Monolithic 3D Resistive Memories

3d ic

Technology

Monolithic 3D IC technology is applied to producing a monolithically stacked single crystal silicon transistor selected RRAM or PCM memory. 1T-1R memory cells enjoy a low number of (shared) litho steps, Cu or Al wiring, and a scalable architecture. An efficient bipolar RRAM is now possible. Peripheral circuits below the monolithic memory stack deliver control functions.

Reduce bit cost of resistive memories without investing in expensive scaling down.

Benefits

  • 2-3X the density of NAND flash with similar number of litho steps
  • Single crystal silicon bidirectional transistor selector
  • Shared litho steps among many memory layers
  • All layer single crystal silicon provides negligible leakage & dramatically better performance/power 
  • Scalable: Multiple generations of cost-per-bit improvement for same equipment cost and process node: use the same fab for 3 generations
  • Forestalls next gen litho-tool risk
  • Density & non-volatility of Flash, but speeds and endurance approaching DRAM

Process Flow

Our 3D resistive memory technology provides:
  • Shared litho steps to create stacked memory at low cost
  • Compatible with whatever resistive material you choose
  • Single crystal Si junctionless transistor selectors allow bipolar operation

3d ic

For more details, please see

[1] Our blog post on 3D resistive memories, June 2011.
[2] "Resistive RAM: Technology and Market Opportunites", Invited talk from MonolithIC 3D Inc. at the IEEE Santa Clara Valley Electron Devices Society, 2010.
[3] Our blog-post on cost of ion-cut, July 2011.