PECVD of poly-SiGe/Ge layers with increased total gas flow

• Published in: Microelectronic engineering Vol. 115; pp. 26 - 31
• Main Authors: Wang, Qiang, Göhlich, Andreas, Ruß, Marco, Yang, Pin, Vogt, Holger
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.03.2014; Elsevier
• Subjects: Applied sciences; Chemical vapor deposition; Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Cross-disciplinary physics: materials science; rheology; Crystallinity; Deposition; Electronics; Exact sciences and technology; Gas flow; Germanium; Growth from solid phases (including multiphase diffusion and recrystallization); Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Materials science; Mechanical instruments, equipment and techniques; MEMS; Methods of crystal growth; physics of crystal growth; Methods of deposition of films and coatings; film growth and epitaxy; Micro- and nanoelectromechanical devices (mems/nems); Micromechanical devices and systems; PECVD; Physics; Poly-SiGe; Post-CMOS integration; Radicals; Residence time; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silicon germanides; Tensile stress; Total gas flow; NTGF; Poly-SiGe; Residence time; Total gas flow; MEMS; PECVD; Crystallinity; Post-CMOS integration; Amorphous material; Electrical conductivity; Ge-Si alloys; In situ; Polycrystals; Very low temperature; Micromachine; Deposition process; Microelectronic fabrication; Gas flow; Complementary MOS technology; Microelectromechanical device; Semiconductor alloys; Crystallization; Doped materials; CVD; Binary alloys; Tensile stress; Boron additions; Germanium
• ISSN: 0167-9317; 1873-5568
• DOI: 10.1016/j.mee.2013.10.027

•Poly-SiGe and Poly-Ge are deposited at substrate temperatures below 380°C with high total gas flow.•Ge-content in the deposited SiGe layers increases with the increased total gas flow.•Crystallinity of the deposited SiGe and Ge layers is improved with the increased total gas flow.•Improved crystallinity is attributed to the reduced residence time of gas in the plasma.•Shorter residence time may cause increased Ge-content (for the SiGe layer) and more XH3 in the plasma. The PECVD of in situ boron doped SiGe and Ge layers with the increased total gas flow was investigated. It was found, that the SiGe layer could be deposited as amorphous or polycrystalline material depending on the quantity of the total gas flow, while other deposition parameters were kept constant. The increased total gas flow favors the crystallization of the deposited SiGe or Ge layers, what is attributed to the reduced gas residence time. The reduced residence time improves the crystallinity of the deposited layers by increasing the Ge content in the layers (in the case of SiGe layers) and probably additionally through the increasing of the XH3 radicals in the plasma. With the deposition method with increased total gas flow, poly-SiGe and poly-Ge layers with very low resistivity (about 1mΩ-cm) can be deposited at very low substrate temperatures (poly-SiGe: ⩽375°C; poly-Ge: ⩽340°C). These layers have small tensile stresses.