A new complementary transistor structure for analog integrated circuits

A new complementary transistor structure has been developed. This paper presents a new technique which provides a fully complementary transistor structure for analog integrated circuits. The pnp transistor is fabricated by triple diffusion process in n type epitaxial layer on p type substrate, and is isolated from the substrate by inserting n- ion implanted layer between p+ collector buried layer and the substrate. This technique results in 5 to 10 times improvement in gain bandwidth product fT, maximum collector current IC(max)and collector saturation voltage VCE(sat)in comparison with conventional pnp transistors. Consequently, a fully complementary pnp transistor to npn transistors can be obtained.