Method for making a BiCMOS semiconductor device

摘要

A method with less processing steps for making a BiCMOS semiconductor device which can be used both in high-integration, high-speed digital devices and in precise analog devices by forming within a single substrate a CMOS transistor, a metal contact emitter bipolymer transistor having the high load driving power and highly effective matching characteristics, and a polycrystalline silicon emitter bipolar transistor having a high-speed characteristic at a low current level. Said device includes a first and a second MOSFET, and a first and a second bipolar transistor on a first conductivity-type silicon substrate, wherein performing a second conductivity-type of ion-implantation for producing a first substrate region to thereon form the first MOSFET, and a third and a fourth substrate region to thereon form the first and second bipolar transistors, respectively on said substrate. The second MOSFET is subsequently formed in a second substrate region being located between the first and third substrate regions.