Patent ID: 8783106

Claim:
A method of fabricating a micro-machined accelerometer, comprising: forming first device-side trenches that extend from a device side of a silicon-on-an-insulator (SOI) through a buried oxide layer to reach a handle layer of the SOI, the first device-side trenches filled with one or more materials different from oxide; forming second device-side trenches that extend from the device side to reach the buried oxide layer, the second device-side trenches filled with oxide; forming accelerometer components at the device side, the accelerometer components comprising an optical detector and at least one suspension spring for a proof mass, the at least one suspension spring having a handle anchor formed from one of the filled first device-side trenches; forming a back-side trench that extends from a bottom surface of the handle layer to reach the buried oxide layer, the back-side trench define a boundary of the proof mass; and removing a portion of the buried oxide layer through the second device-side trenches and the back-side trenches to allow upward and downward movement of the proof mass relative to a top surface of the proof mass.