Forming a Micro Electro Mechanical System

A method of forming a micro-electro mechanical system (MEMS), includes (1) removing material from a first wafer to define a first movable portion corresponding to an x-y accelerometer and a second movable portion corresponding to a z accelerometer, where each movable portion comprises at least one flexure member and at least one proof mass, each proof mass and flexure member being formed by the selective removal of material from a top side and a bottom side of first wafer; (2) bonding the first wafer to a second wafer comprising an electronic circuit, such that a gap is defined between the first wafer and the second wafer. The thickness of the at least one flexure member of the first movable portion is independent of a thickness of the at least one flexure member of the second movable portion and a thickness of the proof mass of the first movable portion is independent of a thickness of the at least one proof mass of the second movable portion.