| 摘要 |
A bipolar transistor is fabricated by means of a BiCMOS process and comprises an active collector (4), emitter (3) and base (2) respectively connected to collector, emitter and base contacts. The performance of the transistor is improved by a material of low electric resistivity which is provided between the connector contact and at least two spaced apart regions of the active collector so as to provide at least two spaced apart shunt regions (10, 12) between which the active collector is interposed. The shunt regions can be formed by implanting a first dopant material into the semiconductor which is then heated so as to spread the dopant into the semiconductor to create a first zone, and by implanting a dopant material at the same position to provide a second zone having lower resistivity than the first zone. There is also provided a method of making a transistor by treating a substrate as to provide thereon a collector a base and an emitter which overlies said collector and base, and respective electrical contacts for the emitter. A protective cover for said emitter is applied during or before said treatment, and prior to the application of the cover a dopant material is implanted into a region adjacent the base so as to provide a path of low resistance between the contact for the base and a region of the base spaced therefrom. <IMAGE> |
