Novel bipolar process utilizing MeV energy ion implantation

High energy ion implantation with a Van-de-Graaff accelerator has been successfully applied to fabricate integrated bipolar devices. High energy As⁺and B⁺ions are implanted in p type substrate through thin oxide and LOCOS field oxide layers to form buried n⁺layer and channel stopping p⁺layer. Base and emitter are also formed by conventional implantation. The isolation leakage current was less than 10^-10A at 50 V. The current gain of the fabricated transister was 70. A collector-base breakdown voltage was 9V in the present As⁺implantation condition. 0.35 ns/gate propagation delay time and 0.4 mW/gate dissipation power were obtained in a 21-stage Non Threshold Logic (NTL) ring oscillator.