Title :
Impact of elevated oxygen concentration on in-situ doped sub-50 nm SiGe and SiGeC base strained layer NPN HBT
Author :
Oleszek, Gerald ; Enicks, Damin
Author_Institution :
Dept. of Electr. & Comput. Eng., Colorado Univ., Colorado Springs, CO, USA
Abstract :
This paper presents the results of studies on oxygen concentration levels in in-situ boron doped sub-50 nm SiGe and SiGeC base strained layer NPN HBTs. The layers were characterized using four-point probe, secondary ion mass spectrometry and X-ray diffraction. The effect of oxygen concentration levels on boron sheet resistance, minority carrier lifetime, and device performance were investigated. It was found that oxygen can incorporate in SiGe by an order of magnitude over silicon. It is also determined that elevated oxygen can reduce the substitutional electrically active boron concentration and/or degrade the mobility, resulting in reduced sheet resistance. Similarly for elevated-oxygen concentration levels greater than 3×1018 at/cc, device performance was found to be degraded.
Keywords :
Ge-Si alloys; X-ray diffraction; boron; carrier lifetime; chemical vapour deposition; doping profiles; germanium compounds; heterojunction bipolar transistors; minority carriers; oxygen; secondary ion mass spectroscopy; semiconductor device measurement; semiconductor materials; silicon compounds; wide band gap semiconductors; 50 nm; LPCVD; O2; SiGe:B; SiGeC:B; X-ray diffraction; elevated oxygen concentration; four-point probe secondary ion mass spectrometry; in-situ doped HBT; minority carrier lifetime; mobility degradation; sheet resistance; strained layer NPN HBT; Boron; Charge carrier lifetime; Degradation; Electric resistance; Germanium silicon alloys; Heterojunction bipolar transistors; Mass spectroscopy; Probes; Silicon germanium; X-ray diffraction;
Conference_Titel :
Integrated Circuit Design and Technology, 2004. ICICDT '04. International Conference on
Print_ISBN :
0-7803-8528-4
DOI :
10.1109/ICICDT.2004.1309956
