| 主权项 |
1. An infrared thermal sensor comprising:
a semiconductor substrate having a cavity defined therein, wherein a bottom wall of said cavity is formed by a continuous surface of the semiconductor substrate, a membrane disposed in or over said cavity, the membrane being adapted for receiving heat transferred by infrared radiation incident on said membrane, said membrane comprising a plurality of openings extending through the membrane, at least one beam for suspending the membrane over the semiconductor substrate, and at least one thermocouple disposed in or on said at least one beam, wherein said plurality of openings are adapted for facilitating the passage of an anisotropic etchant for etching the cavity during manufacture of the infrared thermal sensor, wherein at the top surface of the membrane, each opening of the plurality of openings has a cross-section with a length to width ratio of at least four, wherein the width direction of a first set comprising at least two openings of said plurality of openings is substantially oriented according to a first crystallographic orientation of the semiconductor substrate, said first crystallographic orientation corresponding to a direction lying in a loosely packed crystal lattice face of the semiconductor substrate, and wherein the width direction of a second set of said plurality of openings is substantially oriented along a second crystallographic orientation of the semiconductor substrate, said first crystallographic orientation and said second crystallographic orientation corresponding to different directions lying in loosely packed crystal lattice faces of the semiconductor substrate. |
