| 摘要 |
PURPOSE:To increase the capacitance between a collector and a grounding, to prevent the generation of noise on a power source line, and to obtain the title device having no erroneous operation by a method wherein a bonding pad region is positioned on the upper part of the substrate on which ground potential will be given through the intermediary of an insulating film formed thinner than the surrounding films. CONSTITUTION:Oxidizing and window perforating operations are conducted using a P-type substrate 50, and an N-type buried layer 51 is formed. After an N-type epitaxial layer 52 has been grown on the substrate, a P-type isolation region 53 is diffused, and the region 53 is isolated. At this time, a P-type isolation region 53' is diffused on the region which becomes the lower part of a bonding pad later in such a manner that the whole area of the bonding pad will be covered by the region 53'. Then, a P-type base region 54 is formed, and an emitter N-type diffusion layer 55 and a collector N-type diffusion layer 56 are formed. Then, the insulating film 57 located inside the P-type isolation region 53', which later becomes the lower part of the bonding pad, is removed by etching, and after a window has been perforated, a silicon oxide film 58 is formed. A parasitic capacitance 9 can be increased by forming the bonding pad wide in area and also by thinly forming the lower part of a silicon oxide film 45.
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