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

A method for determining the robustness of a semiconductor device to soft errors generated by alpha-particle and/or cosmic ray strikes, wherein the device includes a transistor with a predetermined logic state, comprising the steps of:

• producing a light pulse having a light pulse energy, said light pulse energy is at a first light pulse energy which is low enough to avoid generating soft errors in the device;
• applying said light pulse to the device at a predetermined location and a predetermined angle;
• varying said light pulse energy to a second light pulse energy higher than said first light pulse energy to generate a soft error;
• and
• detecting said soft error in the device by determining a change in the predetermined logic state of the transistor.

A method for determining the robustness of a semiconductor device to soft errors generated by alpha-particle and/or cosmic ray strikes, wherein the device includes a plurality of transistors with each of the plurality of transistors at a predetermined logic state, comprising the steps of:

• producing a light pulse having a light pulse energy, said light pulse includes a pulse width and an intensity, said light pulse energy is at a first light pulse energy which is low enough to avoid generating soft errors in the device;
• applying said light pulse to the device at a predetermined location and a predetermined angle;
• varying said light pulse energy to a second light pulse energy by adjusting said intensity and said pulse width to generate a soft error, said second light pulse energy is higher than said first light pulse energy;
• and
• detecting said soft errors in the device by determining changes in the predetermined logic states of each of the plurality of transistors.

An apparatus for determining the robustness of a device to soft errors generated by alpha-particle and/or cosmic ray strikes, comprising:

• a first fixture for supporting the device;
• a light source for producing a light pulse which is applied to the device at a predetermined location, said light pulse having a light pulse energy;
• a second fixture for supporting the light source, wherein said first fixture and said second fixtures are movable relative to each other so that said light pulse is applied to the device at a predetermined angle;
• a light pulse energy varying circuit coupled to said light source and configured to vary said light pulse energy;
• and
• a detecting circuit coupled to the device and configured to detect the soft errors in the device.

An apparatus for determining the robustness of a semiconductor device to soft errors generated by alpha-particle and/or cosmic ray strikes, the device includes a plurality of transistors with each of the plurality of transistors at a predetermined logic state, comprising:

• a first fixture for supporting the device;
• a laser source for producing a light pulse which applies to the device at a predetermined location, said light pulse having a light pulse energy;
• a second fixture for supporting the light source, wherein said first fixture and said second fixtures are movable relative to each other so that said light pulse is applied to the device at a predetermined angle;
• a light pulse energy varying circuit coupled to said laser source and configured to vary said light pulse energy;
• and
• a detecting circuit coupled to the device and configured to detecting soft errors in the device, wherein the detecting circuit determines changes in the predetermined logic states of each of the plurality of transistors.