Process flow for thin contactless thermal sensors
AssigneeSTMicroelectronics International N.V.
InventorsEnri Duqi, Giorgio Allegato
Life of this patent
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Abstract
Disclosed herein is a method of forming a thermal sensor, including patterning an active layer on a first face of a handle substrate to form a frame, a mass carrying at least one thermally isolated MOS (TMOS) transistor, and a spring structure connecting the mass to the frame while thermally isolating the mass from the frame. The frame is then bonded to pads on a first face of an integrated circuit substrate. The handle substrate is removed, and a top cap is bonded to the first face of the integrated circuit substrate to enclose at least the mass and spring within the sealed cavity.
Claims19
A method of forming a thermal sensor, comprising:
- patterning an active layer on a first face of a handle substrate to form a frame, a mass carrying at least one thermally isolated MOS (TMOS) transistor, and a spring structure connecting the mass to the frame while thermally isolating the mass from the frame;
- bonding the frame to pads on a first face of an integrated circuit substrate;
- completely removing the handle substrate;
- and
- bonding a top cap to the first face of the integrated circuit substrate to enclose at least the mass and spring within a sealed cavity.
A method of fabricating a thermal sensor, comprising:
- bonding a patterned active layer including a mass carrying at least one thermally isolated MOS transistor and connected to a frame by a spring structure to a first face of an integrated circuit substrate;
- enclosing the patterned active layer with a top cap bonded to the integrated circuit substrate to form a sealed chamber;
- performing the bonding in a vacuum such that the sealed chamber is evacuated;
- and
- depositing a getter material on an interior surface of the top cap to maintain the vacuum during operation of the sensor.
Dependencies are inferred from the claim text.