Abstract: In a monolithic semiconductor integrated circuit, conventional bipolar transistors are fabricated along with thin ion implanted junction field effect transistors, to create BIFET structures. After the conventional isolation diffusion, the surface oxide is stripped off and the semiconductor wafer ion implanted with slow diffusing impurities of a conductivity type, the same as the undiffused surface material. Then the bipolar transistors, along with the junction field effect transistors, are fabricated using conventional oxide masked diffusion processes. The field effect device sources and drains employ the base diffusions of the bipolar transistors while the gate contact is achieved with an emitter diffusion. The field effect device channels are formed at a depth substantially greater than that of the impurities deposited in the original ion implant. If desired, an ion implanted top gate can be established over the channel. The wafer is then annealed and processed in accordance with conventional techniques.

Abstract: In a monolithic semiconductor integrated circuit, conventional bipolar transistors are fabricated along with thin ion implanted junction field effect transistors, to create BIFET structures. After the conventional isolation diffusion, the surface oxide is stripped off and the semiconductor wafer ion implanted with slow diffusing impurities of a conductivity type, the same as the undiffused surface material. Then the bipolar transistors, along with the junction field effect transistors, are fabricated using conventional oxide masked diffusion processes. The field effect device sources and drains employ the base diffusions of the bipolar transistors while the gate contact is achieved with an emitter diffusion. The field effect device channels are formed at a depth substantially greater than that of the impurities deposited in the original ion implant. If desired, an ion implanted top gate can be established over the channel. The wafer is then annealed and processed in accordance with conventional techniques.