The SiGe HBT, integrated with CMOS devices on the same chip, will be the first integrated device combination to realize the long-standing technology goal of fabricating RF systems on a chip. It has been demonstrated that the HBT device can replace the standard GaAs front-end of RF systems and take advantage of the reduced cost available from Si technologies in 200–300mm wafers. However, the SiGe HBT can only be part of a large-scale RF system on a chip when, in the same technology, NFETs and PFETs are provided for low power, low frequency digital logic, and a suite of resistors, capacitors, diodes, and inductor passive elements are provided for the high frequency analog circuitry. Furthermore, all these elements must be manufacturable defect-free at medium and high levels of integration.
This paper covers keyprocess integration issues confronting technologists when integrating a SiGe HBT device with the requisite CMOS and passive elements and at the same time maintaining very high GaAs-like performance. Topics to be discussed are 1) a review of high-performance HBT device integration schemes employed to date and integration issues with each scheme, 2)integration issues in epitaxial cleaning and growth techniques, 3) integration issues influencing crystal defects, and 4) integration issues with passive elements. Status of the IBM SiGe BiCMOS technology will be presented to illustrate the first successful integration of this set of devices into
a manufacturable process.