A micromechanical device comprising; a semiconductor element capable of deflecting or resonating and comprising at least two regions having different material properties, drive or sense means functionally coupled to said semiconductor element, wherein at least one of said regions comprises one or more n-type doping agents, the relative volumes, doping concentrations, doping agents and/or crystal orientations of the regions being configured so that the temperature sensitivities of the generalized stiffness are opposite in sign at least at one temperature for the regions, and the overall temperature drift of the generalized stiffness of the semiconductor element is 50 ppm or less on a temperature range of 100° C. view more

The device according to claim 1, wherein the at least one first region and at least one second region are distinct regions comprising different doping concentrations of the one or more n-type doping agents.

The device according to claim 1, wherein the at least one first region and at least one second region comprise different n-type doping agents.

The device according to claim 1, wherein the at least one first region and at least one second region comprise different crystal orientations.

The device according to claim 1, wherein the temperature sensitivities of the generalized stiffness of said regions are opposite in sign on a majority of said temperature range, preferably essentially throughout the entire temperature range.

The device according to claim 1, wherein the regions are configured so as to produce temperature drift of the generalized stiffness of the semiconductor element of 10 ppm or less on a temperature range of 100° C.

The device according to claim 1, wherein said regions are stacked on top of each other in a thickness direction of the semiconductor element.

The device according to claim 1, wherein said regions are arranged laterally with respect to each other in the semiconductor element.

The device according to claim 1, wherein said regions are arranged in the semiconductor element in a configuration periodically repeating in at least one dimension so as to form a superlattice structure.

The device according to claim 1, wherein said regions are arranged in the semiconductor element as a lateral two-dimensional array.

The device according to claim 1, wherein all said regions are doped with the same n-type doping agent with different concentration.

The device according to claim 11, wherein the doping concentration in one region is 5e19 cm<sup>−3 </sup>or less and more than 5e19 cm<sup>−3 </sup>in another region.

The device according to claim 11, wherein the doping concentration in one region is 2e19 cm<sup>−3 </sup>or less and more than 2e19 cm<sup>−3 </sup>in another region.

The device according to claim 1, wherein the type of regions having a larger n-doping concentration than the other of type of said regions forms at least 35% of the total volume of the semiconductor element.

The device according to claim 1, wherein the doping concentration in each of the regions is essentially homogeneous.

The device according to claim 1, wherein at least one of the regions is a silicon epitaxial layer.

The device according to claim 1, wherein at least one of the regions comprises a trench manufactured by trench refill process.

The device according to claim 1, wherein at least one of the regions is manufactrured by implantation and annealing process.

The device according to claim 1, wherein at least some of the regions have been bonded together by a wafer bonding technique.

The device according to claim 1, wherein the semiconductor element is a resonating element anchored to a supporting structure and the device comprises electrical drive means for exiting a resonance mode to the resonating element.

The device according to claim 20, wherein the resonating element is a plate and adapted to be excited with said electrical drive means to a mode selected from the group of a shear mode, such as a Lamé mode, square extensional (SE) mode, width extensional (WE) mode, flexural mode. view more

The device according to claim 20, wherein the resonating element is a beam and adapted to be excited with said electrical drive means to a mode selected from the group of extensional mode, flexural mode, torsional mode.

The device according to claim 1, comprising one region type with a doping concentration of 5e19-2e20 cm<sup>−3</sup>, this region type amounting to 35-75% of the total volume of the resonating element, another region type being non-doped or having a entration of less than 2e18 cm⁻³, this region type amounting to 25-65% of the total volume of the resonating element. view more

The device according to claim 1, wherein the drive or sense means comprise piezoelectric drive and/or sense means arranged in mechanical contact with the semiconductor element.

The device according to claim 24, wherein the doping concentrations and or relative volumes of the region types are adapted so as to outcompensate the effect of the piezoelectric drive and/or sense means on the temperature coefficient.

The device according to claim 1, wherein said first region has a negative temperature sensitivity of the generalized stiffness at a second temperature different from the first temperature, said second region has a positive temperature sensitivity of the generalized stiffness at the second temperature. view more

The device according to claim 1, wherein said temperature region is centered around 25° C.

The device according to claim 1, wherein the semiconductor element is a resonator element aligned with the crystal matrix of the semiconductor material such that the resonator exhibits a resonator mode whose modal frequency is dominated by the elasticity term (c₁₁-c₁₂) of the semiconductor materials of the resonator element. view more

A method for designing a micromechanical device comprising a semiconductor element capable of deflecting or resonating and comprising at least two regions having different material properties, drive or sense means functionally coupled to said semiconductor element, the method comprising choosing a basic semiconductor material for the semiconductor element, choosing at least one n-dopant to be added to the semiconductor material, designing the inner structure of the semiconductor material, wherein said designing of the inner structure comprises determining at least two n-dopants, n-dopant concentrations and/or crystal orientations of n-doped material, and their relative volumes in the distinct regions of the semiconductor element so that the overall temperature drift of the generalized stiffness of the semiconductor element is less than 50 ppm. view more

The method for designing a micromechanical device according to claim 29, wherein the determining is done so that the overall temperature drift of the generalized stiffness of the semiconductor element is less than 10 ppm on the temperature range of 100° C. view more