| 摘要 |
PURPOSE:To prevent the EB destruction of the other transistor at the time of writing and to enable improving the yield of writing by making the thickness of the emitter contact layer of an ROM transistor thinner than the thickness of the emitter contact layer of the other transistor or by making zero. CONSTITUTION:The first bi-polar transistor B which has a polycrystalline semiconductor emitter contact layer 5 between an emitter region 3 and an emitter electrode 6 and the second bi-polar transistor A wherein the thickness of the similar emitter contact layer 25 is thinner than the thickness of the emitter contact layer 5 of the first transistor B or is zero are mixed on the same semiconductor substrate 1. By making the transistor A an ROM transistor and the transistor B the other transistor, the semiconductor device can prevent the EB destruction of the other transistor B at the time of writing and the yield of writing is improved better than that of a conventional corresponding semiconductor device. |
