NSUF 19-1750: In-situ investigation of irradiation damage on non-volatile memory
The objective of the proposed project is to evaluate the effectiveness of commercial flash memory chip for real-time radiation dosimetry applications. Radiation exposure on flash memory causes data corruption, which is quantified as bit error rate (BER). The novelty in our approach lies in the characterization of radiation-induced signature on memory cells in terms of BER using standard digital interfaces. Since flash memory is ubiquitous in all modern electronic systems, the solution can be integrated into many sensor node applications with zero to very little additional cost.
2) Method: In the proposed dosimeter, the radiation sensor is the flash memory chip itself, and the radiation response data collection, processing, and display is performed using a computer through USB interface with the memory chip. We will use a custom designed memory-interface in order to bypass the error correction mechanism and measure the raw bit error rate. The gamma and high energy neutron beam irradiation will be focused on the NAND flash chip allowing for targeted evaluation of radiation response. Real-time data collection will be performed via connection to the memory controller and, finally, the data processing algorithm to determine BERs will be run on a connected computer. Gamma and neutron irradiation testing will be performed at host site.
3) Impact to the state-of-the-knowledge: Radiation effects on flash memory is extensively studied from the context of radiation-hard memory design. However, the potential to use flash memory for dosimetry application is less explored. Flash technology scaling and increased bit density continues to increase the sensitivity of flash memory chips to radiation and hence the proposed research will identify the effectiveness and limitations of flash-based dosimetry. In addition, the project includes several tasks involving novel measurement techniques, which advance our understanding of radiation effects on semiconductor devices. Examples include: (i) radiation-induced analog threshold-voltage change of flash memory cells, (ii) directionality impact of radiation beams on memory array, (iii) dose enhancement effect when ionizing radiation goes through the back end of the line (BEOL) metal layers of a chip, and (iv) comparison between ionizing effects vs. displacement damage in the context of flash-memory technology.
4) Expected period of performance: 9 months
5) Scientific Outcome: The project provides proof-of-concept demonstration of the novel dosimeter technology via irradiation experiments (gamma rays and neutrons) on commercial memory chips. In addition, the project will (i) identify the potential sources of errors (thermal noise, directionality impact) in the dosimetry measurement (ii) determine the sensitivity, resolution and measurement range of the flash-based dosimeter (iii) provide methods to distinguish ionizing radiation vs heavy-ion exposure in an environment.
Additional Info
| Field | Value |
|---|---|
| Abstract | The objective of the proposed project is to evaluate the effectiveness of commercial flash memory chip for real-time radiation dosimetry applications. Radiation exposure on flash memory causes data corruption, which is quantified as bit error rate (BER). The novelty in our approach lies in the characterization of radiation-induced signature on memory cells in terms of BER using standard digital interfaces. Since flash memory is ubiquitous in all modern electronic systems, the solution can be integrated into many sensor node applications with zero to very little additional cost. 2) Method: In the proposed dosimeter, the radiation sensor is the flash memory chip itself, and the radiation response data collection, processing, and display is performed using a computer through USB interface with the memory chip. We will use a custom designed memory-interface in order to bypass the error correction mechanism and measure the raw bit error rate. The gamma and high energy neutron beam irradiation will be focused on the NAND flash chip allowing for targeted evaluation of radiation response. Real-time data collection will be performed via connection to the memory controller and, finally, the data processing algorithm to determine BERs will be run on a connected computer. Gamma and neutron irradiation testing will be performed at host site. 3) Impact to the state-of-the-knowledge: Radiation effects on flash memory is extensively studied from the context of radiation-hard memory design. However, the potential to use flash memory for dosimetry application is less explored. Flash technology scaling and increased bit density continues to increase the sensitivity of flash memory chips to radiation and hence the proposed research will identify the effectiveness and limitations of flash-based dosimetry. In addition, the project includes several tasks involving novel measurement techniques, which advance our understanding of radiation effects on semiconductor devices. Examples include: (i) radiation-induced analog threshold-voltage change of flash memory cells, (ii) directionality impact of radiation beams on memory array, (iii) dose enhancement effect when ionizing radiation goes through the back end of the line (BEOL) metal layers of a chip, and (iv) comparison between ionizing effects vs. displacement damage in the context of flash-memory technology. 4) Expected period of performance: 9 months 5) Scientific Outcome: The project provides proof-of-concept demonstration of the novel dosimeter technology via irradiation experiments (gamma rays and neutrons) on commercial memory chips. In addition, the project will (i) identify the potential sources of errors (thermal noise, directionality impact) in the dosimetry measurement (ii) determine the sensitivity, resolution and measurement range of the flash-based dosimeter (iii) provide methods to distinguish ionizing radiation vs heavy-ion exposure in an environment. |
| Award Announced Date | 2019-05-14T15:56:59.087 |
| Awarded Institution | Center for Advanced Energy Studies |
| Facility | Microscopy and Characterization Suite |
| Facility Tech Lead | Michael Starr, Yaqiao Wu |
| Irradiation Facility | None |
| PI | Biswajit Ray |
| PI Email | [email protected] |
| Project Type | RTE |
| RTE Number | 1750 |