Micro-machining

A method of fabricating a micro-mechanical sensor comprising taking a first wafer with an insulating layer formed thereon and with a second wafer bonded to the insulating layer and

• (a) patterning and subsequently etching one of either said first or second wafers such that channels are created in said etched wafer terminating adjacent to said insulating layer;
• and
• (b) etching said insulating layer to remove portions of said insulating layer adjacent said etched wafer such that those portions of said etched wafer below a predetermined size become substantially freely suspended above the other wafer
• wherein some of the channels created in said etched wafer prior to the performing of step (b) are refilled with a refill material.

A method of fabricating a micro-mechanical sensor comprising taking a first wafer with an insulating layer formed thereon and with a second wafer bonded to the insulating layer and

• (a) patterning and subsequently etching one of either said first or second wafers such that channels are created in said etched wafer terminating adjacent to said insulating layer;
• and
• (b) etching said insulating layer to remove portions of said insulating layer adjacent said etched wafer such that those portions of said etched wafer below a predetermined size become substantially freely suspended above the other wafer
• wherein stress between the first and second wafer is reduced by providing said insulating layer as a series of at least three layers.