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- All Subjects: programmable metallization cell
- All Subjects: Food Safety
- Creators: Kozicki, Michael
To advance the PMC modeling effort, this thesis presents a precise physical model parameterizing materials associated with both ion-rich and ion-poor layers of the PMC's solid electrolyte, so that captures the static electrical behavior of the PMC in both its low-resistance on-state (LRS) and high resistance off-state (HRS). The experimental data is measured from a chalcogenide glass PMC designed and manufactured at ASU. The static on- and off-state resistance of a PMC device composed of a layered (Ag-rich/Ag-poor) Ge30Se70 ChG film is characterized and modeled using three dimensional simulation code written in Silvaco Atlas finite element analysis software. Calibrating the model to experimental data enables the extraction of device parameters such as material bandgaps, workfunctions, density of states, carrier mobilities, dielectric constants, and affinities.
The sensitivity of our modeled PMC to the variation of its prominent achieved material parameters is examined on the HRS and LRS impedance behavior.
The obtained accurate set of material parameters for both Ag-rich and Ag-poor ChG systems and process variation verification on electrical characteristics enables greater fidelity in PMC device simulation, which significantly enhances our ability to understand the underlying physics of ChG-based resistive switching memory.
This thesis characterizes the effects that ionizing γ-ray irradiation has on the retention of the programmed resistive state of a PMC. The PMC devices tested used Ge30Se70 doped with Ag as the solid electrolyte layer and were fabricated by the thesis author in a Class 100 clean room. Individual device tiles were wire bonded into ceramic packages and tested in a biased and floating contact scenario.
The first scenario presented shows that PMC devices are capable of retaining their programmed state up to the maximum exposed total ionizing dose (TID) of 3.1 Mrad(Si). In this first scenario, the contacts of the PMC devices were left floating during exposure. The second scenario tested shows that the PMC devices are capable of retaining their state until the maximum TID of 10.1 Mrad(Si) was reached. The contacts in the second scenario were biased, with a 50 mV read voltage applied to the anode contact. Analysis of the results show that Ge30Se70 PMC are ionizing radiation tolerant and can retain a programmed state to a higher TID than NAND Flash memory.
So far only microscale radial structures and electrodeposits have been fabricated which limits their use to labeling only high value items due to high cost associated with their fabrication and analysis. Therefore, there is a need for a simple recipe for fabrication of macroscale structure that does not need sophisticated lithography tools and cleanroom environment. Moreover, the growth kinetics and material characteristics of such macroscale electrodeposits need to be investigated. In this thesis, a recipe for fabrication of centimeter scale radial structure for growing Ag electrodeposits using simple fabrication techniques was proposed. Fractal analysis of an electrodeposit suggested information capacity of 1.27 x 1019. The kinetics of growth were investigated by electrical characterization of the full cell and only solid electrolyte at different temperatures. It was found that mass transport of ions is the rate limiting process in the growth. Materials and optical characterization techniques revealed that the subtle relief like structure and consequently distinct optical response of the electrodeposit provides an added layer of security. Thus, the enormous information capacity, ease of fabrication and simplicity of analysis make macroscale fractal electrodeposits grown in radial programmable metallization cells excellent candidates for application as physical unclonable functions.
This is a test plan document for Team Aegis' capstone project that has the goal of mitigating single event upsets in NAND flash memory caused by space radiation.
The purpose of this research is to better understand the potential use environment of a Dendritic Identifier within the current leafy green supply chain, including the exploration of potential costs of implementation as well as non-economic costs. This information was collected through an extensive review of literature and through the engagement in in-depth interviews with professionals that work in the growing, distribution, and processing of leafy greens. Food safety in the leafy green industry is growing in importance in the wake of costly outbreaks that resulted and recalls and lasting market damage. The Dendritic Identifier provides a unique identification tag that is unclonable, scannable, and compatible with blockchain systems. It is a digital trigger that can be implemented throughout the commercial leafy green supply chain to increase visibility from farm to fork for the consumer and a traceability system for government agencies to trace outbreaks. Efforts like the Food Safety Modernization Act, the Leafy Green Marketing Agreement, and other certifications aim at establishing science-based standards regarding soil testing, water, animal feces, imports, and more. The leafy green supply chains are fragmented in terms of tagging methods and data management services used. There are obstacles in implementing Dendritic Identifiers in that all parties must have systems capable of joining blockchain networks. While there is still a lot to take into consideration for implementation, solutions like the IBM Food Trust pose options for a more fluid transfer of information. Dendritic Identifiers beat out competing tagging technologies in that they work with cellphones, are low cost, and are blockchain compatible. Growers and processors are excited by the opportunity to showcase their extensive food safety measures. The next step in understanding the use environment is to focus on the retail distribution and the retailer specifically.
The purpose of this research is to better understand the potential use environment of a Dendritic Identifier within the current leafy green supply chain, including the exploration of potential costs of implementation as well as non-economic costs. This information was collected through an extensive review of literature and through the engagement in in-depth interviews with professionals that work in the growing, distribution, and processing of leafy greens. Food safety in the leafy green industry is growing in importance in the wake of costly outbreaks that resulted and recalls and lasting market damage. The Dendritic Identifier provides a unique identification tag that is unclonable, scannable, and compatible with blockchain systems. It is a digital trigger that can be implemented throughout the commercial leafy green supply chain to increase visibility from farm to fork for the consumer and a traceability system for government agencies to trace outbreaks. Efforts like the Food Safety Modernization Act, the Leafy Green Marketing Agreement, and other certifications aim at establishing science-based standards regarding soil testing, water, animal feces, imports, and more. The leafy green supply chains are fragmented in terms of tagging methods and data management services used. There are obstacles in implementing Dendritic Identifiers in that all parties must have systems capable of joining blockchain networks. While there is still a lot to take into consideration for implementation, solutions like the IBM Food Trust pose options for a more fluid transfer of information. Dendritic Identifiers beat out competing tagging technologies in that they work with cellphones, are low cost, and are blockchain compatible. Growers and processors are excited by the opportunity to showcase their extensive food safety measures. The next step in understanding the use environment is to focus on the retail distribution and the retailer specifically.