Title :
Thermal Coupling in Multi-finger Heterojunction Bipolar Devices
Author :
Schubler, Martin ; Krozer, Viktor ; de la Fuente, Jesus Grajal ; Hartnagel, Hals L.
Author_Institution :
TH Darmstadt, Institut fÿr Hochfrequenztechnik, Merckstr. 25, D-64283 Darmstadt, Germany, email: hfmweOO8@hrzpub.th-darmstadt.de
Abstract :
IThe thermal characteristics of power HBT devices are considered. The analysis includes emitter finger coupling and limitation in power operation due to selfheating. An essential part of the generated heat is dissipated through the top device layers and metal contacts. A strongly uneven temperature distribution in the emitter finger of multi-finger devices is the result of not sufficient temperature drain through the emitter air-bridge. Sufficient thermal dissipation can be additionally obtained by temperature drain through the base and collector metallised areas on top of the device. An optimum distance between individual emitter fingers exists for maximum thermal coupling. This yields better thermal homogeneity.
Keywords :
Analytical models; DH-HEMTs; Electromagnetic heating; Fingers; Gallium arsenide; Heterojunction bipolar transistors; Microwave devices; Temperature dependence; Temperature distribution; Thermal resistance;
Conference_Titel :
Microwave Conference, 1997. 27th European
Conference_Location :
Jerusalem, Israel
DOI :
10.1109/EUMA.1997.337778
