Process and device optimization of an analog complementary bipolar IC technology with 5.5-GHz fT pnp transistors

An analog complementary bipolar IC process has been developed featuring 9.0-GHz f_T npn and 5.5-GHz f_T pnp transistors. Process conditions for emitter, base, and collector of pnp transistors are optimized in order to achieve the best performance tradeoff between current gain, Early voltage, and cutoff frequency. With the optimized process conditions, the H_FE×V_A of pnp transistors is 350 V with f_T of 5.5 GHz and f_max of 8.5 GHz. These high performance pnp transistors have been integrated into an existing 9.0-GHz f_T npn bipolar process without introducing excessive additional process complexity and manufacturing costs. In addition, Schottky diodes, p-channel junction FET´s and laser wafer trimmable precision NiCr resistors have been integrated into the process to enhance analog circuit design capability