Patent ID: 6426239
Filing Date: 2002-07-30
Classification: G01L

Abstract:
A method of manufacturing an electronic component comprising:providing a substrate comprised of crystalline silicon, the substrate having a first surface and a second surface opposite the first surface; forming a first layer over the first surface of the substrate, the first layer comprised of polycrystalline silicon; disposing a dielectric layer over the first layer and the first surface of the substrate; forming a first polysilicon layer overlying the dielectric layer; disposing a first sacrificial layer over the first polysilicon layer; forming a second polysilicon layer overlying the first sacrificial layer and the first polysilicon layer, the second polysilicon layer having a first plurality of holes, the second polysilicon layer electrically isolated from the first polysilicon layer; disposing a second sacrificial layer over the second polysilicon layer; forming a second plurality of holes in the second sacrificial layer and the first sacrificial layer, the second plurality of holes extending through the first plurality of holes in the second polysilicon layer; forming a third polysilicon layer overlying the first and second polysilicon layers and the second sacrificial layer, the third polysilicon layer extending into the first and second pluralities of holes, the third polysilicon layer electrically isolated from the first and second polysilicon layers; removing the first and second sacrificial layers; disposing a first mask layer over the first layer and the first, second, and third polysilicon layers, the first mask layer continuously covering all of the first layer, continuously covering all of the first, second, and third polysilicon layers, and continuously covering substantially all of the first surface of the substrate; disposing a second mask layer over the second surface of the substrate wherein a portion of the second surface of the substrate is exposed; and using an etchant to etch a hole through the substrate by etching from the portion of the second surface of the substrate through the substrate to the first surface of the substrate, wherein the first and second mask layers are etch masks for the etchant, wherein the hole is wider at the first and second surfaces than at a middle portion of the substrate, and wherein the etchant also removes the first layer, wherein after the using step, a portion of the first polysilicon layer is movable relative to the substrate, the second polysilicon layer is immovable relative to the substrate, a portion of the third polysilicon layer is movable relative to the substrate, and the portions of the first and third polysilicon layers are mechanically coupled together.