Method and apparatus for determining the robustness of memory cells to induced soft errors using equivalent diodes

摘要

Apparatus and methods for determining the robustness of a device to soft errors generated by alpha-particle and/or cosmic ray strikes by measuring the charge Qc that flow through a node of an equivalent diode structure when the diode structure is impinged by a light pulse with energy equivalent to that of the alpha-particle and/or cosmic ray strikes. In one embodiment, the method includes the steps of producing a light pulse having a light pulse energy, the light pulse energy is at a first light pulse energy; applying the light pulse to the device at a predetermined location, the predetermined location having an area and a geometry; varying the light pulse energy to a second light pulse energy which generates a soft error; detecting soft errors in the device; providing a diode having the same area and geometry as the predetermined location; applying the light pulse with the second light pulse energy to the diode; and determining the amount of charges that flow through the diode. The present invention additionally provides inexpensive methods and apparatus that would accurately simulate an alpha-particle and/or cosmic ray strike in a predetermined area of a memory cell and for comparing different technologies and SRAM/DRAM designs by comparing this pulse energy needed to produce the soft error.