| 摘要 |
PURPOSE:To reduce the variability in output logical amplitude of a logical circuit while the high speed of circuit action is maintained by a method wherein the slit width of the aperture of the transistor at a constant current section is set larger than the slit width of the aperture of the transistor at a current switching section. CONSTITUTION:The slit width WE1 of the aperture 12 determining the emitter area of the transistor used by the current switching section is set at 1.0mum as the result of a micro fabrication technique, and the variability in slit width WE1 during manufacture is set at + or -0.5mum. As a result, the finished slit width WE1 is 0.5-1.5mum. The slit width WE2 of the aperture 22 determining the emitter area of the transistor at the constant current section is set at 5.0mum so that the influence of a manufacturing variability of + or -0.5mum may become small, and the slit length is equalized with that of the transistor at the current switching section. As a result, the range of variability in slit width WE2 of the transistor at the constant current section is 4.5-5.5mum, and the emitter area varies in a range of + or -10% to the design medium value. Besides, the VF characteristic comes to an end with a variabitlity of approx. + or -3mV, which is a satisfactory tolerance value. |
