Based Hbt Sige Bicmos Technology Design And Technology

Conventional silicon devices and integrated circuits cannot reach the demands of wireless communication development, while SiGe BiCMOS technology has a promising future with higher performance and lower cost. Research on this technology is quite necessary. Based on the research of BiCMOS process and SiGe HBT characteristics, a flow suitable for 1.5μm SiGe BiCMOS is developed in this paper. SiGe HBT devices are designed under this process conditions. The test results show good electrical characteristics.Firstly, based on the international mature SiGe BiCMOS technology, taking consideration of the No. 24 research institute of CETC process condition, a practicable 1.5μm SiGe BiCMOS flow is developed. SiGe BiCMOS device structures are also designed. The process is based on non-selective epitaxy, with SIC (collector selective implantation) and ex-base region self-aligned implantation. This design greatly enhances the device performance and makes the process more feasible. The compatibility with Si CMOS device structure has been considered thoroughly in design. The process of CMOS gate, ploy Si gate, and SiGe HBT ex-base have been optimized in order to simplify the flow. As a result, the integrated level has been improved.Then, through theoretical analysis and simulation, SiGe HBT optimization rules and design steps for 1.5μm SiGe BiCMOS are presented, which include: (1) collector doped level and thickness; (2) width of base and impurity profile; (3) Ge mole fraction profile, (4) poly Si doped level in emitter and thickness of Si cap layer. According to these optimization rules, a SiGe HBT for BiCMOS technology has been designed. The simulation results show expected electrical characteristics, the current gainβ=210, cut-off frequency f_T = 65GHz when V_ce = 2.5V.At last, research has been carried out to study the SiGe pattern epitaxy, which is the key process of SiGe BiCMOS technology. In the experiments, a strained SiGe thin film has been patterned successfully by MBE expitaxy. Through SEM (scanning electronic microscope) and AFM (atom force microscope), the high-resolution photos of material surface are obtained. The root-mean-square surface roughness is less than 0.45nm. The XRD curve shows that the smoothness and strained level have met the demands of material in device fabrication.