US 6,277,712 B1 · Multilayered wafer with thick sacrificial layer using porous silicon or porous silicon oxide and fabrication method thereof

Abstract

A multilayered wafer with a thick sacrificial layer, which is obtained by forming a sacrificial layer of oxidized porous silicon or porous silicon and growing an epitaxial polysilicon layer on the sacrificial layer, and a fabrication method thereof are provided. The multilayered wafer with a thick sacrificial layer adopts a porous silicon layer or an oxidized porous silicon layer as a sacrificial layer such that a sufficient gap can be obtained between a substrate and a suspension structure upon the manufacture of the suspension structure of a semiconductor actuator or a semiconductor inertia sensor. Also, in a fabrication method of the wafer according to the present invention, a p+-type or n+-type wafer doped at a high concentration is prepared for, and then a thick porous silicon layer can be obtained simply by anodic-bonding the surface of the wafer. Also, when polysilicon is grown on a porous silicon layer by an epitaxial process, it is grown faster than when single crystal silicon is grown.

Claims12

Dependent claims

A multilayered wafer with a thick sacrificial layer, comprising:

a silicon wafer for use as a substrate;
a sacrificial layer formed of porous silicon on the silicon wafer;
and
a polysilicon layer formed on the sacrificial layer.

1 more element

Dependencies are inferred from the claim text.

Multilayered wafer with thick sacrificial layer using porous silicon or porous silicon oxide and fabrication method thereof

Life of this patent

Multilayered wafer with thick sacrificial layer using porous silicon or porous silicon oxide and fabrication method thereof

Life of this patent

Abstract

Claims12