| 摘要 |
PURPOSE:To mount an I<2> L having a design margin and a normal bipolar element onto the same chip in mixed shape with the high degree of integration by using a semiconductor layer having low sheet resistance as the emitter of the I<2>L and electrically isolating a bipolar transistor from the I<2>L. CONSTITUTION:An N<+> layer 54 reaching an N<+> Si substrate 50 is formed to a P epitaxial layer 52 on the substrate through selective diffusion and an N<+> layer 56 into the layer 52. An N epitaxial layer is stacked, and isolated by P<+> layers 58, and the surface is coated with SiO2 64. Windows are shaped selectively, and the p type injector 70 and base 72 of the I<2>L 66 and the P base 74 of the bipolar element 68 are formed. N<+> Type collectors 76, 77 and emitter 78 are molded through oxidation and the opening of windows, and Al electrodes are attached. The N<+> substrate 50 functions as the emitter of the I<2>L 66 and the collector of the bipolar element 68. Both devices are electrically isolated by the P<+> layers 58, and the emitter sheet 50 of the I<2>L can be brought to 1OMEGA/? or lower. Accordingly, the floating of I<2>L emitter potential is reduced sufficiently even when currents flow through the emitter layer, the I<2>L having the high design margin is formed, and the IC in which the bipolar element is mounted in mixed shape is obtained. |
