Complementary vertical bipolar transistor process using high-energy ion implantation
High-energy ion implantation is used as a key processing step in the formation of a complementary bipolar process with both transistor types being vertical. Both npn and pnp transistors are made vertically with a deep implanted collector region. Combinations of epitaxial and buried layers are avoided. Both transistors have an ideal Gummel plot with a current gain of about 60. Cutoff frequencies of over 1 GHz have been measured, which is much higher than for conventional lateral pnp transistors.