Title :
Thermal characteristics of submicron vias studied by scanning Joule expansion microscopy
Author :
Igeta, M. ; Banerjee, K. ; Guanghua Wu ; Chenming Hu ; Majumdar, A.
Author_Institution :
Dept. of Mechano-Aerosp. Eng., Tokyo Inst. of Technol., Japan
fDate :
5/1/2000 12:00:00 AM
Abstract :
Thermal characteristics of submicron vias strongly impact reliability of multilevel VLSI interconnects. The magnitude and spatial distribution of the temperature rise around a via are important to accurately estimate interconnect lifetime under electromigration (EM), which is temperature dependent. Localized temperature rise can cause stress gradients inside the via structures and can also lead to thermal failures under high current stress conditions, such as electrostatic discharge (ESD) events. This letter reports the first use of a novel thermometry technique, scanning Joule expansion microscopy, to study the steady state and dynamic thermal behavior of small geometry vias under sinusoidal and pulsed current stress. Measurement of the spatial distribution of temperature rise around a submicron via is reported with sub-0.1 μm resolution, along with other thermal characteristics including the thermal time constant.
Keywords :
CMOS integrated circuits; VLSI; atomic force microscopy; electromigration; integrated circuit interconnections; integrated circuit reliability; temperature distribution; temperature measurement; thermal stresses; AFM; CMOS process flow; W-plug vias; dynamic thermal behavior; electromigration; electrostatic discharge events; high current stress conditions; interconnect lifetime; localized temperature rise; multilevel VLSI interconnect reliability; scanning Joule expansion microscopy; sinusoidal pulsed current stress; small geometry vias; spatial distribution; steady state thermal behavior; stress gradients; submicron vias; temperature rise; thermal characteristics; thermal failures; thermal time constant; thermometry technique; Electromigration; Electrostatic discharge; Life estimation; Lifetime estimation; Microscopy; Steady-state; Temperature dependence; Temperature distribution; Thermal stresses; Very large scale integration;
Journal_Title :
Electron Device Letters, IEEE
