Method and apparatus for determining the robustness of memory cells to alpha-particle/cosmic ray induced soft errors

摘要

Apparatus and methods for determining the robustness of a device to soft errors generated by alpha-particle and/or cosmic ray strikes. In one embodiment, the method includes the steps of estimating energies of the alpha-particle and/or cosmic ray strikes; computing a number of electron-hole pairs generated for a predetermined distance of travel by the alpha-particle and/or cosmic ray into the device based on the estimated energies; computing the absorption coefficient in silicon for a light pulse with a predetermined wavelength; computing a first pulse width/intensity for the light pulse to generate the number of electron-hole pairs for the predetermined distance of travel by the light pulse into the device; producing the light pulse, the light pulse having a light pulse energy which is controlled by a pulse width and an intensity, wherein the pulse width/intensity is at a second pulse width/intensity which is less than the first pulse width/intensity and the light pulse energy is at a first light pulse energy which is low enough to avoid generating soft errors in the device; applying the light pulse to the device at a predetermined location; varying the light pulse energy to a second light pulse energy to generate a soft error; and detecting soft errors in the device. The present invention additionally provides inexpensive methods and apparatus that would accurately simulate an alpha-particle and/or cosmic ray strike in predetermined areas of a memory cell.