An 1 GHz All-implanted Vertical pnp Transistor

Vertical all implanted PNP transistors have been fabricated using high energy ion-implantation. The PNP transistor process can be implemented in standard NPN buried collector processes, with epitaxial layers larger than 2.5 ¿m, to achieve a high performance complementary bipolar process. The collector is formed by implantation of doubly charged boron ions with an energy of 500 keV. Base and emitter regions are also implanted. Independent change of the base concentration is possible. The base and collector currents are ideal over 5 decades. The current gain is ¿ 35 and constant over 4 decades. Cut off frequencies of the PNP transistors of over 1 GHz have been measured.