Title :
Selective SiGeC epitaxy by RTCVD for high performance self-aligned HBT
Author :
Fellous, C. ; Deleglise, F. ; Talbot, A. ; Dutartre, D.
Author_Institution :
STMicroelectronics, Crolles, France
Abstract :
Selective SiGeC epitaxy is desirable for forming the base of self aligned HBTs. Carbon, incorporated into substitutional sites (C/sub s/), should suppress boron outdiffusion in the base. We show that C/sub s/ incorporation is decreased as temperature or total C concentration is increased, leading to defects in the epitaxy and degradation of the base current. Nevertheless, we were able to grow, selectively, high quality SiGeC films with a C dose high enough to block boron diffusion. This is confirmed by the comparison of static and dynamic results between a C-free and a C-doped SiGe HBT Finally, a state of the art 175 GHz ft/180 GHz f/sub MAX/ HBT with a selective epitaxial SiGeC base is presented.
Keywords :
Ge-Si alloys; carbon; chemical vapour deposition; epitaxial growth; heterojunction bipolar transistors; millimetre wave bipolar transistors; semiconductor materials; 175 GHz; 180 GHz; RTCVD; SiGe:C; base current degradation; boron outdiffusion suppression; carbon concentration; carbon dose; epitaxy defects; selective epitaxy; self-aligned HBT base formation; substitutional site carbon incorporation; Bipolar transistors; Boron; Degradation; Distributed control; Epitaxial growth; Germanium silicon alloys; Heterojunction bipolar transistors; Human computer interaction; Silicon germanium; Temperature;
Conference_Titel :
European Solid-State Device Research, 2003. ESSDERC '03. 33rd Conference on
Conference_Location :
Estoril, Portugal
Print_ISBN :
0-7803-7999-3
DOI :
10.1109/ESSDERC.2003.1256918