Analog Devices,inc.

Christine H Tsau

John R Martin

Timothy J Frey

Thomas Kieran Nunan

Kuang L Yang

Li Chen

Changhan Hobie Yun

Michael W Judy

William David Sawyer

A method for forming an alignment feature for back side wafer processing in a wafer fabrication process involves forming a trench into but not entirely through a wafer from a top side of the wafer; forming a contrasting material on surfaces of the trench; and grinding a bottom side of the wafer to expose the trench using the handling wafer to handle the wafer during such grinding, wherein the contrasting material lining the exposed trench provides an alignment reference for precise alignment of the wafer for back side processing the wafer.

Apparatus and method for forming alignment features for back side processing of a wafer

A MEMS apparatus has a substrate, a cap forming first and second chambers with the base, and movable microstructure within the first and second chambers. To control pressures, the MEMS apparatus also has a first outgas structure within the first chamber. The first outgas structure produces a first pressure within the first chamber, which is isolated from the second chamber, which, like the first chamber, has a second pressure. The first pressure is different from that in the second pressure (e.g., a higher pressure or lower pressure).

Sealed MEMS devices with multiple chamber pressures

A method of forming a MEMS device provides first and second wafers, where at least one of the first and second wafers has a two-dimensional array of MEMS devices. The method deposits a layer of first germanium onto the first wafer, and a layer of aluminum-germanium alloy onto the second wafer. To deposit the alloy, the method deposits a layer of aluminum onto the second wafer and then a layer of second germanium to the second wafer. Specifically, the layer of second germanium is deposited on the layer of aluminum. Next, the method brings the first wafer into contact with the second wafer so that the first germanium in the aluminum-germanium alloy contacts the second germanium. The wafers then are heated when the first and second germanium are in contact, and cooled to form a plurality of conductive hermetic seal rings about the plurality of the MEMS devices.

Apparatus and method of wafer bonding using compatible alloy

A method of bonding wafers with an aluminum-germanium bond includes forming an aluminum layer on a first wafer, and a germanium layer on a second wafer, and implanting the germanium layer with non-germanium atoms prior to forming a eutectic bond at the aluminum-germanium interface. The wafers are aligned to a desired orientation and the two layers are held in contact with one another. The aluminum-germanium interface is heated to a temperature that allows the interface of the layers to melt, thus forming a bond. A portions of the germanium layer may be removed from the second wafer to allow infrared radiation to pass through the second wafer to facilitate wafer alignment.

Method of bonding wafers

A MEMS device has a first member that is movable relative to a second member. At least one of the first member and the second member has exposed silicon carbide with a water contact angle of greater than about 70 degrees.

Reduced stiction MEMS device with exposed silicon carbide

A microchip has a bonding material that bonds a first substrate to a second substrate. The bonding material has, among other things, a rare earth metal and other material.

Substrate bonding with bonding material having rare earth metal

Method of substrate bonding with bonding material having rare Earth metal

A method of forming an inertial sensor provides 1) a device wafer with a two-dimensional array of inertial sensors and 2) a second wafer, and deposits an alloy of aluminum/germanium onto one or both of the wafers. The alloy is deposited and patterned to form a plurality of closed loops. The method then aligns the device wafer and the second wafer, and then positions the alloy between the wafers. Next, the method melts the alloy, and then solidifies the alloy to form a plurality of conductive hermetic seal rings about the plurality of the inertial sensors. The seal rings bond the device wafer to the second wafer. Finally, the method dices the wafers to form a plurality of individual, hermetically sealed inertial sensors.

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Arlington, MA, United States of America

Christine H Tsau