ELSEVIER Journal of Crystal Growth 157 (1995) 285-294 ......... CRYSTAL QROWTH A silicon molecular beam epitaxy system dedicated to device-oriented material research W.-X. Ni *, J.O. Ekberg, K.B. Joelsson, H.H. Radamson, A. Henry, G.-D. Shen l, G.V. Hansson Department of Physics, Linkfiping University, S-581 83 Linki6ping, Sweden Abstract Design, performance test, doping capability and grown material quality of a Balzers UMS 630 Si MBE system are reported, particularly concerning measures to obtain good quality of grown films. Good stability, reproducibility and uniformity of deposition rates (Si and Ge) and doping concentrations (Sb and B) have been obtained for growth on a 4 inch Si wafer with sample rotation using a mass-spectrometry controlled e-beam evaporation system, and home-made doping sources, respectively. The quality of grown undoped and modulation doped Si and SiGe layered structures were evaluated using high-resolution XRD, XTEM, SIMS, Hall, and PL measurements. Intense and sharp excitonic PL transitions and high carrier mobility obtained from the grown Si/SiGe heterostructures and quantum wells grown at a wide substrate temperature range (320-650°C) indicate high crystalline quality of grown films. Finally, test HBT structures with a thin SiGe base have been made. Good de characteristics and frequency performance were obtained. I. Introduction With the challenge from current high-speed and opto-electronic devices, high-quality Si-based epitax- ial structures need to be grown with accurate control at low temperatures. Large efforts have been made during the past decade, and among the techniques developed, molecular beam epitaxy (MBE) has shown the capability to provide high-quality epitax- ial Si-based thin film materials. As has been demon- strated during the past few years, high-performance SiGe-based heterojunction bipolar transistors (HBTs) [1,2], high-mobility modulation doped field effect * Correspondingauthor. E-mail: wxn@ifm.liu.se. Present address: Departmentof ElectronicEngineering,Bei- jing Polytechnic University, Beijing 100022,People's Republic of China. transistors (FETs) [3,4], far-infrared detectors [5,6], and room temperature high-efficiency 1.3 /.~m SiGe quantum dot light emitting diodes (LEDs) [7], etc., were successfully fabricated on Si/SiGe heterostruc- ture materials grown using MBE. These new devices have been expected to complement existing, well- established Si technology, and will create a large impact for the future electronic systems. At the same time, the Si-based MBE technique has also been challenged by other recently developed low-temperature growth technologies, e.g. chemical vapour deposition (CVD) combined with ultra-high vacuum pumping capability [8], rapid thermal pro- cessing [9], and fast gas switching facilities [10], etc. Although both MBE and CVD now are able to supply high purity, defect-free Si-based materials with arbitrary doping profiles for various device applications, to industrialise Si/SiGe heterojunction 0022-0248/95/$09.50 © 1995 ElsevierScienceB.V. All rights reserved SSDI 0022-0248(95)00326-6