Methods for producing silicon on insulator structures having high resistivity regions in the handle wafer

摘要

Silicon on insulator structures having a high resistivity region in the handle wafer of the silicon on insulator structure are disclosed. Methods for producing such silicon on insulator structures are also provided. Exemplary methods involve creating a non-uniform thermal donor profile and/or modifying the dopant profile of the handle wafer to create a new resistivity profile in the handle wafer. Methods may involve one or more SOI manufacturing steps or electronic device (e.g., RF device) manufacturing steps.

主权项

1. A method for preparing a silicon-on-insulator structure comprising a handle wafer, a silicon device layer, a dielectric layer between the handle wafer and the silicon device layer, the handle wafer having an axis, a radius, a front surface, a back surface, and a peripheral edge extending in the axial direction from the front surface to the back surface, wherein the front surface of the handle wafer forms an interface with the dielectric layer, with the handle-dielectric interface and back surface being perpendicular to the axis, and wherein the handle wafer further comprises a surface layer extending in the axial direction from the handle-dielectric interface towards the back surface to a depth, Dsl which comprises a high resistivity region and a bulk layer extending from the surface layer towards the back surface, the handle wafer having a resistivity profile in which a peak resistivity Rpeak exists in the high-resistivity region, the resistivity generally decreasing from the peak resistivity towards the bulk layer, the method comprising:
selecting a handle wafer with a given dopant concentration and interstitial oxygen concentration, the handle wafer being doped with a dopant of a first type, the dopant of the first type being either a p-type or n-type dopant; forming a high resistivity region in the surface layer of the handle wafer by
diffusing oxygen either into or out of the handle wafer to form a non-uniform distribution of oxygen in the handle wafer and annealing the wafer having a non-uniform distribution of oxygen to form a non-uniform distribution of thermal donors; forming a dielectric layer on at least one surface of the donor wafer and/or the front surface of the handle wafer; bonding a donor wafer and the handle wafer to form a bonded wafer wherein the donor wafer and handle wafer are separated along the axis by the dielectric layer, the dielectric layer forming a donor-dielectric interface between the donor wafer and dielectric layer and a handle-dielectric interface between the dielectric layer and front surface of the handle wafer, the bonded wafer comprising a bond interface located at the donor-dielectric interface, the handle-dielectric interface or in the dielectric layer between the two interfaces; and removing a portion of the donor wafer from the bonded wafer such that a silicon layer remains bonded to the dielectric layer to form the silicon on insulator structure.