Title :
Novel HBT with reduced thermal impedance
Author :
Hill, Darrell ; Khatibzadeh, Ali ; Liu, William ; Kim, Tae ; Ikalainen, Pertti
Author_Institution :
Corp. Res. & Dev., Texas Instrum. Inc., Dallas, TX, USA
fDate :
11/1/1995 12:00:00 AM
Abstract :
Heterojunction bipolar transistors have been fabricated using a novel process in which the majority of the front side of the chip is metallized to serve as the groundplane. The completed chip is assembled inverted so that the emitters are next to the heat sink; base and collector are contacted using through-wafer vias and microstrip lines on the back side of the chip. These devices show a 50% reduction in thermal impedance compared to conventionally fabricated devices and have achieved power densities of 10 W/mm of emitter length. Such devices are expected to have substantially lower emitter inductance as well, which may lead to improved gain at higher frequencies
Keywords :
heterojunction bipolar transistors; microwave bipolar transistors; microwave power transistors; power bipolar transistors; semiconductor technology; thermal resistance; HBT; emitter inductance; fabrication; gain; groundplane; heat sink; heterojunction bipolar transistor; metallization; microstrip lines; power densities; thermal impedance; through-wafer vias; Assembly; Bipolar transistors; Electromagnetic heating; Gold; Heat sinks; Heterojunction bipolar transistors; Impedance; Inductance; Microstrip; Substrates;
Journal_Title :
Microwave and Guided Wave Letters, IEEE