Ion-Implanted p-Resistor Reliability

One of the key aspects of large-scale integration in bipolar technology depends on the use of high valued resistors. Ion implantation can lead to higher valued resistors not possible with diffused technology. Two different process technologies, pre-emitter and post-emitter, for making ion-implanted resistors are described. Also described are measured profiles, reliability studies carried out on p-resistors made by the two technologies, and a model describing the resistor drift with voltage and temperature.