| 摘要 |
PURPOSE:To reduce the collector resistance of bypolar transistor by a method wherein, after forming a collector region on a semiconductor substrate, a groove is opened aside on the collector region and high impurity concentration region is diffused in the region below an opening of the groove bottom simultaneously covering the sidewalls with insulating film to bury conductive material for fetching electrode in the groove. CONSTITUTION:An N type collector region 2 is diffusion-formed utilizing a mask on the surface layer of P type Si substrate 1 and after removing the mask, overall surface is newly coated with an SiO2 film 6. Next a corresponding opening is made aside on the film 6 and a groove 7 is opened in the region 2 by reactive ion etching process to cover the sidewalls with an SiO2 film 8. Later impurity is diffused in the region 2 below the bottom of groove 7 to form an N<+> type region 9 and a polycrystalline Si 10' abutting against the region 9 is buried in the groove 7 to mount a collector electrode on the surface of Si 10'. Next a P type region 3 adjoining the groove 7 is diffusion-formed wherein an N<+> type emitter region 4 is provided while openings are made on the film 6 to mount electrodes on respective regions. |
