Title :
A compact model for SiGe HBT on thin-film SOI
Author :
Frégonèse, S. ; Avenier, G. ; Maneux, C. ; Chantre, A. ; Zimmer, T.
Author_Institution :
Lab. de Microelectronique IXL, CNRS UMR, Talence, France
Abstract :
Heterojunction bipolar transistor (HBT) fabrication on thin-film silicon-on-insulator (SOI) has been recently demonstrated. Due to the space volume constraint (thin film) for the device fabrication, the HBT structure is different from bulk HBT. In fact, compared to a bulk device, the buried layer has been suppressed and a lateral collector contact configuration is introduced. This device features a vertical expansion followed by a lateral expansion of the base-collector space charge region. This nonconventional charge behavior induces a kink in the base-collector junction capacitance characteristics, and as a consequence a modified Early effect. Furthermore, the low current transit time is modified compared to a bulk HBT. In this paper, all these effects are analyzed and a compact model for SOI-HBT is proposed. The model is validated on real SOI-HBTs with different collector doping levels.
Keywords :
Ge-Si alloys; heterojunction bipolar transistors; semiconductor device models; silicon-on-insulator; thin films; SiGe; base-collector junction capacitance; base-collector space charge region; bulk device; buried layer; collector doping levels; heterojunction bipolar transistor; lateral collector contact configuration; thin-film silicon-on-insulator; transit time; Fabrication; Germanium silicon alloys; Heterojunction bipolar transistors; Semiconductor process modeling; Semiconductor thin films; Silicon germanium; Silicon on insulator technology; Space charge; Thin film devices; Thin film transistors; Bipolar transistor; compact model; heterojunction bipolar transistor (HBT); thin-film silicon-on-insulator (SOI); transit time;
Journal_Title :
Electron Devices, IEEE Transactions on
DOI :
10.1109/TED.2005.862237
