IBM Journal of Research and Development
IBM Skip to main content
  Home     Products & services     Support & downloads     My account  

  Select a country  
Journals Home  
  Systems Journal  
Journal of Research
and Development
    Current Issue  
    Recent Issues  
    Papers in Progress  
    Search/Index  
    Orders  
    Description  
    Patents  
    Recent publications  
    Author's Guide  
  Staff  
  Contact Us  
  Related links:  
     IBM Research  

IBM Journal of Research and Development  
Volume 21, Number 5, Page 402 (1977)
Nontopical Issue
  Full article: arrowPDF   arrowCopyright info





   

Analysis of the Merged Charge Memory (MCM) Cell

by H.-S. Lee
This paper describes a new MOS dynamic RAM (Random-Access Memory) cell which utilizes a merged surface charge transistor structure. The merged charge memory (MCM) cell uses a polysilicon electrode as both a bit sense line and common plate for a column of storage capacitors. The MCM structure is self-aligned, contactless and free of closely spaced p-n junctions. Its spatial density approaches the conceptual limit of the intersection formed by two orthogonal lines or 4W2 where W is the minimum geometry feature. The cell area utilization efficiency is improved because of this simplicity. Preliminary experimental results and ASTAP simulations based on the charge control equivalent circuit for a dynamic potential well are described. Implications for chip design constraints are discussed, and the advantages and limitations of MCM are highlighted where appropriate.
Related Subjects: Circuit and device technology; Memory (computer) design and technology; Physics, solid state