| 摘要 |
PURPOSE:To attain a measured hFE(current amplification factor) value near the actual value in a semiconductor device by forming a base region formed in the device partially on an element isolating region and a ring-like emitter region surrounding the base region on the periphery of the element isolating region as a monitor pattern. CONSTITUTION:An n<+>-type buried region 13 is diffused on a p-type silicon substrate 11, an n-type layer 12 is epitaxially grown on the entire surface including the region 13, and the layer 12 is isolated in an island state through a p-type isolating region 14. When a p-type base region 16 is diffused in the isolated layer 12, one end of the region 16 is superimposed on the region 14. Then, a ring-like n-type emitter 17 is diffused at the periphery in the region 16 as a transistor, and also as a monitor pattern. When a current is flown between the central portion 16' of the region 16 and the substrate 11 in the configuration thus formed, resistance inversely proportional to the thickness 18 of the region 16 under the region 17 is presented to exhibit hFE so as to control the diffusion on the midway of the steps of forming the regions. |
