Abstract: According to one aspect of the present invention, a method of forming a microelectronic assembly, such as an integrated passive device (72), is provided. An insulating initial dielectric layer (32) comprising charge trapping films of, for example, aluminum nitride or silicon nitride or silicon oxide or a combination thereof, is formed over a silicon substrate (20). At least one passive electronic component (62) is formed over the initial dielectric layer (32). In an embodiment where silicon nitride or oxide is used in the initial dielectric layer (32) in contact with the silicon substrate (20), it is desirable to pre-treat the silicon surface (22) by exposing it to a surface damage causing treatment (e.g. an argon plasma) prior to depositing the initial dielectric layer, to assist in providing carrier depletion near the silicon surface around zero bias. RF loss in integrated passive devices using such silicon substrates is equal or lower than that obtained with GaAs substrates.