Compact memory structure including tunneling diode

Abstract

A resonant inter-band tunnel diode (RITD) can be fabricated using semiconductor processing similar to that used for Complementary Metal-Oxide-Semiconductor (CMOS) device fabrication, such as can include using silicon. A memory cell (e.g., a random access memory (RAM) cell) can be fabricated to include one or more negative differential resistance device, such as tunneling diodes, such as to provide a single-bit or multi-bit cell. In an example, a “hybrid” memory cell can be fabricated, such as including one or more negative resistance devices, a MOS transistor structure, and a capacitor structure, such as including an integrated capacitor configuration similar to a generally-available dynamic RAM (DRAM) structure, but such as without requiring a refresh and offering a higher area efficiency.

1 . (canceled) 
     
     
         2 . A method, comprising forming an integrated circuit including:
 forming an integrated transistor;   forming an integrated capacitor coupled to the integrated transistor; and   forming multiple negative differential resistance (NDR) devices;   wherein the integrated transistor, the integrated capacitor, and the NDR devices are arranged to provide a multi-state memory cell.   
     
     
         3 . The method of  claim 2 , wherein the NDR devices comprise tunnel diodes. 
     
     
         4 . The method of  claim 3 , comprising coupling the integrated capacitor and at least one tunnel diode in parallel. 
     
     
         5 . The method of  claim 3 , comprising forming the tunnel diodes in a stacked configuration directly upon at least a portion of the transistor. 
     
     
         6 . The method of  claim 3 , wherein at least one tunnel diode includes at least one resonant interband tunneling diode (RITD).