The Study Of Growth Of SiGe Thin Films And Electrical Properties By UHVCVD

Silicongermanium (SiGe) technology developed very quickly and called for more advanced growth techniques. Ultra-high Vacuum Chemical Vapor Deposition (UHVCVD) was a good choice, it provided a super clean, low temperature, low pressure ambient, and controlled thin films' growth precisely. SiGe thin films were grown at low temperature (<600℃) by using UHVCVD and devices fabricated. The research focused on the growth of SiGe single layer, multi-layers, metal induced growth of poly-SiGe, Schottky barrier diodes (SBDs) were fabricated. Thin films' morphology, crystal quality and electrical properties were measured (HRXRD,SIMS, SEM, TEM, Hall, Ⅰ-Ⅴ,etc) and analyzed.Cross section transmission (XTEM) test of SiGe/Si single layer, multi-layers showed SiGe/Si interfaces were clear and abrupt, the compositions of layers were uniform. SBD had good high frequency electrical properties .The effect of Si cap layer and annealing on its electrical characteristic were also investigated.UHVCVD was combined with metal induced crystallization method to grow high quality poly-SiGe thin films. The thickness of nickel had important effects on the poly-SiGe grain sizes. It was a great benefit that Ni silicides could be used as SBD's bottom ohmic contact.The SBD had good rectification characteristic, its rectification ratio was 8000.