Abstract: A SiGe HBT having low collector-base capacitance is disclosed, which includes: a silicon substrate, including isolation trenches, a collector region situated between the isolation trenches, and lateral trenches; a SiGe base layer formed on the silicon substrate; and an emitter region formed on the SiGe base layer. Each lateral trench is situated in the collector region on one side of an isolation trench, and is connected to the isolation trench. Moreover, a manufacturing method of a SiGe HBT having low collector-base capacitance is disclosed, which includes: performing ion implantation to predetermined regions in a silicon substrate before trench isolations are formed; forming lateral trenches by etching ion implantation regions after the trench isolations are formed; then forming a SiGe HBT device by an ordinary semiconductor process. The present invention can reduce the collector-base capacitance and therefore improve high-frequency characteristics of the device.

Abstract: The present invention discloses a method of SiGe epitaxy with high germanium concentration, a germanium concentration can be increased by reducing the percentage of silane and germane during introduction silane and germane. With the same flow of germanium source, the germanium concentration is significantly increased as the germane flow is reduced, therefore a defect-free SiGe epitaxial film with a germanium atomic percentage of 25˜35% can be obtained. The present invention can balance epitaxial growth rate and germanium doping concentration by using existing equipments to obtain a high germanium concentration, and the epitaxial growth rate is only reduced a little, which can keep the SiGe epitaxial layer having no defect to meet the requirements of devices and can maintain sufficient throughput.

Abstract: A SiGe HBT having low collector-base capacitance is disclosed, which includes: a silicon substrate, including isolation trenches, a collector region situated between the isolation trenches, and lateral trenches; a SiGe base layer formed on the silicon substrate; and an emitter region formed on the SiGe base layer. Each lateral trench is situated in the collector region on one side of an isolation trench, and is connected to the isolation trench. Moreover, a manufacturing method of a SiGe HBT having low collector-base capacitance is disclosed, which includes: performing ion implantation to predetermined regions in a silicon substrate before trench isolations are formed; forming lateral trenches by etching ion implantation regions after the trench isolations are formed; then forming a SiGe HBT device by an ordinary semiconductor process. The present invention can reduce the collector-base capacitance and therefore improve high-frequency characteristics of the device.