US 6,877,209 B1 · Method for sealing an active area of a surface acoustic wave device on a wafer

Abstract

One embodiment disclosed relates to a method for sealing an active area of a surface acoustic wave (SAW) device on a wafer. The method includes providing a sacrificial material over at least the active area of the SAW device, depositing a seal coating over the wafer so that the seal coating covers the sacrificial material, and replacing the sacrificial material with a target atmosphere. Another embodiment disclosed relates to an SAW device sealed at the wafer level (i.e. prior to separation of the die from the wafer). The device includes an active area to be protected, an electrical contact area, and a lithographically-formed structure sealing at least the active area and leaving at least a portion of the electrical contact area exposed.

Claims17

Dependent claims

A method for sealing an active area of a surface acoustic wave (SAW) device on a wafer, the method comprising:

providing a sacrificial material over at least the active area of the SAW device;
depositing a seal coating over the wafer so that the seal coating covers the sacrificial material;
and
replacing the sacrificial material with a target atmosphere,
wherein replacing the sacrificial material comprises:
lithographically patterning the seal coating to create a via through the seal coating and to expose electrical contact pads coupled to transducer structures of the SAW device for conducting electrical current to and from the transducer structures;
etching the sacrificial material by way of the via to create a pocket surrounded by the seal coating;
placing the wafer in the target atmosphere;
and
filling the via to seal the target atmosphere in the pocket.

7 more elements

Dependencies are inferred from the claim text.

Method for sealing an active area of a surface acoustic wave device on a wafer

Life of this patent

Method for sealing an active area of a surface acoustic wave device on a wafer

Life of this patent

Abstract

Claims17