devices an attractive approach for adding customized security and trust features in advanced CMOS nodes-based circuits.
Rashmi Jha, Ph.D. (Committee Chair)
Punit Boolchand, Ph.D. (Committee Member)
Marc Cahay, Ph.D. (Committee Member)
Brian Dupaix, PhD (Committee Member)
John Emmert, Ph.D. (Committee Member)
Ranganadha Vemuri, Ph.D. (Committee Member)
114 p.

Recommended Citations

Citations

  • Schultz, T. (2019). ReRAM based platform for monitoring IC integrity and aging [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573576246158436

    APA Style (7th edition)

  • Schultz, Thomas. ReRAM based platform for monitoring IC integrity and aging. 2019. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573576246158436.

    MLA Style (8th edition)

  • Schultz, Thomas. "ReRAM based platform for monitoring IC integrity and aging." Doctoral dissertation, University of Cincinnati, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573576246158436

    Chicago Manual of Style (17th edition)