Dual-resonator semiconductor die
AssigneeSiTime Corporation
InventorsCharles I. Grosjean, Ginel C. Hill, Paul M. Hagelin, Renata Melamud Berger, Aaron Partridge, Markus Lutz
Life of this patent
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Abstract
A microelectromechanical system (MEMS) resonator includes a substrate having a substantially planar surface and a resonant member having sidewalls disposed in a nominally perpendicular orientation with respect to the planar surface. Impurity dopant is introduced via the sidewalls of the resonant member such that a non-uniform dopant concentration profile is established along axis extending between the sidewalls parallel to the substrate surface and exhibits a relative minimum concentration in a middle region of the axis.
Claims20
A semiconductor die comprising:
- a first MEMS resonator having a first angular orientation with respect to a crystal plane of the semiconductor die;
- and
- a second MEMS resonator having a second angular orientation with respect to the crystal plane of the semiconductor die and having an n-type dopant concentration greater than 1019/cm3, the second MEMS resonator having a frequency of mechanical resonance that is substantially less sensitive to change in temperature than a frequency of mechanical resonance of the first MEMS resonator due, at least in part, to a difference between the first and second angular orientations with respect to the crystal plane of the semiconductor die.
A method of fabricating a semiconductor die, the method comprising:
- forming a first MEMS resonator having a first angular orientation with respect to a crystal plane of the semiconductor die;
- and
- forming a second MEMS resonator having a second angular orientation with respect to the crystal plane of the semiconductor die and having an n-type dopant concentration greater than 1019/cm3, the second MEMS resonator having a frequency of mechanical resonance that is substantially less sensitive to change in temperature than a frequency of mechanical resonance of the first MEMS resonator due, at least in part, to a difference between the first and second angular orientations with respect to the crystal plane of the semiconductor die.
Dependencies are inferred from the claim text.