Identification of radiation-induced parasitic leakage paths using light emission microscopy

• Published in: IEEE transactions on nuclear science Vol. 51; no. 5; pp. 2782 - 2786
• Main Authors: Shaneyfelt, M.R., Paiboon Tangyunyong, Hill, T.A., Soden, J.M., Flores, R.S., Schwank, J.R., Dodd, P.E., Hash, G.L.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.10.2004; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: CMOS technology; Degradation; Integrated circuit technology; Integrated circuit testing; Integrated circuits; Leakage current; Microscopy; Photonic integrated circuits; Radiation hardening; Semiconductors; Silicon on insulator technology; Transistors
• ISSN: 0018-9499; 1558-1578
• DOI: 10.1109/TNS.2004.835074

Eliminating radiation-induced parasitic leakage paths in integrated circuits (ICs) is key to improving their total dose hardness. Semiconductor manufacturers can use a combination of design and/or process techniques to eliminate known radiation-induced parasitic leakage paths. However, unknown or critical radiation-induced parasitic leakage may still exist on fully processed ICs and it is extremely difficult (if not impossible) to identify these leakage paths based on radiation induced parametric degradation. We show that light emission microscopy can be used to identify the location of radiation-induced parasitic leakage paths in ICs. This is illustrated by using light emission microscopy to find radiation-induced parasitic leakage paths in partially-depleted silicon on insulator static random-access memories (SRAMs). Once leakage paths were identified, modifications were made to the SRAM design to improve the total dose radiation hardness of the SRAMs. Light emission microscopy should prove to be an important tool for the development of future radiation hardened technologies and devices.