Patent ID: 7605521

Claim:
A hermetically sealed structure comprising: a base substrate; a lid hermetically bonded to the base substrate by an Au—Ge alloy, the lid being made from a material through which light passes; a first metal layer provided on a surface of the lid bonded to the base substrate, the first metal layer including: a first foundation layer made from Cr formed on the surface of the lid; a first platable layer made from either Au or Al alloy formed on the first foundation layer; a first bonding layer made from Au, the first bonding layer being formed closer to the Au—Ge alloy than the first platable layer; and a first barrier layer made from Ni formed between the first platable layer and the first bonding layer; a second metal layer provided on a surface of the base substrate bonded to the lid, the second metal layer including: a second foundation layer made from Cr formed on the surface of the base substrate; a second platable layer made from either Au or Al alloy formed on the second foundation layer; a second bonding layer made from Au, the second bonding layer being formed closer to the Au—Ge alloy than the second platable layer; a second barrier layer made from Ni formed between the second platable layer and the second bonding layer; wherein the Au—Ge alloy is sandwiched between the first metal layer and the second metal layer; and the base substrate serves as a part of a containing body for a piezoelectric device.