SBIR-STTR Award

The physical scalability of Si based nonvolatile memory is problematic for the terascale integration of space memory. In particular and with regards to Flash, this problem is two-fold as device designs breakdown and photolithographic patterning approaches its limits to minimum feature size. Whereas phase-change and ferroelectric polymer devices have shown promise to scale beyond Flash, these technologies face challenges in regards to cost and read-write speed. Molecular electronics, such as the atomically thin carbon found in both carbon nanotubes (CNT) and graphene sheets, exhibit entirely unique electrical properties that can facilitate novel device designs that overcome these challenges. Specifically, the linear energy-momentum (E-k) dispersion in such monolayer carbon gives rise to a number of electrical phenomena not possible in Si, including ultrafine sensitivity and ballistic transport. As such, radiation hardened graphene sheets can overcome the scaling challenges of Si (or III-Nitride) materials through novel device designs. Harper Laboratories, LLC in collaboration with the Georgia Institute of Technology""s Nanotechnology Research Center will continue development on an ultra-scalable nonvolatile graphene memory device.

Benefit:
Nonvolatile memory is a critical technology in support of a variety of space applications. In particular, radiation hardened memory for geosynchronous satellites is of particular significance for the COTM, SBIRS, and AEHF programs as well as weather and environmental tracking satellites. Higher density space-based memory that is more robust will directly enable a more efficient use of satellite infrastructure in support of next generation Air Force programs. As our technology has potential to replace commercial non-volatile memory devices, such as Flash, our device will enable a paradigm shift in commercial memory markets primed by Intel Corporation and SanDisk.

Nonvolatile memory (NVM) technologies are a critical component of modern satellites. These NVM chipsets perform tasks ranging from storing mission-critical boot code to large multi-gigabyte mission data recorders. This requirement for high-density NVM has shifted focus on to commercial CMOS FLASH. FLASH technologies are capable of high-density devices, compared to resistive or phase-change technologies, and typically scale on pace with Moore’s Law. However, charge pumps and other CMOS FEOL components face reliability concerns from TID and SEE (heavy ion) radiation exposure. As such, there is an inherent need for the introduction of intrinsically rad-hard carbon nanomaterials into commercial CMOS. Whereas previous wafer-scale processes for carbon nanomaterials have been hindered by device-to-device variation, CVD graphene sheets provide the opportunity to control material quality over a 200-400mm wafer. Harper Laboratories, LLC, the Georgia Institute of Technology, Novati Technologies, and BAE Systems will manufacture a graphene-based FLASH bit cell that is CMOS-compatible and capable of forming multiple commercial suppliers. Novati technologies will provide FEOL and BEOL CMOS fabrication capabilities that, combined with Harper IP, will ready a graphene-based FLASH technology for transition to a high-volume CMOS foundry in Phase III. BAE Systems will provide rad-hard testing to validate the technology.

Benefits:
The general anticipated benefit would be a graphene-based FLASH memory technology capable of supporting high-density space memory applications. A secondary benefit is the development of a CMOS-compatible process for patterning graphene devices with low device-to-device variation across a 200-400mm wafer for which a varying number of commercial applications could arise (graphene on-chip interconnects and transistors). In particular, the introduction of a CMOS-compatible graphene processes can provide disruptive shifts in the global semiconductor industry, including post-CMOS technologies.

Keywords:
Graphene, Nonvolatile Memory, CMOS-compatible, Chemical Vapor Deposition, Graphene Nanoribbon