| 摘要 |
PURPOSE:To obtain simply a high gain band width product of the semiconductor device having at least one transistor by heating at low temperature of 600-900 deg.C in O2 atmosphere at the final step of heating at higher than 600 deg.C such as diffusing step in the semiconductor device. CONSTITUTION:An N<->-type layer 2 is epitaxially grown on an N<+>-type semiconductor substrate 1, and with an SiO2 film 2 as a mask a P-type base region 3 and an N-type emitter region 4 are sequentially formed by an ordinary diffusion process. At this time the base diffusing time is set at constant, and the emitter diffusing time is selected in accordance with the current amplification factor required. Thereafter, the substrate 1 is filled in the O2 atmosphere at the end of the diffusion heat treatment, and is heated at low temperature of 600-900 deg.C. Thereafter, contact holes 5, 6 are perforated at the film 2, emitter and base electrodes 7, 8 are mounted therethrough on the exposed regions, and a collector electrode 9 is coated on the back surface of the substrate 1. In this manner, the current amplification factor is not varied to merely enhance the gain band width product. |
