Title :
The enhancement of Q factor in RPCVD SiGe varactors by the structural modification of the base-collector junction
Author :
Mheen, Bongki ; Suh, Dongwoo ; Kim, Sang Hoon ; Shim, Kyu-Hwan ; Kang, Jin-Yeong ; Hong, Songcheol
Author_Institution :
Wireless Commun. Device Res. Dept., Electron. & Telecommun. Res. Inst., Daejeon, South Korea
fDate :
4/1/2003 12:00:00 AM
Abstract :
We designed two silicon germanium (SiGe) varactors enhanced in Q factor through a structural modification by using a cost-effective SiGe heterostructure bipolar transistor (HBT) process, a conventional reduced-pressure chemical vapor deposition (RPCVD). As a result, the suggested structures showed a superiority in Q factor (160/GHz/pF at 2.5 GHz) to the conventional one (70/GHz/pF), even with neither a change in process nor an additional mask. We attributed the enhancement of Q factor to the structural feature of the varactors and quantitatively analyzed it with a lumped element model.
Keywords :
CVD coatings; Ge-Si alloys; Q-factor; heterojunction bipolar transistors; semiconductor materials; varactors; 2.5 GHz; Q-factor; SiGe; base-collector junction; heterostructure bipolar transistor; lumped element model; reduced-pressure chemical vapor deposition; silicon-germanium varactor; Bipolar transistors; Chemical vapor deposition; Germanium silicon alloys; Heterojunction bipolar transistors; Phase noise; Q factor; Radiofrequency integrated circuits; Silicon germanium; Varactors; Voltage-controlled oscillators;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2003.810878
