Method for frequency trimming a microelectromechanical resonator

A method for frequency trimming a microelectromechanical resonator, the resonator comprising a substrate and two or more loading elements layered on one or more surfaces of the substrate and physically separated one from the other, the method comprising:

• selecting a first loading element of the two or more loading elements for frequency trimming;
• locally heating the first loading element to a predetermined temperature sufficient to diffuse at least a portion of the first loading element into the substrate to form a composition layer;
• and
• cooling the composition layer to bond the diffused portion of the first loading element and the substrate;
• wherein the localized heating of the first loading element does not raise the temperature of a second loading element of the two or more loading elements to the predetermined temperature and the second loading element remains undiffused into the substrate.

A method of shifting a resonator frequency from a first resonance frequency to a second resonance frequency, the resonator comprising a first composition and a second composition, the method comprising:

• locally heating a first portion of the first composition to a diffusion temperature sufficient to diffuse at least a portion of the locally heated first portion of the first composition into the second composition;
• wherein prior to the step of locally heating, the resonator has the first resonance frequency;
• and
• wherein subsequent the step of locally heating, the resonator has the second resonance frequency.