| 摘要 |
PURPOSE:To reduce a saturated voltage between the collector and the emitter of a lateral type bipolar transistor by forming a recess on an N type epitaxial layer having a surface density of less than 10<14>/cm<3>, and forming an emitter and a collector on the bottom of the recess and a base under the bottom surface thereof. CONSTITUTION:An N<-> type epitaxial layer 2 is etched on an N<+> type Si substrate 1 to form a recess 11, a P type emitter region 6, a collector region 7 and an N<+> type base pickup layer 8 are formed on the bottom surface of the recess 11, openings are perforated at an SiO2 film 9, and electrodes 10 are attached therethrough. In this configuration the junction of the emitter 6 and the collector 7 is formed at the position having higher density than a surface density of 10<14>/cm<3> by the diffusion from the boundary of the substrate 1, and the series resistance of the emitter and the collector can be resultantly reduced. Accordingly, the saturation VCE can be reduced. Though the base ground current amplification factor is reduced at this time, an N<+> type base pickup layer 8 is disposed around the emitter and the collector to enhance the emitter injection efficiency, and can be easily compensated. |
