Correlation between thermal resistance, channel temperature, infrared thermal maps and failure mechanisms in low power MESFET devices

• Published in: Microelectronics and reliability Vol. 29; no. 2; pp. 117 - 124
• Main Authors: Canali, C., Chiussi, F., Donzelli, G., Magistrali, F., Zanoni, E.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1989; Elsevier
• Subjects: Applied sciences; Electronics; Exact sciences and technology; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transistors; Metal semiconductor field effect transistor
• ISSN: 0026-2714; 1872-941X
• DOI: 10.1016/0026-2714(89)90556-8

Channel temperature T ch of GaAs MESFETs, determined by means of electrical measurements ( ΔV gs), has been compared and correlated with thermal maps obtained by high resolution infrared microscopy. Results show that in low power devices with a small number of gates, the value of T ch derived from ΔV gs measurements is close to the maximum values of temperature measured on the hottest junctions on the chip. Local thermal inhomogeneities, in particular those observed in devices characterized by high values of R th, can explain and confirm results of failure analyses of MESFETs submitted to accelerated life tests in operating conditions where degradation phenomena occur in localized areas of the device.