High-q integrated circuit inductor structure and methods

Abstract

FET IC structures that enable formation of high-Q inductors in a 'flipped' SOI IC structure made using a back-side access process, such as an single layer transfer (SLT) process. Essentially, the interconnect layer superstructure of an IC is split into two parts, a 'lower' superstructure and an “upper” superstructure. In various embodiments, one or more low-resistance interconnect layers are fabricated within an upper superstructure formed after the application of a back-side access process, allowing fabrication of inductors in one or more low-resistance interconnect layer. A significant advantage of such IC structures is that the low-resistance interconnect layer or layers are relocated from being near the handle wafer of a conventional SLT IC to being spaced away from the handle wafer by intervening structures. Fabricating inductors in such spaced low-resistance interconnect layer or layers reduces electromagnetic coupling with the handle wafer and thus increases the Q factor of the inductors.