| 摘要 |
PURPOSE:To reduce the damage of an silicon crystal, and to prevent the extension of an element region by isolating a second semiconductor layer into two in the vicinity of a central section in the direction of extension of laminated structure and forming a collector, an emitter region and a base as a first semiconductor region. CONSTITUTION:A mask 12 for etching is formed on a silicon single crystal semiconductor substrate 11, and the mask is removed and the substrate 11 is thermally oxidized to shape an silicon oxide film 15. A resist is applied on the whole surface, and a mask 16 for etching is formed through patterning. A semiconductor layer 17 is exposed through selective removal in the vicinity of a central section in the direction of extension of laminated structure 22 by repeating an anisotropic etching process twice, and a semiconductor layer 20 is isolated into 20A and 20B. An NPN transistor using one 20A as a collector region, the other 20B as an emitter region and the P type semiconductor layer 17 as a base region is formed. A process for impurity diffusion and heat treatment are removed, an silicon crystal is not damaged, and yield is improved largely. |
